Advanced Hybrid Control of Mobile Cable-Driven Parallel Robot with 8-Cables

Abstract

This paper introduces control algorithms aimed at improving the stability of a mobile cable-driven parallel robot (MCDPR), consisting of four mobile platforms and eight cables during motion. The discussed algorithms include cable length control (CLC), addressing target cable length calculation through inverse kinematics, considering pulley influence; the tension distribution algorithm (TDA) for cable tension calculation to maintain static equilibrium at the end-effector and cable length control based on tension errors; path curvature-based localization (CBL) that estimates robot positions using curved path predictions from robot velocities and angular velocities; and index error feedback (IEF), which sustains robot formation by providing feedback on robot positions. Experimental verification was conducted using a prototype MCDPR. Results indicated that all algorithms reduced both position and tension errors. Notably, algorithms directly affecting cable control, especially CLC and TDA, had a more pronounced impact on tension errors. Failure to apply CLC, in particular, led to extremely high tensions, resulting in slip and tipping in each robot and larger position errors. These findings contribute to the advancement of MCDPR technology, enhancing its stability and reliability for various applications.