6－6型Stewart机器人的可操作性分析及其定义

本文根据并联机器人的特点，运用可操作度的概念，进一步提出了位置可操作度和姿态可操作度的定义。通过对位置反解直接求导，建立了６－６型ｓｔｅｗａｒｔ机器人的位置、姿态和综合可操作度的公式，为并联机器人的运动学分析提供了依据。     

6—6型Stewart机器人的可操作性分析及其定义

本文根据并联机器人的特点，运用可操作度的概念，进一步提出了位置可操作度和姿态可操作度的定义。通过对位置反解直接求导，建立了６－６型ｓｔｅｗａｒｔ机器人的位置，恣态和综合可操作度的公式，为并联机器人的运动学分析提供了依据。     

空间机器人抓捕目标后基于任务相容性的消旋策略

针对双臂空间机器人抓捕自旋目标后的镇定操作,在考虑机器人系统输入约束的条件下,提出了一种基于任务相容性的消旋规划与控制方法。首先,给出空间机器人抓捕目标后的组合系统的动力学模型,作为规划与控制的基础。然后,根据动力学可操作度和任务相容性设计了目标的快速消旋策略,其期望加速度的方向和大小分别取作速度的反方向和机器人系统输入约束允许的最大值。最后,基于所推导的运动学和动力学模型,通过对目标和机械臂末端分别建立柔顺度等式,提出了一种跟踪期望运动轨迹同时对末端接触力进行调节的柔顺控制方法。通过双臂7自由度空间机器人消除目标自旋运动的仿真结果,验证了所提方法的有效性。     

基于运动性能分析的双臂冗余度机器人协调运动研究

为了提高双臂冗余度机器人在其交互工作空间中的协调运动能力,以ABB YuMi为例,提出了一种计算简便并且能够有效反映双臂协调运动灵活性的性能指标。利用D-H法建立了YuMi机器人的运动学模型,分析了双臂可操作度的分布情况,分别研究了两种协调运动方式的运动学约束关系以及相应的运动控制规律,基于灵活性分析构建了双臂协调装配电机转子与轴承以及字母绘制的任务,通过仿真和实验验证了本文双臂可操作度指标的有效性及协调运动规划方法的正确性。     

机器人多指手灵巧抓持规划

抓持规划是机器人灵巧手要完成预期任务所面临的一个重要问题．本文采用主从操作方式进行灵巧手的指尖抓持规划，由人手决定抓持接触点的位置， 灵巧手通过调整其手掌的位置和姿态保证各手指在人手指定的位置上抓持物体．根据灵巧手的操作特点，提出以关节灵活度来描述关节运动各向同性的能力，并据此定义灵巧手操作灵活度，作为灵巧手抓持位形性能的评价指标．以最大操作灵活度作为优化目标函数，寻求最优的抓持性能．同时，借鉴人手的抓持经验，通过主从操作方式，建立从人手到灵巧手的运动映射关系，从而为手掌位置优化问题提供合理的初值．仿真实验结果说明了文中方法的有效性．     

基于地形预测与修正的搜救机器人可通过度

针对搜救机器人的自主导航问题,提出了一种新的可通过度计算算法．文中定义的可通过度包含预测 可通过度和实时可通过度两个部分．通过图像处理的方法计算前方地面的粗糙度和起伏度从而得到预测可通过度, 机器人向可通过度最大的区域运动,在运动过程中通过测量车体的姿态变化率和履带与地面的打滑度来修正预测可 通过度对机器人的导引带来的偏差,并通过旋转式超声测距数据获取距离信息,去除障碍物对纹理信息的干扰．野 外条件下的实际运行实验证明了该导航算法的有效性．     

冗余度机器人的可操作度和有限制条件下的最优轨迹规划

本文以冗余度机器人的逆运动学为基础，引入了扩展雅可比矩阵的概念；给出了便于讨论可操作度的几个重要定理；推导出了一般了发制条件下的癃 运动学最优解与最小范数解的关系。     

基于共享度的FPGA可重构资源分配算法研究

针对FPGA可重构设计中高效率的资源分配面临的困难,提出基于共享度的FPGA可重构设计算法。描述基于共享度对FPGA资源分配策略的实施过程,并给出基于共享度的资源分配最优策略及证明过程。经过模拟测试表明,所设计的FPGA资源分配算法在资源利用率和任务平均等待延时方面均优于传统的FF算法,其平均任务等待延时比传统的FF算法缩短了8%。     

