步行机器人弹性驱动器动力学及驱动特性研究

发布时间：2018-11-26 08:26

【摘要】：本课题来源于国家自然科学基金项目。机器人腿部驱动装置的发展远落后于当今世界机器人工作的未知复杂环境这一特殊的发展要求,本论文以设计一个对未知环境高度适应、性能可靠和灵活运动能力极强的机器人及假肢所需要的弹性驱动器为目标,并对弹性驱动器的机械本体结构、动力学模型及仿真进行了研究。本文从仿生学的角度出发,根据动物腿部肌肉的特性,结合传统的无阻尼弹性驱动器的原理,提出了有阻尼圆筒式弹性驱动器模型,设计了一个更接近肌肉性能的弹性驱动器。建立了无阻尼和有阻尼弹性驱动器的动力学模型,并对这两种机械结构形式的动力学进行了分析,有阻尼弹性驱动器在输出过程中,可以根据负载力的大小被动调节驱动刚度和压缩速度,更好地模拟动物肌肉运动的特性。结合传统的无阻尼弹性驱动器的结构特点,设计了一种有阻尼圆筒式弹性驱动器结构。根据机器人腿部指标的要求,计算出了弹性驱动器所需弹簧的总体刚度为25N/mm,介绍了有阻尼驱动弹性驱动器各组成部件的选取原则。对两种弹性驱动器的关键零件进行了有限元结构强度分析,并对弹性驱动器硬件控制电路进行了设计。利用dSPACE对弹性驱动器的驱动特性进行了分析。首先,通过实验得到弹性驱动器产生的阻尼系数约为0.1Ns/mm；其次,通过不同带宽仿真和实验得到阻尼系数在0-0.2Ns/mm之间,阻尼系数测定实验不仅得到了驱动器本身的阻尼系数而且还验证了不同带宽跟随特性和验证了实验方法的可行性,这为以后深入研究弹性驱动器以及有阻尼弹性驱动器阻尼系数的选取提供了依据。最后,通过不同负载下的位移跟随实验,得到了弹性驱动器不同负载下的位移实际输出情况,根据机器人腿部机构质量指标验证弹性驱动器的可靠性。本文通过对两种弹性驱动器进行动力学分析和驱动特性研究,得出有阻尼弹性驱动器更接近于肌肉特性,能更好地解决机器人行走过程中足部冲击力的问题,降低冲击力对足部的影响,并且通过实验得到阻尼系数对驱动特性的影响及其选取范围。
[Abstract]:This subject comes from the National Natural Science Foundation of China. The development of robot leg driving device lags far behind the special development requirement of unknown complex environment of robot work in the world today. This paper designs a highly adaptable to unknown environment. The elastic actuators needed by robots and prostheses with reliable performance and flexible motion ability are the targets. The mechanical bulk structure, dynamic model and simulation of the elastic actuators are studied. In this paper, according to the characteristics of animal leg muscles and the principle of traditional undamped elastic actuators, a model of damped cylindrical elastic actuator is proposed, and an elastic actuator which is closer to muscle performance is designed from the point of view of bionics. The dynamic models of undamped and damped elastic actuators are established, and the dynamics of these two mechanical structures are analyzed. The driving stiffness and compression speed can be adjusted passively according to the load force, and the characteristics of animal muscle motion can be better simulated. According to the structural characteristics of traditional undamped elastic actuator, a structure of damped cylindrical elastic actuator is designed. According to the requirements of the robot leg index, the total stiffness of the spring needed for the elastic actuator is calculated to be 25 N / mm, and the principle of selecting the components of the elastic actuator with damping is introduced. The finite element structural strength analysis of the key parts of two kinds of elastic actuator is carried out, and the hardware control circuit of the elastic driver is designed. The driving characteristics of elastic driver are analyzed by dSPACE. Firstly, the damping coefficient of the elastic actuator is about 0.1Ns / mm. Secondly, through different bandwidth simulation and experiment, the damping coefficient is obtained between 0-0.2Ns/mm, The damping coefficient measurement experiment not only gets the damping coefficient of the driver itself, but also verifies the different bandwidth following characteristics and the feasibility of the experimental method. This provides a basis for the further study on the selection of damping coefficient of elastic actuator and damping elastic actuator. Finally, through the displacement following experiment under different loads, the actual displacement output of the elastic actuator under different loads is obtained, and the reliability of the elastic actuator is verified according to the quality index of the robot leg mechanism. Based on the dynamic analysis and the study of the driving characteristics of two kinds of elastic actuators, it is concluded that the damping elastic actuator is closer to the muscle characteristics and can better solve the problem of the impact force of the foot during the walking process of the robot. The influence of the impact force on the foot is reduced, and the influence of damping coefficient on the driving characteristics and its selection range are obtained by experiments.
【学位授予单位】：哈尔滨工程大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TP242;TH113

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