Final Thesis Document(SAMPLE) EFI

Don Bosco Technical CollegeComputer Engineering Department

Chapter 1: Introduction

Background

Parking space is a must wherever we go. Whenever we go on a specific place

we always consider if there is an available space where in we can leave our vehicles

without worrying about its security. Nowadays, big establishments like shopping malls

provide parking space for its shoppers. Ensuring the comfort and the security of the

vehicles parked in their establishment, these establishments provide security system

that will monitor the parking system in the entire establishment.

Today, there are parking systems that determine if the establishment's parking

area is fully occupied or not. Observing these systems, the group realized the idea to

innovate these existing parking systems that are used in the industry. The technologies

used in the industry are quite costly due to the number of sensors that are being

deployed for each of the parking slot.1 Using our innovative imaginations, the group

came up in using an alternative implementation of the sensors that will be used. In this

project, the group aims to lower the cost of the system but not taking for granted the

reliability of the system.

Sonar is a technique that uses sound propagation to communicate, detect and

navigate other vessels. This is can be used in getting a location and even in sensing the

existence of a specific object on a certain location. The group came up on taking

advantage of this technique knowing that this can provide a more accurate and a faster

result. Moreover, the group objective is to minimize the use of UD sensors and create an

alternative orientation wherein the group will observe and test two new possible

orientations.

Statement of the Problem

1 Xiamen Keytop Comm.&Tech.Co.,Ltd. Hi-supplier. http://keytop.hisupplier.com/manufacturer-355618-ultrasonic-parking-guidance-system.html (accessed january 2010).

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Main

- How to reduce the number of sensors in parking slot monitoring systems using

new configuration of ultrasonic transducers?

Specific

- How can an ultrasonic transducer detect a vehicle?

- What is the required ultrasonic transducer to use in this project?

- What are the limitations of the ultrasonic transducer?

- How can a multiple-transmitter single receiver orientation detect a vehicle?

- How can a single-transmitter multi receiver orientation detect a vehicle?

- Which of the multiple transmitter, single receiver orientation and single receiver,

multi transmitter orientation is much better overall?

- What is the proper positioning setup of the ultrasonic transducers?

- What are the ways in avoiding the interference in each of the transducers?

- How can the transducers interface with a microcontroller?

Objectives

Main:

- Design a system that introduces new configuration for ultrasonic transducers that

will implement reduced number of sensors in monitoring parking slot availability.

Specific:

- To be able to understand how ultrasonic sensors are used in object detection.

- To be able to prepare appropriate transmitter and receiver circuit for the

ultrasonic transducers of the design.

- To identify the proper positioning setup of the ultrasonic transducers through

theoretical calculations and actual experimentation.

- To be able to interface the ultrasonic transducers with a microcontroller to make

the process of either cited orientations.

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- To observe the appropriate threshold range for the setup defined for the two cited

orientations.

- To solve the problems brought by the two orientations, mainly the possible

interference between the receiving transducers.

- To conduct a series of tests in testing the efficiency and performance monitoring

of the two cited orientations (STMR and MTSR)

- To determine the better of the two cited orientations through a series of tests and

experimentations.

Assumptions

The study assumes that the parking lot users abide by the usual rules and

regulations of a typical parking area – properly parking their cars according to the

boundaries allotted on a parking slot. For this reason, the study assumes that a parking

vehicle shall occupy the expected area covered by a vehicle in the parking slot. The

study also assumes the parking vehicles that shall use the parking slots do not exceed

the vertical clearance of the parking area for parking usage. This study also assume that

one of the two orientations we will implement is much efficient and better than the other,

leading us to trim down this study by focusing on the better orientation we will acquire

through tests and experiments that we will conduct.

Scope and Limitations

The system could only monitor the parking lot availability through the possible

orientation of the technique proposed. The system can only detect the presence of

vehicles if it is parked properly according to the specified parking slot. Also, if it happens

that multiple vehicles would park on the four slots at the same time, there would be a

little time difference on the detection of the presence of the vehicles in the slot since the

algorithm that will be used is in a sequential manner of monitoring. The microcontroller

is only in charge of the control of operation. The transducers are set up in accordance to

the computations and the actual experimentations.

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One of the limitations that the group expects is the angular projection because

the ultrasonic transducer has its specification regarding the directivity of the beam angle.

The transducer used in the study has a 50 degrees beam angle, so the transducer's

angular projection would be limited to 50 degrees as minimum projection. Citing another

limitation of the study, physical obstructions to the ultrasonic transducer's path would

radically affects the output of the system. Next, the height of the vehicle that would be

parked is limited to approximately 2.20 meters knowing that the existing parking system

has specific vertical clearances around 2.2 to 2.3 meters; thus, trucks and other vehicles

that are taller than the vertical clearance are not covered by the scope of this study.

Lastly, the size of the vehicle is also limited to the size of four-wheeled vehicles; thus,

the motorcycles are not covered by the scope of this study.

Significance of the Study

After finishing the study, the implementation of the technique proposed would be

a significant breakthrough in the use of ultrasonic sensors in the parking systems that

are currently used, knowing that all the manufacturers are using the same orientation in

their implementation of the parking system. The study would be beneficial not only to the

manufacturers of the system but also to the investors who are planning to implement a

parking system in their respective establishments. Finishing this study could lower down

the overall cost of implementation of the system. Also, the study could benefit the

motorists who are using the parking area by adding security to their vehicles and at the

same time giving the motorists the comfort of locating a vacant parking slot with ease.

The study will also be beneficial to students who are also undergoing studies

about ultrasonic principles. Upon accomplishment of this study, such help is given for

possible ideas regarding other orientation of installation of the ultrasonic detectors. In the

long run this study could be a reference on other research on other alternate sensors

that can be implemented. This study will also show the comparison between the two

orientations with all the apparent information, data and computations in order to push on

through with this project. Lastly, the ideas brought by the relationship between the new

orientations are significant as well for future researches that ultrasonic transducers may

be included on.

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Chapter 2: Review of Related Literature

As given in the previous chapter of this study, this chapter shall now present the review

of related literatures that supports the ultrasonic transducers application of this study.

Ultrasonic Transducers in Obstruction Detection Application

In an article titled “Ultrasonic Obstruction Detection and Distance Measurement Using

AVR Micro Controller”, the ultrasonic is interfaced with an Atmel ATmega8 AVR

microcontroller in order to implement short range ultrasonic obstruction detection and

distance measurement device. By employing an ultrasonic transducer pair for producing

ultrasonic sounds and sensing the reflected sound waves, the obstructions are detected.

The Atmel ATmega8 AVR microcontroller to facilitate the generation of 40 KHz signal

burst which is used in the transmitter circuit, and also to process the received signal for

measuring the time of flight of reflected waves and exact distance of the obstruction. The

program for this device is developed in WinAVR, and the code generated is dumped into

microcontroller using AVR Studio. Educational aspects of this project include the

mastery of a programming language and corresponding tools, the design of a functional

and intuitive embedded application, and the development of appropriate hardware to

build the device.2

This cited related research enlightens the group on the possibility of creating an

ultrasonic obstruction detection device with the Atmel microcontroller in its operation

control. In this regard, the group as well noticed that the microcontroller used in their

system is considerably too powerful for such operation usage. Hence, the capacity of

those Atmel microcontrollers with lower specification could possibly be considered for

such operation.

2 Pandey, Satish, Dharmendra Mishra, Anchal Srivastava, and Atul Srivastava. "Sensors and transducers." Ultrasonic Obstruction Detection and Distance Measurement, 2008: 50-56.

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Ultrasonic as range finders

A research article about “Ultrasonic Detection and Ranging with Angle measurement”

used ultrasonic to measure the distance and angle of an object. A distance display

shows how far or how near you are to the object. This research shall use MA40S and

MA40R ultrasonic transducers for the application of ultrasonic as range finder with PIC.

In addition, the time of flight observation is the method used in this ultrasonic transceiver

as range finding sensor. In this way, it is necessary to consider some factors that affect

the values obtained, namely the temperature, angle of transducers and the distance

observed for the transducers. And so, to test the procedures, the variation in the setting

in regards of the distance, angle and temperature are all observed in the experimental

test.3

This cited research is the basis of the group on determining the ultrasonic transducers

for the system because this research considers as well practicality for the scope of the

application through using MA40R and MA40S transducers. In this regard, the group also

used this research as the basis of how to test the ultrasonic configurations to meet some

of the objectives in the study. The group also considered variation in the configuration

according to the factors that affect the detection through ultrasonic sensing.

