Analysis and Control of High Compliance Systems with Coulomb Friction

库仑摩擦高柔顺系统的分析与控制

基本信息

批准号：
15360222
负责人：
AOSHIMA Nobuharu
金额：
$ 6.85万
依托单位：
University of Tsukuba
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

项目摘要

First, we show the effects of slight Coulomb friction on a simply supported beam under compressive force, which is a high compliance system. The governing equation, which is a nonlinear partial differential equation, is deduced. By the method of multiple scales, the system is analyzed. As a result it is clarified that very low stiffness and Coulomb friction produces infinite number of stable equilibrium states. The phenomena are identified by bifurcation theory. And the validity of the theoretical result is experimentally confirmed. The high- frequency excitation destabilizes these stable equilibrium points and stabilizes the buckled beam to the straight position. Also, experimental identification method for Coulomb friction is proposed. Furthermore, we propose a motion control of an underactuated manipulator, which is high compliance system. The high frequency excitation produces variety of stable equilibrium states. The change of the excitation direction perturbs the bifurcation phenomena and carries out the position control of the under actuated link without state feedback control. Experimental apparatus of the underactuated manipulator is constructed. The validity of the proposed control method is experimentally confirmed. Furthermore, we consider the case when the underactuated link is flexible. The equation of motion is partial differential equation. Under high-frequency excitation of the active link, the dynamics of the underactuated link is analyzed by introducing multiple time scales. Also, in this case, experiments are conducted and the motion control of flexible underactuated manipulator is experimentally confirmed. Finally, we consider the application of the high compliance system for grip. The grip does not give impact objects because the joint of the grip is freely rotated. This system uses high frequency excitation and carries out motion control.

首先，我们展示了在压缩力作用下轻微库仑摩擦对简支梁的影响，这是一个高柔量系统。推导了控制方程为非线性偏微分方程。采用多尺度方法对系统进行分析。结果表明，非常低的刚度和库仑摩擦会产生无限数量的稳定平衡状态。这些现象是通过分岔理论来识别的。并通过实验证实了理论结果的有效性。高频激励使这些稳定平衡点变得不稳定，并将屈曲梁稳定到笔直位置。此外，还提出了库仑摩擦力的实验识别方法。此外，我们提出了欠驱动机械手的运动控制，这是一种高顺应性系统。高频激励产生多种稳定平衡状态。励磁方向的变化扰动了分叉现象，并在没有状态反馈控制的情况下进行欠驱动连杆的位置控制。搭建了欠驱动机械臂实验装置。实验证实了所提出的控制方法的有效性。此外，我们考虑了欠驱动连杆是柔性的情况。运动方程是偏微分方程。在主动连杆的高频激励下，通过引入多个时间尺度来分析欠驱动连杆的动力学。此外，在这种情况下，进行了实验，并通过实验证实了柔性欠驱动机械臂的运动控制。最后，我们考虑了高顺应性系统在抓地力方面的应用。由于握把的关节可以自由旋转，所以握把不会受到物体的冲击。该系统采用高频励磁并进行运动控制。