Soft-Actuator-Based Robotic Joint for Safe and Forceful Interaction With Controllable Impact Response

Impact safety and response are critical challenges for robots working under dynamic environments and with close proximity to humans. State-of-the-art rigid robots and soft robots both have limitations and tradeoffs due to their characteristics. In this letter, we introduced a hybrid-antagonistic-pneumatic joint (HAP-joint) with soft actuators and rigid structures, achieving safe and forceful interaction. Due to the hybrid approach and the wide working range of the proprietary soft actuators, the HAP-joint could achieve controllable impact responses both predetermined by control parameters and regulated online by real-time feedback. The design, modeling, control, and experimental validation of HAP-joint are presented in detail. Based on the excellent features and performances of HAP-joint, a controller framework is formulated on impact response shaping, combining passive compliance, and online regulating. The controller could achieve both excellent tracking behavior while handling accidental impacts following a desired manner, demonstrating the vast potentials of soft robots for safe and forceful interactive tasks toward various applications.