采用传感器测量联合最小二乘法的机器人路径跟踪控制方法的研究

Research on Robot Path Tracking Control Method Based on Sensor Measurement Combined with Least Square Method

为提高机器人跟踪期望路径的准确性,以改善机器人的工作质量,结合传感器测量和最小二乘法设计一种机器人路径控制方法。通过3个激光距离传感器构造机器人测量系统,利用距离传感器得出平面上3个点的测量距离,从而计算出末端执行器和曲面之间的距离。采用曲面的法向量描述曲面上任意点处的曲面。通过刀具中心点位置和旋转矩阵,求取曲面上每个测量点的位置,进而计算出刀具中心点到曲面上任意点的距离与交点位置。使用二次系数矩阵求取近似曲面的z分量,采用距离传感器测量所得的当前和先前测量点,进行最小二乘近似来确定未知平面和抛物面参数,进而根据期望路径求取路径方向和刀具方向,从而实现对期望路径的跟踪。结果表明:与模糊PI控制方法相比,利用所提方法跟踪平面和立体期望路径时准确度较高,验证了所提方法能控制机器人对期望路径进行准确跟踪,为改善机器人的工作质量提供参考。

In order to improve the accuracy of robot tracking the desired path and improve its work quality,a robot path control method was designed based on sensor measurement and least square method.The robot measurement system was constructed by using three laser distance sensors,and the measurement distances of three points on the plane were obtained by using the distance sensor to calculate the distance between the end effector and the surface.The normal vector of the surface was used to describe the surface at any point on the surface.Through the position of the tool center point and the rotation matrix,the position of each measuring point on the surface was obtained,and then the distance and intersection position from the tool center point to any point on the surface were calcu⁃lated.The z component of the approximate surface was obtained by using the quadratic coefficient matrix,and the current and previous measurement points measured by using the distance sensor were used to determine the unknown plane and paraboloid parameters by using the least square approximation,and then the path direction and tool direction were obtained according to the desired path,so the tracking of the desired path was realized.The results show that compared with the fuzzy PI control method,the proposed method has high accuracy in tracking the plane and the stereo expected path,which verifies that the proposed method can be used to control the desired path accurately and provide reference for improving the work quality of the robot.