DataSheet1_Trajectory Generation for Flexible-Joint Space Manipulators.pdf

Space manipulator arms often exhibit significant joint flexibility and limited motor torque. Future space missions, including satellite servicing and large structure assembly, may involve the manipulation of massive objects, which will accentuate these limitations. Currently, astronauts use visual feedback on-orbit to mitigate oscillations and trajectory following issues. Large time delays between orbit and Earth make ground teleoperation difficult in these conditions, so more autonomous operations must be considered to remove the astronaut resource requirement and expand robotic capabilities in space. Trajectory planning for autonomous systems must therefore be considered to prevent poor trajectory tracking performance. We provide a model-based trajectory generation methodology that incorporates constraints on joint speed, motor torque, and base actuation for flexible-joint space manipulators while minimizing total trajectory time. Full spatial computer simulation results, as well as physical experiment results with a single-joint robot on an air bearing table, show the efficacy of our methodology.

空间机械臂（Space manipulator arms）通常兼具显著的关节柔性与受限的电机输出转矩。未来太空任务（涵盖卫星在轨服务与大型空间结构组装）或需操控大质量物体，这将进一步加剧上述两类局限。当前宇航员依托在轨视觉反馈来抑制振荡问题并改善轨迹跟踪表现。鉴于在轨平台与地球之间存在显著的通信时延，该场景下地面对遥操作将面临极大挑战，因此亟需探索自主作业方案，以摆脱对宇航员人力的依赖并拓展空间机器人的作业能力。由此，针对自主系统的轨迹规划研究迫在眉睫，需避免轨迹跟踪性能劣化的问题。本文提出一种基于模型的轨迹生成方法，该方法可针对柔性关节空间机械臂（flexible-joint space manipulators），兼顾关节转速、电机转矩与基座驱动约束，并实现总轨迹时长的最小化。全空间计算机仿真结果，以及气浮台（air bearing table）上单关节机器人的物理实验结果，均验证了所提方法的有效性。