Abstract Twisted string actuators (TSAs) have been used where conversion of the rotational motion of a motor into a translatory motion by twisting two strings to control the length of the actuator is needed, e.g., in robot applications. Speed mode TSA (SM-TSA) improves the translatory motion achieved in previous TSAs by adding a shaft between two strings. However, the nonlinear response of the translatory displacements remains a problem. Modeling has been one approach, but payload changes or disturbances make it difficult to solve the nonlinear response of SM-TSA through modeling. Here, proportional–integral–derivative (PID) control and time delay control (TDC) in SM-TSA are evaluated as feedback mechanisms during translatory displacements. By following the desired trajectory through PID control and TDC under conditions of payload changes and spring disturbances in SM-TSA and evaluating tracking results, we show that both control methods can provide somewhat precise positional control in SM-TSA even if there are payload changes or spring disturbances. However, TDC shows smaller tracking errors and yields more robust performance against payload changes and disturbances compared to PID control.

中文翻译：

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基于时间延迟估计的扭弦致动器速度模式的鲁棒控制算法

摘要 双绞线致动器 (TSA) 已被用于需要通过扭转两根弦来控制致动器长度将电机的旋转运动转换为平移运动的情况，例如，在机器人应用中。速度模式 TSA (SM-TSA) 通过在两根弦之间添加轴来改进以前 TSA 中实现的平移运动。然而，平移位移的非线性响应仍然是一个问题。建模一直是一种方法，但有效载荷的变化或干扰使得很难通过建模来解决 SM-TSA 的非线性响应。在这里，SM-TSA 中的比例积分微分 (PID) 控制和时间延迟控制 (TDC) 被评估为平移位移期间的反馈机制。通过在 SM-TSA 中的有效载荷变化和弹簧扰动条件下通过 PID 控制和 TDC 跟踪所需轨迹并评估跟踪结果，我们表明，即使有效载荷发生变化或春季干扰。然而，与 PID 控制相比，TDC 显示出更小的跟踪误差，并针对有效载荷变化和干扰产生更强大的性能。