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1.
针对7自由度冗余机器人实时运动控制,对机器人逆运动学提出了一种新的求解方法.采用位姿分解方式,使7自由度冗余机器人逆运动学简化为4自由度位置逆运动学求解.在梯度投影法得到位置优化解的基础上,利用机器人封闭解公式求得一组优化解.通过对7自由度机器人仿真分析,表明了该方法的有效性.  相似文献   

2.
约束条件下的巡线机器人逆运动学求解   总被引:6,自引:0,他引:6  
高压输电线路巡检机器人是一种多关节悬挂运动机构,要实现其运动控制就需要根据机器人的本身机构特点和悬挂系统的运动约束条件进行运动学分析.本文利用微分扭转法对巡线机器人的正向运动学进行了求解,并通过对机器人悬挂系统的力学分析,得到了机器人运动学的约束条件,并在这种约束条件下,采用了一种可用来进行实时控制的迭代循环坐标下降(CCD)算法,来进行机器人的逆运动学求解.这种迭代算法对于有运动约束系统的逆运动学求解具有较强的适用性,而且它具有较好的收敛性和有效性,适合于在线计算,便于巡线机器人的实时运动控制.  相似文献   

3.
6R机器人实时逆运动学算法研究   总被引:4,自引:0,他引:4  
提出一套解决各类6R机器人逆运动学问题的实时算法. 一般算法通过矢量计算和16阶矩阵分解得到一般6R机器人的最多16组逆运动学解. 封闭解法直接提取运动学等式求出关节变量的解析解. 组合算法将封闭解法或一般算法的结果作为初始值, 采用牛顿-拉夫森方法迭代出逆运动学精确解, 适用于所有接近满足封闭解条件或一般算法条件的6R机器人. 求解实验结果表明, 整套算法最大算法时间约为2.03 ms, 为任意几何结构的6R机器人应用于强实时系统提供了逆运动学解决方案.  相似文献   

4.

针对-自由度冗余机器人实时运动控制,对机器人逆运动学提出了一种新的求解方法.采用位姿分解方式,使-自由度冗余机器人逆运动学简化为,自由度位置逆运动学求解.在梯度投影法得到位置优化解的基础上,利用机器人封闭解公式求得一组优化解.通过对-自由度机器人仿真分析,表明了该方法的有效性.

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5.
针对一类冗余自由度超声检测机器人的传统逆运动学求解算法耗时长且准确度低的问题,提出了一种基于集合划分和解析解法相结合的逆运动学求解算法。首先采用De-navit-Hartenberg方法建立检测机器人的运动学方程;其次,利用解析解法求出机器人逆解的解析表达式,并提出三种自由度分配方案;最后,选择合适的自由度分配方案,据此对超声波探头位姿集合作划分,结合逆解解析式求出运动学逆解。实际应用中,借助十一轴超声波检测机器人,利用该算法对具有复杂外形的飞机螺旋桨叶片进行检测。结果表明,与传统的纯数值解法相比,该算法能够快速得到精确的运动学逆解。  相似文献   

6.
为解决一般6自由度旋转关节机器人逆运动学问题,提出了一种用牛顿一拉夫逊迭代法逐次逼近目标位姿的逆解算法.根据正运动学方程建立雅克比矩阵,采用基于豪斯霍尔德的SVD分解求其伪逆来避免雅克比矩阵的奇异性问题,通过建立迭代规则并逐次迭代找到最优的逆运动学单解,实际应用时无需再建立多解取优策略.本算法具有较好的局部快速收敛性,能够达到较好的精度和速度,并在基于ARM9的嵌人式系统上实现了此算法.相应的测试表明:算法实时性能够满足系统要求,可应用于机器人实时控制系统.  相似文献   

