柔性机械臂关节作动的振动抑制方法和原理性验证

Principle Verification and Joint-Actuator Method for Vibration Suppression of Flexible Manipulator

空间机械臂具有柔性大、振动频率低等特点,受激后振动的持续时间长、自然衰减慢。针对空间机械臂运行完成后留存的残余振动,采用固定界面子结构方法推导出关节转动与航天器-机械臂组合体振动的动力学显式关系。从中发现了控制关节转动并使其角速度正比于组合体振动的模态坐标,便能消耗组合体的机械能,加速组合体振动衰减的力学机理。据此,设计了逻辑关系简洁的机械臂关节角速度控制律,分别通过数值仿真和试验件实测对航天器-机械臂组合体的原理性模型开展了振动抑制效果的验证。结果表明:机械臂关节作动可以显著缩短受激后组合体残余振动的持续时间。

Space manipulators have the characteristics such as large flexibility and low vibration frequency. After being stimulated,the vibration duration is long,and the natural attenuation is slow. Aiming at the residual vibration of space manipulators after operation,the fixed interface substructure method is used to derive the dynamic explicit relationship between the joint rotation and the vibration of the spacecraft-manipulator assembly. It is found that controlling the rotation of the joint so that its angular velocity is proportional to the modal coordinate displacement of the combined body vibration can consume the mechanical energy of the combined body and thus accelerate the vibration attenuation of the combined body. Based on this,a simple relationship is designed to control the angular velocity of the robotic arm joints. Numerical simulation and tests are carried out to verify the vibration suppression effect of the principle model for the spacecraft-manipulator assembly. The results show that the action of the manipulator joint can significantly shorten the duration of the residual vibration of the combined body after being stimulated.