| Recently, with the gradually increasing requirements of vehicle handling andstability, ride comfort, and safety, only by controlling one subsystem in order tooptimize the local performance of the vehicle in the past can not meet today’srequirements of rapid development of the automotive industry. Due to the integratedchassis control system can significantly improve the overall performance of vehicle, thistechnique would be the key research direction of the automotive field in the future.The target yaw control system can improve the handling and stability understeering condition by actively distributing diving torque between left and right wheels.At the same time, the semi-active suspension system can optimize the ride comfort andthe ride performance due to the damping-adjustable characteristic. In this paper, take thetwo subsystems as the research objects and achieve the improved overall performanceof vehicle by studying the joint control of the two subsystems. The mainly work carriedon in this research was as follows:①Analyzed the torque distribution characteristics of the target yaw control systemwhich was composed of a Three-Linkage gear and a planetary line. The linear dynamicmodel was built by considering the changes of vertical load of tires, and the nonlineardynamic model was built by considering the nonlinear characteristic of lateral dynamicresponse of the tire. The overall structure of vehicle dynamics model was confirmed,and vehicle mathematical models were established, which includes driver model, enginemodel, transmission model, wheel rolling model and the H.B.Pacejka tire model, thesemi-active suspension model and the auxiliary calculation module.②The calculation method of target yaw rate and target sideslip angle based on twodegrees of freedom linear vehicle model was analyzed. The principle of the slidingmode variable structure control was analyzed, and the target yaw control system basedon the sliding mode variable structure control was designed. Torque distribution controlalgorithm was proposed based on the stable response of vehicle. Identified the controllerstructure of the semi-active suspension system, and the control system based on doublefuzzy controllers was designed.③The simulation platform based on the combined control of wheel torquedistribution and semi-active suspension was carried up by Matlab/Simulink, and wassimulated under the random road, the J-turn steering angle input, the steering conditions on split-μ road. The simulation results indicate: Torque distribution control algorithmbased on the target yaw control can distribute the driving torque between wheelsaccording to the state of vehicle, the performance of vehicle steering and handlingstability was improved. The semi-active suspension control system based on doublefuzzy controllers can reduce the body vibration acceleration and suspension dynamicdeflection, and the ride performance and ride comfort were improved. The combinedcontrol with the two subsystems can improve the overall performance of vehicle underthe premise of the guarantee of automobile dynamic property. |
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