Research On Double Skyhook Semi-active ISD Suspension Control Considering Vehicle Body Attitude Coordination

The simplicity of the inerter and damper double skyhook control algorithm,with both road condition and load adaptation capabilities,provides a new idea for semi-active suspension control research.However,the current research on double skyhook control is mainly aimed at suppressing body droop vibration and does not involve the control of vibration in both pitch and roll degrees of freedom.In this context,this paper proposes a double skyhook hierarchical control algorithm considering body attitude on the basis of double skyhook control,coordinating the ideal double skyhook control forces of each suspension,suppressing pitch and roll vibrations and controlling body attitude changes,thus further improving the smoothness of vehicle driving.Firstly,the load adaptation and road condition adaptation principles of the double skyhook control are clarified in relation to the ideal double skyhook suspension model and its kinematic equations.Based on the established ideal double skyhook impedance model,the optimum double skyhook coefficients are determined by optimization.An adjustable device with integrated inertance and damping is designed,on the basis of which an inertancedominated double skyhook control algorithm and a damping-dominated double skyhook control algorithm are proposed.Secondly,the vehicle semi-active ISD suspension dynamics model is established and the designed double skyhook control algorithm is simulated and analyzed.The simulation results show that the inertance-dominated double skyhook control outperforms the dampingdominated double skyhook control in terms of suppressing droop vibration,however,the body pitch and roll vibration of both control algorithms show a deteriorating trend.To this end,a double skyhook hierarchical control strategy considering body attitude is proposed,where the lower controller uses a double skyhook control strategy to control vertical vibration and the upper controller uses variable domain fuzzy control to coordinate the ideal dual canopy control forces to achieve coordinated control of body attitude.Thirdly,a seven-degree-of-freedom suspension model is built based on Simulink and simulated for different levels of random road surfaces to verify the effectiveness of the designed attitude coordination algorithm,while a joint simulation based on Carsim-Simulink is carried out to verify the control performance of the control algorithm on body attitude under three typical driving conditions: speed bumps,emergency braking and fishhook conditions.Finally,a single-wheel suspension control system semi-physical test rig is built based on D2 p rapid prototype to verify the vertical vibration isolation performance of the inertancedominated and damping-dominated double skyhook control algorithms.The results show that the inertance-dominated double skyhook control has better vibration isolation performance and can balance the ride smoothness and handling stability more effectively.A complete vehicle suspension hardware-in-the-loop test platform based on NI Veristand simulation test software and D2 p rapid prototyping was established to verify the effectiveness of the attitude coordination control algorithm on body attitude control,and the results showed that the designed control algorithm is feasible and effective.