D-H法建立连杆坐标系存在的问题及改进

Problems and Improvement of D-H Method for Establishing Connecting Rod Coordinate System

广泛使用的标准D-H法允许坐标系建立在轴线的延长线上,会导致不能针对所有关节连杆进行建模、建立的机器人模型与实体不一致,以及无法进行局部关节位置分析等问题。为了得到统一、直观、准确的模型建立方法,提出了一种统一的实体建模方法——坐标系固定在实体上的D-H表示法(简称CFDH法)。说明了CFDH法坐标系建立的方法、参数获取过程。以一个六自由度机械臂作为仿真对象,分别用D-H法和CFDH法对其进行建模,然后采用Newton-Raphson求逆解,比较两者计算复杂度并对两种建模方法进行整体对比。仿真和实验结果表明,CFDH法满足机器人运动学建模的需求,解决了D-H法存在的问题。

Robot kinematics modeling needs clear physical concepts.Widely used standard D-H method allowed the coordinate system to establish on the extension of axis,leading to the problems such as inapplicability for all the joints modeling,the model unmatching the entity and wrong local joint position analysis,etc.In order to get unified,intuitive and accurate modeling method,a unified entity modeling method,the coordinate system fixed on the entity of D-H notation（CFDH）was presented.How to establish the coordinate system with CFDH and the method to obtain the parameters were illustrated;a six DOF mechanical arm model was built using the D-H and CFDH method respectively,and Newton-Raphson inverse solution was used for the two methods,then comparing with the computational complexity.Simulation and experimental results show that CFDH method meets the requirements of robot kinematics model,solved the problems exiting in D-H method.