KDL(Kinematics and Dynamics Library)中定义了一个树来代表机器人的运动学和动力学参数,ROS中的kdl_parser提供了工具能将机器人描述文件URDF转换为KDL tree. Kinematic Trees: 链或树形结构.已经有多种方式来定义机构的运动学结构,KDL使用图论中的术语来定义: A closed-loop mechanism is a graph, 闭链机构是一幅图 an open-loop mechanism is a tree, 开链机构是
When performing inverse kinematics (IK) on a complicated bone chain, it can become too complex for an analytical solution. Cyclic Coordinate Descent (CCD) is an alternative that is both easy to implement and efficient to process.逆运动学问题一般采用解析法和基于Jacob
The damped least squares method is also called the Levenberg-Marquardt method. Levenberg-Marquardt算法是最优化算法中的一种.它是使用最广泛的非线性最小二乘算法,具有梯度法和牛顿法的优点.当λ很小时,步长等于牛顿法步长,当λ很大时,步长约等于梯度下降法的步长. The damped least squares method can be theoretically justified as follo
Solving the FK problem of simple kinematic chains is trivial (just apply the desired joint values to all joints in the chain to obtain the position and orientation of the tip or end effector). However it is less trivial to solve the IK and FK problem
IK groups and IK elements VREP中使用IK groups和IK elements来进行正/逆运动学计算,一个IK group可以包含一个或者多个IK elements: IK groups: IK groups group one or more IK elements. To solve the kinematics of a simple kinematic chain, one IK group containing one IK element is need
There are two ways of using the Jacobian matrix to solve kinematics. One is to use the transpose of the Jacobian JT. The other is to calculate the inverse of the Jacobian J-1. J is most likely redundant and non square,thus an ordinary inverse is not
机器人运动学逆解的问题经常出现在动画仿真和工业机器人的轨迹规划中:We want to know how the upper joints of the hierarchy would rotate if we want the end effector to reach some goal. IK Solutions: Analytical solutions are desirable because of their speed and exactness of solution. For
TRAC-IK和Orocos KDL类似,也是一种基于数值解的机器人运动学求解器,但是在算法层面上进行了很多改进(Specifically, KDL’s convergence algorithms are based on Newton’s method, which does not work well in the presence of joint limits — common for many robotic platforms. TRAC-IK concurrently runs
安装SolidWorks to URDF exporter插件 下载SolidWorks to URDF Exporter插件后按照网站上的步骤进行安装(目前该插件已经在Win 7 64位系统+Solidworks 2017上验证过.So far this add-in has been tested only on Windows 7 64bit with SolidWorks 2017 64bit. It currently does not install on 32bit machine
The geometric constraint solver is slower and less precise at solving kinematic problems, but might be easier and more intuitive to use. Moreover, it allows interacting with a mechanism in a more flexible way than the inverse kinematics calculation m
VREP中的simRMLMoveToPosition函数可以将静态物体按照设定的运动规律移动到指定的目标位置/姿态.If your object is dynamically enabled, it will not work (since in that case the position of the object is dictated by the physics engine). In that case, make sure to uncheck the Body is dynami
