运动学补偿的宏2微机器人连续轨迹控制研究

一小机械手附在一大机械手末端构成的系统称为宏－微机器人系统,介绍了宏－微机器人连续轨迹控制的新方法,对宏－微机器人的控制在关节空间进行,通过微机械手的快速运动对宏机械手的轨迹误差在线补偿,宏－微机器人轨迹规划离线进行,通过任务放大的方法分解宏－微机器人运动学冗余,仿真和实验证明了方法的有效性。     

激光作业的宏-微机器人及其控制系统

一小机械手附在一大机械手的末端构成的机器人系统被称为宏-微机器人系统．本文详细介 绍了我们研制的采用激光作业的宏-微机器人本体和控制系统的结构和工作原理,以及在连 续轨迹跟踪和汉字雕刻方面的实验结果．     

宏-微机器人: 概念、动态、控制及几点看法

宏－微机器人即一小机械手附在一大机械手的末端构成的机器人系统，这种机器人有减小末端有效惯量、扩充频带的特性．本文介绍了这种机器人的概念、国外研究动态、控制方法，并对这一机器人的研究提出了我们的几点看法．     

宏-微机器人: 概念、动态、控制及几点看法

宏－微机器人即一小机械手附在一大机械手的末端构成的机器人系统，这种机器人有减小末端有效惯量、扩充频带的特性．本文介绍了这种机器人的概念、国外研究动态、控制方法，并对这一机器人的研究提出了我们的几点看法．     

加速度约束条件下的非完整移动机器人运动控制

将移动机器人的运动规划与跟踪控制问题合并在一起，对加速度约束条件下的非完整移动机器人运动控制问题进行研究，提出基于贝塞尔曲线的路径规划方法，以满足机器人的非完整约束．在考虑所受加速度约束的条件下，通过规划机器人状态时问轨线的方法实现了时间最优的轨迹规划．基于控制李亚普诺夫函数推导出了轨迹跟踪的控制律．仿真实验结果表明所提出的算法是有效的．     

基于动态Snake模型的机械手运动轨迹视觉跟踪

针对机械手运动在图像序列空间的轨迹分布，提出一种基于时空轨迹线的动态Snake跟踪模型.定义相应的能量函数，可使其在机械手轨迹分布上取得极小，通过Snake能量的轨迹收敛实现对机械手运动点的跟踪定位.利用轨迹能量系数的动态调节，可避免Snake搜索过程陷入局部极小．使用平方轨迹最小二乘预测器对轨迹点位置进行预测，可提高Snake搜索的实时性和准确性．微装配机械手运动实验证明了该模型及跟踪算法的有效性.     

双足机器人的鲁棒控制

利用拉格朗日法建立了双足机器人的动力学模型．在双脚支撑地时，运动学方程的约束造成双足机器人自由度的冗余，本文引入拉格朗日因子消除了双足机器人的冗余自由度．采用鲁棒控制法对双足机器人的轨迹跟踪进行控制，仿真实验结果证明, 鲁棒控制法对模型不精确或外部干扰对双足机器人产生的影响有很好的抑制作用，对双足机器人轨迹跟踪控制是有效的．     

基于解耦控制的非完整移动机器人实时轨迹跟踪

本文研究了非完整两轮移动机器人的实时轨迹跟踪问题．首先,在介绍了一般的非线 性系统的输入 输出线性化方法的基础上,并研究了在两轮驱动移动机器人轨迹跟踪中的应 用;然后在研制的非完整两轮驱动移动机器人的实验平台上对该算法进行了实时轨迹跟踪实 验,结果表明了该非线性跟踪控制算法的有效性．     

基于宏微机器人的焊缝跟踪研究

提出了一种基于宏微运动机器人的焊缝跟踪方法．首先,通过若干点的简单示教获得焊缝位置信息,并通过拟合建立焊缝模型．在该模型的基础上,对机器人的宏动进行运动规划．采用激光结构光视觉测量焊缝坐标,并根据焊缝图像偏差控制机器人的微动．结合机器人的宏动规划运动和微动自动调整,实现大范围、高精度的焊缝跟踪．利用宏微运动平台进行了焊缝跟踪实验,实验结果验证了所提出方法的有效性．     

