PRESENTER:WAMBASI FRED

BUTETE (BSC).

SUPERVISOR:

SELF.

MMUST

ENGINEERING

AND

TECHNOLOGY

CONFERENCE.

Concept Theme: Integration of

Microcomputer Systems in Increasing Automobile

Crash Safety.

Concept: Auto Crash Automobile

Evasion System.

Introduction.

It is an automobile safety system designed to reduce

the possibility and severity of an accident. These

systems have evolved over time from the dumb

systems to current intelligent systems in operation

and under research.

MOTIVATION.

Automobile collision has become a major safety concern in the present

world. Such collisions lead to damage of automobiles and sometimes even the

death of the crew on board. Cases of pedestrians being knocked to death by

automobiles is also on the rise in busy towns and highways, Wildlife remains a

precious investment and wild animals are constantly being knocked by vehicles on

highways passing through animal parks .

This scenarios however have to be avoided using a crash evasion systems.

In most cases drivers fail to notice the presence of obstacles ahead and brakes too

need a driver’s response to operate thus increasing the response time, hence

reducing their reliability.

Crash Evasion Efforts.

Currently a lot research is being undertaken on crash evasion technologies for improving safety and accident prevention. Automobile industries are currently working with institutions of higher learning to research on and design high reliability pre-crash systems, an example is the efforts of the Toyota motor corporation in partnership with Nagoya institute(JAPAN).

The need for collision safety started long in 1880’s through implementation of brakes in automobiles, later side mirrors were included and safety lighting in form of turn lights, stop lights and hazard were incorporated in automobiles. Intelligent systems too have attracted a lot of professionals to research into collision evasion, intelligent systems providing warning signals and braking have been impimented and tested to reduce collision risk.

The motivation for Crash evasion systems is that once implemented they reduce the number of fatalities and injuries on the roads. Crash evasion technology constantly evaluates a driver's position as well as any objects on the road, in order to prevent or minimize damage that may be caused by an accident. The associated costs of repair are thus avoided and pedestrian safety guaranteed.

Some of the current systems.

In 2003, Lexus introduced its ground-breaking, millimeter wave radar-based Pre-Collision System (PCS).

Ford's Collision Warning with Brake Support Using Laser, introduced in 2009 on the Lincoln MKS and MKT and the Ford Taurus vehicles. This system provides a warning through a Head up Display that visually resembles brake lamps. If the driver does not react, the system pre-charges the brakes to enable preventive braking.

For the 2013 model year, Most USA manufactured luxury vehicles had optional forward-collision warning based on millimeter wave radar and some of them having autonomous braking. Forward collision warning is standard on the Acura ZDX, BMW 760i, Honda Crosstour AWD, Hyundai Equus, and Toyota Land Cruiser.

Among others: (Documentation available).

Limitations in Current systems.

RADAR BASED SYSTEMS: Radar systems are expensive technology to implement on cars thus remains a preserve for luxury vehicles only. Also there are cases when the oncoming obstacle vehicle is persistent or the driver being out of shock loses consciousness and is unable to steer the automobile, therefore need for steering control and break sensitization.

LASER BASED SYSTEMS: In environments with high luminosity it is difficult to detect laser beams. Also lasers are dangerous for use in such an application because of their harm to human beings and the environment, consideration of safety to the human eyes is thus a concern.

WHY THIS SYSTEM.

With Ultrasonics,burst is harmless to humans and living things, Laser method is dangerous to the eyes and therefore ultrasonic sensors proves to be advantageous. The use of ultrasonic sensors can be applied to detect any obstacle and have a relatively inexpensive cost; hence a low cost implementation is possible, light weight, low power consumption, and low computational effort, compared to other ranging sensors. In some applications, such as in rainy, foggy, misty and low-visibility environments, ultrasonic is often the only viable sensing modality. The proposed system is also easy to easy to integrate in both new and old automobiles.

Main Objective of study

To design a prototype automobile crash

evasion system that will be used to

demonstrate the capabilities of a low cost

crash evasion system that can be installed

at a low cost in all types of automobiles

Project Objectives.

To design a sensing sub-system for

obstacles and automobiles.

To Implement a visual display sub-system;

LEDs , hazard lights and warning sub-systems using

a buzzer for minimum distance.

Design output signal sources for

automatically activate braking system and steering

control.

Problem Statement.

Automobile collision has become a major safety concern in the present world. Such collisions lead to damage of automobiles and sometimes even the death of the crew on board. Cases of pedestrians being knocked to death by automobiles is also on the rise in busy towns and highways, Wildlife remains a precious investment and wild animals are constantly being knocked by vehicles on highways passing through animal parks .This scenarios however have to be avoided using a crash evasion system. In most cases drivers fail to notice the presence of obstacles ahead and brakes too need a driver’s response to operate thus increasing the response time, hence reducing their reliability.

This project aims at designing a system that is intelligent and capable of engaging precautionary measures as it warns the driver upon risk of collision. The system proposed herein is a model concept for coming up with an automatic, easy to integrate and cost effective electronic system that will serve important in the reduction of collisions.

Buzzer

Voltage regulator+12V

Range sensor 1

Range sensor 2

ATMEGA 328

Microcontroller LH direction.

RH direction.

Hazard Lights ON.

Brake assist And Braking ON.

70+M 50-70M 50-30M System ON

ATMEGA 328p

Power Supply

Fig: The circuit is used to obtain 5V stabilized power supply for the circuit.

