【作者】 刘国才；

【导师】 蔡鹤皋； 王鹏飞；

【作者基本信息】 哈尔滨工业大学 ， 机械工程， 2017， 博士

【摘要】 液压驱动双足机器人与地面非连续接触的运动特点使其能够适应野外的复杂路面,腿数较少的结构特点便于穿越丛林缝隙,液压装置功率密度比大的驱动特点为野外恶劣环境下运动提供了动力保证,因此,液压驱动双足机器人在野外环境中运动具有很大优势。但由于双足机器人在运动过程中的有限足底支撑面积,使其在受到干扰力时具有容易跌倒的问题,因而限制了双足机器人在现实生活的应用。步行和站立是双足机器人两种最常见的运动状态,在这两种状态中,双足机器人都有可能因受到干扰力而发生跌倒,因此,研究双足机器人的动态平衡步行和站立的控制方法,具有重要的实际意义。本文通过对人体运动过程的简化分析,建立了具有步行和站立能力的带足线性倒立摆模型;通过对带足线性倒立摆模型的动力学分析,得出了支撑腿髋关节力矩、双足切换步长、支撑腿踝关节力矩和身体高度等对身体运动状态影响关系,为双足机器人动态平衡步行和站立控制提供了模型和理论基础。基于干扰力必将转化为身体运动状态变化这一力学规律,结合本文所提出的带足线性倒立摆模型的动力学方程,分析了腿部动作与身体运动状态之间的对应控制关系,搭建了双足机器人动态平衡运动控制框架;建立了以支撑腿髋关节伺服身体姿态、以支撑腿膝关节伺服身体高度,以双足切换步长和支撑腿踝关节伺服身体水平运动的双足机器人动态平衡运动控制算法,同时进行了仿真实验验证,并阐述了该算法向三维空间内拓展的方法,为双足机器人的动态平衡运动提供了控制算法。以人体作为参考,研制了具有力和位置伺服的液压双足机器人样机,并建立了带足线性倒立摆模型与液压双足机器人之间的映射关系;为减小双足机器人关节耦合和着地冲击力引起的液压缸伺服精度误差,研制了基于PQ伺服阀、带力位双反馈的液压缸组件,并建立了伺服阀驱动电流与液压缸输出力与输出位置之间的数学关系,并依据此关系建立了带前馈控制的液压伺服系统,提高了液压双足机器人的伺服精度,为双足机器人动态平衡步行和站立控制算法提供了载体。搭建了包含电控系统和软件系统在内液压双足机器人实验平台;进行了双足动态平衡站立实验,验证了双足站立的动态平衡能力;进行了双足机器人的往复运动试验,验证了控制算法的步行能力;进行了在遭受哑铃撞击、手推、脚踢等多种形式干扰力下的步行实验,验证了双足步行的动态平衡能力。通过以上一系列实验,验证本文所提出的控制算法能够实现双足机器人动态平衡步行和站立。更多还原

【Abstract】 A hydraulic actuated biped robot’s non-continuous contact motion characteristic prompts it to adapt to the complex roads in the field,and the fact that it has fewer legs makes it easy to cope with jungle conditions,as well the high power density ratio of its hydraulic system provides the necessary driving force in the harsh environment.These mean that hydraulic actuated biped robots have great advantages when moving in the field environments.However,due to the limited foot supporting area of the biped robot,it can easily fall down when suffering disturbance force,which greatly limits the application of biped robot in actual life.Standing and walking are the two most common motion states for biped robots,accordingly,the research on dynamic balance walking and standing of biped robots has important practical significance.A footed inverted pendulum model with walking and standing ability was established by simplifying human motion process.Through the dynamic analysis of the footed linear inverted pendulum model,obtained the relationships between body motion states and leg actions’ including the stance hip torque,the step switch length,the stance ankle torque and the body height.These then provided a model and a theoretical basis for the dynamic balance walking and standing control for biped robots.Based on the Newton’s laws of motion that the disturbed force will be transformed into the changes of body motion states,and according to the dynamic equations for the footed linear inverted pendulum model proposed in this paper,the corresponding control relationship between leg action and body motion were analyzed.Based on this,a framework for dynamic balance motion control for biped robots was established,which included controlling body postures by hip stance,controlling body height by knee stance,and controlling body level movement by the biped switching step length and ankle torque.The algorithm then was verified by simulation.Then,a method of extending the algorithm to three-dimensional space was illustrated,which provided a control algorithm for biped robot dynamic balance when the robot is in motion.A hydraulic biped robot with a force-position servo was developed by taking the human body as a reference.The mapping relationship was established between the footed linear inverted pendulum model and a hydraulic actuated biped robot.To decrease the hydraulic servo error imposing by joints coupling and touchdown impact of biped robots,a hydraulic cylinder assembly was developed with a PQ servo valve and force-position feedback.The mathematical relationship between the PQ servo valve input current and hydraulic cylinder output force and position was established.According to this relationship,a hydraulic servo system with feed-forward control was established,and improves the servo accuracy of the hydraulic biped robot,which provided a carrier for the biped dynamic balance walking and standing control algorithm.A hydraulic biped robot test platform,including electronic control boards and associated control software,was developed;a dynamic balance standing test was carried out,which verified the standing capability.A round-trip movement test of a biped robot was carried out to verify the walking ability of the control algorithm.Walking tests,with interference from dumbbells,hand-pushing,kicking and other forms of balance disruptions were carried out,which verified the dynamic balance walking capability.Through the above series of tests,it was verified that the control algorithm proposed in this paper could achieve dynamic balance walking and standing for biped robots.更多还原