四自由度模块化机械臂运动学建模

首先根据四自由度(MT-R)模块化机械臂的结构特点和运动学约束,利用D-H算法对机械臂进行表示和建模,得到了以关节角度为变量的正运动学模型。利用矩阵逆乘的解析法求解机械臂逆运动学的完整解析解;最后通过仿真和实验验证了正运动学模型及运动学逆解的正确性。验证结果为机械臂末端执行器的精确定位和轨迹规划提供了理论依据。     

基于激光测距的微型机械臂关节控制模型

为了更加深入探究并提升机械臂关节控制效果,提出一种基于激光测距的微型机械臂关节控制模型,通过激光测距技术对微型机械臂周边环境进行感知,同时进行数据点扫描,将全部数据点集进行直线分割以及拟合等相关操作,获取二维环境地图。在上述基础上,通过坐标变换矩阵获取微型机械臂的正运动学模型,利用正运动学模型得到机械臂逆运动学模型。将获取的动力学模型转换为仿射非线性系统的形式,利用输入输出反馈线性化方法选取合适的状态变换和反馈变换,通过滑膜控制方法构建微型机械臂关节控制模型,采用模型进行关节控制。仿真实验结果表明,所提模型可以获取理想的微型机械臂关节控制结果。     

五自由度仿人灵巧手运动学研究

为了深入掌握灵巧手运动过程,需要对灵巧手各关节的位移、速度、加速度、静力进行研究,得到运动学相关的理论数据。在分析了Shadow仿人灵巧手的机械结构特点的基础上,运用D-H坐标法,建立Shadow仿人灵巧手的运动学模型,推导出运动学正、逆方程,求解出正、逆解析解和雅可比矩阵,分析了灵巧手的微分运动学,求解出雅克比矩阵,并且得到了静力学相关参数,为下一步的理论研究和仿真实验提供数据参考。     

激光聚焦次镜支撑小型三自由度机构运动分析

提出了利用一种可实现一个移动和两个转动的小型3自由度(3-DOF)并联机构来控制支撑激光聚焦次镜的方案。采用传统的欧拉角描述动平台运动方式,建立了小型3-PRS机构的运动学模型,分析了机构的正、逆运动学性能,进行了包括约束雅克比矩阵的建立和伴生运动的求解。基于运动学分析,定性分析了机构的奇异位形。联合ADAMS与MATLAB,计算了机构的可达工作空间,动平台绕x轴最大运动角度为15.167 1;绕y轴最大运动角度为13.319 4;沿z轴方向的移动大约为9.954 1 mm,分析证明该小型3-PRS机构完全满足支撑激光聚焦次镜结构的设计要求。     

串联机械臂运动控制系统设计

由于加工装配的累积误差,驱动控制,机械臂的柔性变形以及实际工作环境中振动等因素的干扰,导致无法准确获取机械臂的运动学模型和动力学模型,导致机械臂实际的运动性能与期望的高精度运动性能相比出现较大的差距。针对上述问题,文中通过研究串联机械臂轨迹优化算法,设计了一套简单且实时性的机械臂控制变量补偿系统,以减少甚至消除机械臂的运动学误差。这一技术的实现,将对提高装备制造业中机械臂运动精度关键技术的发展起到推动作用。     

4-DOF多功能机器人运动控制算法的研究

随着机器人技术的不断发展,机器人在现在社会发展中发挥着越来越重要的作用。文中对实验室研发的多功能4-DOF机器人的运动控制相关问题进行研究。首先对4-DOF机器人的机构整体设计并PROE三维建模,然后通过基于D-H法建立机械臂坐标系,对4-DOF机器人进行运动学正逆解分析,在逆解计算中,提出了当两轴平行两轴耦合的计算方法,即将两轴关节角视为整体计算,再利用代数方法依次得出单个关节角。同时针对机械臂的连续轨迹运动给出轨迹规划的方法,为设计机械臂控制器的实现和机械臂的运动控制提供了依据。     

基于3DS Max 与OpenGL的机械臂仿真与控制

阐述了在以Vc＋＋6．0为平台的基础上，利用3DSMax与OpenGL对机械臂进行可视化三维仿真的一种方法。为满足蒸汽发生器六轴机械臂检修控制系统的要求，建立一个多功能的实验仿真平台。一方面从正解、反解两个方面对机械臂进行了运动学分析，从而实现了机械臂的各轴在多种控制下的运动；另一方面将OpenGL与3DSMax相结合建立系统模型，给出机械臂在空间运动与抓顶的三维动画实现过程。实验结果证明仿真平台在实际工程中具有一定价值。     

基于MATLAB Robotics TOOIs的机械臂仿真

在MATLAB环境下,对puma560机器人进行运动学仿真研究,利用Robotics Toolbox工具箱编制了简单的程序语句,建立机器人运动学模型,与可视化图形界面,利用D-H参数法对机器人的正运动学、逆运动学进行了仿真,通过仿真,很直观的显示了机器人的运动特性,达到了预定的目标,对机器人的研究与开发具有较高的利用价值。     

基于MATLAB Robotics Tools的机械臂仿真

在MATLAB环境下,对puma560机器人进行运动学仿真研究,利用Robotics Toolbox工具箱编制了简单的程序语句,建立机器人运动学模型,与可视化图形界面,利用D-H参数法对机器人的正运动学、逆运动学进行了仿真,通过仿真,很直观的显示了机器人的运动特性,达到了预定的目标,对机器人的研究与开发具有较高的利用价值。     