Moving object counting using ultrasonic sensor networks

A moving object counting system is intended to be a smart system, which is capable of

recording information on how many objects, such as pedestrians or cars, have passed

through a given area, such as a gate, a tunnel or an intersection. Such a system is also

responsible for analyzing the direction of each moving object.4

3 Biazon, Cortez, Cruz, Lico, and Paterno. "Ultrasonic Detection and Ranging wtih Angle measurement." 2004: 1-9.

4 Chen, Quanbin, Min Gao, Jian MaDian Zhang, Lionel M. Ni, and Yunhao Liu. "Int. J. Sensor Networks, Vol. 3, No. 1." MOCUS: moving object counting using ultrasonic, 2008: 56-64.

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Ultrasound or ultrasonic is the most appropriate sensing technology for counting moving

objects based on the following observations. Firstly, it can work both indoors and

outdoors, and in both sunlight and dark. Secondly, by not identifying individuals, privacy

can be protected. Thirdly, the information retrieved by ultrasound sensors is relatively

simple, so very few processing and communication resources are needed. Finally, the

deployment of ultrasound sensors is much easier compared with pressure sensors, and

the power requirement is much lower than that of infrared.3

From this related researches the group observed the citation given to ultrasonic usage

as most appropriate to sensing technology to moving objects. And in relation to the study

the group aims to do, vehicles are the objects to be observed in this study through the

ultrasonic transducers. Lastly, this related research shows the implementation of

ultrasonic sensor networks configured in an elevated positioning which the group

considers for the study’s system configuration as well.

Signal-transmitting and multi-receiving method of detecting obstacle and parking

apparatus using the same

The single-transmitting and multi-receiving method of detecting obstacle comprises acts

of (a) presetting a time period and multiple preset distances, wherein each present

distances is defined between adjacent ultrasonic sensors mounted on a vehicle; (b)

transmitting and receiving procedure wherein one of the ultrasonic sensors is controlled

to output ultrasonic detecting signal and then all ultrasonic sensors are controlled in the

receiving status after the ultrasonic detecting signal is not output; (c) receiving an output

signal of each ultrasonic sensor; (d) determining whether the ultrasonic sensor outputs

the reflected detecting signal; wherein if a determining result is negative, go to act (b),

but if the determining result is positive go to next act; (e) calculating distances of the

reflected detecting signals; (f) reading the preset distances; and (g) calculating the

shortest distance between a vehicle and an obstacle, wherein trigonometric equations

are calculated by the distances from act (c) and the present distances obtain the

shortest distance.5

5 Li, Shih-Hsiung. "Uk patent application." Signal-transmitting and multi receiving method detecing obstacle and parking apparatus using the same , 2008: 1-21.

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This related literature cited is the main source of inspiration of this study in using

ultrasonic transducer in modified configuration. The related literature cited the single-

transmitting and multi-receiving method of detecting obstacle for cars when parking

which made the group realized that usage of multiple ultrasonic transducers together to

detect objects is really possible. The group study further this paper and this made a

further realization that the shifting of the operation control of the ultrasonic transducer is

the technique that allows such modification to the conventional configuration usage of

ultrasonic transducers.

Parking guidance system using ultrasonic transducers

One Chinese company named Xiamen Keytop markets UD (ultrasonic detector) which is

one of the main parts of parking guidance system that identifies available parking

spaces. One parking space needs one UD which is installed in the middle of the car park

space. UD takes use of ultrasonic wave to detect the car space to see if it is occupied by

vehicles and transfer relative command to LED Indicator which will turn from green to

RED when occupied, or it will keep GREEN; meanwhile, the UD transmit its status

message to ZCU immediately, and ZCU will collect and forward the information to CCU;

CCU processes these data and sends the relevant command to ZCU and LED panel.

The cost of a single UD is about 50 dollars.6

Specification:

Size: diameter = 100*23mm

Weight: 113g

Principle: Ultrasonic

Work temperature: -20~+80℃Current rating: 13mA + 17mA (LED indicator)

Voltage rating: DC 24V

Detecting arrange 0.1~3.5m

Max error: 0.1m

6 Xiamen Keytop Comm.&Tech.Co.,Ltd. Hi-supplier. http://keytop.hisupplier.com/manufacturer-355618-ultrasonic-parking-guidance-system.html (accessed february 2010).

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Detecting area (3.5m): 0.4sq. m.

Communication: RS-485

baud velocity: 4800bps, N, 8, 1

Available distance: ≤1000

This UD is used and implemented in parking guidance system of many malls around

Asia. To name some are the SM Megamall (July 2010) and SM Mall of Asia (September

2008) of the Philippines.5

Through this related literature, the group identified that the pricing of the conventional

single ultrasonic detector for parking guidance system are quite expensive as shown.

Other sensors use in parking monitoring system

A commercialized intelligent system named Parksys implements a parking monitoring

system that provides a guide to available parking spaces. It shows real-time parking

information and statistics for every parking lot on public roadway. In this system,

magnetic sensor is used for sensing the presence of a vehicle and parking space

availability.7 This type of parking monitoring system focuses on implementation for street

parking that’s why it considered setup installation in the ground, which however adds

cost to the overall system cost upon installation. This is the reason why installation in

elevated position is much preferred for easy installation and less cost while having easy

and good maintenance.

Parking study

In a study “Safety Comparison of Angle and Parallel Parking”, the research shows that

the utilization of the study sites which is the parking slots are used at the ranged from

2.97 to 8.05 cars per 8 hour day with an average utilization rate of 85-100% per 8 hour

parking days on the study sites and 92-94% on the comparison sites. 8 This research

7 Parksys. "Parking monitoring system." On street information and guidance parking system. 3.

8 Oregon Department of Transportation. "Safety Evaluation Of Converting On-Street Parking From Parallel To Angle." Safety Comparison of Angle and Parallel Parking, 2001: 2.

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allowed the group identifies the statistical values on the number of parking slot usage in

a daily basis for the experimental test of the study.

Vehicle Height Specifications according to its Classification

Tabulated records from the vehicle height specifications of vehicles according to their

classification are given below:

Classification Lowest height Highest height Average heightSedan 1.65m 1.8m 1.73mCoupe 1.6m 1.8m 1.7m

Convertibles 1.6m 1.84m 1.72mPick-Up Trucks 1.89m 2.05m 1.97m

MPV 1.77m 1.98m 1.88mHatchbacks 1.66m 1.8m 1.73m

Wagons 1.6m 1.8m 1.7mSUV 1.69m 1.9m 1.75m

The vehicle details tabulated here considers only 1995 model until the present models.9

Based on this table, the group observes the vertical limit to be assigned in the system

setup. Likewise, this survey of car specification details serves as the basis of the

classifications observed in the different vehicles used in the tests of the research study.

Chapter 3: Design Considerations

Theoretical Framework

9 Source InterLink Media. Car Specifications – View Complete New and Used Car Specs & Data at InternetAutoGuide.com. http://www.internetautoguide.com/car-specifications/index.html. (accessed April 2010)

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A. Ultrasonic

The term "ultrasonic" applied to sound refers to anything above the

frequencies of audible sound, and nominally includes anything over 20,000 Hz.

Frequencies used for medical diagnostic ultrasound scans extend to 10 MHz and

beyond. Sounds in the range 20-100 kHz are commonly used for communication and

navigation by bats, dolphins, and some other species. Much higher frequencies, in

the range 1-20 MHz, are used for medical ultrasound. Such sounds are produced

by ultrasonic transducers.

A.1. Operating principle of ultrasonic sensor

Angled thru-beam sensor the emitter and receiver are separate, and the axes

of the emitter and receiver transducers intersect each other at an angle. Having

separate units for the emitter and receiver reduces the unusable area

considerably, because it is not subject to delays while waiting for oscillations of

the emitter to die out.

A.2. Attenuation of sound in air

The attenuation of sound in air due to viscous, thermal and rotational loss

mechanisms is simply proportional to f 2. However, losses due to vibration

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relaxation of oxygen molecules are generally much greater than those due to the

classical processes, and the attenuation of sound varies significantly with

temperature, water-vapor content and frequency. A method for calculating the

absorption at a given temperature, humidity, and pressure can be found in ISO

9613-1 (1993). The table gives values of attenuation in dB km−1 for a temperature

of 20°C and a pressure of 101.325 kPa. The uncertainty is estimated to be ±

10%.

