Development of a Novel Fuzzy Controlled Electromagnetic Suspension System

7/30/2019 Development of a Novel Fuzzy Controlled Electromagnetic Suspension System

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A PHD RESEARCH TOPIC PROPOSAL

RESEARCH TOPIC:

DEVELOPMENT OF A NOVEL FUZZY CONTROLLED

ELECTROMAGNETIC VEHICLE SUSPENSION SYSTEM

INTRODUCTION

In general, vehicle suspension system provides improved passenger comfort as well as improved

handling with the effective isolation from road disturbance[1]. Electromagnetic Suspension

Systems have been developed using both conventional and fuzzy control techniques. In these

schemes, to provide incresed passenger comfort, the control system responds to disturbanceinputs upon the automobile wheels. Electromagnetically-levitated actuators supporting rotating

shafts provide low-noise, high-precision bearings for spacecraft actuators, for example reaction

and momentum wheels, CMGs and power storage flywheels. Design of electromagnetic

actuators and control of these is a challenging problem due to the highly nonlinear relationship

between operating current, airgap and suspension force [2]. Other interesting applications of

magnetic levitation are magnetic levitation for ground transportation, low friction bearings, and

levitation melting of conductive metals [3]. The magnetic levitation principle is also used in the

design of active magnetic bearings which can be used to reduce frictional losses in moving parts

of wind turbines which are now gaining ground as alternative energy source.

STATEMENT OF THE PROBLEM

Transportation of patients in ambulances, especially in developing countries, where road

conditions are far from ideal, is sometimes traumatic as the patient is tossed up and down as the

ambulance negotiates rough roads. Also the smoothness of a car ride is of prime importance to

the majority of car owners. It is unfortunate that notwithstanding the technological advancements

that have been recorded in the auto industry, a car ride over rough terrain is far from being

perfectly smooth. This may be due to the inherently mechanical nature of automobiles.

Passenger comfort (combined with handling and safety) is an ever increasing demand, whereeverybody expects ever improving comfort and handling from the automotive industry [4]. It

would be worthwhile to develop a suspension system for the automobile seat which will

eliminate the effects of bumps and potholes in roads. This will greatly increase ride comfort,

reduce fatigue and hence help in preventing accidents. With a steady vehicle doctors and other

health personnel will be able undertake procedures that would otherwise have to be left until the

hospital is arrived at. Therefore the realization of optimal suspension will help increase ride

comfort, reduce fatigue, prevent accidents and even reduce deaths from automobile accidents.


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In the current suspension control systems the disturbance is dealt with as it occurs (eg bumps on

the road), therefore due to the inherent delay in the system the disturbance is infinged on the

vehicle body before the necessary corrective action is implimented.

In this project a proposal is presented for the design of an active electromagnetic suspension

system for vehicles with capability of initiating corrective action before the disturbance is

reached by the vehicle wheel.

OBJECTIVES OF THE STUDY

The aim of this project is to develop an active electromagnetic seat suspension system for road

vehicles to minimize disturbances due to uneven road surfaces.

In this work the use of sensors is proposed to detect road level variations ahead of the vehicle

wheels. Therefore bumps and potholes are registered before the wheel comes upon them. The

inputs from these sensors are combined with the other parameters such as vehicle speed to

initiate control action which will make the electromagnetic actuators to enable compensation of

the disturbance as the vehicle moves over the disturbance. This will predictably provide

bumpless ride to the vehicle occupants. The following objectives will be realized in this work:

1. Develop a model of the suspension system.

2. Design the permanent magnet suspension system part.

3. Design the electromagnetic active suspension system part.

4. Derive an overall model of the system.

5. Develop a controller for the system.

8. Conduct simulations and analyses of the model to determine th best control strategy to

employ.

7. Build the overall test system.

SCOPE OF THE STUDY

This work is centered around the development of an electromagnetic vehicle suspension system

with the capability of predicting road conditions so that delay-less control action can be taken to

provide the smoothest ride possible.

Selection or design of optimal sensors for the monitoring of road conditions is a crucial part of

the study.

Modeling of the various parts of the overall system will also have to be performed. The

suspension system will be modeled, so also the controller.