腹腔镜机器人控制系统的设计及实现

根据机器人辅助微创手术任务的特点设计了腹腔镜机器人控制系统．研究了基于运动控制卡的 开放式机器人控制器结构,设计了机器人伺服系统及相应控制器硬件接口,采用面向对象的技术和模块化思 想开发了系统控制软件,应用灵活度和可操作度概念建立了腹腔镜机器人的手术规划和控制平台．通过调试 伺服参数提高了系统控制性能．实验表明,该腹腔镜机器人控制系统具有稳定性、高可靠性和多任务适应性, 满足微创手术需求．     

基于可操作度的虚拟人手部避障运动控制算法

研究复杂作业环境中虚拟人手部避障运动的高精度控制问题,问题的关键是解决虚拟人手的设计.为了灵活操作能在操作的末端临时变换姿态,给控制过程中手臂转动路线,速度,加速度等参数的控制带来较大困难.传统的控制方法通过增加控制自由度来解决这个问题,但是一旦自由度增加,会带来冗余控制影响,弊端较为明显.提出一种采用可操作度矩阵的逆向运动学控制算法,引入可操作度模型进行肢体末端效应器运动路径的生成,与HAL链IK分析求解方法相结合,实现了真实感较强的肢体实时运动控制.通过仿真和动作捕获实验验证了算法的有效性,可应用于人机工程仿真中的避障控制和干涉检查.     

Dynamic Manipulability of Multifingered Grasping

In this paper, we extend the concept of dynamic manipulability to evaluate the dynamic property of multifingered grasping systems consisting of a multifingered hand and a grasped object, and propose a measure of dynamic manipulability of multifingered grasping. Similar to the original dynamic manipulability, the proposed measure evaluates the mapping from a set of realizable joint torques to a set of resultant accelerations of the grasped object, which forms an ellipsoid under a constant internal force constraint. It is clearly shown that the internal forces not only affect the volume of the ellipsoid, but also the amount of offset of the ellipsoid, while the gravity forces simply induce an offset. A new measure, i.e., omnidirectionality, is introduced to add a penalty to the original manipulability measure, which simply evaluates the volume of the ellipsoid, depending on how much the ellipsoid is offset. Numerical examples by using a simple two-fingered robot hand are shown to demonstrate the effectiveness of the proposed measure.      

Manipulability analysis of a parallel machine tool: Application to optimal link length design

In this article, an input–output transmissivity analysis of the Eclipse^TM, which is a parallel machine tool capable of five‐face rapid machining, is investigated. By splitting the weighted Jacobian matrices into two parts, the linear velocity, angular velocity, and force–moment transmissivities are analyzed. A new manipulability measure, which combines the volumes of manipulability ellipsoids and the condition numbers of the splitted Jacobian matrices, is proposed. Two link parameters, the radius of the upper platform and the length of a supporting links, are optimally designed by maximizing the new manipulability measure introduced. Computer simulations are provided. © 2000 John Wiley & Sons, Inc.     

Kinematic optimal design of a new parallel-type rolling mill: paramill

In this paper, a kinematic optimal design of a new parallel-type rolling mill based upon two Stewart platform manipulators is investigated. To provide the end-effector (work roll) with sufficient d.o.f. and to achieve the structural stability of each stand, a parallel manipulator with six legs is considered. The objective of this new parallel-type rolling mill is to pursue an integrated control of the strip thickness, strip shape, pair-crossing angle, uniform wear of the rolls and strip tension. By splitting the weighted Jacobian matrices into two parts, the linear velocity, angular velocity, force and moment transmissibilities are analyzed. A manipulability measure, as the ratio of the manipulability ellipsoid volume and the condition number of a split Jacobian matrix, is defined. The two kinematic parameters, the radius of the base and the angle between two neighboring joints, are optimally designed by maximizing the global force manipulability measure defined in the entire workspace. The maximum exerting force needed in hydraulic actuators is also calculated using the kinematic structure determined and the Plücker coordinates introduced. Simulation results are provided.     