基于视觉的移动机器人地面轨线跟踪导航研究

地面轨线跟踪是机器人视觉导航控制基本技术之一．文中针对曲率变化较大的地面轨线跟踪提出了一种新的状态控制方法．该方法从图像中提取参考轨线的方向和幅度参数作为状态控制的输入，调整速度和转速实现跟踪控制．为改善控制性能，当由于摄像机倾角较大而引起的图像畸变较大时，利用射影变换把参考轨线参数从图像坐标系映射到机器人坐标系，而无须提供位置、曲率等参数．实验表明该方法控制效果良好．     

Dynamic Analysis of a Macro–Micro Redundantly Actuated Parallel Manipulator

In this paper the dynamic analysis of a macro–micro parallel manipulator is studied in detail. The manipulator architecture is a simplified planar version adopted from the structure of the Large Adaptive Reflector (LAR), the Canadian design of next-generation giant radio telescopes. In this structure it is proposed to use two parallel redundant manipulators at the macro and micro level, both actuated by cables. In this paper, the governing dynamic equation of motion of such a structure is derived using the Newton–Euler formulation. Next, the dynamic equations of the system are used in the open-loop inverse dynamics simulations, as well as closed-loop forward dynamics simulations. In the open-loop dynamic simulations it is observed that the inertial forces of the limbs contribute only 10% of the dynamic forces required to generate a typical trajectory and, moreover, the total dynamic forces contribute only 10% of the experimentally measured disturbance forces. Furthermore, in the closed-loop simulations using decentralized PD controllers at the macro and micro levels, it is shown that the macro–micro structure results in a 10 times more accurate positioning than that in the first stage of the macro–micro structure. This convincing result promotes the use of the macro–micro structure for LAR application.     

Kinematic Analysis of a Macro–Micro Redundantly Actuated Parallel Manipulator

In this paper the kinematic and Jacobian analysis of a macro–micro parallel manipulator is studied in detail. The manipulator architecture is a simplified planar version adopted from the structure of the Large Adaptive Reflector (LAR), the Canadian design of the next generation of giant radio telescopes. This structure is composed of two parallel and redundantly actuated manipulators at the macro and micro level, which both are cable-driven. Inverse and forward kinematic analysis of this structure is presented in this paper. Furthermore, the Jacobian matrices of the manipulator at the macro and micro level are derived, and a thorough singularity and sensitivity analysis of the system is presented. The kinematic and Jacobian analysis of the macro–micro structure is extremely important to optimally design the geometry and characteristics of the LAR structure. The optimal location of the base and moving platform attachment points in both macro and micro manipulators, singularity avoidance of the system in nominal and extreme maneuvers, and geometries that result in high dexterity measures in the design are among the few characteristics that can be further investigated from the results reported in this paper. Furthermore, the availability of the extra degrees of freedom in a macro–micro structure can result in higher dexterity provided that this redundancy is properly utilized. In this paper, this redundancy is used to generate an optimal trajectory for the macro–micro manipulator, in which the Jacobian matrices derived in this analysis are used in a quadratic programming approach to minimize performance indices like minimal micro manipulator motion or singularity avoidance criterion.     

基于多传感器信息的冗余度机器人运动规划与控制

提出了一种基于多传感器信息的冗余度机器人规划与控制的模型,利用不同传感器本身的特性，分阶段地对多传感器的信息进行融合，减少规划时间, 并在冗余度机器人的运动过程中，不断地提高位姿检测的精度．将远距离的宏观规划和近距离的微调结合起来，增加了抓持的可靠性．利用移动冗余度操作臂系统结构的几何特点进行了运动学分析、避奇异的方法研究及仿真对比分析．应用所提出的研究方法获得了较好的实验效果．     

Parallel and distributed trajectory generation of redundantmanipulators through cooperation and competition among subsystems

