Design and Control of a Portable Continuum Robot for Pipe Inspection Assisted by a Rigid Manipulator

Inspired by the behaviors of animals, the continuum robot provides superior flexibility, deformability, and adaptability within a lightweight structure, making it ideal for use in confined spaces. However, most continuum robots are designed for a specific application and lack versatility and mobility due to their bulky actuation system. This chapter introduces a portable tendon-driven continuum robot that, due to its modular design, can be easily mounted on various rigid robot platforms, providing additional manipulation capability and a larger workspace. In this design, 1) a lightweight and portable structure that integrates the actuation units, control electronics, and sensors into a compact tubular base; 2) a modularized actuator unit with force sensing capability, are proposed. To test the portable continuum robot, the actuation base is mounted on an industrial manipulator. Assisted by the rigid manipulator, the continuum robot is used to inspect a pipeline with the robot body in a compliant state using a closed-loop tendon force control. Finally, the experiments are evaluated by the measured tendon forces and the images captured by an endoscope camera placed inside a hollow flexible backbone. The results of the experiments show that the proposed continuum robot can be used for pipe inspection and has considerable potential for other applications. Moreover, the manipulation capability of a continuum robot could be enhanced significantly by cooperatively working with a rigid manipulator.