基于耦合ADRC原理的机器人无标定手眼协调

研究机器人的无标定手眼协调问题．基于耦合的自抗扰控制器思想，通过对系统建 模的不确定性及其未知外扰进行非线性补偿，完成了相互耦合的不依赖于系统特定任务的无 标定手眼协调控制器的设计，实现了广泛意义的机器人无标定手眼协调，最后的仿真和实验 说明了该方法的可行性．     

基于优化神经网络ADRC的机器人无标定视觉跟踪

研究机器人无标定视觉跟踪,采用基于神经网络的耦合自抗扰控制器,并用自适应遗传算法训练BP网络的初始权值,优化控制器参数,实现了六自由度机器人的无标定手眼协调控制,仿真结果验证了算法的可行性.     

ADRC理论和技术在机器人无标定视觉伺服中的应用和发展

针对Active disturbance rejection controller (ADRC) 理论和方法在机器人无标定视觉伺服研究领域中的应用及取得的成果进行综述. 剖析了机器人无标定视觉伺服研究的本质特性和关键问题, 说明其与ADRC理论和思想在方法论上的一致性, 特别以机器人无标定手眼协调这一典型应用为例, 展示了ADRC理论和技术用于处理机器人无标定手眼协调问题的合理性. 给出了控制器的基本设计过程, 并在已有成果的基础上讨论了控制器的收敛性以及ADRC设计中的参数整定方法. 最后讨论了一些尚未解决的问题, 指出了今后继续研究的方向.     

眼在手上机器人手眼无标定三维视觉跟踪

在未标定手眼关系及摄像机模型的情况下,建立了机器人三维视觉跟踪问题非线性视 觉映射关系模型,并据此设计了基于人工神经网络的视觉跟踪控制器.仿真结果表明该算法能 完全消除稳态跟踪误差,具有很强的环境适应性和容错能力,算法简单,易于实时实现.     

一种新的双环结构机器人无标定自抗扰视觉伺服控制方法

在研究基于自抗扰控制器的机器人无标定视觉伺服方法的基础上，提出了一种新的双环结构机器人无标定自抗扰视觉伺服控制方法．内环采用Kalman滤波算法进行图像雅可比矩阵的在线辨识，可较好地逼近真实模型；外环采用自抗扰控制器，利用非线性观测器实时估计系统相对于当前估计模型的总扰动，并在控制中加以动态补偿．针对六自由度工业机器人进行了二维运动目标的跟踪实验，实验结果表明了该方法的可行性和有效性．     

基于立体视觉的机器人手眼无标定三维视觉跟踪

本文在未标定手眼关系及摄像机模型的情况下,建立了机器人立体视觉跟踪问题非线性视觉 映射关系模型,并据此设计了基于人工神经网络的视觉跟踪控制器．仿真结果表明该算法能 完全消除稳态跟踪误差,具有很强的环境适应性和容错能力,算法简单,易于实时实现．     

基于遗传优化自抗扰控制器的机器人无标定手眼协调

研究机器人无标定手眼协调控制，提出了自适应遗传算法(AGA)选取与优化自抗扰控制器(ADRC)参数的方法，较好地解决了其过多参数难以调节的问题．采用两个结构相同的一阶ADRC实现了六自由度机器人的无标定视觉跟踪控制，以及Motoman-SV3XL机器人的视觉定位．实验结果验证了算法的可行性和有效性．     

基于自适应免疫整定的机器人无标定自抗扰视觉伺服控制

研究了机器人无标定自抗扰视觉伺服控制问题. 针对系统中所用的自抗扰控制器参数选取困难问题, 提出了基于自适应免疫算法的自抗扰控制器参数整定方法. 证明了系统中所用的非线性离散二阶扩张状态观测器稳定的充要条件, 并将该条件应用在参数整定过程中. 6 自由度工业机器人的实验结果表明了该方法的可行性和有效性.     

