机器人视觉伺服研究综述

首先对于3种机器人视觉伺服策略,即基于位置的视觉伺服、基于图像的视觉伺服以及2.5维视觉伺服进行了讨论.然后,对于视觉伺服的研究方向和面临的主要问题,如机器人位姿提取、视觉伺服系统的不确定性研究、图像空间的路径规划、智能视觉伺服等进行了分析和讨论.在此基础上,对于机器人视觉伺服领域的未来研究重点,包括如何使参考点位于视场之内,高速伺服策略以及鲁棒视觉伺服技术进行了分析和展望.     

基于模糊PID的机器人视觉伺服控制

本文将模糊PID控制应用到机器人视觉伺服控制系统中,用以克服机器人视觉伺服系统的强耦合何非线性因素得影响。以二自由度机器人视觉伺服系统为例,仿真实现了其对直线运动和圆周运动轨迹跟踪,结果验证了控制器的效果。     

机器人视觉伺服综述

系统论述了机器人视觉伺服发展的历史和现状。从不同角度对机器人视觉控制系统进行分类,重点介绍了基位置的视觉伺服系统和基于图像的视觉伺服系统。对人工神经网络在机器人视觉伺服方面的应用情况作了介绍。讨论了视觉伺服中图像特征的选择问题。对机器人视觉所涉及的前沿问题进行阐述,并指出了目前研究中所存在的问题及今后发展方向。     

多目视觉伺服控制棒材分离系统研究

大型工业设备的视觉伺服控制系统需要采用多目视觉监测较大的工作场景,即对多个执行机构进行视觉伺服控制。系统要求价格低廉、适应性和实时性好、维护简单等是工业视觉伺服系统面临的挑战。针对钢铁企业的棒材生产线的多目视觉伺服控制系统的总体设计、视觉检测方式、图像特征提取、控制策略等方面进行研究。该多目视觉伺服控制的大型棒材分离系统已投入实际应用。     

基于无模型自适应控制的视觉伺服

传统的机器人视觉伺服控制技术需要已知机器人精确的动力学和运动学模型以及机器人的手-眼参数。然而,由于机器人建模、手-眼标定等过程存在一定误差,因此很难精确获得视觉伺服控制模型,从而影响机器人视觉伺服系统的精度和收敛速度。针对这一难题,本文提出一种基于无模型自适应控制方法（MFAC）的机器人视觉伺服技术。利用视觉伺服系统的输入与输出数据,实现自适应视觉伺服控制,即通过MFAC在线估计机器人伺服控制器中的雅各比矩阵,并结合滑模控制器,实现机器人对目标的快速精确跟踪。实验结果表明,本文提出的方法在系统参数变化引起的未知扰动情况下仍能保证伺服控制器平稳收敛,并且能够减小视觉跟踪误差。     

机器人视觉伺服研究进展

介绍了机器人视觉伺服系统的结构和主要研究内容,比较了当前几种主要的视觉伺服方法,针对当前 机器人视觉伺服所面临的主要问题,详细阐述了近期提出的一些解决方法.     

多气囊柔性试衣机器人的视觉伺服控制仿真

研究多气囊柔性试衣机器人问题,提出了一种视觉伺服控制方案.上述视觉伺服控制方法通过直接控制目标外形的变化,相对于传统的以囊内气压作为反馈的控制方案,能够提供更高的控制精度,但其难点在于如何建立检测精度高、实时性能良好的视觉检测系统.通过基于无模型自适应控制的控制算法进行视觉伺服控制仿真,结果验证了系统的可行性,表明提出的视觉伺服系统方案,在多气囊柔性试衣机器人的控制中能够得到良好的控制效果.     

