A Preliminary Evaluation of Static Tests to Detect Slip Using Tyre Strain Sensing System in Robotic Platforms

Wheel slip estimation is a determinant factor in improving performance of wheeled mobile robots. Conventional wheel slip estimation methods relied upon sensors which are far from the tyre-ground interface; hence, they required the use of approximated models and complex transformations. A modern method which directly measures tyre-ground contact quantities utilising in-tyre sensors helps develop accurate and direct wheel slip estimation techniques. In this paper, an optimum sensing system for small, non-pressurised robotic tyres is presented. Data processing algorithms are proposed to show possible techniques for deploying the readings of this system to estimate tyre forces and slip variables. These algorithms analyse the sensing system's measurements in both longitudinal and lateral directions with respect to the tyre direction of motion. Performance of the system is evaluated with static tests using a custom-built, bench-top rig. In these tests, different angular positions, vertical forces, and horizontal forces were tested. Results of these tests demonstrated that the system is capable of detecting tyre slip with a suffcient degree of consistency and robustness.