基于自抗扰控制器的机器人无标定三维手眼协调

研究机械臂在手眼关系未知情况下依靠视觉信息引导完成三维空间定位及跟踪问题. 基于耦合自抗扰控制原理,设计了不依赖于特定任务的广泛意义下的手眼协调控制器.利用 两个全局摄像机组成双目视觉系统,由图像特征可充分地确定机器人三维空间中的位置信 息.仿真和实验对这一方法的可行性和有效性进行了验证.     

一种新的三维测量机器人手眼标定方法

为了提高三维测量机器人的手眼标定精度以更好地满足工业需求,提出了一种采用动态改变变异率的自适应差异进化算法进行手眼标定的新方法;首先构建了由线结构光测头和机器人组成的视觉测量系统,利用齐次坐标变换的方法建立了测量系统的数学模型;然后针对数学模型中的手眼关系,使用半径已知的球体,采用定点变位姿的方法,进行粗略的估计,并对手眼关系求解的精度进行分析;最后采用动态改变变异率的自适应差异进化算法对手眼关系做进一步寻优;实验结果表明,算法具有较高的求解精度;该方法用于手眼标定是可行的、有效的,整个标定过程简单,便于实际应用。     

Calibration-free robotic eye-hand coordination based on an auto disturbance-rejection controller

This paper addresses the calibration-free robotic eye-hand coordination in a way other than the conventional image Jacobian matrix approach that has been studied extensively in literature. A nonlinear mapping rather than the linear mapping used in the image Jacobian matrix between the image space and the robotic control space is proposed. This mapping is regarded as the system's unmodeled dynamics expressed in system state equations. An extended state observer is designed first to estimate the unmodeled dynamics as well as the external disturbance of the system. With the estimation results as the compensation, a system controller is designed based on the nonlinear state-error feedback control strategy. Convergence of the extended state observer as well as the overall controller for a typical eye-hand coordination system is proved. Compared with the conventional calibration-free robotic eye-hand coordination with a Jacobian matrix, the proposed controller is independent of specific tasks and system configurations. Thus, a general design procedure is proposed for the calibration-free robotic eye-hand coordination. Simulation and experiment results demonstrate the satisfactory performance and effectiveness of the proposed approach.     

多机械臂协调控制研究综述

多机械臂系统的协调控制是当今机器人领域的研究热点.针对机器人基坐标系标定,协调系统动力学建模,控制器综合方法等问题,介绍近年来多机械臂系统在协调控制上研究工作的进展,主要从系统的动力学模型建立方式和协调运动的控制综合方式两个方面进行深入介绍.全面系统地介绍多机械臂系统协调控制问题的研究现状与发展方向,并指明未来工作的研究方向.     

In-field self-calibration of robotic manipulator using stereo camera: application to Humanitarian Demining Robot

A robotic manipulator using a stereo camera mounted on one of its links requires a precise kinematic transformation calibration between the manipulator and the camera coordinate frames, the so-called hand–eye calibration, to achieve high-accuracy end-effector positioning. This paper introduces a new method that performs simultaneous joint angle and hand–eye calibration, based on a traditional method that uses a sequence of pure rotations of the manipulator links. The new method considers an additional joint angle constraint, which improves the calibration accuracy when the circular arc that can be measured by the stereo camera is very limited. Experimental results using a manipulator developed for humanitarian demining demonstrate that relative errors between the end effector and the external points mapped by the stereo camera are greatly reduced compared to traditional methods.     

微操作机器人的视觉伺服控制

视觉伺服控制是微操作机器人实现精确运动,完成自动操作的必要手段．本文介绍 了实现微操作机器人视觉伺服控制的方法．首先论述了微操作机器人的视觉伺服结构,并以 建立的面向生物工程的双手微操作机器人系统为例,介绍了基于二维显微视觉信息的三自由 度柔性铰链微操作机器人的运动学建模方法,针对压电驱动器控制器的特点提出了基本的PI D视觉伺服控制规律实现方法,并进行了点到点运动和圆轨迹跟踪实验．实验结果表明,视 觉伺服控制克服了由于标定以及环境等因素导致的运动模型不准确而引入的误差．     

Nonlinear trilateral teleoperation stability analysis subjected to time-varying delays

