采用Denavit-Hartenberg方法建立了关节式坐标测量机的数学模型,分析了影响关节式坐标测量机的误差源,并对第一关节的误差分布进行了仿真。通过关节式坐标测量机的第一关节在不同初始位姿下对被测工件进行测量与真值进行比较,分析在不同初始位姿下所测得结果的不同,得到了其第一关节的误差分布。实验表明关节式坐标测量机在采用相对角度编码器时,第一关节选择最佳初始位姿,可以有效地提高测量精度,减小误差。
The ideal mathematical models of multi - joint coordinate measuring machine (MCMM) were established by using Denavit Hartenberg. The error sources which were influenced by the multi joint coordinate measuring machine has been analysed and simulation has been given to the first joint' s error distribution. Compared the measuring results which reached by using the MCMM with standard values, one conclusion that different initial positions have different values has been reached. Experiments showed that using relative angle encoder,the MCMM selects optimum initial positions could enhance the accuracy of measurement.