Research On Optimal Design And Control Of A Hybrid Electromagnetic Active Suspension Actuator

Active suspension system can adjust its working mode in real time according to the real-time driving conditions of vehicle,which can improve the comfort and safety of vehicle.Thus,it has attracted wide attention.And the actuator that is the executive part of the active suspension system is the core of the suspension system.At present,scholars at home and abroad have introduced motor technology into the active suspension system to develop the electromagnetic actuator.And common electromagnetic actuators mainly includes rotary motor electromagnetic actuator and linear motor electromagnetic actuator.However,rotary motor electromagnetic actuator has the disadvantages of complicated structure.Though the structure of linear motor electromagnetic actuator is simple,its reliability is poor.Thus,this paper integrates linear motor with traditional hydraulic shock absorber,and proposes a new structure of hybrid electromagnetic active suspension actuator,which improves the reliability and the dynamic performance of the system.And the main research contents are as follows:Firstly,the structure selection of linear motor which is the key component of hybrid electromagnetic actuator is carried out.And the working principle of the selected permanent magnet synchronous linear motor is introduced.The linear motor is designed and analyzed from the relative position between the coil windings and the permanent magnets,the magnetizing mode of the permanent magnet and the structure of iron core.Based on this,the structural scheme of the hybrid electromagnetic actuator is proposed.And its working mode is described.Secondly,based on the quarter hybrid electromagnetic active suspension system,the parameters of hybrid electromagnetic actuator are optimized by using the modified sky-hook control strategy.And the sky-hook damping coefficient,passive damping coefficient and the peak electromagnetic thrust force of linear motor are obtained.According to the demand of thrust force,the structural parameters of the hybrid electromagnetic actuator are optimized by establishing the equivalent magnetic circuit model and carrying out the finite element analysis.And the prototype of hybrid electromagnetic actuator is developed on the basis of the obtained structural parameters.Then,the double-loop control system for hybrid electromagnetic active suspension is designed.The outer loop adopts the modified sky-hook control strategy,and the inner loop adopts the current hysteresis control.And the mathematical model of the hybrid electromagnetic actuator that is the linear motor is derived based on the principle of vector transformation.The double-loop control model of the hybrid electromagnetic active suspension system is established,which verifies the effectiveness of the double-loop control system.And the dynamic performances of the hybrid electromagnetic active suspension system and passive suspension system are compared and analyzed from time domain and frequency domain,which verifies the advantages of the hybrid electromagnetic active suspension system on improving vehicle dynamic performance.Finally,the bench tests on the hybrid electromagnetic active suspension are conducted,including the external characteristics test of the actuator and the active control test.The test results show that compared with passive suspension system,the hybrid electromagnetic active suspension system can significantly improve the vehicle dynamic performance.And the simulation results are in good agreement with the test results,which verifies the feasibility of the structural scheme of the hybrid electromagnetic actuator and the correctness of the control strategy.