7.
以机器人运动学方程为基础,基于变换矩阵中旋转子矩阵正交的特性,提出一种6R机器人运动学逆解算法.通过矢量运算,得到含有4个未知变量的4个常系数非线性方程,辅以其它方程,最终得到8组封闭解.通过对钱江一号焊接机器人的实例求解,验证了该算法解决逆解问题仅需0.087 ms,比传统的反变换法具有更优的实时性能;平面工况的运动仿真验证了该算法的有效性.该算法可应用于6R机器人的强实时在线控制系统.  相似文献   

8.
《机器人》2016,(6)
针对冗余机器人逆运动学插值优化算法运算量大、实时性差的缺点,提出一种基于流形的多目标优化算法.将冗余机器人逆运动学解空间看作一个光滑流形,对位置工作空间流形和姿态工作空间流形分别进行降维分析,然后结合提出的优化目标函数得到冗余机器人相应的优化逆解.在冗余机器人多目标优化中各个优化性能指标很可能是相互对立矛盾的,这就需要根据优先权的高低进行加权设置,以达到冗余机器人解空间的整体优化,得到的优化逆解往往不是单个的解,而是一个优化的解流形.最后利用飞机S形进气道进行逆运动学仿真验证了所用方法的合理性.  相似文献   

9.
针对一般机器人逆运动学求解过程中存在的求解速度慢、精度低的问题,将多种群遗传算法(multiple population genetic algorithm,MPGA)引入径向基函数神经网络(radial basis functions neural network,RBFNN),提出一种适用于一般机器人的高精度MPGA-RBFNN算法。该算法采用3层结构的RBFNN进行一般机器人逆运动学求解,结合一般机器人的正运动学模型,采用MPGA优化RBFNN的网络结构和连接权值的方法,同时应用混合编码和演化的方式,实现了从机器人工作空间位姿到关节角度的非线性映射,从而避免了复杂的公式推导并提高了求解速度。采用6R一般机器人作为实验平台进行实验,实验结果表明:MPGA-RBFNN算法不仅提高了一般机器人在逆运动学中的求解速度,而且MPGA-RBFNN算法的训练成功率和逆解的计算准确率也得到了提高。  相似文献   

10.
针对冗余液压驱动四足机器人运动学逆解问题,提出一种基于扩展雅可比矩阵的冗余液压驱动四足机器人运动控制方法.该方法既能解决冗余自由度带来的逆解多解问题,还能使机器人足端入地角度满足摩擦锥要求避免足端滑动.首先,规划机器人足端轨迹得到机器人足端速度,在分析机器人足端入地角度对机器人运动性能影响的基础上,结合机器人腿部结构几何关系,建立扩展雅可比矩阵,确立机器人关节角度速度和足端速度的映射关系,即得到机器人关节角度的解.然后,在对角步态下,通过仿真对传统的梯度投影法和提出的扩展雅可比矩阵法进行对比,理论分析及仿真表明传统的梯度投影法存在误差累积,且在实时性上不如扩展雅可比矩阵法.最后,实验验证了基于扩展雅可比矩阵逆运动学分析方法的可行性和有效性.  相似文献   

11.
This paper proposes a heuristic algorithm for near-optimal handling of the redundancy in robot mechanisms, applied to a 3D scanning platform consisting of a 6-DOF articulated robot arm which moves a laser sensor around a workpiece placed on a rotary table. The proposed method handles both static constraints, like avoiding joint limits, kinematic singularities or collisions, modelled using a configuration map viewed as a grayscale image, and dynamic constraints like velocity and acceleration. The algorithm is compared with Dijkstra algorithm, which gives the optimal solution, but is very slow, and with two other heuristics which are very fast, but give suboptimal solutions.  相似文献   

12.
《Advanced Robotics》2013,27(4):431-440
In solving inverse kinematics problems, traditional methods such as RMRC (resolved motion rate control) and the IKM (inverse kinematic method) are mostly complicated and time-consuming. Using a neural network, however, a practical algorithm for obtaining accurate joint angles in a much shorter time is possible. The neural network approach assumes a transfer function between inputs and outputs and trains the network to satisfy the representative input-output pairs in the least squares sense. First, a test of the appropriateness of the neural network method is performed for the case of a planar two degrees of freedom (DOF) robot. Then the neural network method is employed to find three joint angles of a planar 3-DOF robot maximizing local manipulability. In this algorithm, the proximal redundant joint angle is determined from a neural network and then the remaining joint angles are determined from analytical functions. The results from this method compare favourably with those from the other two traditional methods.  相似文献   