Attenuation of sound in air (dB km−1)10

Frequency(kHz)

Relative Humidity %

10 20 30 40 50 60 70 80 90

1 14 6.5 5 4.7 4.7 4.8 5 5.1 5.3

1.25 21 9.4 6.7 5.9 5.7 5.7 5.9 6.1 6.3

1.6 32 14 9.8 8.1 7.5 7.2 7.2 7.4 7.5

2 45 22 14 11 9.9 9.3 9 9 9.1

2.5 63 32 21 16 14 12 12 11 11

3.15 85 49 32 24 20 17 16 15 15

4 110 75 49 36 30 26 23 21 20

5 130 110 74 55 44 38 33 31 28

6.3 160 160 110 84 68 57 50 45 42

8 180 220 170 130 110 89 78 69 63

10 190 280 240 190 160 130 120 100 95

12.5 210 360 340 280 240 200 180 160 140

16 230 430 470 420 360 320 280 250 230

20 260 510 600 580 520 470 420 380 350

25 300 580 740 770 730 680 620 570 520

31.5 360 670 890 990 1000 960 900 840 790

10 NDT resource center. NDT course material . http://www.ndt-ed.org/EducationResources/CommunityCollege/Ultrasonics/cc_ut_index.htm (accessed February 2010).

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40 460 780 1100 1200 1300 1300 1300 1200 1200

50 600 940 1300 1500 1700 1700 1700 1700 1700

63 840 1200 1500 1800 2100 2200 2300 2300 2300

80 1200 1600 2000 2300 2600 2800 3000 3100 3100

A.3. Speed of sound in air

The speed of free progressive sound waves in standard dry air containing

0.03% CO2 by volume is 331.46 ± 0.10 m s−1 at a temperature of 0°C and a

pressure of 101.325 kPa (see Cramer, 1993). The speed of sound in air changes

with temperature, water vapor content, and CO2 content. The table gives values

of the speed in m s−1 for a range of temperatures and humidity at 0.03% CO2 by

volume. The uncertainty in the values in the table is estimated to be 0.1 m s−1.

Speed of sound in air (m s−1)9

Temperature °C

Relative Humidity %

10 20 30 40 50 60 70 80 90

0 331.5 331.5 331.5 331.6 331.6 331.6 331.7 331.7 331.7

5 334.5 334.6 334.6 334.7 334.7 334.7 334.8 334.8 334.9

10 337.5 337.6 337.7 337.7 337.8 337.9 337.9 338.0 338.0

15 340.5 340.6 340.7 340.8 340.9 341.0 341.1 341.2 341.2

20 343.5 343.6 343.7 343.9 344.0 344.1 344.2 344.4 344.5

25 346.4 346.6 346.8 347.0 347.1 347.3 347.5 347.6 347.8

30 349.4 349.6 349.9 350.1 350.3 350.5 350.8 351.0 351.2

A.4. Reflection and Transmission Coefficients (Pressure)

Ultrasonic waves are reflected at boundaries where there is a difference

in acoustic impedances (Z) of the materials on each side of the boundary. (See

preceding page for more information on acoustic impedance.) This difference in

Z is commonly referred to as the impedance mismatch. The greater the

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impedance mismatch, the greater the percentage of energy that will be reflected

at the interface or boundary between one medium and another.

The fraction of the incident wave intensity that is refracted can be derived

because particle velocity and local particle pressures must be continuous across

the boundary. When the acoustic impedances of the materials on both sides of

the boundary are known, the fraction of the incident wave intensity that is

reflected can be calculated with the equation below. The value produced is

known as the reflection coefficient. Multiplying the reflection coefficient by 100

yields the amount of energy reflected as a percentage of the original energy.

Since the amount of reflected energy plus the transmitted energy must

equal the total amount of incident energy, the transmission coefficient is

calculated by simply subtracting the reflection coefficient from one.

A.5. Acoustic Impedance

Sound travels through materials under the influence of sound pressure.

Because molecules or atoms of a solid are bound elastically to one another, the

excess pressure results in a wave propagating through the solid.

The acoustic impedance (Z) of a material is defined as the product of its density

(p) and acoustic velocity (V).

Z = pV

Acoustic impedance is important in determination of acoustic

transmission and reflection at the boundary of two materials having different

acoustic impedances, designing of ultrasonic transducers and assessing

absorption of sound in a medium.

One of the most frequently asked questions is “How far the transducer

could reach?” This question can be answered by a simple calculation that is

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based on the published specifications in the Ultrasonic Ceramic Transducer Data

Sheets. The basic procedure is to first determine the minimum sound pressure

level developed at the front end of the receiver for a specific transmitter driving

voltage and distance between the transmitter and receiver (transceiver has

double distance between reflect target). This SPL must then be converted “Pa”

(Pascal) or “μbar” (microbar) units. The sensitivity of the receiver must then be

converted from a dB reference to an absolute mV/Pa or μbar level present to

obtain the final output.

A.6. Ultrasonic sensors

Ultrasonic sensors are designed for robust performance in harsh and

problematic environments where there are a variety of reflective forms, and

where precise detection is essential. They have features that allow them to

operate in environments where traditional sensing devices are unsuitable. They

are unaffected by target color, ambient noise or dusty atmospheric conditions,

provide noncontact distance measuring and their longer and wider sensing

ranges help solve some pretty tough applications. Ultrasonic bridges the gap

between proximity and photoelectric sensing by allowing a longer sensing

distance in dusty/dirty environments. They are especially effective in detecting

unusually shaped targets or monitoring objects with a relatively high density and

high acoustic reflectivity such as solids, liquids and granular materials.

A.7. Ultrasonic transmitter

Ultrasonic transmitters convert an electrical signal into sound energy,

firing a burst into the air which travels to the target and then is reflected back to

the transducer.

A.8. Ultrasonic receiver

Ultrasonic receiver acts as a receiving device and converts the sonic

energy back into an electrical signal contained in the transceiver.

B. Microcontroller

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A microcontroller (also microcomputer, MCU or µC) is a small computer on a

single integrated circuit consisting internally of a relatively simple CPU, clock, timers,

I/O ports, and memory. Program memory (whether a NOR flash or OTP ROM) is

also often included on chip, as well as a typically small amount of RAM.

Microcontrollers are designed for small or dedicated applications.

B.1 AT89C2051 Microcontroller

The AT89C2051 is a low-power, high-performance CMOS 8-bit

microcomputer with 8Kbytes of Flash programmable and erasable read only

memory (PEROM). The device is manufactured using Atmel’s high-density

nonvolatile memory technology and is compatible with the industry-standard

80C51 and 80C52 instruction set and pin-out. The on-chip Flash allows the

program memory to be reprogrammed in-system or by a conventional nonvolatile

memory programmer. By combining a versatile 8-bit CPU with Flash on a

monolithic chip, the Atmel AT89C2051 is a powerful microcomputer which

provides a highly-flexible and cost-effective solution to many embedded control

applications.

C. Indicator Lights (LED)

A light-emitting diode (LED) is a semiconductor light source. LEDs are used as

indicator lamps in many devices, and are increasingly used for lighting. The LED is

based on the semiconductor diode. When a diode is forward biased (switched

on), electrons are able to recombine with holes within the device, releasing energy in

the form of photons. This effect is called electroluminescence and the color of the

light (corresponding to the energy of the photon) is determined by the energy gap of

the semiconductor.

D. C language

C is a general-purpose computer programming language developed in 1972

by Dennis Ritchie at the Bell Telephone Laboratories for use with the UNIX operating

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system.11 The C programming language is a popular and widely used programming

language for creating computer programs. Programmers around the world embrace

C because it gives maximum control and efficiency to the programmer.

D.1. C language for Microcontroller

Microcontrollers were originally programmed only in assembly language,

but various high-level programming languages are now also in common use to

target microcontrollers. These languages are either designed especially for the

purpose, or versions of general purpose languages such as the C programming

language. Compilers for general purpose languages will typically have some

restrictions as well as enhancements to better support the unique characteristics

of microcontrollers. Some microcontrollers have environments to aid developing

certain types of applications. Microcontroller vendors often make tools freely

available to make it easier to adopt their hardware.

Conceptual Framework

11 Stewart, Bill (January 7, 2000). "History of the C Programming Language". Living Internet. Retrieved 2006-10-31.

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http://www.livinginternet.com/i/iw_unix_c.htm


Figure 1: Parts of the System’s Operation

The system has three main parts in regards to its operation: the microcontroller, the

availability indicators and the parking slots monitor. The system is focused on monitoring

four parking slots. The parking slot monitor is based on the operation of ultrasonic

transducers. The ultrasonic transducers are use to detect if the parking slots are

available or not. In regards to this, the system introduces two possible modified

orientations in the use of ultrasonic transducers. These two orientations are called by the

group as multiple-transmitter, single-receiver (MTSR) and single-receiver, multiple-

transmitter (STMR) sensor configuration. For both configurations, the full operation of

the system shall be controlled by a microcontroller as shown in Figure 1. The

microcontroller will be responsible for the arrangement in the flow of operation to perform

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the detection of the parking lot availability. The microcontroller is mainly concerned to

operate the monitoring operation in a sequential and one-at-a-time manner. This is to

reduced the error factor within the system and at the same time propagate the better

control and recognition in each transducer during operations. Lastly, the indicators

serves as the means to make the users of the parking lot know what is available or not.

