时延以及不确定性等因素容易造成双边遥操作系统操作性能差,甚至不稳定等问题。为了解决这一问题,针对主、从端不同的任务特点,提出一种新的双边遥操作系统控制结构。由于主端在实现力反馈时易受扰动影响,设计一种非线性扰动观测器用于扰动的在线估计并进行补偿;从端采用基于滑模的阻抗控制以保证精确的位置跟踪和与环境的期望交互。利用Liewellyn绝对稳定准则推导出时延下保证系统稳定性的条件以及参数选取依据。在建立的单自由度遥操作系统试验平台上进行了试验研究,结果表明本文所提方法能够在保证系统鲁棒性的条件下有效提高操作性能。
The performance and stability of bilateral teleoperation system are easily degraded by time delay and uncertainty factors.In order to solve this problem,a new control structure is proposed concerning different task characteristics of master and slave sides.Because the master-side is vulnerable to disturbance in the realization of force feedback,a kind of nonlinear disturbance observer is designed for online estimate and compensation.At the slave-side,impedance control based on sliding mode is applied to ensure precise position tracking and desired interacting with the environment.The Liewellyn absolute stability criterion is adopted to derive stability condition and parameter selection criteria under a time delay.The proposed method is validated by experiments with a single-DOF teleoperation platform,and the results show that the proposed method can improve operational performance while having good robustness.