气电混合式力控末端执行器接触力控制研究

Research on the Contact Force Control of Pneumatic-Electric Hybrid Force-Controlled End-Effector

针对机器人打磨、抛光应用需求,设计了一种气电混合式力控末端执行器,其动平台与定平台之间通过音圈电机、空气弹簧和拉伸弹簧三者并联连接。该末端执行器的上、下支架均采用了轻量化镂空结构,并通过有限元方法对其结构刚度进行校核。为提高力控末端执行器在硬质接触环境下的力控稳定性和力跟踪精度,采用了一种基于导纳控制的间接力控制方法,并搭建力控实验平台测试了系统的动态性能。实验结果表明,系统的阶跃力跟踪响应时间约70 ms,力控精度为±0.2 N,控制带宽可达20 Hz,其力控性能明显优于传统的力控末端执行器,能够满足实际工艺需求,具有较高工程应用价值。

Aiming at the requirements of robot grinding and polishing applications, a pneumatic-electric hybrid force-controlled end-effector is designed. The moving platform and the base are connected in parallel by voice coil motor, air spring, and tension spring. The upper and lower brackets of the end-effector adopt a lightweight hollow structure, and their structural stiffness is checked by finite element method. In order to improve the force control stability and force tracking accuracy of the force-controlled end-effector under the hard contact environment, this paper adopts an indirect force control method based on admittance control, and builds an experimental platform to test the dynamics performance of the system. The experimental results show that the response time of the system under step force tracking is about 70 ms, the force control accuracy is ± 0.2 N, and the control bandwidth is up to 20 Hz. Its force-controlled performance is significantly better than traditional force-controlled end-effectors, which can meet the actual process requirements, and has higher engineering application value.