These indicators are controlled by the microcontroller through determining the reception

of the ultrasonic signals through the ultrasonic receiver circuit. To further realized the

operation of the two cited sensor configurations, a precise description of the orientations

studied in this system design is given below.

Modified MTSR and STMR sensor configurations

- In this study, the two configurations are specifically designed for simple application of

detecting the availability of only four parking slots in a single setup. These shall

optimize the usage of the ultrasonic transducers by introducing these new possible

configurations of the transducers. Transducers assigned as transmitters and

receivers are placed on calculated positions in accordance to the capacity and limits

of the ultrasonic transducers. The MTSR and STMR sensor configuration are both an

experimental based technique introduced to give an alternative to the conventional

way of application of ultrasonic transducer. Both are synonymous in terms of

operation, differing only on the account of number of receiver or transmitter used in

the respective configuration. Other than the determining of whose multiple and single

in the operation, the main difference between the two orientations is observation of

the direction of the transducers. For the MTSR, the transducer set as receiver shall

be placed strategically in the center of the transmitters. The receiver is on a fixed

position having its focus on a vertical manner while the transmitter is angled focusing

its respective parking slot to detect its availability. The concept described is just the

opposite for the STMR configuration, wherein the receivers observe the angle

focusing on its respective parking slot while the transmitter is on a fixed vertical focus

in the center of the receiver. The angle of the transducer, the distance of the

transducers from one another and the possible distance of travel of the signal in both

configurations are all based on a theoretical calculation, which is being considered

for the applicability of the technique proposed in this configuration. Please refer to

the diagram below:Page 19 of 59


Figure 2: MTSR and STMR Sensor Configuration

- MCU controls the transmitter and receiver. Receiver is set on during operation while

transmitter is turned on in a “sequential manner” for the MTSR sensor orientation. On

the other hand, the receiver is the one turned on in a sequential manner and the

transmitter is set on during operation for the STMR sensor orientation. For both

orientation, the operation works on a one-at-a-time basis.

- Set a threshold value in regards with the received values of the receiver when the

ultrasonic wave is acquired (need to conduct experiment for threshold assumption)

- In the MTSR orientation, the single receiver is placed at the center responsible to

indicate the availability of the respective parking lot of the working transmitter at a

time. On the other hand, in the STMR orientation the single transmitter is the one

place on the center of the position of the multiple receivers. The reception of

ultrasonic wave indicates the availability based on the value derived from the

received signal as compared to the threshold value assumed from the

experimentation. (Note: Reception of correct frequency of the ultrasonic signal at the

receiver circuit shall be the basis)

If ultrasonic signal frequency received is within range of set threshold value, then

Available

If ultrasonic signal frequency received is not within range of set threshold value,

then Not Available

- Then, the MCU shall perform the operation on the most appropriate sequence of

time for the checking of the availability of the parking lots.

Page 20 of 59


Theoretical Computations

First to consider for computations is the dimension of the parking spaces to be

considered in the implementation of the orientation. The average width and

length of the car is 15ft long and 5.5ft wide. Thus, the group assumed to consider

a dimension for each parking space to be at 16ft long and 8ft wide.

MA40B8-R/S has a directivity of 50° and a detecting range of 0.4 m up to 6 m.

If a = 6m; (max range of transducer)

If a = 3 m;

If a = 2.5 m;

Based on the computation above, the group continued the computation to

estimate the probable ideal distance of the transmitter to the receiver. Having

identified the value of b, we can now obtain the probable distance of the

transmitter from the receiver if the transmitter shall have the center of its

directivity on the angle of 25°. It can simply assume through observing

trigonometric laws regarding triangles having same dimensions and angle. Thus,

the probable ideal distance = 2b.

If height (h) = 3m and b = 1.2989 m, Then d = 2.5978m

If height (h) = 2.5m and b = 1.1658 m, Then d = 2.3316m

Another parameter needed to have computations is the allowed travel distance

the signal can do, which is based on the data sheet is not more than 6m due to

the detecting range. Hence, the boundary of the directivity of the signal which is

Page 21 of 59


the hypotenuse of the observe triangle in the diagram must not exceed 3m to

assure reception of ultrasonic wave after bounce.

If a = 2.5 m;

*Distance travelled by the ultrasonic wave = 2h = 5.5168m

In the proposed orientation, the ultrasonic wave is expected to bounce through

the floor before going to the reception. Thus, the group shall compute the

reflected and transmitted signal amplitude. To do this, the acoustic impedance of

the sound in air and the concrete must be observed. The acoustic impedance of

the two shall be used to compute the acoustic reflection and transmission

coefficient which shall be use to estimate the signal amplitude change.

Z = p V wherein: p = density;V = velocityZ1 = acoustic impedance in airZ2 = acoustic impedance of concreteZ1 = 406.2 N-s/m2

Z2 = 1507 N-s/m2

Rcoef = 2 = 2 = 0.33105 = 33.105%

Signal amplitude change = log (Rcoef) x 20 = -9.6 dB

Tcoef = 2 = 1 – 0.33105 = 0.66895 = 66.895%

Signal amplitude change = log (Rcoef) x 20 = -3.39 dB

- On the computation obtained regarding the signal amplitude change caused by

the impedance mismatch, the group now can calculate the total percentage of

Page 22 of 59


the signal that will be able to come back to the transducer. In regards to this, the

flow of the ultrasonic wave shall be observed and a diagram below shows a

typical reflection and transmission of sound based on the two materials cited:

In regards with the attenuation of sound in air, the group searched and found out

that the ISO 9631-1:1993 is specifically about the attenuation of sound on its

propagation on outdoors or simply in short, attenuation of sound in air. Thus, the

group continued research on it and found sites that allow us to calculate the

attenuation in consideration of the various parameters that affects the sound in

air – temperature, relative humidity, pressure, and frequency of the sound. The

group obtained the value of the attenuation of sound in air and the details are

shown below:

Attenuation of 40 KHz sound in air @ Temp = 20°; Humidity = 80%;

Pressure = 101.325KPa 1.23 dB/m

Attenuation of 40 KHz sound in air @ Temp = 30°; Humidity = 80%;

Pressure = 101.325KPa 1.02 dB/m

Now, the group continued the computation for the ultrasonic implementation.

Here the group performed calculations to see how far the transducer

transmission can reach. Details for the computations are shown below: (assumed

transmitter driven @ 20Vrms)Page 23 of 59


SPL Gain for 20Vrms driving voltage = 20 * log (20V/10V) = 6 dB

SPL Reduction at 6 meters = 20 * log (0.3m/6m) = -26.0206 dB

Wave absorption = 1.02 dB/m * 6m = 6.12 dB

SPL at 6m = 120 + 6 -26.0206 -6.12 dB = 93.8594 dB

Convert SPL to µbar:

93.8594 dB = 20 * log(X/0.0002 µbar)

4.693 = log(X) - log (0.0002)

0.994 = log(X)

X = 9.8635 µbar

Determining Receiver Sensitivity in Volts/µbar:

-63 dB = 20 * log(S/1Volt/µbar)

-3.15 = log(s) - log (1)

-3.15 = log(S)

S = 0.7079 mV/µbar

Voltage generated under X: S * X =9.8635 µbar * 0.7079 mV/µbar = 6.98mV

Based on this calculation on the signal amplitude in terms of the voltage, the

value set on the transmitter must be set higher than the typical 20Vrms like on

the sample. This is to assure that the voltage generated will be high enough of

the required output value in the MCU processing.

Definition of Terms

Transducer Any device that converts one form of energy into another

AttenuationDecrease in intensity of a signal, beam, or wave as a result of absorption of energy and of scattering out of the path of a detector, but not including the reduction due to geometric spreading.

TransmitterAn electronic device that generates and amplifies a carrier wave, modulates it with a meaningful signal derived from speech or other sources, and radiates the resulting signal from an antenna.

Page 24 of 59


ReceiverA device that receives incoming radio signals and converts them to perceptible forms, such as sound or light.

ImpedanceA measure of the opposition to the flow of an alternating current equal to the square root of the sum of the squares of the resistance and the reactance, expressed in ohms.

Detection The act or process of extracting information from an electromagnetic wave.

Microcontroller(MCU)

A single chip that contains the processor (the CPU), non-volatile memory for the program (ROM or flash), volatile memory for input and output (RAM), a clock and an I/O control unit.

System A combination of two or more sets generally physically separated when in operation, and such other assemblies, subassemblies, and parts necessary to perform an operational function or functions.

Signal An impulse or a fluctuating electric quantity whose variations represent coded information.

