非对称气电混合式机器人末端执行器及其静态力控特性研究

针对现有气动式机器人力控末端执行器存在力控精度低和响应慢等缺点, 提出一种非对称气电混合式力控末端执行器, 采用变参数PID控制器对非对称气缸的气动力与永磁直线同步电机的电磁力进行协调控制, 实现机器人连续接触式作业中接触力的实时补偿与精确控制. 通过对气动系统、永磁电机和控制器等进行建模与仿真分析, 研究其控制特性与力-位移特性. 仿真结果表明, 相比气动力控系统, 气电混合式力控系统可有效消除摩擦力与跟随误差等引起的滞环和爬行现象, 控制特性最大误差由9.2N(2倍最大静摩擦力+动静摩擦力差值)减小至1N, 其力-位移特性最大误差由9.6N(2倍动摩擦力+气动力波动)也减小至1N, 提高了力控精度, 可提升机器人连续接触式作业质量.

The asymmetrical pneumoelectric robotic end-effector and its static force control characteristics

To address the problem of low precision and slow response of the existing pneumatic robotic end-effector with force control, a novel asymmetrical pneumoelectric end-effector is proposed. Pneumatic force of asymmetric cylinder and electromagnetic force of Permanent Magnet Linear Synchronous Motor (PMLSM) are coordinated by variable parameter PID controller to achieve real-time compensation and precise control of the contact force in continuous contact operation of robot. Through modeling and simulation analysis of pneumatic system, PMLSM and controller, the control characteristics and force-displacement characteristics are both studied. The result shows that the pneumoelectric force control system can eliminate effectively the hysteresis and crawling phenomenon caused by friction and following errors compared to the pneumatic control system. The maximum error of the control characteristic is reduced from 9.2N (double the maximum static friction + dynamic and static friction difference) to 1N as well, and that of the force-displacement characteristic is also reduced from 9.6N (double the dynamic friction + pneumatic force fluctuation) to 1N. The quality of continuous contact operation can be improved by the pneumoelectric robotic end-effector with increased force control accuracy.