安全扭矩约束下的多关节机器人轨迹跟随方法

Trajectory Following Method of Multi-Joint Robot Under SafeTorque Constraints

为了减轻机器人与环境碰撞产生的不良影响,常需要机器人在跟随指令轨迹的同时约束各关节的最大扭矩。针对多关节机器人动力学约束下的笛卡尔空间路径保持与快速跟随问题,分析机器人关节空间力矩约束对笛卡尔空间轨迹的速度和加速度的影响,在机器人保持原笛卡尔路径不变的同时,实时分析当前允许的最大加速度,并计算得到相应的速度和位置,实现指令轨迹的快速跟随,达到安全作业的目的。该方法在一台自研六自由度轻量化机械臂平台上进行了验证。结果表明,该方法能够将扭矩约束到设定范围内,重新规划后的轨迹保持笛卡尔路径不变,且能够快速跟随指令轨迹。

To reduce the effects of collision between the robot and environment,it is generally required to limit the maximum torque of each joint while the robot follows the command trajectory.For keeping the Cartesian path unchanged and following quickly under the dynamic constraints of a multi-joint robot,the effects of joint space torque constraints on the velocity and acceleration of Cartesian space are analyzed.The maximum acceleration allowed is analyzed in real time,and the corresponding velocity and position are calculated while the robot keeps the Cartesian path unchanged.The purpose of safe operation is achieved.The method was verified on a self-developed six-degree-of-freedom lightweight manipulator.The result shows that the method can constrain the torque to a set range,the replanned trajectory keeps the Cartesian path unchanged,and the command trajectory is followed quickly.