遥操作软体机械臂的末端力反馈系统分析

Research on Teleoperation and End Force Feedback System of Soft Actuator

软体机械臂具有天然的柔顺性,作为末端执行器可以实现传统刚性机械臂难以实现的功能,例如可以轻松实现柔性抓取和柔性运动等,而且其对人体友好,在人机交互上具有高度的安全性。文中提出了一种软体机械臂的遥操作以及末端力反馈系统,并基于运动学模型和力反馈方法对其进行控制研究,建立了弯曲模型、伸长模型和力反馈模型,提出了控制方法和控制流程。操作人员通过操作手柄,实现了对位于另一物理空间的软体机械臂的遥操作控制,不仅能控制软体机械臂向任意方向弯曲,还可以控制其在曲率不变的情况下伸长。其中软体机械臂由3个周向均匀布置的波纹管构成,末端力反馈效果通过手柄内部的气动元件实现。该手柄是一种新型主手结构,包括手柄A和手柄B,分别控制软体机械臂的弯曲和伸长,且手柄B具有一定的力觉临场感。文中对提出的系统进行了实验验证,证明了软体机械臂在弯曲、伸长、力反馈阶段的功能,并配备皮肤模型验证软体机械臂作为末端执行器在超声波检测场景下的功能,实验数据表明,软体机械臂末端压力达7N,力反馈控制循环时间在1s左右。文中所建立的系统一方面发挥了软体机械臂的柔顺性,另一方面还增加了其远程控制的功能,并且带有力觉临场感,在未来可广泛应用在远程医疗、按摩等领域。

The soft actuators are flexible in nature,and as an end-effector,it can realize functions that are difficult to be achieved by the traditional rigid actuator,such as flexible grasping and flexible motion.Moreover,it is friendly to human body and has a high degree of security in human-machine interaction.This paper presented a teleoperation and end force feedback system of soft actuator.Its control was studied based on kinematic model and force feedback method.The bending model,elongation model and force feedback model were established,and the control method and control flow were presented.Through a pair of handles,the operator realized the remote control of the soft actuator located in another physical space,which can not only control the soft actuator to bend in any direction,but also control its elongation with the same curvature.The soft actuator is composed of three bellows uniformly arranged in the circumferential direction,and the force feedback effect of the end is realized by the pneumatic components inside the handle.The pair of handle is a new type of main hand structure,including handle A and handle B,which control bending and elongation of soft mechanical arm respectively.Handle B has a certain force sense of presence.The proposed system was experimentally verified,and the functions of the soft manipulator were proved in the bending,elongation and force feedback stages,and the skin model was equipped to verify the functions of the soft actuator as the end-effector in the ultrasonic detection scene.The experimental data show that the pressure at the ends of soft actuator is 7 N,force feedback control loop time is around 1 s.The system established in this paper,on the one hand,plays the flexibility of the soft actuator,on the other hand,it also increases the function of remote control,and has a powerful sense of presence,which can be widely used in telemedicine,massage and other fields in the future.