基于PMSM驱动的柔性关节空间机械臂轨迹跟踪控制方法

Trajectory tracking control method of flexible joint space manipulator driven by PMSM

摘要:

针对目前柔性关节空间机械臂轨迹跟踪控制方法忽略了不同重力影响下的机械臂驱动力变化,导致柔性关节空间机械臂轨迹跟踪控制效果较差的问题,提出了基于PMSM驱动的柔性关节空间机械臂轨迹跟踪控制方法。基于构建PMSM驱动数学模型,采用PMSM的矢量控制方法,分析驱动力矩矢量。根据驱动力矩矢量分析结果,分析不同重力环境下有、无摩擦时的驱动力矩。构建柔性关节模型,分析其在不同重力环境下遇到的重力释放问题,使用自适应反演滑膜控制方法,设计控制率,保证机械臂能够按照既定的方向运动,使机械臂具有鲁棒性。根据柔性关节空间机械臂动力学特性,分析不同重力环境下基于PMSM驱动力矩,确定重力项是随之发生改变的。设计控制器,构建动力学模型,确保空间阶段能够最大限度跟踪运动轨迹。实验结果表明,所提方法X轴、Y轴的末端跟踪结果均与实际运动轨迹一致,误差为0。关节控制力矩在时间为3s时,出现了最大为0.5N.m的误差,说明所提方法的跟踪控制效果较好。

Abstract:

Aiming at the problem that the current trajectory tracking control method of flexible joint space manipulator ignores the change of manipulator driving force under the influence of different gravity, resulting in poor trajectory tracking control effect of flexible joint space manipulator, a trajectory tracking control method of flexible joint space manipulator based on PMSM drive is proposed. Based on the PMSM driving mathematical model, the PMSM vector control method is used to analyze the driving torque vector. According to the analysis results of driving torque vector, the driving torque with and without friction in different gravity environments is analyzed. The flexible joint model is constructed, the gravity release problem encountered in different gravity environments is analyzed, and the adaptive inverse synovial control method is used to design the control rate to ensure that the manipulator can move in the given direction and make the manipulator robust. According to the dynamic characteristics of flexible joint space manipulator, the driving torque based on PMSM in different gravity environments is analyzed, and the gravity term is determined to change accordingly. The controller is designed and the dynamic model is constructed to ensure that the motion trajectory can be tracked to the greatest extent in the space stage. The experimental results show that the end tracking results of x-axis and y-axis are consistent with the actual motion trajectory, and the error is 0. The maximum joint control torque is 0.5N.m when the time is 3s, which shows that the tracking control effect of the proposed method is good.