Autonomous distributed control (ADC) is one of the most attractive approaches for more versatile and autonomous robot systems. The paper proposes a parallel and distributed trajectory generation method for redundant manipulators through cooperative and competitive interactions among subsystems composing the ADC that is based on a concept of virtual arms. The virtual arm has the same kinematic structure as the manipulator except that its end point is located on a joint or link of the manipulator. Then the redundant manipulator can be represented by a set of the virtual arms. Trajectory generation and point to point control of the redundant manipulator are discussed, and it is shown that the kinematic redundancy of the manipulator can be utilized positively in the generated trajectories by using the virtual arms.     

Fuzzy redundancy resolution and motion coordination for underwater vehicle-manipulator systems

The problem of redundancy resolution and motion coordination between the vehicle and the manipulator in underwater vehicle-manipulator systems (UVMSs) is addressed in this paper. UVMSs usually possess more degrees of freedom than those required to perform end-effector tasks; therefore, they are redundant systems and kinematic control techniques can be applied aimed at achieving additional control objectives besides tracking of the end-effector trajectory. In this paper, a task-priority inverse kinematics approach to redundancy resolution is merged with a fuzzy technique to manage the vehicle-arm coordination. The fuzzy technique is used both to distribute the motion between vehicle and manipulator and to handle multiple secondary tasks. Numerical case studies are developed to demonstrate effectiveness of the proposed technique.     

Robust nonlinear control of a planar 2-DOF parallel manipulator with redundant actuation

A new robust nonlinear controller is presented and applied to a planar 2-DOF parallel manipulator with redundant actuation. The robust nonlinear controller is designed by combining the nonlinear PD (NPD) control with the robust dynamics compensation. The NPD control is used to eliminate the trajectory disturbances, unmodeled dynamics and nonlinear friction, and the robust control is used to restrain the model uncertainties of the parallel manipulator. The proposed controller is proven to guarantee the uniform ultimate boundedness of the closed-loop system by the Lyapunov theory. The trajectory tracking experiment with the robust nonlinear controller is implemented on an actual planar 2-DOF parallel manipulator with redundant actuation. The experimental results are compared with the augmented PD (APD) controller, and the proposed controller shows much better trajectory tracking accuracy.     

Evaluation of head-collision safety of a 7-DOF manipulator according to posture variation

As the need for the improvement of the productivity in the manufacturing process grows, industrial robots are brought out of the safety fences and used in the direct collaborative operation with human workers. Consequently, the intended and/or unintended contact between the human and the robot in the collaborative operation is no longer an extraordinary event and is a mundane possibility. The level of the risk of the collision depends on various quantities associated with the collision, for example, inertia, velocity, stiffness, and so on. MSI (manipulator safety index) which is based on HIC (head injury criteria) conventionally used in the automotive industry is one of the practically available measures to estimate the risk of the collision between the human and the manipulator. In this paper MSI is applied to evaluate the collision safety of a 7-DOF articulated human-arm-like manipulator. The risk of the collision could be reduced by choosing different postures without deviating from the given end-effector trajectory using the redundant degree of freedom in the 7-DOF manipulator. The paper shows how the redundant degree of the freedom is utilized to design safer trajectories and/or safer manipulator configurations among many available. A parametric analysis and simulation results for a given trajectory illustrate the usefulness of the concept of the trajectory design for alleviating the risk of the manipulator operation in the human–robot coexisting workspace.     

Collision-Free Trajectory Planning for Two Cooperative Redundant Manipulators Using the Minimum-Time Criterion

An approach is proposed to generate collision-free, near time-optimal trajectories for two cooperative redundant manipulators between two sets of end-points. The time-optimal trajectory of one manipulator is found first. Then by considering this manipulator as a moving obstacle, the collision-free trajectory for the other manipulator is found. After obtaining the trajectories of both manipulators, an iterative approach is proposed to scale the time profile of the trajectories to minimize the traveling time. A simulation example is included to illustrate the validity of the proposed approach.