考虑关节动力学优化的机器人复杂轨迹规划

摘要

Considering the impact of joint-torque variation of robot on the working quality,and aiming at the force control problem during the complex trajectory planning,an optimized algorithm for dynamics problems based on direct collocation method was proposed.With the analysis of robot's dynamical model,the direct collocation method was used to turn the robot's dynamic optimization problem into multi-objective optimization problem of nonlinear equations,and the sequential quadratic programming was used to solve the equations.For the initial value sensitivity problem which exists in the highly non-convex function extreme value solving process of the equations,the linear quadratic regulator was used to provide iterative initial values for sequential quadratic programming.Theoretical analysis and numerical simulation results indicated that the proposed method can guarantee smooth variation of robot's torque,angle and angular velocity during complex trajectory operation,stabilize working quality,and it can control energy consumption during working process more reasonably.%考虑到关节型机器人工作时关节力矩变化对工作质量的影响,针对机器人复杂工作中各关节受力平稳性控制问题,本文提出改进直接配点法优化求解复杂轨迹上机器人关节动力学问题.在对机器人动力学模型进行分析的基础上,使用直接配点法将沿复杂轨迹运动的机器人动力学优化求解问题转化为非线性方程组的多目标优化求解问题,并采用序列二次规划算法求解;针对方程组中高度非凸函数极值求解过程中对初值敏感的问题,采用线性二次调节器为序列二次规划算法提供迭代初值.理论分析和数值仿真结果表明:提出的算法可保证机器人各关节在复杂轨迹上力矩、角度及角速度变化平缓,稳定工作质量,同时也能更合理地控制机器人工作时的能耗水平.