EmitterThe region in a transistor in which the charge-carrying holes or electrons originate

Range The limits within which any fluctuation takes place

Parking lot An area for parking motor vehicles

Autonomous Not controlled by others or by outside forces; independent

SequentialCharacterized by or having a regular sequence; in regular succession without gaps

CoverageThe extent or degree to which something is observed, analyzed, and reported

Circuit A complete path through which an electric current can flow

IndicatorAn instrument that displays certain operating conditions in a machine; device to attract attention

Configuration The direction followed in the course of a trend, movement, or development

MTSR (Multi Transmitter, Single Receiver) a setup wherein a system uses 2 or more transmitters alongside with a single receiver for reception

STMR (Single Transmitter, Multi Receiver) an setup wherein a system uses 2 or more receivers alongside with a single transmitter for transmission

Page 25 of 59


Chapter 4: Project Plan

Methodology

This study showcases a design of a proposed new configuration technique to

reduce the number of ultrasonic sensors use in a parking slot monitoring system. The

project study shall be completed through achieving the following stages: the research

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and theoretical computations, the system setup development which includes

experimentation, the software development, and the test and analysis.

The research stage includes the finding of the appropriate related articles that

shall give basis for the carrying through of the objective of the study. A number of topics

are required for full comprehension of the study and these are the ultrasonic

fundamentals, the application of ultrasonic transducers, the current systems of parking

monitoring systems and the configuration applied. Moreover, in this stage a theoretical

calculation for the system setup shall be made based on the observation on the

fundamental concepts in the research to make the system. Next, system setup

development is concern mainly on implementation of prototype of the system. And for

this reason, the study requires as well in this stage to involve an experimentation to

determine the actual limits of the parameters needed to be observed on the sensing

capacity of the ultrasonic transducers. This is to assure on an actual basis the accuracy

of the theoretical computations made in the research stage. The experimentation shall

also determine the better configuration to implement for the system, getting the best out

of the options for the study. In addition, the experimentation shall be also the means to

identify the threshold value observe for determining reference range of values going to

be obtained by the receiver in the operation. Moving on, the control program for the

operation of the system in the microcontroller shall be done in the software development

stage. Then, a test and analysis stage shall be performed to assure the correctness of

the implemented system. Here the group shall test the system whether it has achieved

the objectives of the study and if probably there are errors that are needed to be

modified. Upon checking of the whole system functionality and correctness, the group

shall perform the analysis to the observations met in the different steps performed.

Lastly, the conclusions and recommendations regarding the system can be detailed out

and prove the hypotheses created from the start of the study.

Project Plan

(See Gantt chart of the Project making on the next page)

Page 27 of 59


Budget

ITEMS QUANTITYPRICE / UNIT

(Pesos)Total Cost

(Pesos)MA40B8S (transmitter) 4 601 2,404

MA40S4R (receiver) 1 350 350AT89C2051 1 100 100

CD4049 6 13.50 81Crystal Oscillator

(11.059MHz)1 15 15

Power Supply 1 400 400NE555 4 10 40LM567 1 34 34

Page 28 of 59


LM311 1 17 17LM358 1 13 131N4001 4 1 42N2222 4 3 12Relay 4 35 140

3362 top adjust potentiometer

6 20 120

Super bright LED 8 7 56Flash Light Bulb 4 12 48

Wires 60 (meters) 15 900Pre-Sensitized Circuit Board w/ Developer

(4 X 6)4 90 360

7805 voltage regulator 1 12 12Chrome pipes 5 320 1,600

Capacitors 50 1.50 75Resistors 100 .50 50

Connector (m/f) 7 10 70TOTAL: P 6,901

T

Page 29 of 59


Table 2: Total Budget for MTSR sensor configuration

Chapter 5: System Design1. System Concept

System Diagram

Figure 3: System Diagram

Here is the system’s diagram showing the subsystems of the design and its roles

in the process. As shown, the first subsystem is the ultrasonic sensors which serve as

the input of the system. The input which is the ultrasonic sensors is responsible for the

observation of data regarding the parking slot. Using the ultrasonic waves, the

characteristics observe in the process of the transmission and reception of the ultrasonic

wave shall be the basis of the necessary data as input of the system. Then, the next

subsystem of the system is the system processor itself which is the Microcontroller-

Based Control Unit. It is responsible on the processing of the data observed through the

input obtained by the ultrasonic sensors in its respective parking slots. Also, this

subsystem is the one responsible in controlling the phasing of the four sensors. Since

the new orientation will use a single transmitter/receiver, it is necessary to control the

Page 30 of 59


switching on and off of the multiple receiver/transmitter to lessen the error that might

occur in acquiring the needed sound waves. Thus, this subsystem makes the system

performance more reliable. The last subsystem simply illustrates the indicator of the

processed data by the system. This is the one which will make the system useful to the

human eye by interpreting the results of the data gathered and processed by the first two

subsystems.

2. Block Description

Block Diagram

Figure 4: Block Diagram

Referring to the block diagram given above, the group identifies the blocks of the

process observed by the system. In reference to the system diagram, the blocks of

the processes observed in the input, the control system and the output are describe

in this part of research. First, the three parts are powered by a power supply. The

operation starts with the microcontroller initializing the transmission of the ultrasonic

waves thru the input block of the system. The input block has two inner function

blocks in its operation. The first inner function block is the ultrasonic transmitter

Page 31 of 59


circuit which serves as the main source of input to the system. The ultrasonic

transmitter is responsible of producing the ultrasonic waves that shall be received by

the ultrasonic receiver circuit, which is the second function block inside the input

block of the system. Next, the control system block contains two blocks as well: the

microcontroller unit and the comparator. The control system block is responsible of

processing the observed data of the system through the two blocks identified. The

comparator processed the received ultrasonic waves of the ultrasonic receiver and

assess whether it shall consider the value as a sign of “no availability” or “availability”

of the respective parking slot. After checking the value on the reception of signal, the

comparator sends out a signal in accordance to the result of the comparison to the

microcontroller unit. Now the microcontroller unit handles the control overall by

observing the inputs given to it. Depending on the value sent by the comparator, the

microcontroller shall assign what display the LED indicator on the output side shall

display. From there, the microcontroller shall control again the start of the operation

by starting the operation for the next parking slot to observe.

Circuit Design

Microcontroller Circuit

The group decided to use the AT89C2051 as the microcontroller of the system

because of the following criteria: I/O pin requirements and program memory size. It is

true that there are so many better microcontrollers than AT89C2051; however, in this

reason as well the group chose AT89C2051 rather than the better microcontroller.

The AT89C2051 I/O pins and memory size is sufficient enough to handle the control

function vested on the microcontroller of the system. Thus, using microcontroller with

higher specification is considerably in no need at all and shall be impractical for that

matter as well.

In regards to the microcontroller circuit design of the system, the MCU’s Port 1

and 3 shall be fully utilized for the operation control of the system (transmitter,

receiver and LED indicator control). The circuit shall also incorporate usage of

connectors for simpler interfacing with the other circuits of the system.

Page 32 of 59


Transmitter Circuit

The group considers MA40B8S as the ultrasonic transducer for the transmitter

circuit. We came up in using such type of transmitter because this has the

capability of transmitting ultrasonic waves at a longer distance of up to 6 meters.

This transmitter also has a 50 degrees beam angle which would be suffice enough

for the needs of the new configuration to be done. Next, the group incorporates the

usage of a 555 timer to produce the oscillation of 40 KHz for the ultrasonic

transmitter. The 555 timer has its reset terminal connected to the microcontroller for

operation control purposes. Another part of the transmitter circuit is the inclusion of

CD4069 IC to serve as current driver of the ultrasonic transmitter.

Receiver Circuit

The group considers MA40S4R as the ultrasonic transducer for the receiver

circuit. This type of receiver meets the specifications needed in the study. The

MA40S4R can receive ultrasonic waves by up to 4 meters while having a beam

angle of 80 degrees, which shall be sufficient enough to meet the setup needs to

have the new configurations. The receiver circuit also includes the usage of LM 358

OP-AMP to have the voltage received from the ultrasonic transmission amplified.

The receiver circuit also includes the usage of LM 567 tone decoder as a band-pass

filter to reject out the unwanted signals. This shall be done through the phase

locked loop design of LM 567 that shall detect input frequency within a certain range

(40 KHz for this application). Calculation for the components connected to LM 567

is done to determine the band-pass detection range. The last part of the receiver

circuit is the comparator that shall determine the logic state to be sent to the

microcontroller circuit.

3. Software Description

Development Environment/Tools

Page 33 of 59


The development environment or programming language in use in this

system design is C language for microcontroller programming. The group shall

use the C-compiler and assembler MIDE-package. The group specifically chose

this because it is an open-source C-compiler and assembler. MIDE-package is

capable of compiling C language for programming microcontroller. Programs

made shall be compiled through the compiler then from there a machine

language shall be produce in the form of hex file, which will be the one uploaded

to the microcontroller. The uploading of the hex file to the microcontroller will be

through a specific microcontroller programmer in which in this case will be the

Alexan’s 89CX051 programmer.