基于DSP的机器人视觉伺服系统研究

机器人视觉伺服系统的研究是机器人领域中的重要内容之一,其研究成果可以直接用于机器人自动避障、轨迹线跟踪和运动目标跟踪等问题中。本文针对机器人视觉伺服系统要求快速准确的特点,设计了基于TMS320C6201的机器人视觉图像处理系统,并分析了基于图像雅可比矩阵的机器人视觉伺服方法的基本原理。     

移动机器人视觉伺服镇定quasi-min-max预测控制

针对受限移动机器人视觉伺服系统,提出一种移动机器人视觉伺服镇定准最小最大模型预测控制策略. 基于移动机器人视觉伺服镇定误差模型,建立移动机器人视觉伺服线性参数时变预测模型,进而引入准最小最大策略,设计移动机器人视觉伺服镇定模型预测控制器.与传统视觉伺服预测控制器相比,所提控制器只需求解线性矩阵不等式表示的凸优化问题,降低了视觉伺服预测控制器的计算耗时,同时保证了闭环视觉伺服系统的渐近稳定性.仿真结果验证了所提出策略的有效性和在计算效率上的优越性.     

视觉伺服机器人对运动目标操作的研究

机器人视觉伺服系统是机器人领域一重要的研究方向，它的研究对于开发手眼协调的机器人在工业生产、航空航天等方面的应用有着极其重要的意义．本文着眼于视觉伺服机器人操作运动目标这一问题，分析了建立此类系统的控制结构并指明其特点；同时，详细地阐述了三个组成环节：视觉图像处理、预测及滤波、视觉控制器的研究方法和现状．最后，分析了今后的研究趋势．     

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．     

Vision-Based Robotic Motion Control for Non-autonomous Environment

A visual servo control system with SOPC structure is implemented on a retrofitted Mitsubishi Movemaster RV-M2 robotic system. The hardware circuit has the functions of quadrature encoder decoding, limit switch detecting, pulse width modulation (PWM) generating and CMOS image signal capturing. The software embedded in Nios II micro processor has the functions of using UART to communicate with PC, robotic inverse kinematics calculation, robotic motion control schemes, digital image processing and gobang game AI algorithms. The digital hardware circuits are designed by using Verilog language, and programs in Nios II micro processor are coded with C language. An Altera Statrix II EP2S60F672C5Es FPGA chip is adopted as the main CPU of the development board. A CMOS color image sensor with 356 ×292 pixels resolution is selected to catch the environment time-varying change for robotic vision-based servo control. The system performance is evaluated by experimental tests. A gobang game is planned to reveal the visual servo robotic motion control objective in non-autonomous environment. Here, a model-free intelligent self-organizing fuzzy control strategy is employed to design the robotic joint controller. A vision based trajectory planning algorithm is designed to calculate the desired angular positions or trajectory on-line of each robotic joint. The experimental results show that this visual servo control robot has reliable control actions.     

Incremental visual servo control of robotic manipulator for autonomous capture of non-cooperative target

This paper develops a new autonomous incremental visual servo control law for the robotic manipulator to capture a non-cooperative target, where the control input is the incremental joint angle to avoid the multiple solutions in the existing inverse kinematics. The position and motion of the non-cooperative target are estimated by an eye-to-hand vision system in real time by integrated photogrammetry and extended Kalman filter. The estimated position and motion of the target are fed into the newly developed position-based visual servo control law to drive the manipulator incrementally towards the dynamically predicted interception point between trajectories of the end effector and the target. To validate the proposed approach, a hardware-in-the-loop simulation has been conducted where the position and motion of the target is estimated by a real eye-to-hand camera and fed into the simulation of the robotic manipulator. The simulation results show the proposed incremental visual servo control law is stable and able to avoid the multiple solutions in the total inverse kinematics.     

Constrained visual servoing under uncertain dynamics

In visual servoing, limitations in the field of view of the vision sensors are either ignored or treated at the kinematic level. The former can easily jeopardise task success, while the latter reduces the maximum achievable robotic motion speeds. In this work, the aforementioned literature gap is filled by designing and rigorously analysing a torque controller that guarantees prescribed transient and steady-state performance attributes on the image feature coordinate errors, while respecting the field-of-view constraints. No path planning and no information regarding the actual system dynamics are required. In addition, no approximation structures (i.e. neural networks, fuzzy systems, etc.) are utilised to acquire such knowledge. The proposed visual servo controller is static, involving very few and simple calculations to produce the control signal, making its implementation on embedded control platforms straightforward. Simulation studies are utilised to illustrate the motivation and to clarify–verify the theoretical findings.     

