六轮机器人逆运动学的几何诱导迭代法研究

摘要

The automatic control of robot has a higher requirement of real-time,and it is important for automatic control to get the solu-tion of robot inverse kinematics. In the traditional method,the solution by numerical iteration is always used,which is universal,but with the problems of slow convergence or non-convergence. Numerical iteration applied to robot inverse kinematics solution may bring the dis-advantage of heavy calculation,slow convergence,the unique result not to guarantee,and good real-time performance not to determine. Therefore,a method using the geometric characteristics of robot mechanism is demonstrated to accelerate iteration convergence. It tries to find the parameters describing the geometric characteristics of mechanism studied,and need merely calculation of the iteration of key vari-ables,while the other variables can be obtained by the analytic formula figured out by the geometric characteristics of mechanism. Apply-ing the method can achieve the required precision by less number of iterations on the premise of meeting the real-time performance. Six-wheeled is a model of robot rover which has extensive research and complex mechanism. Numerical simulation of concrete mechanism shows the availability and high efficiency of the method.%机器人控制对实时性要求高，其逆运动学的快速求解是机器人控制领域的重要问题。在传统的逆运动学求解方法中，大多采用数值迭代的方法，该方法具有一定的通用性，但是该方法同时也有迭代收敛慢或者不收敛的问题。针对数值迭代法在机器人逆运动学求解过程中遇到的运算量大、收敛速度慢、结果唯一性难保证、无法确保实时性要求的问题，提出利用机器人机构的几何特点加速迭代收敛的方法。研究机构的几何特点，找出其表达参数，仅对必要的变量进行迭代运算，其他关节变量由机构几何特点获得的解析式求得。在满足实时性要求的前提下，该方法能以较少的迭代次数达到需要的求解精度。六轮机器人是广泛研究的一种月球探测车模型，机构较为复杂。针对该具体结构的数值仿真表明，该方法快速有效。