Flow Chart / System Flow Diagram

(See next page)

Page 34 of 59


Figure 5: Program Flowchart

Page 35 of 59


Pseudo code

main menu:

initialize x = 0; // shifting variable for transmitter and indicator

initialize P1 = 1; // inverse logic for inverter power driver

initialize a = 0; // variable for no reception events

enter while (1);

turn on transmitter(x);

start on-time count with checker;

while on-time count is not finish

If P3_7 = 1; // signifies no reception

a++;

If a > threshold number for no reception

Indicator(x) set to “Not Available”

Else a < threshold number for no reception

Indicator(x) set to “Available”

Increment x;

If x > 3;

Then x = 0;

a = 0;

Go back to start of loop;

Chapter 6: Experimental Results

Page 36 of 59


1. Test Procedures

A. Configuration Testing (Determining between MTSR / STMR Configuration)

Tools/Equipments:

Ultrasonic receiver, ultrasonic transmitter, power supply

Input: Received signals of the transmitter and receiver.

Process: Recognition of the received signals.

Output: Electronic output logic signals the ultrasonic transducers

transmission and reception

1) Prepare the transmitter circuit first. Have the necessary calibration

for the frequency to be use on the oscillation of the signal to be used

in the ultrasonic transducer.

2) Assure desired input voltage (12V+) be applied on the circuit and

check the output voltage on the ultrasonic transmitter. (be at least

12V).

3) Let the transmitter operate. Check the frequency of the ultrasonic

signal created. This must be on 40 KHz.

4) Prepare the receiver circuit. Assure correct supply voltage in it and

prepare the necessary amplification circuit for its input received from

the ultrasonic signal.

5) Test the functionality of the transmitter and receiver through

implementing a basic transmit-and-receive thru-beam setup. The

functionality is observed when the receiver is able to produce a

considerable output voltage. (Refer to the theoretical computations)

6) Once a simple thru-beam setup is found functional, test the

transmitter and receiver circuit in an angled thru-beam setup. Here,

the group shall perform the observation for both two new

configurations propose in this study.

7) Observe first the setup for the STMR configuration by having the

transmitter on a perpendicular position in respect to ground and a

receiver angled based on the prepared experimentation setups.

Page 37 of 59


8) Fill up the tables prepared for the test of STMR configuration by

recording signal reception strength observed in the receiver side. Do

the multiple trials indicated in the experimentation table and observe

the parameters designated for each trial of the experiment.

9) Signal reception strength will be observed via LED indicator of the

comparator side of the receiver circuit. Only an ultrasonic reception

will lit on the LED indicator of the comparator of the receiver circuit;

thus, LED is lit off when there is no reception. The reception strength

will be categorized prior to the characteristic of the LED during

reception; based on the time the LED is lit on during observation time

of around five (5) seconds. Percentage of the observation time prior to

the reception observed shall be the basis of categorizing the signal

reception strength.

10) Then use the MTSR configuration, prepare the configuration by

having now instead the receiver on a perpendicular position in respect

to ground while the transmitter observing a specific angle desired in

the experimentation table.

11) Fill up the tables prepared for the test of MTSR configuration by

also recording the signal reception strength observed in the receiver

side. Do the multiple trials indicated in the experimentation table and

observe the parameters designated for each trial of the experiment.

12) Tabulate all of the results of the two configurations and compare

which is better to use.

13) Analyze and determine which configuration is better based on the

results obtained in the experiment. The main basis in choosing the

better configuration is the reception capability depicted on the results.

B. Software and MCU Testing

Tools/Equipment: Microcontroller software simulator, AT89C2051

Input: Setting up of the values in the simulator

Process: Sensor and Indicator control

Output: Output depicted in the LED Indicator

Page 38 of 59


1) Open the programming environment to be used.

2) Write the program, when done run and debug.

3) Test the functionality of the program by writing it down to the IC.

4) Once written, install the IC to the circuit.

5) Initiate the system operation and observe if the behavior of the

system follows the written program.

6) Check if the control on the transmitter is correctly implemented in

respect to the setup of the configuration.

7) Check if the receiver is controlled correctly as well in respect to

the setup of the configuration.

8) Both procedure 6 and 7 shall be performed through observing the

control pins assigned on the transmitter and receiver by using LED in

displaying the logic in the pins during operation.

9) Note that proper shifting on control on either transmitter or

receiver shall be implemented depending on what configuration is

chosen between STMR and MTSR. Therefore, the program is

expected to be created based on the chosen configuration because

the two configurations shall have a difference on its control system

management.

10) Check the time allotted as delay for each parking slot observed

through the configuration observed. The group expects to have at

around 5-6 seconds waiting time for each parking slot monitoring.

11) Check the total time of operation in completing the monitoring

operation in all parking slots. As waiting time is expected to be at

around 5-6 seconds, this means that the total time of operation in

completing the monitoring operation in all parking slot should be

around 20-24 seconds.

12) Next, check the appropriate processing condition for the reception

checking of the microcontroller of the ultrasonic transmission. The

microcontroller must be able to set level of sensitivity on the reception

of the ultrasonic transmission through setting threshold figure in the

Page 39 of 59


code. This shall be done through tapping the assigned pins to either

logic 1 or logic 0 for some time during the shifting.

13) Re-program the microcontroller if such error in regards of

operation is met during the observation.

14) Prepare the microcontroller circuit for interfacing on the system

once fully operational of its control system function.

C. Actual Testing

a. System’s performance Testing

Tools/Equipments: Ultrasonic receiver, ultrasonic transmitter, MCU,

availability indicator

Input: Ultrasonic waves transmitted and received by the sensors

Process: Evaluation of the sound wave received

Output: Operation functionality and stability of the system

1) Install the system to an area possible for parking lot of vehicles.

(real parking lot if only possible)

2) Initiate the system operation.

3) This actual test shall be focus on serving an accuracy test for the

detection the availability and non-availability of the monitored

parking slots.

4) The accuracy test shall involve four different test – detection

checking for available parking slots, detection checking for single

used parking slot at a time, detection checking for two adjacent

used parking slots and the detection checking on all-four used

parking slots. The four slots shall have its corresponding LED

indicator for visual determinant of the detection made by the

system. LED indicator shall be turned on if its respective parking

slot is available; LED indicator should turn off if its respective

parking slot is not available or occupied.

5) The detection checking for available parking slots shall be having

the four slots left vacant to have the system be observed whether it

Page 40 of 59


shall indicate correctly for each parking slot the availability of it. The

result of the test shall be tabulated to observe whether error shall

occur.

6) The detection checking for single used parking slot at a time is a

test wherein a vehicle will be parking in a single slot at a time

(meaning the other three slots will be left available). The result of

the test shall be tabulated to observe whether error shall occur.

7) The detection checking for two adjacent parking slots usage at a

time is a test wherein two vehicles will be parking in two adjacent

slots at a time (meaning the other two slots will be left available

during each trial). The result of the test shall be tabulated to

observe whether error shall occur.

8) Then the fourth parking trials of the accuracy test is the detection

checking on all-four used parking slot at a time. It is a test wherein

all the four parking slots will be occupied by four vehicles at a time

(all slots occupied, no available). The result of the test shall be

tabulated to observe whether error shall occur.

9) The last part of the actual test has a different focus among the

previous three. This time around the observation of the test is to

determine the accuracy on parking different vehicles through all the

slots at a time, to completely depict in this research all the normal

scenarios observed in a parking lot usage. The test shall involved

observing the four typical kinds of vehicles being parked multiple

times in each slot. Similar to the previous test, in each slot the

detection of vehicles made shall be tallied to determine the

percentage error during the trials.

10) After completing all the parking trials, analysis about the tallied

results shall be performed by the group.

2. Test Results

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The testing area the group conducted the following test is not parking lot vicinity but

rather a vacant dead-end road inside a subdivision. The area is within Antipolo City,

which is a mountain-side area having wind mostly all over the day. Here the group

claims that the testing area is not the exact appropriate area having the interference of

wind present most of the time. Nevertheless, the group still continued the following test

in the area so the test will be conducted while including stress on the system capacity

already. (Presence of wind interference)

A. Configuration Testing

Data and Results Table of Configuration Testing (implemented for MTSR and STMR)

Signal Reception Strength:

1 – Strong (100% Reception)

2 – Moderate (above 60% Reception; LED is on for above 3 seconds)

3 – Weak (60% and below Reception; LED is on for 3 seconds and below)

5 – No Reception

The following must be noted prior to the test:

o The reception capability is the one being observed which shall be considered

based on its signal strength.

o The observation of signal reception strength is categorized into four prior to the

observed reception time during observation time allotted in each test.

o The signal reception strength is observed through an LED indicator of the

comparator side in the receiver circuit.

o The LED indicator is turned on when there is reception of ultrasonic signal on the

receiver circuit; the LED is turned off when there is no reception.

o Observation time will be five seconds; based on the observation time of the SM

Megamall ultrasonic-based parking system.

