Cooperative Research on the Vibration and High-Speed Controls of Flexible Robot Arm

本项目是在过去三年中，在日本东北大学和韩国全北国立大学的合作下进行的，以构建有效的控制方案，以实现在尖端具有重有效载荷的轻型机器人机械手的高速定位，同时考虑到机械手连杆的灵活性。该项目的具体内容如下。详细研究了一种简单的端部传感和基座力矩控制方案，该方案通过安装在空间的间隙传感器在每个连杆的端部测量位置反馈。然后将测量结果与估计的终点速度一起用作向连杆的另一端施加控制扭矩的基础。为此，建立了考虑链路柔性的系统控制方程，并进行了仿真，得到了系统的最优PD反馈增益.在东北大学和全北国立大学建造了几个原型机械手和控制器，看看这里提出的控制方案的有效性。结果表明，该简单的控制方案对单连杆和多连杆柔性机械臂的设定点都有较好的控制效果.研究了柔性机械臂的逆动力学问题，其中臂基作横向平移，使臂尖实现预定运动。这是一种开环控制方案，比闭环PD控制容易得多。理论计算和相应的实验结果表明，开环控制同样适用于柔性臂系统的点对点控制。

The present project was pursued for the past three years under the collaboration of Tohoku University, Japan and Chonbuk National University, Korea to construct effective control schemes to accomplish high-speed positioning of light-weight robotic manipulators with heavy payload at the tip, taking into account the flexibility of the manipulator links. The details of the project are as follows.1. A simple scheme of tip sensing and base torquing was studied in detail, where the position feedback was measured at the ends of each links by gap sensors fixed in space. The measurement was then used together with the estimated endpoint velocity as a basis for applying control torque to the other end of the link. To this end, governing equations of the system that takes into account the flexibility of the links were constructed and the simulation results were obtained to find the optimum PD feedback gains of the controller.2. Several prototype manipulators and the controllers were constructed at both Tohoku University and Chonbuk National University to see the effectiveness of the control scheme proposed here. It was found that the simple control scheme works well for the set-point of the single-link and multi-link flexible manipulators.3. Inverse dynamics of the flexible manipulator was examined, in which the arm base was translated in the lateral direction so that the arm-tip realizes a prescribed motion. This is an open-loop control scheme, much easier than the closed-loop PD control. Theoretical calculation and the corresponding experimental results showed that the open-loop control again works well for the point-to-point control of the flexible arm system.