【作者】 张江涛；

【导师】 汪增福； 关胜晓；

【作者基本信息】 中国科学技术大学 ， 模式识别与智能系统， 2008， 博士

【摘要】 仿人机器人是机器人领域的一个研究热点。与大多数机器人不同,仿人机器人对机械结构以及驱动装置有许多特殊的要求。其中,设计和实现可以满足使用要求的关节及其驱动装置是仿人机器人研究的一项主要任务。目前,机器人关节的驱动方式主要有液压、气动、电磁电机驱动等几种。将这些驱动方式用于仿人机器人时存在一定的不足。本文以两足仿人机器人的人工肌肉与关节为研究对象,提出了一种新型的仿人机器人驱动结构。该结构由大力矩自锁回转关节和人工肌肉所构成。与传统关节型机器人中的回转动力驱动部件不同,我们所设计的大力矩自锁回转关节主要用于完成对机器人本体的支撑和位姿保持功能,而对臂、肢的回转驱动以及对手爪或末端操作器负载的夹持驱动则主要由人工肌肉来完成。为了使得所设计的人工肌肉和关节满足仿人机器人的驱动要求,本文开展了以下几个方面的研究:(1)总结和归纳了压电陶瓷堆的基本工作特性;分析了超声波电机和尺蠖电机在原理上的本质差别,并对箝位端的运动轨迹做了详细的分析,比较了各种箝位端运行轨迹对摩擦的建立以及对系统性能的影响;在尺蠖驱动的基本形式的基础上,提出了一种改进的尺蠖驱动形式,并将其用于人工关节(尺蠖型旋转驱动器)的设计中。(2)基于逆压电效应和尺蠖运动的基本形式,提出了一种新型的人工肌肉驱动器。一体化的设计方案和独特的柔性铰链结构提高了系统的工作频率和工作速度;此外,所引入的箝位中心调节装置,放松了对驱动器的加工要求,也增加了系统的稳定性。(3)构建了人工肌肉驱动器中压电陶瓷堆的仿真模型,并通过对箝位系统、伸缩系统的动力学分析,建立了相应的动力学方程和仿真模型。此外,对经典库仑摩擦模型、状态转换模型以及复位积分模型等三种摩擦模型进行了比较研究,并用复位积分模型法建立了人工肌肉系统的摩擦模型。在此基础上,利用仿真对人工肌肉的工作特性进行了分析,得到了人工肌肉的运行方式、运行频率、负载和系统工作速度的关系等。仿真结果表明,系统具有良好的输出性能。(4)基于逆压电效应和尺蠖运动的基本形式,提出了另外一种人工肌肉的结构设计。这种人工肌肉与前面介绍的人工肌肉主要存在结构上的不同,驱动原理一样。同时,基于逆压电效应和尺蠖运动的改进形式,也提出了一种新型的人工关节,对人工关节的结构和驱动原理都做了详细的介绍和分析。研究表明这种人工关节具有大力矩和自锁的特性,为仿人机器人的位姿保持提供了研究的基础。从研究的结果来看,所设计的人工肌肉和关节驱动器在性能指标上能够满足仿人机器人的驱动要求,为今后从事仿人机器人的研究打下了良好的基础。更多还原

【Abstract】 Recently, humanoid robot has become the focus of robot research. Humanoid robot imposed rigorous requests on mechanic and drivers. The designs of joint and its driver are the key problems. Traditional drivers for robot’s joint include fluid drive, pneumatic drive, and electromagnetic motor, etc, but there are many limits when they are applied on humanoid robots. This paper has proposed a new drive structure for humanoid robots. The drive structure includes artificial muscle and artificial joint which has large torque. The muscle and the joint were designed independently while cooperated with each other. The artificial joint was not as the rotary part as in traditional robot but worked for supporting and maintaining the gesture. The drivers of limb and end operator were fulfilled by the artificial muscle.In order to satisfy the requests of large force/velocity output and high precision of robots’ actuator, this research mainly concludes the following studies.The basic working characteristics of piezoelectric pile were summarized and induced. The essential differences between piezoelectric ultrasonic motor and inchworm actuators were analyzed. The motion trajectories of the end of clamping structure were exploited, and the effects of the motion trajectories to friction were compared. The basic principle of inchworm, which was applied in artificial muscle, was concluded and a new model of inchworm motion, which was applied in artificial joint, was proposed.A new artificial muscle was proposed based on basic inchworm motion and converse piezoelectric effects. The actuator designed has unique flexible hinge and can adjust the center of anchoring/loosening. The principle, mechanical realization, and finite element analysis for the major parts were introduced. The actuator can work at high frequency and possess high speed, large travel, and high load. It also has high operation stability and practical value.In order to get and optimize the performance of the actuator, the kinetics models were founded for the clamping system, the driving system, and friction system, etc. Three friction models, including classical (coulomb) friction model, the karnopp model, and the reset integrator model, were compared. As the reset integrator modal is the most precise model, it was applied in the friction system model. The simulation was processed and the relationships between the velocity and load, the signal’s frequency, and work style, were also analyzed. As an actuator, the artificial muscle has favorable performance.Another artificial muscle and a new artificial joint were designed. The principle, mechanical realization was introduced. This artificial muscle had different mechanic structure but the same driving principle with the muscle introduced in the front of this paper. The new artificial joint was designed based on the new model of inchworm motion. According to the research, the joint has large torque and self-locking characteristic.As a result, the performance of the artificial muscle and joint which were designed in this paper could satisfy the humanoid robot well. It established the foundation for the further humanoid driver research.更多还原