STMR (Single-Transmitter, Multiple-Receiver Configuration)

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d = 2.1mTX angle h = 2.1m h = 2.2m h = 2.3m

20-24 degrees 5 5 525-29 degrees 5 5 530-34 degrees 5 5 535-40 degrees 3 5 5

Table 3.1: Experiment Result Table 1 for STMR Reception observation

Note: Due to these results, the group decided not to continue the configuration test of

STMR. Moreover, the group concludes through these results that STMR configuration is

low receptive in this distance and will not be able to meet the requirements of the target

system application.

MTSR (Multiple-Transmitter, Single-Receiver Configuration)d = 2.1m

TX angle h = 2.1m h = 2.2m h = 2.3m20-24 degrees 2 2 225-29 degrees 2 2 230-34 degrees 1 1 135-40 degrees 1 1 1

Table 3.2: Experiment Result Table 1 for MTSR Reception observationd = 2.6m


Table 3.3: Experiment Result Table 2 for MTSR Reception observationd = 3.1 m


Table 3.4: Experiment Result Table 3 for MTSR Reception observation

B. Software and MCU TestingTX operation TX1 TX2 TX3 TX4 Operation Time Allotted

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modes (ON-time)TX1 mode 1 0 0 0 5.70 secondsTX2 mode 0 1 0 0 5.67 secondsTX3 mode 0 0 1 0 5.72 secondsTX4 mode 0 0 0 1 5.74 seconds

Table 4.1: Software Functionality TestingNote: The table indicates Logic 1 for the working transmitter; Logic 0 for the non-working

transmitter during each operation mode. A complete TX operation includes all TX operation modes being processed.

For Reception processing condition checking:

The group adjusted the value to obtain the correct sensitivity during the actual

test preparation itself. The group found out the necessity to set the threshold value at

around almost 50% of the ON-time count of the program to secure a good receptive

ultrasonic setup. (The ON-time count set in the code of the program is 103, which

indicates the iteration to complete the target operation time allotment for each TX mode.

The threshold value of the sensitivity checker is set at 50 in the code after all adjustment

made.)

C. Actual Testing

Parking Trials Test Results:

Table 5.1: Experiment on Parking Trials Part 1(Detection checking for available parking slots)

Parking Trials 2# of complete TX operations made with a car parked in a single slot at

# of detection of vehicles made

% error

Page 44 of 59

Parking Trials 1# of complete TX operations

made with vacant parking slots

# of availability detection made % error

Slot 1 10 10 0%Slot 2 10 10 0%Slot 3 10 10 0%Slot 4 10 10 0%


a timeSlot 1

(Parked with Toyota Altis)10 10 0%

Slot 2(Parked with Toyota Altis)

10 10 0%


10 10 0%


10 10 0%

Table 5.2: Experiment on Parking Trials Part 2(Detection checking for single used parking slot at a time)

Parking Trials 3# of complete TX operations made

with vehicles parked in two adjacent parking slots at a time

# of detection of vehicles made % error

Slot 1 & Slot 2 (Parked with Toyota Avanza & Altis)

10 20 0%

Slot 1 & Slot 3 (Parked with Toyota Altis & Avanza)

10 20 0%

Slot 2 & Slot 4 (Parked with Toyota Avanza & Altis)

10 20 0%

Slot 3 & Slot 4 (Parked with Toyota Altis & Avanza)

10 20 0%

Table 5.3: Experiment on Parking Trials Part 3(Detection checking for two adjacent parking slots usage at a time)

Parking Trials 4# of complete TX operations made with all parking slots

occupied

# of detection of vehicles made % error

Slot 1(Parked with Toyota Corolla)

10 6* 40%


10 10 0%

Slot 3(Parked with Toyota Avanza)

10 10 0%

Slot 4(Parked with Nissan Sentra)

10 10 0%

Table 5.4: Experiment on Parking Trials Part 4(Detection checking of all-four used parking slots at a time)

Note: * - cause by height difference of transducer position with the vehicle being parked in the slot

Parking Trials 5Parking Parking Parking Parking # of detection of % error

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Car (3x) SUV (3x) MPV (3x) Pick-Up (3x) vehicles madeSlot 1 1 1 1 1 1 1 1 1 1 1 1 1 12 0%Slot 2 1 1 1 1 1 1 1 1 1 1 1 1 12 0%Slot 3 1 1 1 1 1 1 1 1 1 1 1 1 12 0%Slot 4 1 1 1 1 1 1 1 1 1 1 1 1 12 0%

Table 5.5: Experiment on Parking Trials Part 5(Detection checking of parking Cars, SUVs, MPV and Pick-Ups in each slot at a time)

Noted Test Details: Parking Trials 2, 3, 4 and 5 Setup Details:Transducer Height: 2.2mTransducer Distance: 3.3mTransmitter Angle: 40 degrees

Parking Trials 5 Car Classification: Passenger car or Car SUV or Sport Utility Vehicle MPV or Multi-Purpose Vehicles Pick-Up trucks

Chapter 7: Conclusions and Future Directives

Analysis

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In this research study, many factors has been considered to complete the

objectives and some tests are set as well to support and observe all of the factors

required. The group has the test divided into main three parts: the Configuration Testing,

Software and MCU Testing and the Actual Testing.

The first test which is the configuration testing supposedly must be performed to

determine the better performing configuration between the MTSR and STMR

configuration. In the course of the preparation of the configuration test, more factors

were met by the group that are really important to be considered. STMR configuration

test is the first test considered by the group as given in the table 3.1. The group realized

the difficulty in STMR configuration as we have found out the calibration of the receiver

was much more complicated and difficult compared to the transmitter calibration. In

support to this, even the test as shown in the results of table 3.1, the STMR

configuration is very low receptive if not receptive at all even. Hence, the group

concluded the STMR configuration will not be appropriate for the target system

application. Then the group performs the test for MTSR. In the MTSR configuration test

the group eyes to observe the parameters the best receptive setup for ultrasonic waves;

the parameters are the distance of the transducer from one another, the angle and the

height of the transducer position. Set of tables which observe different combinations of

the said parameters were prepared for the MTSR configuration test. During the test the

signal reception was being observed through the LED indicator placed on the

comparator side of the receiver circuit. When the LED lights on, reception of the

ultrasonic transmission was made. The intensity of the LED light signifies as well the

strength of the reception. Based on this, the group categorized the signal reception

strength which was being considered as the data to be observed in the configuration

testing. The categories of the signal reception strength are as follows: 1 – strong or

100% of the time of observation the LED indicator is lit on, 2 – moderate or above 60%

of the time of observation the LED indicator is lit on, 3 – weak or below 60% of the time

of observation the LED indicator is lit on and 5 - no reception. The observation time

allotted to determine the signal reception strength is five seconds. The objective of doing

this is to determine the desirable setup for good ultrasonic reception through considering

setups with at least strong or moderate signal strength reception. The test results of

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tables 3.2 up to 3.4 shows that the system MTSR configuration setup is completely

capable to function for the target objective of this research. Tables 3.2 up to 3.4 shows

as well the MTSR configuration setup is overall receptive at all trials made in any

conditions of the parameters cited. Second, the system setup is relatively sensitive to

interference, mainly the wind. During the test the group noticed the variations of the

signal reception strength during the chances that the wind blows in the testing area. This

is the reason why some parts of the results in this test received a rating for the signal

reception strength of 2 or even 3. The group believes that the reception can easily be

made even at long distances if the system setup will be free from interference. Thus, the

group concludes that parking areas with low or free from wind interference is the best fit

for ultrasonic-based parking monitoring system.

The next test is the software and MCU testing which mainly involves two vital

part of the system setup: the shifting of the transmission operation and the processing of

the reception to determine the availability of the parking slot monitored. In the test, the

group points out that the microcontroller shall control the transmitter involving delay for

each transmitter operation shift. The delay created in the program was observed if it’s

within the target waiting time for a single shift operation. Table 4.1 simply focused on

observing the shifting operation on the four transmitters if performing correctly as well as

if the delay is on schedule to meet the target total iteration time of the shifting operation.

Then the group studied the nature of the reception in the preparation of the actual test.