机器人灵巧手的运动学分析及仿真

为了实现对灵巧手各关节的实时控制,提高灵巧手工作的"灵巧度",本文以英国Shadow公司的Shadow仿人灵巧手为研究对象,研究了Shadow灵巧手机械结构特点,运用D-H坐标法,建立了灵巧手的运动学模型,推导出灵巧手的单指正、逆运动学方程,求解出正、逆解析解及相关参数,并且运用Matlab软件对结果进行了验证和仿真,为进一步研究灵巧手动力学问题提供理论依据。     

Dynamics of a four degrees-of-freedom parallel manipulator with parallelogram joints

A comprehensive dynamics analysis of a four degrees-of-freedom Schönflies parallel manipulator with parallelogram joints is presented. First, the manipulator kinematics and workspace analysis is performed. Then, the dynamics model is calculated using the Lagrangian formulation. The existence of parallelograms in the structure of the manipulator introduces passive variables in the model. Other authors have simplified the dynamics of the parallelograms in order to calculate the dynamics model more easily and eliminate these passive variables. In this work, the full dynamics of the manipulator is considered and passive variables are not eliminated. The model resulting from the Lagrange multiplier elimination produces a symmetric, positive-definite inertia matrix and the relation between the constraint Jacobian and the Jacobian of the constraint equations arises naturally. Finally, the dynamics model is experimentally validated using a prototype of the proposed manipulator.     

Tool-Center-Point control of the KAI manipulator using constrained QP optimization

The KAI manipulator is a four joint mobile manipulator, which will be used within the German road clearance package to investigate improvised explosive devices and ordnance from within an armored vehicle. To improve handling of the manipulator, a Tool-Center-Point (TCP) control is implemented. By using constrained quadratic optimization (cQP) it is possible to allow for the control of the manipulator within three different operating spaces. The QP is formulated to account for constraints in the joint angular rates and TCP velocities, as well as additional velocity constraints, e.g. on the movement of the center of mass of the manipulator. The proposed algorithm is able to handle redundant as well as non redundant manipulator kinematics. By using an efficient QP solver the algorithm can be used within a real-time trajectory generation scheme. The performance of the algorithm is demonstrated using simulation results and validated by measurements of the TCP control.     

A Mixed Real-time Algorithm for the Forward Kinematics of Stewart Parallel Manipulator

Aimed at the real-time forward kinematics solving problem of Stewart parallel manipulator in the control course, a mixed algorithm combining immune evolutionary algorithm and numerical iterative scheme is proposed. Firstly taking advantage of simpleness of inverse kinematics, the forward kinematics is transformed to an optimal problem. Immune evolutionary algorithm is employed to find approximate solution of this optimal problem in manipulator＇s workspace. Then using above solution as iterative initialization, a speedy numerical iterative scheme is proposed to get more precise solution. In the manipulator running course, the iteration initialization can be selected as the last period position and orientation. Because the initialization is closed to correct solution, solving precision is high and speed is rapid enough to satisfy real-time requirement. This mixed forward kinematics algorithm is applied to real Stewart parallel manipulator in the real-time control course. The examination result shows that the algorithm is very efficient and practical.     

Simplified approach for dynamics estimation of a minor mobility parallel robot

This paper presents the identification of an approximated polynomial model for the dynamics of a parallel kinematics machine. The case study of a specific translational Cartesian manipulator is faced. Firstly, an analysis of robot dynamics is performed to verify the presence of poorly relevant terms. A polynomial simplified model is then built by fitting the actual behaviour of the robot prototype. The seek of the coefficients of the interpolating polynomials has been constrained taking advantage of robot peculiarities, such as symmetry and intrinsic properties of multibody systems dynamics. The effectiveness of the proposed simplification is then verified by comparison with robot behaviour.     

Machine learning-based framework for optimally solving the analytical inverse kinematics for redundant manipulators

Solving the analytical inverse kinematics (IK) of redundant manipulators in real time is a difficult problem in robotics since its solution for a given target pose is not unique. Moreover, choosing the optimal IK solution with respect to application-specific demands helps to improve the robustness and to increase the success rate when driving the manipulator from its current configuration towards a desired pose. This is necessary, especially in high-dynamic tasks like catching objects in mid-flights. To compute a suitable target configuration in the joint space for a given target pose in the trajectory planning context, various factors such as travel time or manipulability must be considered. However, these factors increase the complexity of the overall problem which impedes real-time implementation. In this paper, a real-time framework to compute the analytical inverse kinematics of a redundant robot is presented. To this end, the analytical IK of the redundant manipulator is parameterized by so-called redundancy parameters, which are combined with a target pose to yield a unique IK solution. Most existing works in the literature either try to approximate the direct mapping from the desired pose of the manipulator to the solution of the IK or cluster the entire workspace to find IK solutions. In contrast, the proposed framework directly learns these redundancy parameters by using a neural network (NN) that provides the optimal IK solution with respect to the manipulability and the closeness to the current robot configuration. Monte Carlo simulations show the effectiveness of the proposed approach which is accurate and real-time capable ($\approx$ 32 µs) on the KUKA LBR iiwa 14 R820.     

基于模糊RBF神经网络的冗余机械手运动学逆解

利用模糊RBF神经网络对冗余机械手的运动学逆解函数逼近进行研究，为解决冗余度引起的多解问题，文中提出了关节最佳柔顺性附加准则，并将多目标多参数优化问题转化为单目标单参数优化问题，使网络训练数据能顺利得到。仿真所得结果令人满意，证明了本文的方法行之有效的。     

Design and implementation of the motion control system of the mobile robot based on PID

A kind of motion control system of the autonomous mobile robot was introduced,and a PID closed-loop control method was proposed that controlling the robot moving along the expected direction and speed effectively through establishing the kinematics model of the autonomous mobile robot.In addition,the modular software program and the hardware system were developed whose main components were the STC12C5A60S2 microprocessor,the MC33886 motor driver chip and hall sensors.Finally,experiments proves the control method and the system effective and stable.