行波型超声电机振动模态滑模观测器研究

行波超声电机（TWUSM）具有强非线性和系统参数不确定性，其不易观测的两相振动模态对输出转矩性能有着直接的影响。基于该分析，设计了具有鲁棒性的振动模态线性滑模观测器（SMO），并利用Lyapunov法对该观测器的鲁棒性和稳定性给予证明，最后，通过仿真和实验对观测器进行验证。结果表明，该SMO能够准确获得TWUSM两相振动模态。此外，仿真和实验还表明，根据所设计的SMO的观测结果，可调节驱动电压，优化振动模态，从而降低输出转矩脉动，提高电机控制精度。

Research on the Sliding Mode Observer of TWUSM Vibration Modes

The traveling-wave ultrasonic motor(TWUSM)has strong nonlinearity and parameter uncertainty,and its two-phase vibration modes,which are not easy to measure,have a direct impact on the output torque performances.Based on the above analysis,a vibration modes linear sliding mode observer(SMO)with robustness was designed,and then,the robustness and stability of the SMO were proved using the Lyapunov method,furthermore,the feasibility of SMO was verified by simulations and experiments.And the results showed that the SMO can accurately obtain the TWUSM two-phase vibration modes.In addition,the results also showed that adjusting the driving voltage based on the observation successfully optimizes the vibration mode to reduce the ripple of output torque and then improve the control accuracy.