Study On Structure Design And Control Of Linear Electromagnetic Actuator Matched With Non-pneumatic Tire

As the only medium of contact and interaction between vehicle and road,tire is the key component of vehicle driving system,which is directly related to vehicle driving safety.The traditional pneumatic tire is easy to burst in the environment of high temperature,high speed and heavy load,which brings a huge safety risks to drivers and passengers.Through the special structure design and material application,the non-pneumatic tire can avoid the risk of tire burst in different environments,and realize the leap forward improvement of vehicle driving safety.However,with the increase of mass and radial stiffness of the non-pneumatic tire,it has a negative impact on the ride comfort and road holding under high-speed.The damping system composed of tire and suspension is related to the ride comfort,road holding and other vehicle dynamic performance.Thus,the most direct and effective way to improve the vertical dynamic performance of the non-pneumatic tire vehicle is the matching design and reasonable control of the suspension system.With the support of the general project of National Natural Science Foundation of China(Project No.: 51975253),this paper established the suspension system model including non-pneumatic tire,explored the dynamic performance and energy recovery potential of the non-pneumatic tire vehicle,and carried out the structure matching design of linear electromagnetic suspension actuator with base value passive damping.Three working modes of passive energy feedback,active control and hybrid control are proposed,which provides a theoretical guidance for the chassis control of nonpneumatic tire vehicle.Firstly,the vertical mechanical model of non-pneumatic tire and the quarter suspension system model of non-pneumatic tire vehicle are established,and the evaluation indexes of vehicle dynamic performance and energy dissipation are given.The dynamic performance and energy recovery potential of non-pneumatic tire vehicle are analyzed by comparing the same specification pneumatic tire vehicle.The modified sky-hook algorithm,which has a good fit with the designed electromagnetic actuator,is selected as the suspension control strategy.The genetic algorithm is used to optimize the control parameters,and the base value passive damping and rated electromagnetic thrust of the electromagnetic actuator are determined according to the activation force output.Secondly,the type,topological structure and the arrangement scheme of mover/stator of actuator are selected.The type of motor is determined as cylinder permanent magnet synchronous linear motor,and the arrangement scheme of slotted Halbach moving magnet is adopted.The basic structure of linear motor is designed,including the length of mover/stator,the combination of pole slot number,coil winding and pole distance.According to the thrust force and thrust fluctuation,the structure size of permanent magnet is optimized.The ratio of thickness of axial magnetized permanent magnet to pole distance and the ratio of outer radius of permanent magnet to coil are determined.The aluminum ring is designed with the largest size,and the eddy current damping generated by the aluminum ring and the stator core is used to meet the demand of base value passive damping.And the structure parameters,performance parameters and motor model of the actuator are given.Thirdly,the vector mathematical model and control system of the linear motor are built,and three working modes are designed for the electromagnetic actuator: passive energy feedback mode,active control mode and hybrid control mode.The simulation analysis is carried out with the passive suspension as the comparison object,including the dynamic response in time/frequency domain,force of actuator and energy recovery/consumption.Finally,in order to verify the working performance of the designed actuator and the correctness of the simulation results,the bench test of the electromagnetic actuator is carried out.The test results show that the base value passive damping and electromagnetic thrust performance of the electromagnetic actuator meet the design requirements.And the vehicle dynamic response and energy recovery/consumption are basically consistent with the simulation analysis.