Vehicle Chassis Sass And ESP Integrated Control Based On Damper With Solenoid Valve

With the rapid development of modern automobile manufacturing and technical level, a variety of electronic control technology is widely applied in the automobiles, the applications of the semi-active suspension system (SASS) and the Electronic Stability Program (ESP) has greatly improved the ride comfort, handling stability and security. To make up for the disadvantages, the limited range of functions for the controllable subsystems of chassis, the integrated control on tht multiple subsystems of the chassis in order to explore the potential functions has become a research hotspot of the vehicle dynamics. The dissertation author investigates the depth study of the semi-active suspension system with solenoid valve damper(SASS) and the Electronic Stability Program (ESP) then the the theoretical analysis and experimental research.for the integrated control of the two subsystems are achieved.On the basis of the analysis of the nonlinear characteristics of the tire,the vehicle dynamics model that reflects the interaction between the vehicle longitudinal, lateral and vertical dynamics, has been established. which can better reflect the influenced relationship and non-linear characteristics of the tire.of the chassis, suspension, braking and steering subsystems.The structure and principle of a new type of continuously adjustable damper with solenoid valve is studied.thoroughly, the hydraulic model the mathmatic model of rebounce stroke and compress stroke are established.The main structure parameters to the damping characteristic are analysed, the damper is tested on the lch dynamic servo suspension tester, and the theoretical reference is provided for the design and engineering of the continuously adjustable damper with solenoid valve.The control algorithm of H∞is applied to design the Semi-active suspension controller for enhancing whole vehicle synthesis performance in a multi-conditions.Considering the restriction of the road adhesion coefficient to tire force, the method of vehicle stability control is proposed, which is based on the calculation and allocation to the longitudinal composition of forces and yaw torque. The feasible region of the longitudinal composition of forces and yaw torque is determined in real time by offline numerical optimization metod, and the longitudinal composition of forces and yaw torque is adjusted to the feasible region, the longitudinal composition of forces and yaw torque is dynamically allocated to the wheels adopted the tire force inverse model structure by the three layer BP network, avoiding the lateral forces estimated of the rear wheels under the accuracy ensured, it can track the yaw angle better, improve track holding capacity and the influence of the low adhesion road to the vehicle stability, and a driver-in-the-loop test of Lab VIEW PXI and veDYNA have been carried up to verify the effectiveness of the control strategy.A coordinated control method based on the function allocation is proposed with regard to integration control problems of SASS and ESP subsystem.The upper function allocation controller can get the output weights of each controller, adjust the initial allocation coefficient of the sub ESP and SASS controller, strength or weak some function of subsystem, and the relationship between vehicle conditions and the function allocation coefficient of the bottom subsystems is determined by the method of fuzzy reasoning which is based on vehicle conditions and the changes of main control objectives under the current conditions.It can enhance optimal vehicle performance goals under the current conditions, but also improve the efficiency of the subsystem, reduce the design difficulty.of sub-controllerThe hardware and software system design of the SASS control system is carried out based on ARM7development platform, the SASS and ESP coordinated controller based on the function allocation which the signals shared, transmission and control command sent is based on the CAN bus. Finally, the controllers have been equipped on the vehicle and the experimental study of the SASS and integrated control of two systems are carried up to verify the effectiveness of the control strategy.