控制力矩陀螺驱动的空间机器人轨迹跟踪控制

提出一种新的空间机器人设计概念，并研究其轨迹跟踪控制问题.系统中的各机械臂以自由球铰连接，在机器人平台和每节机械臂上均安装有一组控制力矩陀螺（CMGs，Control Moment Gyroscopes）作为控制力矩执行机构.采用改进的罗格里得斯参数（MRPs，Modified Rodrigues Parameters）描述平台和各节机械臂的姿态，利用Kane方程建立了系统的动力学模型.在此基础上，用逆动力学方法设计了系统的轨迹跟踪控制律，用以实现卫星平台的位置/姿态和机械臂末端作用器位置的轨迹跟踪控制.采用带有零运动的CMGs操纵律以使CMGs准确输出力矩并回避构型奇异.基于两关节机械臂系统和金字塔构型CMGs的数值仿真结果验证了所设计的控制律和操纵律的有效性，以及自由球铰连接方式在提高末端作用器运动自由度和降低系统动力学耦合方面的优越性. 

Trajectory tracking control of space robot actuated by control moment gyroscopes

A new design concept of space robotic system was proposed, as well as a trajectory tracking control approach. Unlike traditional manipulator arms, the space robot employs free ball joints as manipulator link connections. A group of control moment gyroscopes (CMGs), serving as torque actuators, was mounted on each link and the base. The modified Rodrigues parameters (MRPs) were employed to describe the attitude of the base and the links, and the equations of motion were derived by using Kane's equations. To accomplish trajectory tracking control of both the base position/attitude and the end effector position, a control law was designed using the inverse dynamics method. A steering law with null motion was adopted for each group of CMGs to achieve simultaneous desired torque output and singularity configuration avoidance. The simulation results based on a two-joint space robot system with pyramid-configuration CMGs demonstrate the effectiveness of the proposed control law and steering law, as well as the ball joint advantage in increasing the degrees of freedom of the end effector and decreasing the system dynamical coupling.