TWUSM振动模态鲁棒滑模观测器研究

Research on Robust Sliding Mode Observer for TWUSM Vibration Modes

考虑到行波型旋转超声电机(TWUSM)控制精度与定子两相振动模态有关,但其不易测量。因此,该文提出了一种具有参数鲁棒性的滑模观测器以实现优化定子振动模态。首先,分析定子两相振动模态及合成行波对TWUSM高精度控制的影响;其次,利用电机可测的电流、电压信号建立振动模态滑模观测器,分析TWUSM参数时变特征,并证明观测器的稳定性与鲁棒性;最后,通过仿真与实验对所提出的振动模态滑模观测器进行验证。结果表明,滑模观测器能准确估计两相振动模态,且具有参数鲁棒性。此外,基于观测结果改善驱动电压,实现定子振动模态优化,从而降低输出转矩脉动,提高电机控制精度。

Considering that the control accuracy of travelling-wave rotating ultrasonic motors(TWUSMs)is directly related to the two-phase vibration modes of the stator,but which are not easy to measure,a sliding mode observer(SMO)with parameter robustness is proposed to optimize the stator vibration modes.Firstly,the influences of the two-phase vibration modes of the stator and the travelling wave to the control accuracy of TWUSMs are analyzed.Secondly,the SMO with vibration modes is established using the measurable current and voltage signals,and then its stability and robustness are proved under the time-varying parameters.Finally,the proposed sliding mode observer with vibration mode is verified through simulation and experiment.The results show that the SMO can accurately estimate the two-phase vibration modes and has the parameters robustness.In addition,based on the observation results,the driving voltage is improved,and the stator vibration mode is optimized,thereby reducing output torque ripple and improving motor control accuracy.