基于双目视觉的伺服控制半物理仿真系统设计

在不具备真实目标条件下,为了验证捕获系统捕获目标卫星过程中基于双目视觉的伺服控制技术,采用三维图形库OpenGL开发了目标模拟器,研究了针对三角形帆板支架的视觉测量技术,规划了捕获系统的运动轨迹,直观演示了视觉伺服控制过程,设计了一套视觉伺服控制半物理仿真系统;仿真结果表明,目标模拟器能够生成仿真所需要的投影目标,双目视觉系统能够对投影目标进行精确的位姿测量,视景演示系统能够对视觉伺服的结果进行直观显示,仿真平台能够验证双目视觉伺服控制技术。     

机器人实时视觉伺服系统控制方案的研究

本文针对机器人实时视觉伺服系统,考虑了机器人关节伺服反馈与视觉伺服反馈之间的相互联系,提出了实时控制方案,设计了合理的关节饲服控制器与视觉伺服控制器,以达到改善系统性能的目的。试验结果表明,当采用上述两个控制器时,系统的动静态性能得到了明显的改善。     

旋翼飞行机械臂系统的混合视觉伺服控制

旋翼飞行机械臂是一种具有强耦合特性的机器人系统,借助视觉进行自主作业还存在诸多问题,如实时深度估计、目标极易丢失以及目标笛卡尔空间模型重建等.本文针对传统的基于图像与基于位置的视觉伺服的缺陷以及系统自身欠驱动等问题,建立了运动学模型和提出了基于力平衡原理的动力学联合建模,并通过欧几里得单应性矩阵分解设计出旋翼飞行机械臂系统的混合视觉伺服控制方法,在图像空间控制平移、笛卡尔空间控制旋转,减弱了平移与旋转之间的相互影响实现解耦效果,改善了系统对非结构因素的抗扰性能和全局稳定性.通过仿真和实验检验了系统鲁棒性和算法优越性.     

<Emphasis Type="Italic">HumanPT</Emphasis>: An Open-source,HumanPT Architecture-based,Robotic Application for Low Cost Robotic Tasks

In this paper, first HumanPT architecture for low cost robotic applications is presented. HumanPT architecture differs than other architectures because it is implemented on existing robotic systems (robot  robotic controller) and exploits the minimum communication facilities for real-time control that these systems provide. It is based on well-known communication methods like serial communication (USB, RS232, IEEE-1394) and windows sockets (server–client model) and permits an important number of different type of components like actuators, sensors and particularly vision systems to be connected in a robotic system. The operating system (OS) used is Microsoft Windows, the most widely spread OS. The proposed architecture exploits features of this OS that is not a real-time one, to ensure – in case that the robotic system provide such a facility – control and real time communication with the robotic system controller and to integrate by means of sensors and actuators an important number of robotic tasks and procedures. As implementation of this architecture, HumanPT robotic application and experimental results concerning its performance and its implementation in real tasks are provided. HumanPT robotic application, developed in Visual C++, is an integrated, but simultaneously an open-source software that can be adapted in different types of robotic systems. An important number of robotic tasks or procedures including sensors and particularly vision systems can be generated and executed. Small enterprises by means of the proposed architecture and the open source software can be automated at low cost enhancing in this way their production.     

A Neural Net Predictive Control for Telerobots with Time Delay

This paper extends the Smith Predictor feedback control structure to unknown robotic systems in a rigorous fashion. A new recurrent neural net predictive control (RNNPC) strategy is proposed to deal with input and feedback time delays in telerobotic systems. The proposed control structure consists of a local linearized subsystem and a remote predictive controller. In the local linearized subsystem, a recurrent neural network (RNN) with on-line weight tuning algorithm is employed to approximate the dynamics of the time-delay-free nonlinear plant. The remote controller is a modified Smith predictor for the local linearized subsystem which provides prediction and maintains the desirable tracking performance. Stability analysis is given in the sense of Lyapunov. The result is an adaptive compensation scheme for unknown telerobotic systems with time delays, uncertainties, and external disturbances. A simulation of a two-link robotic manipulator is provided to illustrate the effectiveness of the proposed control strategy.