【作者】 刘磊；

【导师】 李丽；

【作者基本信息】 燕山大学 ， 控制科学与工程， 2020， 硕士

【摘要】 遥操作系统对处理远端危险环境下的任务具备极大优势,这些优势体现在对未知环境的适应性和操作的灵活性上,这对提升灾后救援、未知空间探索等能力具有重大的理论研究价值。虽然网络技术的发展使得遥操作系统的实现更加便利,但是主从两端的机械臂具有很强的非线性以及远端执行器受到内外扰动的影响,仍然难以获得十分精确的模型以实现较好的控制性能。另外,主从两端信息传递过程中产生的时延问题,严重影响遥操作系统主从之间的同步性能。综合考虑系统非线性、内外扰动和时延问题,基于相对精准的非线性模型设计遥操作系统的抗扰控制器,进而提升系统的稳定性是本文的主要研究内容。本文主要工作如下:(1)研究了具有不可测力信息和时变时延的双边遥操作系统的跟踪控制问题。为了获得更好的透明性,通过设计非线性状态观测器来获得不可测力信息。利用四通道波变量方法设计一种基于力反馈的自适应控制律,以保证双边遥操作系统的无源性。利用相依锥准则和自稳定域分析了非线性状态观测器的有效性并利用李雅普诺夫函数给出系统稳定性的充分条件。最后通过仿真表明,所提出的控制律在考虑时变时延的情况下具有良好的抗扰能力。(2)研究了具有时变时延和动态不确定性的双边遥操作系统的跟踪控制问题。该跟踪控制方案基于扩张状态观测器、时延部分观测器和连续终端滑模控制策略。针对双边遥操作系统的动态不确定性,采用扩张状态观测器进行估计。利用两个时延部分观测器估计具有不可测导数的时变时延。在不知道跟踪误差二阶导数的情况下,采用连续终端滑模控制策略保证双边遥操作系统的有限时间收敛。最后,对双边遥操作系统进行了实验,验证了所提出的跟踪控制方案的有效性。(3)研究了具有动态不确定性和随机时延的双边遥操作系统的跟踪控制问题。设计降阶扩张状态观测器用于处理双边遥操作系统的动态不确定性。利用连续时间马尔可夫过程建立随机时延下的遥操作系统模型,提出基于降阶扩张状态观测器的跟踪控制策略以保证闭环系统的稳定性,利用马尔可夫无穷小算子证明闭环双边遥操作系统的同步性能。最后,对双边遥操作系统进行了实验,在随机时延下,双边遥操作系统是稳定的,所设计的控制策略是可行和有效的。更多还原

【Abstract】 Reflected in adaptability to unknown environment and flexibility of operation,teleoperation systems have great advantages in dealing with tasks in remote dangerous environment.Thus the teleoperation systems have great theoretical significance in improving abilities of post disaster rescue and unknown space exploration.With the development of network technology,the teleoperation systems have been more convenient to realize.However,not only manipulators at both sides at the master and slave have strong nonlinearities but also the remote actuator is affected by internal and external disturbances.Therefore,it is difficult to obtain an accurate model to obtain great control performance.In addition,time-delays make the information transmissions between a master side and a slave side delay,which seriously affects synchronization performance of the teleoperation systems.Disturbance rejection controllers will be designed by a relatively accurate nonlinear model so as to improve stability of the teleoperation systems,which is main researches of this paper.Main work is given as follows:The tracking control problem of bilateral teleoperation system with unmeasurable force information and time-varying delay is studied.In order to obtain better transparency,the unmeasurable force information is obtained by designing a nonlinear state observer.An adaptive control law based on the force feedback is designed by a four channel wave variable method to ensure passivity of the bilateral teleoperation systems.The effectiveness of the force observer is analysed via contingent cone criteria and self-stability regions.Moreover,sufficient conditions for stability are given by a Lyapunov-Krasovskii function.Finally,simulation results show that the proposed control law has good anti-interference ability under time-varying delays.A tracking control scheme is investigated for the bilateral teleoperation systems with time-varying delays and dynamic uncertainties.The tracking control scheme is based on an extended state observer,a time-delay part observer and a continuous terminal sliding mode control strategy.The dynamic uncertainties are dealt with by the extended state observer for the bilateral teleoperation system.The time-varying delays withunmeasurable derivatives are estimated by the time-delay part observers.The continuous terminal sliding mode control strategy is used to ensure finite-time convergence for the bilateral teleoperation system without knowing the second derivatives of tracking errors.Finally,experiment results are shown for the bilateral teleoperation system to demonstrate effectiveness of the developed tracking control scheme.A synchronization control problem is investigated for the bilateral teleoperation systems with dynamic uncertainties and random delays.Reduced-order extended state observers,which make calculations of gain matrices be easier than full-order extended state observers,are proposed to estimate the dynamic uncertainties and unmeasurable joint velocities.The model of the bilateral teleoperation systems with random time delay is established by continuous time Markov process.A tracking control strategy based on the reduced order extended state observers is proposed to ensure stability of the closed-loop system.The synchronization performance of the closed-loop bilateral teleoperation systems is proved by the Markov infinitesimal operator.Lastly,experiment results are shown for the bilateral teleoperation system to verify effectiveness of the developed techniques.更多还原