Design of Lock/Unlock Controllable Joint for Wire-driven Robotic Arms

Wire-driven robotic arms are characterized by high redundancy and a high length-to-diameter ratio, enabling them to navigate and explore effectively in confined environments by controlling and changing their configurations timely, such as during internal reactor inspections following accidents at nuclear facilities. Their flexibility is achieved by changing the configurations of the robotic arms, which can be controlled by using multiple wires in each segment for control, or by using combinations with fewer wires and lock/unlock joint mechanisms. Such mechanisms (e.g., latch) have some limitations in terms of control, energy, response, and long-term reliability. To address, we designed a lock/unlock controllable joint for wire-driven robotic arms using the electromagnetic brake, which can improve the joint capability. This preliminary study progressed through prototype design, control system design, and preliminary testing. We analyzed the challenges associated with existing wire-driven robotic arms with lock/unlock joints. A prototype and control system were then designed and preliminarily tested. Based on the results, the usability of this joint was discussed. This preliminary study laid the groundwork for the subsequent optimization of wire-driven robotic arms.