With the increasing demand of the drive safety and ride comfort of vehicles, various new technologies are being applied in vehicle suspension system. In this case, the magnetorheological damper can adjust the damping dynamically, and fuzzy logic controller development to track the desired damping force is possible. The combination of two will effectively improve the suspension performance. Thereafter, a model built in Simulink is composed by road model, quarter vehicle model, Magneto Rheological damper model based on Bouc Wen model, damper coil current controller model and Fuzzy logical controller to track the desired damping force. The results obtained from road models have been used in combined simulation model. Finally, the comparative simulation experiments of passive suspension and semi-active suspension with magneto rheological damper was performed. The results show that, the ride comfort of quarter car model has been improved 10% compared to passive suspension; and vehicle stability 30% respectively.

to meet the demand on precise control of electronic control in diesel engine, study on electronic control of cylinder pressure feedback in common rail diesel engine is made. On the basis of brief analysis for cylinder pressure physical meaning, mechanism and sketch of electronic control based on cylinder pressure feedback is presented, pressure characteristic variable orienting to control is provided, cylinder pressure feedback is obtained by means of fitting of multi-nominal. Electronic control system with dual micro-processor based on MPC555 and DSP56F807 is designed, hardware of pressure acquisition unit (PAU) is presented, include fiber-option pressure sensor, encoder and electric circuit. Hardware of electronic control unit (ECU) is designed, include power drive and signal processing circuit. Software for dynamic acquisition and control system is programed. Primary test in 4100 diesel engine with high pressure common rail system is made, testing result showed an effect of electronic control of common rail based on cylinder pressure feedback.