Research on Teleoperation and End Force Feedback System of Soft Actuator

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.