末端执行器压脚气动伺服控制系统设计

Pneumatic servo control system design for pressure foot of an end-effector

针对机器人自动制孔系统中末端执行器压脚作用到工件表面时产生冲击问题,提出压脚机构位置缓冲控制方法.在建立压脚机构气动非线性模型基础上,通过摩擦力模型补偿,设计一种滑模控制器,以压脚与工件之间的相对位置作为控制输入,压脚相对于执行器的位移作为控制反馈,构成压脚机构位置全闭环控制系统,实现压脚机构快速定位到工件表面,同时减小对工件表面的冲击.实验结果表明,压脚机构经过位置缓冲控制后,对工件表面冲击力减小到无缓冲控制时的2.5%.

This paper presents a cushion control method to reduce the impact force when the pressure foot presses onto the workpiece in the robotic drilling process. The design of a slide mode controller, which is based on a non-linear model of the pneumatic servo system of the pressure foot and a friction compensation model, is presented. A closed-loop motion control system of the pressure foot is implemented, in which the relative position between the pressure foot and the workpiece is used as the command and the movement between the pressure foot and the feed axis of the end-effector is used as the feedback signal. By employing the developed motion control system, fast positioning of the pressure foot onto the workpiece can be achieved with low impact force. According to the experimental results, when controlled with the proposed controller, the impact force of the pressure foot onto the workpiece can be reduced to 2.5 % of that without position servo cushion control.