During this time as well the group identified the appropriate threshold number to be

observed to adjust the sensitivity of the indication of availability of a given parking slot

monitored. The trial of the actual test preparation itself served up as the means of

obtaining the best sensitivity threshold number in the program. This was the means

because not all four transmitters were working at the exact capacity and so the

adjustment of it should be for the general effectiveness in the setup. And so after some

trials and observation on the reception of the system setup, the group found out that it is

better to make the threshold number be at almost 50% of the delay count in the

program. This allowed the setup be more considerate on the reception mishaps caused

by the interference of wind, determining only no availability during block or almost block

of reception. Thus, the set threshold value in the code has compensated to make the

system capable enough to function well in the midst of some interference.

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The last part of the test being conducted for the research study is the actual test

of the complete system setup itself. The actual test is focused on checking the accuracy

of the system setup to determine the correct availability status of all four parking

monitored slots. The actual test includes five parking trials that include tables to be filled

up: Table 5.1 Parking trials 1 (detection checking for available parking slots), Table 5.2

Parking trials 2 (detection checking for single used parking slots at a time), Table 5.3

Parking trials 3 (detection checking for two adjacent parking slots usage), Table 5.4

Parking trials 4 (detection checking on all-four used parking slots at a time) and Table

5.5 Parking trials 5 (detection checking of different parking vehicles in each slots at a

time). The parking trials 1 shall depict the accuracy observation in all parking slot during

its available status. The group tested the parking trials 1 for 10 complete transmission

operations, having each slot observe for 10 chances for observation. On the parking

trials 2, the observation of the accuracy focuses on the detection checking of a single

used parking slot. The parking trials 2 involves observation of a single parking slot being

used by a vehicle during 10 complete transmission operations, to observe if the

monitoring shall depict no availability for the parking lot during the usage. Next, the

parking trials 3 covers the detection checking for two adjacent parking slots while having

both being used by two vehicles within 10 complete transmission operations. Then the

parking trials 4 observes as well the monitoring during the parking slot usage while only

having this time all four parking slots being used within the 10 complete transmission

operations. The group tallied all the observation made during the parking trials 1 to 4.

The results show the complete functionality of the system setup during its available

status and occupied status. The test in parking trials 1, 2 and 3, as shown by Tables 5.1

up to 5.3, showed a perfect performance having all trials with 0% error. Unfortunately

due to the group’s lack of observance during the Table 5.4 Parking trials 4, an error

occurred in the monitoring of parking slot 1 because of the height difference of the

transducer from the ground. The group has misplaced the stand assignment to the

parking slots that’s why the parking slot 1 transducer stand was too tall for the slot. It

was like the position of the transducer with respect to its area of coverage was made

over the 2.2m assignment for the parking trials 4. This situation mattered because the

group made the height of the stands adjustable according to the parking slots for the test

area does not have a flat surface and has low points and high points. Thus, the parking

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slot 1 monitoring during the parking trials 4 concur a 40% error during the test while

having all other monitoring slots perfect with 0% error. This mistake led to unexpected

error but regardless of this, the results depicted by Tables 5.1 to 5.4 are considerable.

This test confirms the functionality of the MTSR configuration setup during the available

and occupied status of the four parking slots.

The last test to be conducted will sum it all the possibilities of the normal

scenarios being observed in any parking scenarios. The last test covers the accuracy

test in monitoring all four slots while parking different kind of vehicles in each slot at a

time. The test includes four kinds of vehicles that resemble the different height of

vehicles fitted in the vertical limit of the research study: a passenger car, an MPV, an

SUV and a Pick-Up truck. The basis of choosing these classifications of vehicles for the

test is the research conducted by the group regarding the average height of every known

classification of vehicles (given in the related literature). Each type shall be tested into

parking 3 times in each slot. The test sequence in the parking trials 5 of the different

kinds of vehicles will be at a random manner, meaning the arrangement shown in the

table 5.5 is only tabulated for simplified representation of the test. This means the

different kinds of vehicles parks on each slot in a very random manner to be observed

individually. The random manner of testing is chosen for parking trials 5 to make the test

similar to normal scenario of parking usage. The parking trials 5 as given in Table 5.5

results showed a perfect tally of detection of all kinds of vehicles with 0% error. All the

kinds of vehicles being used in the test are now concluded by the group as detectable by

the system setup.

Overall, the group had a good data gathering from all tests performed in this

research study. The test led the group to completing the functionality of the target

system setup with the MTSR configuration setup. The test results of Table 5.1 up to 5.5

are good enough to confirm the applicability of the suggested configuration setup from

the research made.

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Conclusion

This research study was able to introduce the MTSR configuration for ultrasonic

transducers that will implement reduced number of sensors in monitoring parking slot

availability. The MTSR configuration was better than its opposite STMR configuration as

shown with its better results in the tests conducted. In line with the test conducted, the

research was able as well to observe the parameters vital in obtaining the proper

positioning setup of the MTSR configuration. The wind blow, the current temperature

and the direction or the beam angle of the transducers are must be considered because

these serves as deciding parameters in regards with the performance of ultrasonic

transducer-based systems. The research also included the observation of finding the

right sensitivity for optimal performance of the MTSR configuration setup through the

series of actual test. The series of actual test that covers all sorts of normal scenarios in

a parking system concludes the applicability of MTSR configuration in parking monitoring

applications. The research determined in the process the threshold range for the

configuration setup to have the correct sensitivity, in both the processing part in the MCU

and the frequency settings of the receiver PLL. This also concludes the importance of

the inclusion of MCU for the control of the system operation. The microcontroller

programming made the system handle the occurrence of interference, making the

system insusceptible to wind interference. Overall the research study has been a

success in achieving all the objectives it desired to attain in completion of this research

study.

Recommendations / Future Works

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The MTSR configuration is indeed successful to implement reduced number of

ultrasonic transducers used in monitoring parking slots usage; however, improvements

are still present for better efficiency in its usage. Now that the MTSR configuration of

ultrasonic transducer is proved as a working efficient setup in monitoring parking slots,

the group sees this opportunity of recommending possible future works on the system

shall enhance the application purposes beyond the research study initial objective of

claiming the usage possibility of MTSR.

Most of the possible future works for this research would be based on the

enhancement of the processing capability of the system which will allow further inclusion

of add-ons features for the parking monitoring system. One notable technique that may

be incurred is the inclusion of time of flight calculation in the processing side of the

system for some upgrade features like the classification of the vehicles being parked in

the parking slots. Another future work which the group recommends in regards to the

processing capability is the inclusion in the monitoring of the system to take note the

time of usage of each parking slot.

Another recommendation of the group is that the system should be with better

system structure and cabling management. In the research, the group only prepared the

system structure is versatile enough for all the testing necessary to be made in achieving

the optimal setup of the ultrasonic-based system. Better cabling management shall give

this kind of setup attain its best condition setup because the group found out in the

research that ultrasonic-based systems requires good signal conditioning.

Lastly, if all the cited recommendations are met, the group recommends the

research on the multiple networked MTSR configuration setup of this ultrasonic-based

system. Putting the MTSR configuration inside a parking slot monitoring network shall

further incur reduction of cost in large parking slot systems.

Bibliography

Biazon, Cortez, Cruz, Lico, and Paterno. "Ultrasonic Detection and Ranging wtih Angle measurement." 2004: 1-9.

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Oregon Department of Transportation. "Safety Evaluation Of Converting On-Street Parking From Parallel To Angle." Safety Comparison of Angle and Parallel Parking, 2001: 2.

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Arnsby, Joakim, Joakim Baltsén, Simon Nilsson, and Erik Osvaldsson. "EDA385 – Embedded SystemsDesign‐ Advanced Course." Ultrasonic Positioning, 2008: 4-12.

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APPENDIX A – SOURCE CODE

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#include<8051.h>

unsigned char TX[]={0x0E,0x0D,0x0B,0x07};unsigned char x, a;

void check(unsigned char c){unsigned char i, j ,k;for(i = c; i != 0; i--) {

if (P3_7 == 1) { a++; }for(j = c; j != 0; j--) {

for(k = c; k != 0; k--) ; } } }void main(void){x = 0;a = 0;P1 = 1;

while(1){P1 = TX[x];check(103);if (a >= 50){

if (x == 0) P3_2 = 0;if (x == 1) P3_3 = 0;if (x == 2) P3_4 = 0;if (x == 3) P3_5 = 0;

}else if (a < 50){

if (x == 0) P3_2 = 1;if (x == 1) P3_3 = 1;if (x == 2) P3_4 = 1;if (x == 3) P3_5 = 1;

}x++;if (x > 3) { x = 0; }a = 0;

}}

APPENDIX B – CIRCUIT DIAGRAM

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Microcontroller Circuit Diagram

Transmitter Circuit Diagram

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Receiver Circuit Diagram

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APPENDIX B – CIRCUIT BOARD DESIGN

MCU board

Transmitter board

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Receiver Board

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Documents

Final Thesis Document(SAMPLE) EFI