Research On Electronic Control Unit Of Driver Seat Intelligent Suspension Of Off-Road Vehicles

With the extensive application of automotive, the comfort of driver seat has aroused wide concern. The paper researched on the driver's seat suspension with air spring with auxiliary chamber and MR damper of seat and designed the electronic control unit. The major work and conclusions are as follows:1. The development of seat suspension was introduced. The differential equations were established which was based on the motion characteristics of driver's seat suspension with air spring with auxiliary chamber and MR damper of seat. The control characteristics were analyzed through the simulation and performance experiment, then the control scheme of seat suspension was eventually built.2. The hardware system was made up of LM3S615 microprocessor, filter amplifier circuit, current drive circuit, and power circuit. System control program used the structural and modular method to design, consisting of system initialization module, A/D transformation module, input variables calculation module, FFT algorithm module, UART display module, PWM module and control output module. The software design and implementation methods and other key technologies of LM3S615 microprocessor were researched, and the overall software design idea was given in the paper, then the design of each module was finished in IAR software integrated development environment.3. The paper finished the experimental research of electronic control unit of driver's seat suspension with air spring with auxiliary chamber and MR damper of seat. The control unit took the automobile body's vertical acceleration signal as the input value and the input current of MR damper as the control value, using the switch mode current drive to supply the damper. The control unit made FFT processing to the acceleration signal which came from acceleration sensor and compared it with the target set, then the current regulation trend was given to change the damping parameters. The single frequency excite experimental research indicated that this control system could change the power supply of MR damper in time according to the vertical acceleration signal, so that the damping parameters of MR damper could be effectively regulated to improve vehicle ride comfort. This control unit has high intelligence and reliability, and it can obviously enhance the vehicle's comfort, which has a broad application prospect.