Motion Planning and Control of Nonholonomic Mechanical Systems

在本项目中，我们研究了非完整机械系统的运动规划与控制。首先，我们阐明了各种机器人非完整系统的共同数学结构。然后，我们建立了利用各种机器人系统的非完整理论的方法。本课题的主要成果概括如下：(1)建立了空间多体系统动力学的高效计算格式。研究了空间欠驱动机械系统的不可积性。(2)提出了用自由关节连接刚体来构建空间多体结构。建立了这种空间多体结构的稳定控制方法。这样的系统没有弹性诱发的结构振动。结构的可重构性是另一个优势。讨论了受非完整运动学约束的机器人系统的各种问题。水下机器人的跟踪控制、自由飞行空间机器人的非完整冗余度、自由飞行空间机器人不可行运动的近似、弹性空间结构的非完整漂移运动等都属于这类问题。(4)研究了空间机器人系统的节能控制。提出了利用控制动量陀螺的冗余度来释放/存储再生动能。(5)提出了一种非完整机械手。这是一种革命性的机器人机械手，只用两个电机就可以控制它的N个关节。非线性控制使之成为可能。建立了系统的能控性和链式变换。目前正在研究自由后退/自由前进式控制，并正在进行机械设计。

In this project, we studied on Motion Planning and Control Nonholonomic Mechanical Systems. First, we clarified the common mathematical structure of various robotic nonholonomic systems. Then, we established methodologies for utilizing nonholonomy of various robotic systems. The main results of this project are summarized in the following five items :(1) An efficient computational scheme for the dynamics of space multibody systems was established. Nonintegrability of space underactuated mechanical systems was investigated.(2) We proposed to build a space multibody structure by connecting bodies with free-joints. A stabilization control of such space multibody structure was established. Such a system is free from elastically induced structural vibration. Reconfigurability of the structure is another advantage. It will be efficiently used for example as a space storage system.(3) Various problems of robotic systems subject to nonholonomic kinematic constraints were discussed. Tracking control of underwater robotic vehicles, nonholonomic redundancy of a free-flying space robot, approximation of infeasible motion of a free-flying space robot, nonholonomic drift motion of elastic space sturctures were the issues in this category.(4) Energy-saving control of space robot systems were investigated. It was proposed to utilize the redundancy of control-momentum-gyro to release/store kinetic energy obtained through regeneration.(5) A nonholonomic manipulator was proposed. This is a revolutionary robotic manipulator that control its N joints with only two motors. Nonlinear control made it possible. Controllability and chained-form transformation were established. Freedback/freedforward control is currently being studied and mechanical design is undergoing.