The damper is capable of providing a continuously variable dampering force/torque in response to a magnetic field. It consists of an upside cap and an underside cap with a rotor located between them, the magneto-rheol...The damper is capable of providing a continuously variable dampering force/torque in response to a magnetic field. It consists of an upside cap and an underside cap with a rotor located between them, the magneto-rheological （MR） fluid is filled into the gaps between the rotor and the caps. When the viscosity of the MR fluid increases under the influence of the magnetic field, the movement of the rotor will be resisted. The output torque is made up of the torque caused by the magnetic field, the torque caused by the plastic viscosity of the MR fluid, and the torque caused by the coulomb friction. The viscous torque can be calculated by a simple method and the frictional torque can be obtained by experiments. The torque dependent on the magnetic field is obtained by electromagnetic finite dement analysis. Experiments are done on the damper prototype and the validity of the design is verified.展开更多
Universal challenge lies in torque feedback accuracy for steer-by-wire systems,especially on uneven and low-friction road.Therefore,this paper proposes a fusion method based on Kalman filter that combines a dynamics-r...Universal challenge lies in torque feedback accuracy for steer-by-wire systems,especially on uneven and low-friction road.Therefore,this paper proposes a fusion method based on Kalman filter that combines a dynamics-reconstruction method and disturbance observer-based method.The dynamics-reconstruction method is designed according to the vehicle dynamics and used as the prediction model of the Kalman filter.While the disturbance observer-based method is performed as an observer model of the Kalman filter.The performance of all three methods is comprehensively evaluated in a hardware-in-the-loop system.Experimental results show that the proposed fusion method outperforms dynamics reconstruction method and disturbance observer-based method.Specifically,compared with the dynamics-reconstruction method,the root mean square error is reduced by 36.58%at the maximum on the flat road.Compared with the disturbance observer-based method,the root mean square error is reduced by 39.11%at the maximum on different-friction and uneven road.展开更多
Precise,prompt,and comfortable road feel information feedback is crucial in the steer-by-wire(SBW)system to ensure safe and satisfactory experiences for drivers in intelligent vehicles.This paper presents an enhanced ...Precise,prompt,and comfortable road feel information feedback is crucial in the steer-by-wire(SBW)system to ensure safe and satisfactory experiences for drivers in intelligent vehicles.This paper presents an enhanced rack force observer-based road feel feedback torque control approach for the SBW system.Firstly,to perform accurate and timely rack force estimation under varying conditions,two improved observers are proposed,namely,a linear reduced-order extended disturbance observer(ROEDO)and a nonlinear super-twisting sliding mode observer(STSMO)with parameter tuning based on a particle swarm optimization(PSO)algorithm.Besides,an improved rapid tracking differentiator(IRTD)is applied to derive accurate and low-delay rack displacement differential signals for the observers.Next,the performance of these observers is evaluated through simulations across diverse conditions to identify one suitable observer for road feel feedback torque rebuild.Simulation results indicate that the ROEDO exhibits superior efficacy.Furthermore,a vehicle speed-based low-pass filter that extracts effective information from the estimated rack forces is applied to ensure driver comfort.Then,the road feel is formulated by combining the main torque with variable road feel strength and compensation torque to achieve a high-quality road feel.Finally,hardware-in-the-loop(HIL)experiments are carried out,and the test results validate the effectiveness of the designed road feel control algorithm in providing the driver with a timely and comfortable road feel and in facilitating real-time implementation.展开更多
基金The National Basic Research Program of China(973Program) (No2002CB312102)the National Natural ScienceFoundation of China (No60675047)
文摘The damper is capable of providing a continuously variable dampering force/torque in response to a magnetic field. It consists of an upside cap and an underside cap with a rotor located between them, the magneto-rheological （MR） fluid is filled into the gaps between the rotor and the caps. When the viscosity of the MR fluid increases under the influence of the magnetic field, the movement of the rotor will be resisted. The output torque is made up of the torque caused by the magnetic field, the torque caused by the plastic viscosity of the MR fluid, and the torque caused by the coulomb friction. The viscous torque can be calculated by a simple method and the frictional torque can be obtained by experiments. The torque dependent on the magnetic field is obtained by electromagnetic finite dement analysis. Experiments are done on the damper prototype and the validity of the design is verified.
文摘Universal challenge lies in torque feedback accuracy for steer-by-wire systems,especially on uneven and low-friction road.Therefore,this paper proposes a fusion method based on Kalman filter that combines a dynamics-reconstruction method and disturbance observer-based method.The dynamics-reconstruction method is designed according to the vehicle dynamics and used as the prediction model of the Kalman filter.While the disturbance observer-based method is performed as an observer model of the Kalman filter.The performance of all three methods is comprehensively evaluated in a hardware-in-the-loop system.Experimental results show that the proposed fusion method outperforms dynamics reconstruction method and disturbance observer-based method.Specifically,compared with the dynamics-reconstruction method,the root mean square error is reduced by 36.58%at the maximum on the flat road.Compared with the disturbance observer-based method,the root mean square error is reduced by 39.11%at the maximum on different-friction and uneven road.
基金supported in part by the Jilin Province Science and Technology Department Program of China under Grant(No.20230101121JC)in part by the FAW Volkswagen China Environmental Protection Foundation Automotive Environmental Protection Innovation Leadership Program.
文摘Precise,prompt,and comfortable road feel information feedback is crucial in the steer-by-wire(SBW)system to ensure safe and satisfactory experiences for drivers in intelligent vehicles.This paper presents an enhanced rack force observer-based road feel feedback torque control approach for the SBW system.Firstly,to perform accurate and timely rack force estimation under varying conditions,two improved observers are proposed,namely,a linear reduced-order extended disturbance observer(ROEDO)and a nonlinear super-twisting sliding mode observer(STSMO)with parameter tuning based on a particle swarm optimization(PSO)algorithm.Besides,an improved rapid tracking differentiator(IRTD)is applied to derive accurate and low-delay rack displacement differential signals for the observers.Next,the performance of these observers is evaluated through simulations across diverse conditions to identify one suitable observer for road feel feedback torque rebuild.Simulation results indicate that the ROEDO exhibits superior efficacy.Furthermore,a vehicle speed-based low-pass filter that extracts effective information from the estimated rack forces is applied to ensure driver comfort.Then,the road feel is formulated by combining the main torque with variable road feel strength and compensation torque to achieve a high-quality road feel.Finally,hardware-in-the-loop(HIL)experiments are carried out,and the test results validate the effectiveness of the designed road feel control algorithm in providing the driver with a timely and comfortable road feel and in facilitating real-time implementation.
