SMA电机控制中的极限环抑制

Quenching of limit cycles in control of SMA actuators

为了探讨SMA电机的理想控制策略,提出了用于纤维式形状记忆合金及SMA电机的切换控制器,可以动态调整切换层宽度,使之正比于电机运动速率,从而得到阻尼响应,能有效抑制极限环。实验结果表明,阻尼响应在维持相同稳态精确度前提下,大大降低了上升时间,可使SMA电机快速准确达到设定位姿。

The controller was originally designed to drive an ideal Shape Memory Alloy (SMA) actuator consisting of a number of thin NiTi fibers woven in a counter rotating helical pattern around supporting disks. By allowing the upper switching level to be proportional to the velocity, it is possible to achieve a damped response, effectively quenching the limit cycle. With this damping, it is possible to decrease the rise time by almost half and maintain the same steady state accuracy.