基于航天员运动特性的机器人宇航员安全作业研究

The utilization of robot astronaut for space auxiliary or exploration is one of the most important strategies for the development of space technology in China. Due to the influence of space microgravity, the motion characteristics of robot are significantly different from those of the ground. Further, the robot is very sensitive to the external disturbance and motion error in these microgravity surroundings, which makes it unstable and difficult to be controlled. Thus, the safety operation of the robot astronaut is still one of the most significant challenges for us. This project is based on the mechanism of human astronaut motion. Specifically, this project firstly parameterizes the movement characteristics of human astronaut and maps them to the robot astronaut motion pattern. On the basis of this, the motor dynamics model is used to feed the end force / torque directly back to the motor control voltage, which will speed up the response time. Meanwhile, an adaptive impedance control method is proposed, which focuses on the coordination mechanism of arms and the optimization method of impedance control parameters, and solves the problem of dual-arm closed-chain operation and sensitivity to external disturbance. Finally, the algorithm and parameters are verified and analyzed by the microgravity simulation system. The iterative mechanism is used to find the consistency of the parameters and the data to confirm the effectiveness of the algorithm. This project provides a theoretical basis for the robot astronauts to assist or even replace astronauts through the cross fusion of bionics and robotics, and provides a new method for the development of space robot, which has important academic significance and application value.

利用机器人宇航员进行空间辅助或探测工作是我国空间技术发展的重要策略。受空间微重力影响，机器人运动特性与地面显著不同，且对外界扰动与运动误差异常敏感，容易出现失稳现象，给其安全作业提出新的挑战。本项目借鉴航天员作业运动规律，将航天员运动特性参数化并向机器人宇航员运动模式映射。在此基础上，结合地面机器人控制策略，利用电机动力学模型将操作末端力/力矩直接反馈到电机控制电压，加快响应速度；同时，提出一种参数自整定控制方法，重点研究双臂协调机制与阻抗控制参数优化方法，解决双臂闭链对外界扰动及运动误差异常敏感问题。最后，通过微重力仿真系统对算法及参数进行验证与差异性分析，通过迭代机制，寻求参数修正规律与数据一致性，验证算法有效性。项目通过仿生学和机器人学科的交叉融合，为机器人宇航员辅助或代替航天员作业提供理论基础，为空间机器人的发展提供新方法，具有重要的学术意义及应用价值。

相对于人类生理条件的限制，机器人在恶劣空间环境下进行工作和探索具有很大优势。利用空间机器人在空间站进行辅助或探测工作，是我国空间技术发展的重要策略。但是，由于空间微重力环境的影响，空间机器人的灵活性与安全性难以兼顾。机器人宇航员由于具有人一样的外形和自由度配置，可以较为方便的使用为航天员配备的各种工具与设施，完成作业任务。因此，本项目以仿人形的机器人宇航员作为研究目标，旨在研究微重力环境下机器人宇航员作业过程中易出现的抖动、失稳等问题。航天员通过失重训练后对空间站微重力环境有一定的适应能力，本项目首先从仿生的角度出发，通过地面微重力模拟平台采集人体运动数据，分析航天员微重力环境下作业运动机理，完成了机器人的动力学建模。为提高关节控制器的响应速度，建立驱动电机动力学模型，结合机器人动力学，提出基于关节伺服动力学的双前馈控制方法，同时保证机器人运动的稳定。为解决机器人双臂同时作业过程中产生的纷争力引起的失稳问题，提出基于参数自整定函数的阻抗控制方法。本项目为机器人宇航员在内外力作用下的稳定控制，提供一种有效途径，为我国早日实现机器人辅助或代替宇航员进行空间作业打下基础。