Research On Embedded Electronic Control Unit For Lighr Vehicle Driving Force Control

When vehicle driving on the low-friction-coefficient road,the driven-wheels areeasy to over slip,it will lead to bad adhesion between wheels and road and makesthe vehicle's traction performance and stability become worse Through activecontrol of the vehicle drive torque,It can reduce the driven-wheels'slip and enhancethe adhesion using efficiently,which will improve the traction performance andstability The traction controller collect the sensor signals and calculate the target slipof the driven-wheels,then control the engine throttle,transmission gear,wheelbraking torque to keep the wheel slip at the target range,so as to achieve thepurpose of driving force control The foreign countries have done lots of research ondriving force control system and already have mature products,but in domestic theresearch is just sta rted and still infancy,there is a big gap between foreign countriesand our country,so it is meaningful to research the driving force control system andil's controllerThis paper is about driving force control system research which is based on a keynational research project,the target vehicle is a light vehicle The main work includesestablish the control algorithm of the driving force control system,design thecontroller hardware and use the OSEKturbo real-time operating system to developthe soEware set up a hardware in the loop test platform utilize lhem doing hardwarein the loop simulation test and road test,verify the drive force control strategy andperformance of the controller1 Establish Driving Force Control AlgorithmAccording to the characteristics of the target vehicle,establish the scheme of thedriving force control system；setup the objectives and the corresponding control strategies for different conditions Propose identification algorithm for the two typicaconditions such as driving on u-split road and turning driving According to thedriving state of the vehicle,determine the target slip,and establish the driving forcecontrol logic to start and exit the control Design the engine throttle control modulebased on PID,driven wheel brake torque control module based on the logicthreshold and the AMT gear coordination module2 Design driving force controller's hardware and soltwareAccording to the requirement of the driving force control system,define the structureofthe controller,complete the micro controller selection and circuit design,in order tomeet the real time performance requirement,develop the driving force controlsol[ware based on embedded real time operating system RTOS Driving forcecontroller choose Freescale's 32-bit micrOprOcessOr MPC565 as the core,design thecircuit of power management module,the clock module,wheel speed signal collectmodule,switch signal detection module,analog signal acquisition module,powerdriven module,serial communication module and CAN communication module Withthe embedded real-time operating system(RTOS)platform,establish the division oftasks and scheduling mechanism for driving force control system,improved the realtime performance for the system And set up a sol[ware development platform fordriving force controller3 Driving force controller hardware-In-the-LoopNormally the road test for driving force control system need to be done on thelow-friction-coefficient road in winter,time is limited and it will cost a lot of manpowerand resources,if all the tests are done through road test,we will spend a lot of timeUsing HIL system,we can use vehicle dynamics model to replace the real vehicleand simulate the low friction coefficient road do the embedded controller functional verification,as well as dynamic response characteristics ofthe whole system andreal time characteristic research,to shorten development timeThe HIL system composed of vehicle dynamics model,pa rt hardwires of the targetvehicle,sensors,controllers,actuators,industrial computer and dSPACE real—timesimulation system The driving force controller collect the sensor signal frOm thedSPACE,calculate the target value and drive the actuators to work Using twowheels driven module do HIL tests of startup straightly on ice and u—split road andcornering on ice Preliminary validate the performance of the controller and the HILsystem4 Road test for driving force controllerAlthough HIL test can validate the control algorithm and parameters,considering thevehicle model accuracy and the problems which would happen when the embeddedcontroller running the car,the road test is still decisive ways to validate driving forcecontrol systemDriving force control system's sensors,controllers,actuators and data acquisitionsystem are integrated to the vehicle and all passed debug The driving force controlsystem road test includes startup straightly on ice and u—split road and cornering onice FrOm the test results we can see that the performance of the controller can meetthe driving control system's requirement The driving force controller can greatlyenhance the vehicle's traction and stability on low friction coefficient road...