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After the preliminary investigations have shown a feasible solution, the whole suspension system

will be modelled, where appropriate using finite element techniques.

The system is expected to be quite nonlinear, therefore the controller to be developed for the

system is expected to be a fuzzy controller. Fuzzy control is a practical alternative for a variety

of challenging control applications since it provides a convenient method for constructing

nonlinear controllers via the use of heuristic information [5].

The system model and the controller will then be simulated using the Simulink software.

A prototype system will then be developed and the controller will be implemented using an

appropriate microcontroller.

LITERATURE REVIEWVarious control strategies have been presented in [1], [6], and [7] for different approaches to

vehicle suspension, but in all these schemes the when a bump or pothole is encountered on the

road the vehicle is affected by the bump before corrected action is taken, and that is mainly what

this work aims to eliminate. In this work information on the nature of the road terrain is fed to

the controller before the wheel reaches the particular location so that if there is abump ahead the

controller will ensure that by the time the vehicle reaches the bump it is appropriately

configured to pass over the bump without noticeable jolt being felt by the occupants.

RESEARCH METHODOLOGY

1. Develop a preliminary state-space model of the suspension system.

2. Design the permanent magnet suspension system part using finite element techniques.

3. Design the electromagnetic active suspension system part.

4. In no.3 various airgap fillers will be studied and an optimal one will be choosen.

5. Derive a full state-space model of the overall system.

6. Develop an appropriate fuzzy controller for the system.

7. Develop Simulink/Matlab models of the system.

8. Conduct simulations and analyses of the model to determine th best control strategy to

employ.

7. Build the overall test system.


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REQUIRED DATA

Data on the magnetic properties of various media will be collected during the investigation to

enable the selection of an optimal airgap medium. Also data on road surface irregularities will beinvestigated to determine the optimal airgap distances required for various driving conditions.

EXPECTED FINDINGS AND SUMMARY

The expected end product of the research is a full scale model of the active magnetic suspension

system with the fuzzy controller implemented using a microcontroller integrated circuit.

RELEVANCE IN THE OIL AND GAS SECTOR

In the oil industry the results of the research can be applied in the design of bearingless drives

that include electric motors, which are widely used in the industry, and also in pumps. Theprinciples can also be used in the design of magnetic actuators which are applicable in

positioning and manipulating devices. In fact the range of applications of the control strategy that

would be developed in this research is very wide.

In the various applications of magnetic suspension systems, contact between moving parts

eliminated, therefore failure rate in system components will be minimized. In the long run

maintenance costs are minimized which is of relevance especially in developing nations where

maintenance facilities are usually inadequate.

REFERENCES1. J W Sohn, S B Choi and N M Wereley,Discrete-time Sliding Mode Control for MR VehicleSuspension System, 11th Conference on Electrorheological Fluids and Magnetorheological

Suspensions, Journal of Physics: Conference Series 149 (2009) 012080.

2. http://www.ee.surrey.ac.uk/SSC/prospective/topics.

3. Marc T. Thompson,Electrodynamic Magnetic Suspension-Models, Scaling Laws, and

Experimental Results, IEEE Transactions on Education, Vol.43, No.3, August 2000.

4. Bart L.J. Gysen, Johannes J.H. Paulides. Jeroen L.G. Janssen, and Elena A. Lomonova,

Active Electromagnetic suspension System for improved Vehicle Dynamics, IEEE Vehicle

Power and Propulsion Conference (VPPC), September 3-5, 2008, Harbin, China.

5. Passino, Kevin M.,Fuzzy Control, 1998 Addison Wesley Longman, Inc.

6. K. Hyniova, A. Stribrsky, J. Honcu and Ales Kruczek,Active Suspension System with Linear

Electric Motor, WSEAS TRANSACTIONS on SYSTEMS,Issue 2, Volume 8, February 2009.


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7. Y. M. Sam, N. M. Suaib, J. H. S. Osman,Hydraulically Actuated Active Suspension System

with Proportional Integral Sliding Mode Control, WSEAS TRANSACTIONS on SYSTEMS

and CONTROL, Issue 9, Volume 3, September 2008.

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Development of a Novel Fuzzy Controlled Electromagnetic Suspension System