Research On Hardware-in-the-Loop Simulation Of Brake And Traction Control For Light Vehicles

Enhancing the vehicle drivability under the status of driven and emergency braking was an intractable issue in recent years. The Traction Control System (TCS) prevents the vehicle from skidding on the low adhesion value road surface during starting, accelerating and climbing, improving the accelerating ability, handling and stability. Meanwhile, the brake control system prevents the wheels from locking during emergency braking, enhancing the performance of braking and direction stability.Decades of years has passed since the braking control system launched. Contrarily, TCS system, one of the active safety control system, was developed based on the Anti-lock Braking System (ABS) in the middle of 1980s. The wheels are controlled under the state whose skid value is the corresponding value of the top-value adhesion coefficient based on the Skid-Braking Coefficient Curve. Not only do the wheels have high longitudinal adhesion value, but the vehicle has the perfect lateral stability as well. Compared with the traditional method for developing the vehicle braking and traction system, which needs plenty of road test to debug the system hardware and software, the semi-object simulation technology has some advantages, such as decreasing the times of road test and reducing the developing period and cost, due to the developing circumstance established in the room which approaches to the real environment.The dissertation proposes the method of establishing the semi-object simulation platform based on domestic and overseas references. The ABS fussy controller and TCS throttle and braking fuzzy controller are established together with the vehicle dynamic simulation model. Otherwise, the dynamics simulation software is programmed under the Matlab software, and the TCS and ABS semi-object simulation are performed during different proper work status, whose result verifies the control strategy is valid at all.The establishment of semi-object simulation platform includes the analysis of the hardware configuration of aim vehicle and the research requirement of braking force and traction force, confirmation of the hardware configuration of the semi-object simulation platform, establishment of braking and traction control semi-object platform including sensor, actuator and part of test vehicle hardware system, which is based on the fleetness developing system. The fleetness developing system includes industrial computer, data collection card, input and output circuit, dynamics simulation software, prototype of control strategy and ISA bus communication interface program. Not only could the platform be researched on the aspect of 2WD and 4WD work status, but also it could be used for 4 wheels ABS control strategy development as well. Also, the experimenter could modify the program via MATLAB or C, debugging the traction control strategy, matching the software and hardware and recording the data real time.Analysis of different control strategies that are used for TCS and ABS, which confirms the fuzzy control strategy to be developed. Based on the design regulation of fuzzy controller, the TCS controllers which includes the throttle control and driven wheels control are designed. Design of ABS controller is a part of the research work.Establishment of engine, power train, vehicle system,braking system and tire models which are designed as modular, the programming of dynamics simulation model under MATLAB/SIMULINK and the input interface of parameter under MATLAB/GUIDE are all used for offering the software platform to realize the semi-object simulation.Typical linear traction and braking work status are chosen for simulating on the semi-object platform. The result indicates that not only could the control strategy prevent the vehicle from skidding and enhance the traction and braking performance, but it make some contribution for vehicle stability as well.