The input capacitor Ci is used to cancel the inductive effects associated with lower power

distribution leads. The Output capacitor Co improves transient response. The Two capacitors thus

smoothen ripples so as to have a smooth output, thus keep steady power and decouple other

parts of the circuit. Thus capacitors are used to chop off the ripples developed on the DC

voltage converted from AC

Untitled1.pdf

Prototyping Board: Control Unit.

Fig: Arduino board to be used for prototyping: Consists of Atmega 328p

Microcontroller.

Ultrasonic Ranging MODULE;A device

for distance measurement.

The ultrasonic sensor works at a frequency ranges of 42 KHz .

Determination of distance.

To determine distance, a short pulse is send to the module attime zero, this is done by sending a HIGH pulse to the triggerpin(Trig),this pulse should last at least 10µS,in this project a10µs high pulse in used. This triggers the sensor to output aburst of 8 sonic cycles at 40 kHz and detect the echo back. Thetransmitted burst once reflected by an object and retransmittedback to the sensor module as an echo, sensor receives this signaland converts it to an electric signal, and the duration is taken asa high pulse and fed to a microcontroller for calculation ofdistance. The next pulse can be transmitted when the echo isfaded away. This time period is called cycle period. Therecommended cycle period should be not less than 50ms in thisproject 150ms is chosen for stability of readings. If no obstacleis detected, the output pin will give a 38ms high level signalwhich corresponds to 6.5 meters and this is the maximumcalibrated range of the sensor used herein for prototyping.

Determination of distance.

The time of high output IO duration is captured which represents the time from sending ultrasonic to returning.

Since sound travels at a velocity of 340m/s in air or 1130 feet per second.

Test distance=high level time x velocity of sound/2

Division by two is because the high time includes sending time to object and receiving time for the echo.

Instead of using the Speed of Sound, we can also use the "Pace of Sound" as described in .

The Pace of Sound= 1/(Speed of sound)

=1/0.03435=29.1 µs/cm

Therefore,

Test distance=(high level time)/2 x 1/(pace of sound).

Transistor switch design

Rb

Buzzer

5V

GND

Analog

pin.BC 337 Transistor.

We find Rb in this case;

Rb is given by;

To Get Rb We use the formula.

Ib=Vs/Rb

Therefore

Rb=Vs/Ib

Therefore we need to know the value of Rb at saturation state, then using the transistor parameters at saturation state we have: From datasheets that;

Ib=50mA.

And

Therefore; Rb=5V/50mA=100Ω.

The Buzzer operates at voltages of 3V-24V dc and in this project 5V dc is used.

LEDs Driving Resistor.

+5V

Gnd

RL

Analog Pin

VRL

VLED

5V

LED

Design calculations for LED Resistor.

Since; Vs is supply voltage,Vs=5V

But supply drops across LED and RL, thus,5v=VRL+VLED

But;VRL=RL x I

Thus; RL=(5V-VLED)/I

The value of current through LED being 20mA in our case.

Some Calculated Resistances( for LEDs)

Red Led is powered through RL =220 Ohms.

Orange Led is powered through RL=220

Ohms.

Yellow Led is powered through RL=180 Ohms.

Green Led is powered through RL=180 Ohms.

Blue Led is powered through RL=100 Ohms.

White Led is powered through RL=100 Ohms.

Hazard lights are controlled by a body microcontroller that is supplied with signals from

the main microcontroller; body computer here is implemented as body microcontroller.

The signal supplied for control of hazard light s is PWM for the following reasons;

To allow for different rates of hazard lights flickering depending on the level of danger

imposed, this is possible by use of varying signal rates send to the body microcontroller.

To allow for control of hazard light brightness depending on the level of risk of crash.

A component of interest in design is the optocoupler for switching ON the hazard lights;

Optocoupler is also called optoisolators and provides electrical separation between

devices.

Hazard Lights

Hazard lighting system implementation

Main

Microcontroller.

Body

Microcontroller.

PWM signal.

5V dc supply.

Optocoupler Switching

Unit.

Foward

Hazard

Lights.

Rear

Hazard

Lights.

RHfoward.

LH foward.

RH rear.

LH rear.

5V dc

supply.

12 V

dc supply.

Modern automobiles have an onboard computer and body computer or

ECU(electronic control unit ) which can be used to control hazard lights)

Brakes and brake assist.

Based on PWM.

DUTY CYCLE of 50%

Enables Brake assist(Sensitizing)

DUTY CYCLE of 75%

Enables braking.

Observation.

The implemented system was able to determine the separation distances between automobile and obstacle appropriately, give warning by means of on board warning systems, and engage braking and steering control if the minimum separation distance is not provided .

Recommendations

The system could be implemented on an

automobile as opposed to a prototype.

The incorporation of fuel injection control

can be used which in combination with braking

control will be able to provide more precise

automobile speed control.

Stepper motor control for swinging

ultrasonic sensors through 360° will ensure that side

collisions are also catered for.

Integration with current Automobiles.

Most current automobiles

in production are equipped with on

board computers and body

computers.Hence easy to integrate

the system with.

CONCLUSION

The main objective is to implement a systemthat will detect obstacles, warn drivers andcontrol automobile motion behavior in thepresence of automobiles and obstacles.

Being a low cost, easy to integrate andhigh reliability safety system I look forwardto its production and implementation.

THANK YOU