Yang Yana, Hua Changchun, Guan Xinping
IEEE Trans Cybern. 2016 Mar;46(3):609-19. doi: 10.1109/TCYB.2015.2410785. Epub 2015 Mar 25.
Due to the cognitive limitations of the human operator and lack of complete information about the remote environment, the work performance of such teleoperation systems cannot be guaranteed in most cases. However, some practical tasks conducted by the teleoperation system require high performances, such as tele-surgery needs satisfactory high speed and more precision control results to guarantee patient' health status. To obtain some satisfactory performances, the error constrained control is employed by applying the barrier Lyapunov function (BLF). With the constrained synchronization errors, some high performances, such as, high convergence speed, small overshoot, and an arbitrarily predefined small residual constrained synchronization error can be achieved simultaneously. Nevertheless, like many classical control schemes only the asymptotic/exponential convergence, i.e., the synchronization errors converge to zero as time goes infinity can be achieved with the error constrained control. It is clear that finite time convergence is more desirable. To obtain a finite-time synchronization performance, the terminal sliding mode (TSM)-based finite time control method is developed for teleoperation system with position error constrained in this paper. First, a new nonsingular fast terminal sliding mode (NFTSM) surface with new transformed synchronization errors is proposed. Second, adaptive neural network system is applied for dealing with the system uncertainties and the external disturbances. Third, the BLF is applied to prove the stability and the nonviolation of the synchronization errors constraints. Finally, some comparisons are conducted in simulation and experiment results are also presented to show the effectiveness of the proposed method.
由于人类操作员的认知限制以及缺乏关于远程环境的完整信息,在大多数情况下,此类遥操作系统的工作性能无法得到保证。然而,遥操作系统执行的一些实际任务需要高性能,例如远程手术需要令人满意的高速度和更精确的控制结果以确保患者的健康状况。为了获得一些令人满意的性能,通过应用障碍李雅普诺夫函数(BLF)采用误差约束控制。利用受约束的同步误差,可以同时实现一些高性能,如高收敛速度、小超调量以及任意预定义的小残余受约束同步误差。然而,与许多经典控制方案一样,误差约束控制只能实现渐近/指数收敛,即随着时间趋于无穷大同步误差收敛到零。显然,有限时间收敛更可取。为了获得有限时间同步性能,本文针对位置误差受约束的遥操作系统开发了基于终端滑模(TSM)的有限时间控制方法。首先,提出了一种具有新变换同步误差的新型非奇异快速终端滑模(NFTSM)面。其次,应用自适应神经网络系统来处理系统不确定性和外部干扰。第三,应用BLF来证明稳定性以及同步误差约束不被违反。最后,进行了一些比较,并给出了实验结果以证明所提方法的有效性。