A trilateral teleoperation system facilitates the collaboration of two users to share control of a single robot in a remote environment. While various applications of shared-control trilateral haptic teleoperation systems have recently emerged, they have mostly been studied in the context of single-DOF, LTI robotic systems. On the other hand, robotic manipulators with multiple degrees of freedom (DOF) and therefore nonlinear dynamics have recently found many applications such as in robotic-assisted surgery and therapy, space exploration and navigation systems. In this paper, considering the full nonlinear dynamical models of multi-DOF robots, stability analysis of a dual-user haptic teleoperation system is considered over a communication network subjected to asymmetrical time varying delays and through a dominance factor suitable for trainer–trainee applications. Stability in free motion and contact motion and asymptotic position tracking of the trilateral haptic teleoperation system in free motion are proven via Lyapunov stability analysis and Barbalat's lemma where operators and the environment are assumed to be passive. Simulation and experimental results concerning robot position tracking and user-perceived forces for three 2-DOF robots and experimental analysis of user-perceived stiffnesses for three 3-DOF robots validate the theoretical findings pertaining to the system stability and demonstrate the efficiency of the proposed controller.     

Design and Implementation of a Low Cost Multi-Fingered Robotic Hand Using a Method of Blocks

The control of a mechanical robotic hand is plagued by an inability to derive accurate dynamic models of such a mechanism. The aspects of static and kinetic friction are major obstacles in the control of a mechanical hand. This paper presents a fuzzy-like based controller and its implementation for a low cost robotic hand. The controller has the ability to automatically regenerate the member set during the translation of any arbitrary joint in a robotic hand. A series of simulations has been conducted that illustrate the effectiveness of this controller for providing smooth translation independent of frictional forces.The implementation of the controller used here is based on an IBM compatible computer using a custom designed acquisition/conversion interface and a mechanical hand assembly. A hand with a progressively linked finger structure has been used for simplicity. The acquisition system used here allows bidirectional communication with the sensors and actuators of the hand.A series of experiments have been conducted which verify that the method of blocks was successful for controlling joint position. The simulation results include both fine movements, needed for dexterity, and gross movements that can be used for grasping. This robotic hand produces good results in a low cost implementation.     

Task‐driven latent active correction for physics‐inspired input method in near‐field mixed reality applications

Calibration accuracy is one of the most important factors to affect the user experience in mixed reality applications. For a typical mixed reality system built with the optical see‐through head‐mounted display, a key problem is how to guarantee the accuracy of hand–eye coordination by decreasing the instability of the eye and the head‐mounted display in long‐term use. In this paper, we propose a real‐time latent active correction algorithm to decrease hand–eye calibration errors accumulated over time. Experimental results show that we can guarantee an effective calibration result and improve the user experience with the proposed latent active correction algorithm. Based on the proposed system, experiments about virtual buttons are also designed, and the interactive performance regarding different scales of virtual buttons is presented. Finally, a direct physics‐inspired input method is constructed, which shares a similar performance with the gesture‐based input method but provides a lower learning cost due to its naturalness.     

A note on using only position equations for robotic hand/eyecalibration

In two previous papers, we proposed an iterative algorithm for robotic hand/eye calibration. We stated that the iterative algorithm has two distinct advantages over traditional linear approaches: it is less sensitive to noise and it can calibrate the hand/eye matrix by using only relative sensor position measurements. In this correspondence, we point out that although the iterative algorithm does not require direct measurement of the sensor relative rotation, it still needs the user to provide the same amount of sensor orientation information. We also explain why the accuracy performance of the iterative algorithm was not improved by the inclusion of rotation equations.     

空间机器人控制系统硬件仿真平台的研究

建立了空间机器人控制系统的硬件仿真平台。研究了空间机器人基于手眼视觉的控制问题,建立了系统关键部件的模拟设备。仿真平台由中央控制器、关节模拟器、手眼模拟器、动力学/运动学仿真计算机和三维动画显示计算机组成。基于该平台,对空间机器人控制特性和仿真过程中的延时环节进行了研究。系统自主捕获仿真试验结果表明,所采用的运动控制算法能够稳定收敛于目标,仿真平台能够较好地完成对实际机器人系统控制过程的模拟测试及系统控制算法的验证。