Purpose

The Continuous Damping Control (CDC) shock absorber, as the core damping regulating element, plays a key role in vehicle vibration suppression. On the basis of building a suspension system based on a CDC shock absorber, this research intends to introduce a feasible semi-active control strategy to further improve the comprehensive performance of the suspension system.

Methods

A 2-DOF semi-active suspension system model of 1/4 vehicle based on CDC shock absorber is built. The Parallel-compound Fuzzy and PID (PcFPID) control is introduced to adjust the damping force of the CDC shock absorber, and a comprehensive performance evaluation function H_cp(ξ, ζ) based on riding comfort is designed. Three typical road excitations are selected as the road input of the suspension system and the vibration control simulation is carried out. The comprehensive performance indexes under different control strategies are compared and analyzed to verify the improvement effect of PcFPID control on the comprehensive performance of the suspension system.

Results

The comprehensive performance evaluation index H_cp based on riding comfort shows that the comprehensive performance improvement rate of the suspension system with the PcFPID control is 26.45%, 24.47%, and 24.97%, respectively, under the three typical road excitation of grade C random road excitation, single bump excitation, and inverted triangle pit excitation. While the comprehensive performance improvement rates of PID control and self-adaptive fuzzy PID control are only about 17.92% and 19.83%, respectively.

Conclusions

After introducing the PcFPID control strategy, the semi-active suspension system based on the CDC shock absorber gives consideration to the handling stability on the basis of focusing on improving the riding comfort and improves the comprehensive performance of the vehicle suspension system to the optimal.