End-effector with Force Sensors for Process Monitoring of Tire Changers

To monitor processes of a tire changer that demounts a tire from a wheel, this paper proposes an end-effector with internally integrated force sensors and a process monitoring algorithm using its output. In the tire demounting processes, the tip of the proposed end-effector interacts with the tire and wheel rim. To measure the interaction force efficiently, the proposed end-effector is designed with a T-shaped beam for stress concentration, and the resulting strains along three orthogonal axes are detected by strain gauges. The sensor outputs are amplified and calibrated to decrease crosstalk and to improve accuracy. As a result, the proposed end-effector achieves high accuracy with a linearity of less than 1% FS. To utilize the proposed end-effector for process monitoring, an algorithm is developed and experimentally validated on a tire changer. The experimental results show that the proposed end-effector can correctly monitor and detect errors in the tire demounting processes using the proposed algorithm with a high success rate of 97%.