【摘要】 针对空间机械臂在太空处于微重力环境,在地面装调时需要考虑重力及由重力引起的摩擦的影响的问题,以平面运动的二自由度机械臂为例研究了摩擦补偿控制,提出了一种主动补偿控制方法,用来减小甚至消除由地面重力作用产生的摩擦的影响。该方法首先采用几何方法求解运动学逆解,根据力矩平衡计算摩擦力矩,再结合Kane方程推导出系统的动力学模型,最后运用PD控制算法分别在考虑摩擦和不考虑摩擦两种情况下对机械臂动力学模型进行仿真研究,并在不同关节质量的条件下进行轨迹跟踪仿真研究。仿真结果表明,摩擦对控制机械臂运动的驱动力以及轨迹跟踪精度所产生的影响与重力密切相关,重力越小,影响越小。更多还原

【Abstract】 The effects of the gravity caused friction on space manipulators were studied because they work in the microgravity environment in space so the friction caused by gravity should be considered during their ground alignment.Then,an active compensation control method was developed to reduce or even eliminate the influence of friction caused by the ground gravity and its effectiveness was validated on a two-DOF manipulator.The method consists of three steps;first,the inverse kinematics is derived by using a geometric method;next,the friction torque and dynamic equations are derived based on the torque balance and the Kane equation;finally,the dynamic properties with and without friction are studied,and the trajectory tracking in different joint qualityies is simulated by using the PD control algorithm.The simulation results show that the influences of the friction on the driving force of the manipulator motion control and the trajectory tracking accuracy are closely related with the gravity.Namely the smaller the gravity is,the smaller the influence will be.更多还原