13.
李家霖  杨洋  杨铁  赵亮  于鹏 《机器人》2020,42(6):651-660
为了更好地促进机器人适应复杂的遥操作任务,开发了能够精确获取人体上肢运动信息的外骨骼式遥操作主手,并通过异构映射算法,实现对6自由度协作机械臂的遥操作.首先,基于人体仿生结构,设计了可穿戴式8自由度外骨骼主手(臂部7自由度和手部1自由度);其次,通过改进的D-H(Denavit-Hartenberg)方法建立遥操作系统的运动学模型,基于Matlab的机器人工具箱进行了工作空间仿真,并设计主从异构映射算法;最后,实验验证外骨骼主手在遥操作系统中的可操作性,以及工作空间异构映射算法的可行性.实验表明,外骨骼主手能够控制从端机械手臂,且保证末端位置和姿态一致,可在大范围工作空间内复现人体上肢精细运动,主从跟随误差达2 mm,工作空间类似于直径1.08 m的半球形.因此,可穿戴式的外骨骼主手使操作者能更加直观地参与到遥操作系统当中,辅助操作者更加高效地完成精细复杂任务.  相似文献   

14.
In robotic machining process, the kinematic errors of serial structure and compliance errors caused by external cutter-workpiece interactions can result in considerable deviation of the desired trajectory. Therefore, this paper proposes an efficient calibration methodology by establishing a unified error model about kinematic errors and compliance errors based on Lie theory, which simultaneously calibrates the kinematic parameters and joint compliances of a serial machining robot. In this methodology, the propagation law of kinematic errors is investigated by analysis of the kinematic error model, and the corresponding equivalent kinematic error model is thus obtained, in which the joint offset errors are regarded as one source of twist (joint twist and reference configuration twist) errors. On this basis, with the segmentation and modelling of the joint compliance errors caused by the link self-weight and cutting payloads, the unified error model is developed by linear superposition of configuration errors of the robotic end-cutter, calculated from the kinematic errors and compliance errors respectively. Meanwhile, to improve the accuracy of parameters calibration, the observability index is adopted to optimize the calibration configurations so as to eliminate the twist error constraints. The calibrated kinematic parameters and joint compliances are obtained eventually, and used to compensate the kinematic and compliance errors of the serial machining robot. Finally, to validate the effectiveness of the proposed unified error model, simulation analysis is performed using a 6-DOF serial machining robot, namely KUKA KR500. The comparisons among calibrated parameters show that the unified error model is more computationally efficient with optimal calibration configurations, rendering it suitable for the calibration of kinematic parameters and joint compliances in actual machining applications.  相似文献   

15.
This paper deals with the conceptual design and dimensional synthesis of a 3-DOF parallel mechanism module which forms the main body of a newly invented 5-DOF reconfigurable hybrid robot named "TriVariant." The TriVariant is a modified version of the Tricept robot, achieved by integrating one of the three active limbs into the passive limb. The idea leading to the innovation of the module is systematically addressed. Its kinematic performance is optimized by minimizing a global and comprehensive conditioning index subject to a set of appropriate mechanical constraints. It is concluded that the proposed hybrid system is more cost-effective and has a competitive kinematic performance in comparison with the well-known Tricept robot.  相似文献   

