Research On Electronically Controlled Air Suspension Control Strategy And Controller

Electronically controlled air suspension system (ECAS) is that the traditional steelplate spring was replaced of the air spring, which has low vibration frequency and thecharacteristics of variable stiffness, impact resistance of pavement and so on, the ridingcomfort of vehicle, riding comfort and handling stability was improved, the road damagealso was reduced about the vehicles. So the ECAS system was applied in the domesticcommercial vehicles and some advanced foreign cars. Current research and developmentwas focus on the development of the control strategy and the designing of controller.This paper was based on the key project of Hubei province “Passenger car controlstrategy research about electronically controlled air suspension system (D20082302)”,the ECAS control strategy was designed and the controller development was researched.The main contents were as follows:First of all, the outside characteristics of a variable damping shock absorber about theECAS system was analysis and simulated based on Matlab/Simulink, at the same time thesoft and hard characteristics was applied in1/4ECAS system, the PID control algorithmwas joined, which good control effect was achieved.Second, ECAS system hardware circuit was designed, Freescale16-bit single chipmicrocomputer was applied of the software modules about the controller, the air springinflating and deflating was realized of ECAS system under different conditions.Finally, a fault diagnosis knowledge base was established, fault logic reasoningmechanism and diagnosis reasoning mechanism of BP neural network was applied, thereasons of the failure phenomenon was judged, and the ECAS calibration and faultdiagnosis system software was designed based on GUI, through a serial port debugging,fault diagnosis and display was implemented.