室外移动机器人遥操作系统的设计与实现

遥操作是移动机器人指挥控制的重要手段之一.介绍了一种新型的室外智能移动机器人遥操作系统.本系统改变传统的固定指挥站,采用基于移动指挥站的操作方式,大大提高了操控的灵活性和系统的隐蔽性.同时,本系统还使用了先进的无线通信技术,开发了良好的人机交互界面,设计了功能全面的遥操作终端、定向天线云台控制系统以及多传感器环境信息采集系统.实验表明,系统能够在野外环境中高效、稳定地完成各种遥操作任务.     

基于波变量补偿的阻抗匹配时延双边遥操作

通信时延是遥操作系统中固有的问题,它会严重影响遥操作的性能,降低系统的稳定性和跟踪性。基于无源理论的波变量法可以保证遥操作系统在任意时延下稳定,是解决时延问题的一个重要方法。然而,波变量法带来的波反射会阻扰有用信号的传输,降低了主从端信号的跟踪性,严重时甚至会导致整个系统振荡。针对这一问题,提出了一种基于波变量补偿的阻抗匹配双边遥操作系统结构,旨在减少波反射,提高操作者的临场感和系统的跟踪性。通过仿真实验,结果表明所提方法能够保证固定时延条件下遥操作系统的稳定性,并具有较好的跟踪性。     

基于虚拟环境的多操作者多机器人协作遥操作系统

建立了基于虚拟环境的多操作者多机器人协作遥操作系统,采用3层C/S结构的控制系统软件构架.根据实验系统平台工作场景对分布式虚拟环境进行建模,以实现多操作者对多机器人的分布式控制.结合多操作者多机器人遥操作系统的结构特点,采用本地滞后原理对分布式虚拟环境的一致性控制进行了研究,解决了遥操作系统一致性控制中时钟同步、滞后时...     

无源散射变换的双边移动机器人网络遥操作

网络遥操作系统的随机时延给控制器设计带来巨大挑战,严重时破坏系统的稳定性。首先对遥操作无源理论及其波变量控制方法做了简单综述,然后提出直接无源散射变换方法,它将无源双边控制方法推广到具有随机时延的网络遥操作系统中去,保证网络遥操作系统在任何不对称随机网络时延情况下稳定。最后基于此变换方法设计了一个虚拟主从手双边移动机器人网络遥操作方案,并进行了仿真验证,结果表明结出的设计方法能满足系统性能要求。     

时延遥操作系统控制的波变量法

时延稳定性是遥操作系统面临的难题之一.基于无源性理论的波变量法可以保证遥操作系统在任意时延下稳定,已成为遥操作控制系统设计的一个重要方法.本文对波变量法的理论基础、波变量与波控制器、实际使用中的注意事项以及波变量法的最新进展做了系统的、全面的阐述,并指出其未来的研究方向.     

单自由度遥操作系统的虚拟现实环境建模研究

虚拟现实技术是目前解决遥操作控制系统中时延问题的有力手段.本研究建立了一个基于自主探测的单自由度遥操作视觉虚拟现实系统,根据视觉信息构建环境的虚拟模型.摄像机校准时选取机器人不同位姿的棱角点作为标定点,减小了运动累积误差的影响,从而减少了停顿机器人运动以进行模型修正的次数,保持了运动的连续性.同时将现场返回的视频图像和虚拟模型进行动态融合,实现了基于虚拟现实的单自由度遥操作系统.     

基于Internet的绘图机的网络遥操作系统设计

构建了一个基于Internet的网络遥操作系统,该系统提供了一种进行网络设计的方法,区别于其他的网络遥操作采用摄像头进行反馈的方法,采用光电码盘进行位置反馈,并对绘图机的网络遥操作的各组成部分实现进行了分析.     

大时延遥操作系统的波变量双边自适应控制

针对通信时延对遥操作系统稳定性和透明性的影响,研究了一种基于双边自适应控制和波变量理论的控制方法。通过设计波控制器保证通信传输模块的无源性,在保证系统稳定的基础上,调节波阻抗系数来提高系统的透明性,并在时延10 s的情况下进行主从端速度、位置和力的跟踪仿真实验,结果表明该方法和已有的双边自适应方法相比既能保证系统稳定且透明性好,达到较好的控制效果。     

基于波变量的时延双边遥操作系统设计

针对波变量法在任意时延下能保证时延双边遥操作系统的稳定,但却降低主从端之间跟踪性的问题,提出一种改进基于波变量遥操作系统的设计方案;该方案引入PD控制器调整主从端速度误差,并采用PI控制器控制从端;最后,对调整和未调整的基于波变量双边遥操作系统分别进行仿真实验;实验结果表明,与未调整的系统相比,调整的系统在一定程度上极大地降低了主从端位置、速度和力的跟踪误差,使得该方案在保证系统稳定的前提下有效提高了系统透明性。     