16.
A new control method for kinematically redundant manipulators having the properties of torque-optimality and singularity-robustness is developed. A dynamic control equation, an equation of joint torques that should be satisfied to get the desired dynamic behavior of the end-effector, is formulated using the feedback linearization theory. The optimal control law is determined by locally optimizing an appropriate norm of joint torques using the weighted generalized inverses of the manipulator Jacobian-inertia product. In addition, the optimal control law is augmented with fictitious joint damping forces to stabilize the uncontrolled dynamics acting in the null-space of the Jacobian-inertia product. This paper also presents a new method for the robust handling of robot kinematic singularities in the context of joint torque optimization. Control of the end-effector motions in the neighborhood of a singular configuration is based on the use of the damped least-squares inverse of the Jacobian-inertia product. A damping factor as a function of the generalized dynamic manipulability measure is introduced to reduce the end-effector acceleration error caused by the damping. The proposed control method is applied to the numerical model of SNU-ERC 3-DOF planar direct-drive manipulator.  相似文献   

17.
A time-optimal motion planning method for robotic machining of sculptured surfaces is reported in this paper. Compared with the general time-optimal robot motion planning, a surface machining process provides extra constraints such as tool-tip kinematic limits and complexity of the curved tool path that also need to be taken into account. In the proposed method, joint space and tool-tip kinematic constraints are considered. As there are high requirements for tool path following accuracy, an efficient numerical integration method based on the Pontryagin maximum principle is adopted as the solver for the time-optimal tool motion planning problem in robotic machining. Nonetheless, coupled and multi-dimensional constraints make it difficult to solve the problem by numerical integration directly. Therefore, a new method is provided to simplify the constraints in this work. The algorithm is implemented on the ROS (robot operating system) platform. The geometry tool path is generated by the CAM software firstly. And then the whole machine moving process, i.e. the feedrate of machining process, is scheduled by the proposed method. As a case study, a sculptured surface is machined by the developed method with a 6-DOF robot driven by the ROS controller. The experimental results validate the developed algorithm and reveal its advantages over other conventional motion planning algorithms for robotic machining.  相似文献   

18.
Visual motor control of a 7 DOF robot manipulator using a fuzzy SOM network   总被引:1,自引:0,他引:1  
A fuzzy self-organizing map (SOM) network is proposed in this paper for visual motor control of a 7 degrees of freedom (DOF) robot manipulator. The inverse kinematic map from the image plane to joint angle space of a redundant manipulator is highly nonlinear and ill-posed in the sense that a typical end-effector position is associated with several joint angle vectors. In the proposed approach, the robot workspace in image plane is discretized into a number of fuzzy regions whose center locations and fuzzy membership values are determined using a Fuzzy C-Mean (FCM) clustering algorithm. SOM network then learns the inverse kinematics by on-line by associating a local linear map for each cluster. A novel learning algorithm has been proposed to make the robot manipulator to reach a target position. Any arbitrary level of accuracy can be achieved with a number of fine movements of the manipulator tip. These fine movements depend on the error between the target position and the current manipulator position. In particular, the fuzzy model is found to be better as compared to Kohonen self-organizing map (KSOM) based learning scheme proposed for visual motor control. Like existing KSOM learning schemes, the proposed scheme leads to a unique inverse kinematic solution even for a redundant manipulator. The proposed algorithms have been successfully implemented in real-time on a 7 DOF PowerCube robot manipulator, and results are found to concur with the theoretical findings.  相似文献   

19.
In this study, we measure the compliance characteristics of the 7-degree-of-freedom (DOF) vertical multiarticulated Mitsubishi PA-10 robot. To determine the compliance characteristics of the robot, numerical values of joint compliance are identified by a partial simultaneous measurement method using a force/torque sensor and a 3-D measurement system. The identified compliance is derived from an extended 10-DOF link model that comprises three additional virtual joints and seven actual joints. The virtual joints, which can be handled in the same manner as the actual joints, can be used for more accurate identification. The modeling error derived from link flexibility may be compensated by introducing the extended link model with additional virtual joints. To investigate the accuracy of the compliances identified with the extended link model, verification experiments were conducted. The results show that precise compliance characteristics are obtained from the extended link model. Finally, we reveal the compliance model of the Mitsubishi PA-10 robot, which comprises the numerical values of the joint compliance and a simple kinematic modeling.  相似文献   

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