Design and Implementation of a Cable-Driven Continuum Spraying Robot With a Stiffness-Enhanced Flexible Joint

Abstract To address the issues of traditional spraying robots, such as heavyweight and limited adaptability to complex environments, a cable-driven continuum spraying robot (CDCSR) with pulley-winding flexible joints (PWFJs) is proposed, leveraging the high flexibility and compliance of continuum robots. The overall structure of the robot with transition joints and a stiffness-enhanced flexible joint is designed. The kinematic analysis of the CDCSR is conducted, and the mapping relationships among its configuration space, workspace, and actuation space are established. Additionally, a preliminary stiffness analysis of the flexible joint was performed based on the kinematic analysis and force conditions. Finite element analysis of a single flexible joint is carried out. Subsequently, simulation analysis is conducted on the workspace and kinematic mapping of continuum robots with one or two bending joints, followed by result comparison. A prototype of the robot is constructed, and bending performance tests, joint bending stiffness tests, as well as spraying experiments in obstacle environments are conducted. Simulation and experimental results validated that the CDCSR exhibits higher joint stiffness (compared to conventional continuum mechanisms), superior motion performance, and environmental adaptability.