应用遥编程的大时延遥操作技术

如何克服通信线路中的大时延和有限带宽,是空间遥机器人面临的最重要的一个问题．本文 阐述了应用遥编程技术提高大时延遥操作的稳定性和操作精度的基本思想．提出了一种将操 作区分段,采取复合控制策略的遥操作方法．同时介绍了基于遥编程概念的遥操作实验系统 的设计及其试验结果．     

Cooperative modalities in robotic tele-rehabilitation using nonlinear bilateral impedance control

A nonlinear model reference adaptive bilateral impedance controller is proposed that can accommodate various cooperative tele-rehabilitation modes for patient–therapist interaction using a multi-DOF tele-robotic system. In this controller, two reference impedance models are implemented for the master and slave robots using new model reference adaptive control laws for the nonlinear bilateral teleoperation system. “Hand-over-hand” and “adjustable-flexibility” are two modes of patient–therapist cooperation that are realized using the proposed strategy. The Lyapunov-based stability proof guarantees the patient’s and the therapist’s safety during the cooperation and interaction with robots, even in the presence of modeling uncertainties of the multi-DOF teleoperation system. The performance of the proposed bilateral impedance controller is experimentally investigated for upper-limb tele-rehabilitation in the two mentioned cooperation modes.     

基于正交小波变换的心冲击图自适应去噪方法

研究了心冲击图的正交小波变换最小均方自适应去噪;阐述了基于正交小波变换的最小均方自适应去噪原理;利用径向高斯核函数对心冲击图进行自适应时频联合分析,得到了中心频率并确定了小波分解尺度;提出了通过选择小波基函数和输入信号长度确定自适应滤波器阶数的方法;从矩阵角度给出了算法的实现步骤,并分析了正交小波变换提高最小均方算法收敛速度的原因.实验结果表明,正交小波变换最小均方算法使自适应去噪后的心冲击图更快达到稳态,随心动周期的变化趋势更加明显.比较去噪前后心冲击图的功率谱密度可知,正交小波变换最小均方算法在保留心冲击图特征的同时自适应地去除了其中的时变噪声,获得了良好的去噪效果.     

多自由度伺服系统的非线性解耦控制

多自由度伺服系统各轴之间存在的非线性耦合,是影响系统控制性能的一个重要因素,为了提高系统控制性能,本文研究了多自由度伺服系统的解耦控制．首先建立了多自由度伺服系统的一般化耦合数学模型;然后根据Singh法求出逆系统;最后结合期望的标称线性传递函数,算出解耦控制规律．本算法避开微分几何理论,直接对矩阵进行运算,易于理解．文章给出了应用此方法对3轴仿真转台进行解耦控制的例子．     

Bilateral teleoperation of a group of mobile robots for cooperative tasks

A visual and force feedback-based teleoperation scheme is proposed for cooperative tasks. The bilateral teleoperation system includes a haptic device, an overhead camera and a group of wheeled robots. The commands of formation and average velocities of the multiple robots are generated by the operator through the haptic device. The state of the multiple robots and the working environment is sent to the human operator. The received information contains the feedback force through the haptic device and visual information returned by a depth camera. The feedback force based on the difference between the desired and actual average velocities is presented. The wave variable method is employed in the bilateral teleoperation of multiple mobile robots with time delays. The effectiveness of the bilateral teleoperation system is demonstrated by experiments. The robots in the slave side are able to follow the commands from the master side to interact with the environments, including moving in different formations and pushing a box. The results show that the scheme enables the operator to manipulate a group of robots to complete cooperative tasks freely.     

Robust Output Feedback Controller Design for Time‐Delayed Teleoperation: Experimental Results

In this paper, a robust output feedback control strategy is proposed for a nonlinear teleoperation system which can deal with stability as well as transparency despite the variable time‐delay and uncertain dynamics. The proposed approach is composed of two steps. First, local Lyapunov based adaptive controllers are applied to both master and slave sides in order to suppress the nonlinearities in the system dynamics. Afterwards, a new observer‐based controller scheme is proposed to achieve stability and performance (transparency) of the teleoperation system. Using the Lyapunov techniques, stability and performance objectives are cast as some linear matrix inequality (LMI) feasibility conditions. To evaluate the performance of the proposed controller, a set of simulations and experiments are performed. Through simulation results, it is demonstrated that the proposed approach significantly outperforms the existing methodologies reported in the literature.     

A novel approach for stability and transparency control of nonlinear bilateral teleoperation system with time delays

In this paper, a novel control approach is presented to improve the stability and transparency of the nonlinear bilateral teleoperation system with time delays, where a four-channel (4-CH) architecture using modified wave reflection reduction transformation is explored in order to guarantee the passivity of the communication channels in the nonlinear bilateral teleoperation system; a sliding-mode controller is proposed to compensate for the dynamic uncertainties and enhance the system synchronization performance in finite time. The system stability has been analyzed using Lyapunov functions. The proposed method is validated through experimental work based on a 3-DOF bilateral teleoperation platform in the presence of time delays. The experimental results clearly demonstrate that the proposed control algorithm has superiority on system transparency over other wave-based systems.