基于关节电机性能约束机器人的运动轨迹平滑规划

Smooth trajectory planning for robot based on joint-motor performance constraints

为了使机器人运动过程平滑,采用机器人的逆动力学特性,通过约束机器人关节电机性能得到一种运动轨迹平滑规划方法。该方法中平滑运动轨迹使用五次样条曲线,以笛卡尔空间粗插补和关节空间精插补相结合,在考虑关节角速度约束和逆动力学得到的关节力矩约束下,建立角速度和关节力矩等关节电机性能与粗插补周期的关系式,便可通过修改粗插补周期得到满足关节电机性能约束的平滑运动轨迹,避免因优化平滑运动轨迹而带来的大量计算,更容易操作。通过与三次B样条曲线插补算法规划的轨迹相比,结果表明:此规划能大大提升机器人关节运动的平稳性,减小冲击和振动对机器人运动的影响。

In this article,in order to ensure the robot's smooth motion,the method of smooth trajectory planning is proposed by using the robot's inverse dynamics characteristics and constraining its joint-motor performance.The smooth trajectory planning uses the quintic spline curve,and combines rough interpolation in the Cartesian space and fine interpolation in the joint space.Efforts are made to set up the relationship between the performance of joint motor such as angular velocity and joint torque and the period of rough interpolation,with the joint-torque constraint obtained by considering the joint's angular velocity constraint and the inverse dynamics taken into consideration.As a result,the smooth trajectory planning which meets the requirement of joint-motor performance constraints can be obtained by modifying the period of rough interpolation;a lot of calculation caused by the optimization method to achieve smooth trajectory planning is avoided;it is easier to operate.Compared with the trajectory planned by means of the cubic B-spline curve interpolation algorithm,the experiments show that this planning method can greatly improve the smoothness of the robot's joint motions as well as reduce the influence of impact and vibration on robot motions.