【作者】 刘成军；

【导师】 李祖枢； 薛方正；

【作者基本信息】 重庆大学 ， 控制理论与控制工程， 2011， 博士

【摘要】 双足机器人具有广阔的应用前景,是近年来机器人学领域的研究热点之一。但就目前发展水平来看,还远未达到人类期望的大范围动态步行水平,具体表现为运动性能较差,存在能耗高、速度低、环境适应能力低等问题。欠驱动双足机器人是为了研究快速、自然动态步行而提出的一种机器人结构。机器人没有脚掌,与地面点接触形成欠驱动系统,这给机器人的稳定控制带来巨大挑战。机器人不能形成稳定域,静止站立十分困难;需要通过不断变换支撑点位置实现动态平衡。但由于欠驱动机器人可以充分利用重力和惯性力,其步态具有高效、高速、动作自然等特点,为双足机器人运动控制研究提供了新的思路。针对目前欠驱动双足机器人足地间接触假设性条件过多等问题,提出了一种从实际角度考虑的双足机器人行走动力学特性模型,包含足地间接触关系和反映人类自然行走的膝关节限制特性,为控制策略设计提供基础。以“仿人”、“仿生”为指导,深入分析人类行走过程中的运动机理,运用仿人智能控制的研究方法,提出了欠驱动双足步行仿人运动控制方案。对双足动态步行这一复杂任务分解,研究仿人智能控制理论在步行控制中的特征选择、控制模态的确定等关键技术,实现欠驱动双足行走机器人高效能动态步行,并与其它典型控制策略开展仿真比较研究。针对欠驱动双足机器人步行过程中环境不确定性问题,指出不摔倒是稳定性的重要表征,当双足步行过程受到干扰时,原有的步态模式不能继续保持,就需要进行调整以适应变化。通过模仿人的控制行为,实时判断系统出现的不稳定趋势,提出能够保持机器人不摔倒的稳定性监控方案,以适当的控制量对欠驱动双足行走机器人进行在线步态调整保证系统运行,分析了实现步态调整后双足机器人的稳定性。充分利用开源软件的优越性,建立了一个通用的基于开源物理引擎的双足机器人步行控制研究仿真平台。通过抽象仿真平台的开发过程,设计了计算机与开发人员都可以理解的结构表以提高仿真平台的品质,进而设计双足机器人仿真平台的开发框架,在该框架下实现具有实用性的仿真平台,并注重开放性、灵活性和简洁性,为双足机器人仿真平台的设计者展示了一条快捷方便的开发途径。设计了基于CAN总线集中式控制结构的双足机器人样机系统,解决关节实时驱动控制器和地面力测量装置中存在的软硬件设计问题,感知系统实时监测双足机器人自身状态的各项指标,同时从外界环境中采集各种有用信息,而双足机器人的控制系统则根据感知系统提供的各种信息,对驱动系统进行控制,使双足机器人实现双足步行功能,对关节控制器提出应用仿人智能控制策略以抑制驱动电机转矩脉动。更多还原

【Abstract】 Biped robot is a focus in the field of robotics research in recent years for its broad potential application. But to the developmental level of biped technology,it achieves far from the expectation of human being for a wide range dynamic walking. To be more specific, movement capability of current biped robots is very poor,and the biped walking is slow, inefficient and poor adaptation to the environment.So,underactuated biped robot is brought forward to research high speed and naturally dynamic walking.The robot has no soles and touches ground with points,which brings great challenges to biped stability control for its underactuated method.For example,it has no stable region,still standing is almost impossible and its supporting points may keep moving to achieve dynamic stability.But the greatest merit is that the underactuated biped robot can walk naturally with high speed and high efficiency for taking full advantage of gravity and inertia force. Therefore,the appearance of underactuated biped robot offers new methods for biped motion control.The main contributions of the dissertation include the following:A more accurate model which can reflect the dynamics of the biped robot, including the contact method of the leg tip with the ground in line with the actual situation and the kneecap limit which can reflect the characteristics of human natural walking is presented to avoid current inappropriate assumptions and provided to be the basis for control strategy design.With the Human-Simulated Intelligent Control method, the complex process of dynamic walking for underactuated biped robot is divided through in-depth analysis of human walking mechanism under the direction thought of“human-simulated”and“biologies-simulated”.The Human-Simulated motion control scheme is developed for underactuated biped robot.The key technology of characteristic selection and control mode decision are researched. A comparative study is carried out with other typical simulation and the efficient dynamic walking of underactuated biped robot is achieved.When the underactuated biped robot is subjected to the environmental uncertainty, it will fall down or not,which is an important symbol of stability. When the underactuated biped robot is put in an uncertain environment, the biped robot can’t keep walking with the original gait patterns which need to be adjusted. By mimicking human behavior, the instability trend can be observed in real time. The stability supervision and control method which can maintain the robot not falling are presented through adjusting walking gait on line to maintain balance. The stability of the biped robot is analyzed after the walking gait adaptation.An ODE (Open Dynamics Engine) based integration solution of the wide range dynamic walking for biped robot simulator is presented to get an universal simulator. The development procedure of the ODE based biped robot simulator is abstracted and the advantage of open source is taken. The structure of a biped robot is described by a robot structure table that can be understood by simulator designers and the computer to improve the performance of the simulator. Then the development framework of a biped robot simulation platform is designed and the simulation platform is realized. The simulation platform is focused on openness, flexibility and simplicity and shown a convenient way for the designer of the biped robot simulation platform.The centralized control system of biped robot prototype platform based on CAN bus is designed. The design of hardware and software of the real-time controller for driving joint is presented,so do with the measuring device of contact force of ground. The biped robot’s own state is monitored in real-time and a variety of useful information of the environment is collected by the sensing system. The underactuated biped robot controls the drive system with the information to achieve biped walking. A HSIC control strategy is also presented to reduce the torque ripple of drive motor.更多还原