Research on composite fractional order skyhook control strategy for linear motor energy regenerative suspension

To study the application effect of linear motor energy regenerative suspension in semi-active suspension of automobiles, a 1/4 two degrees of freedom semi-active suspension dynamic model, energy regenerative circuit, and current hysteresis loop control model were established. Establish an integer order skyhook control semi-active suspension, use an improved Oustaloup filter algorithm to establish a fractional order skyhook control semi-active suspension based on fractional calculus, and compare and analyze it with a composite fractional order skyhook control semi-active suspension based on fractional order skyhook control. The simulation results show that when the vehicle is driving at a constant speed of 60 km/h on a C-grade road, compared with passive suspension, semi-active suspension has a significant improvement in sprung mass acceleration, suspension working space, and dynamic tire load. Among them, fractional order skyhook control semi-active suspension and composite fractional order skyhook control suspension have better sprung mass acceleration and dynamic tire load than integer order skyhook control semi-active suspension. However, suspension working space deteriorates to some extent compared to integer order skyhook controlled semi-active suspension. When there is a time delay in the system, as time delay increases, the control effect gradually deteriorates. When the time delay is within a certain range, the composite fractional order skyhook control suspension performs better than the other two control methods. In summary, while maintaining the control performance of fractional order semi-active suspension, the composite fractional order skyhook control has certain improvements and improvements in various aspects compared to integer order skyhook control semi-active suspension, especially when there is a certain range time delay in the system.