Development of Wearable Lightweight Continuum Manipulator to Enhance Capability of Human Arm

A wearable continuum robot to supplement human capability is proposed. For this purpose, a light, flexible, and wearable robotic manipulator is designed and a 255-mm-long prototype, with a maximum diameter of 26mm and weight of 58g is fabricated. The prototype consists of two units: a continuum unit, which comprises several rigid links connected via a bar spring and three wires, a drive unit, which is used to tension wires to bend and control the continuum unit, including a control-and- power module. The drive unit contains three small motors and is equipped with pulleys to pull the wires. A model to simulate the behavior of the continuum unit is developed based on the capstan equation. The proposed model is used to estimate the posture of the continuum unit from the tension of wires. Furthermore, the validity of the proposed model is demonstrated experimentally. The results indicate a linear relationship between the bending angle and external force. The results suggest that the proposed model can be used to estimate external forces from the posture of the continuum unit. Object holding functions of the prototype worn on the wrist is demonstrated as an example of enhancement of human arm capabilities by wearable continuum manipulator.