D-H 法建立连杆坐标系存在的问题及改进

摘要

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 w rong local joint position analysis ,etc .In order to get unified ,intuitive and accurate modeling method ,a unified en-tity modeling method ,the coordinate system fixed on the entity of D-H notation(CFDH) was presen-ted .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 compu-tational complexity .Simulation and experimental results show that CFDH method meets the require-ments of robot kinematics model ,solved the problems exiting in D-H method .%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，C FD H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。