基于比例谐振控制的被动式力矩伺服系统

Passive torque servo system based on proportional-resonant control

当被动式力矩伺服系统动态加载时,由于承载系统的主动运动,轴上输出的负载力矩中含有较大的干扰力矩,降低了被动式力矩伺服系统的加载性能。为了提升加载精度和加载频宽,提出基于比例谐振的控制方法。通过构建相应频率的比例谐振控制器,实现对期望正弦转矩信号无静差跟踪及有效抑制干扰力矩;提出了单位比例谐振控制器的结构,结合根轨迹及频域设计方法实现了单频率和多频率谐振控制器稳定性参数设计;加入承载系统速度前馈控制,降低加载起始阶段干扰力矩对整个系统及转矩传感器的瞬时冲击。仿真及实验结果验证了所提方法能够在有扰加载条件下,实现对20 Hz单频率正弦力矩的无静差加载及周期负载力矩的高精度跟踪。

When passive torque servo system is used to simulate load torque, the load torque acted on ac-tuator contains high disturbance torque due to the movement of actuator. In order to realize precise load torque simulation, a novel electric passive torque servo system was proposed, in which proportional reso-nant controller was added to the outer control loop. By embedding proportional resonant controller with the same frequency, sinusoidal torque signal was tracked with zero steady-state error, and disturbance torque caused by periodic motion of loaded actuator was restrained effectively;combining with root locus and frequency domain design method, unit proportional resonant controller was put forward to design pa-rameters of controller;moreover, speed feed-forward compensation method was used to reduce impact of disturbance torque acted on system and torque sensor in the beginning. Simulation and experimental re-sults show that 20 Hz sinusoidal load simulation can be tracked with zero steady-state error and periodic load simulation can be tracked with high precision under dynamic load mode.