Mobile Arm for Disabled People Assistance Manipulability Measure for Redundancy Solve

The addition of a mobile platform to a 6-DOF arm raises the question of the exploitation of redundancy with respect to needs. The application field concerns assistive robotics for object manipulation tasks. Works deal with the utilisability of a mobile arm, which is a complex system, by a disabled person with reduced motor and perception abilities. In this paper, we present the influence of mobility on manipulability measure. Manipulability is a well-established tool for motion analysis which we use as criterion in control scheme to improve the coordination of two subsystems. We propose a normalized measure to solve problems inherent to the use of different physical units and velocity limits for both components of the system, arm and mobile platform. Simulation results for a 3D positioning task are given to show the effect of nonholonomic constraint on manipulability measure.     

Application of robotic manipulability indices to evaluate thumb performance during smartphone touch operations

This study examined whether manipulability during smartphone thumb-based touch operations could be predicted by the following robotic manipulability indices: the volume and direction of the ‘manipulability ellipsoid’ (MEd), both of which evaluate the influence of kinematics on manipulability. Limits of the thumb's range of motion were considered in the MEd to improve predictability. Thumb postures at 25 key target locations were measured in 16 subjects. Though there was no correlation between subjective evaluation and the volume of the MEd, high correlation was obtained when motion range limits were taken into account. These limits changed the size of the MEd and improved the accuracy of the manipulability evaluation. Movement directions associated with higher performance could also be predicted. In conclusion, robotic manipulability indices with motion range limits were considered to be useful measures for quantitatively evaluating human hand operations.     

Comparative study of performance indices for fundamental robot manipulators

In this paper, conventional global and local indices–structural length index, manipulability measure, condition number and Global Conditioning Index (GCI)–have been examined for the workspace optimization of the sixteen fundamental robot manipulators classified by B. Huang and V. Milenkovic [Kinematics of major robot linkages, Robotics International of SME 2 (1983) 16–31]. To find the optimum link length and volumes of these robot manipulators, two design objectives have been used: maximize the workspace area covered by the robot manipulator and maximize the local indices. As an example, a three-link robot manipulator has been studied based on the above design objectives. Also, optimization results of the sixteen robot manipulators have been compared to each other and summarized in tables.     

A new index of serial-link manipulator performance combining dynamic manipulability and manipulating force ellipsoids

The inertia matching ellipsoid (IME) is proposed as a new index of dynamic performance for serial-link robotic manipulators. The IME integrates the existing dynamic manipulability and manipulating-force ellipsoids to achieve an accurate measure of the dynamic torque-force transmission efficiency between the joint torque and the force applied to a load held by an end-effector. The dynamic manipulability and manipulating-force ellipsoids can both be derived from the IME as limiting forms, with respect to the weight of the load. The effectiveness of the IME is demonstrated numerically through the selection of an optimal leg posture for jumping robots and optimal active stiffness control, and experimentally through application to a pick-up task using a commercial manipulator. The index is also extended theoretically to the case of a manipulator mounted on a free-flying satellite.     

The kinematic analyses of the 3-DOF parallel machine tools

A 3-degree-of-freedom (3-DOF) parallel machine tool based on a tripod mechanism is developed and studied. The kinematics analysis is performed, the workspace is derived, and an analysis on the number of conditions of the Jacobian matrix and manipulability is carried out. A method for error analysis and manipulability is introduced. Hence, the manipulability analysis of the parallel machine tool is accomplished.     

Trajectory optimization for kinematically redundant arms

A review of local optimization methods for resolving joint configurations in underconstrained manipulation tasks is conducted. A new approach is developed for observing joint limits and avoiding obstacles during the trajectory planning. The methodology is used in a four-link arm example to avoid a workspace singularity and is compared with results using the extended Moore-Penrose technique. An alternative measure of arm “manipulability” based directly on the rank of the Jacobian is also introduced.     

3-d.o.f. Wire Driven Planar Haptic Interface

A 4-wire driven 3-d.o.f. planar haptic device, called the Feriba-3, is described. The particular geometric configuration of the end-effector ensures a closed form kinematic pose solution and good manipulability. Moreover, the structural arrangement adopted makes the Feriba-3 a well-performing haptic device, whose major features are low inertia, low friction, and full dexterity in a large workspace. The manipulability analysis has been performed by introducing a complete set of manipulability indices.