【作者】 王建宇；

【导师】 刘宏；

【作者基本信息】 哈尔滨工业大学 ， 机械电子工程， 2008， 博士

【摘要】 航天服是载人航天必不可少的防护装备,是航天员个人生命保障系统中最重要的分系统。随着载人航天的深入,我国航天员将实现舱外行走。舱外航天服既要为航天员提供基本的生命保障,还应具有高的活动性能,尤其是上肢的活动性能,是航天员能够有效地完成各种舱外作业的保证。目前我国舱外服的设计加工工作已基本完成,为了能够检验和评价自行研制的舱外航天服,迫切需要航天服性能检测系统。本文结合国家“载人航天”工程项目“舱外航天服关节力学测试系统”的研制,提出新的航天服关节力学特性测量方法,研究和发展基于新的测量方法的理论体系,搭建测试系统平台,通过具体实践检验理论体系的正确性和可行性。舱外航天服关节力学特性的测量包括航天服手臂关节力学特性测量和航天服手套关节的力学特性测量。舱外航天服手臂关节力学特性测量装置是利用现有的舱内航天服手臂关节力矩测试装置,在保持其机械和电路部分不变,解决舱外航天服手臂的运动学和静力学算法问题,并对软件部分进行扩展,使其同时具备对舱外航天服手臂的测试能力。本文还提出基于机器人理论的舱外航天服手套关节力学特性测量方法,并针对这一测量方法,研制了外骨骼三指测量机器人测试系统。研制的新型外骨骼手指利用平行四边形连杆机构使手指关节在旋转的同时能够伸长,可实现对手套的包络运动避免了干涉情况。单手指关节之间利用齿轮-连杆组合机构实现运动的耦合,减少了系统自由度,降低了设计的复杂性和成本,减轻了系统的重量。外骨骼手指的多连杆系统对其运动学研究带来困难,利用其运动特点,通过建立虚拟手指,很好的解决了正运动学问题。外骨骼三指测量机器人集机构、驱动、传感、控制为一体,基于FPGA的从控制器,不仅实现各手指传感器信息的采集、电机的驱动还完成与主控制器间的点对点高速串行通讯高速通讯。作为主控制器DSP/FPGA控制卡完成手指的轨迹规划和控制算法,机器人的这种分级控制结构满足实时控制和力学特性测量精度的要求。本文提出了基于扰动观测器(DOB)和鲁棒反馈控制器的双回路控制策略。DOB作为内环补偿器,通过估计系统的干扰来减小其对系统造成的不良影响;在外骨手指动力学研究基础上,对系统模型进行了线性化处理和不确定分析,并基于结构奇异值理论设计了外环反馈控制器,对系统的不确定性仍可实现系统性能要求。这种控制策略不但可以保证系统的鲁棒性能,而且可以克服外界的强干扰,对于系统动力学的不确定都具有很好的鲁棒性。本文分别建立了舱外航天服手套和手臂的数学模型并对逆运动学算法进行了研究。针对舱外航天服手臂的特殊软关节结构和多自由度的特点,提出基于最近邻的快速逆运动学解法,能够保证在任何测量位置都会得到航天服关节角度的近似解。提出的空间分块二步搜索策略解决了基于最近邻方法求解舱外航天服手臂逆运动学,内存占用量大和效率低的缺点。仿真结果表明基于最近邻的快速逆运动学解法在计算精度和实时性上均能满足测试系统的要求。本文最后在实际的测试系统平台上进行舱外航天服手套和手臂关节力学特性测试实验,并对航天服手臂的测量提出了卡具重力补偿和关节重力补偿,提高了测量的精度。实验结果证明舱外航天服手套和手臂力学特性测试系统完全能够满足航天服上肢关节力学特性测量的要求。更多还原

【Abstract】 Spacesuit is the necessary protective equipment of manned spaceflight. It is the most important component of life security system of astronaut. With the development of manned spaceflight, astronaut will make astronauts’extravehicular walking possible in the near future in my country. EVA spacesuit provides not only life security system for astronaut but also excellent movability performance, especially the movability performance of upper limbs can ensure astronauts to complete EVA tasks smoothly. Currently, the EVA spacesuit’s design and processing has almost been completed. A spacesuit measuring system is required to verify and evaluate our own spacesuits. This dissertation comes from the design and manufacture of measuring system for spacesuit joint’s damping parameters, which is applied in National Manned Spaceflight Project. A novel method of measuring spacesuit joints’damping parameters has been put forward. A theoretical system based on this method has been developed. The test has been built. Experiments prove that the correctness and validity of the measuring principle have been done.The test of EVA spacesuit’joint damping parameters include EVA spacesuit arm and EVA spacesuit glove. The testing device of EVA spacesuit arm joint damping parameters is the same as IVA spacesuit joint torque testing device. Keeping the original mechanical devices and hardware unchanged, this project will mainly focus on solving the kinematics and dynamic algorithm problem of EVA spacesuit arm and meanwhile extending the software making it qualified both in testing EVA and IVA spacesuit arms. Based on the theory of robotics a novel measuring method for EVA spacesuit glove has been put forward. Based on the novel measuring method, a three fingers exoskeleton robot system has been developed.A new type of exoskeleton manipulator based on planar four-bar parallelogram mechanism was developed. This kind of manipulator joint could rotate about a fixed center that can avoid disturbance between exoskeleton fingers and glove. The relative motion of finger different joint is coupled through gear-linkages. This design can reduce DOF and complexity of finger system. It is difficult to calculate kinematics for mlti-linkages system. Rely on manipulator special motion character a kinematics model of the manipulator is given through built a virtual finger.The mechanical components, drive components, sensor components and control components are integrated in one exoskeleton finger. The slave controller (FPGA) not only realizes all sensors information acquisition, motor drive, but also realizes the high-speed point to point communication with master controller. The DSP/FPGA control card as master controller realizes control algorithm and trajectory planning. The distributing control strategies of robot satisfy real time control and the requirements of glove measuring.Based on disturbance observer (DOB) and robust feedback controller, a new two-loop control strategy is proposed. In the inner-loop, DOB is designed to compensate effect of disturbance. Depend on the dynamic of exoskeleton finger the proper linear plant mathematical model is built that load dynamics are represented by a feedback uncertainty model, and system uncertainties are analyzed. Based on structure singular value theory outer-loop feedback controller is designed, for system uncertainties which ensure system performance. Applied two-loop control strategy, the system can restrain big disturbance and has robust performance and robust stability for model uncertainties.The models of EVA spacesuit arm and glove have been built and kinematics algorithm has been developed. Based on EVA spacesuit arm special flexible joint structure, a new and high efficiency inverse kinematics algorithm, nearest neighbor algorithm is presented. It can obtain approximate spacesuit joint angle on anyone measuring position. Presented spatial sphere two steps searching method solve the defects of large memory and low searching efficiency. The emulator results from the SGI work station verify that the new algorithm can meet the testing system’s need very well in calculation precision and real-time capability.Measuring experiments of spacesuit joint damping parameters have been done on the actual platform. For improving EVA spacesuit arm joint measure precision, the compensation of chuck weight and joint gravity is used. Experimental results proved that the theoretical system is correct and available, and the measuring system have high preciseness.更多还原