Spherical-Joint Force Measurement Enables Wheel Force Sensing in Vehicles

This article presents a wheel force sensing method based on spherical-joint force measurement. The force measurement uses strain gauges on L-shaped linkages connecting the wheel to the double wishbone suspension system. It does not require the wireless power supply and signal transmission because it does not rotate with the wheel. Using the measured joint-forces to solve the suspension mechanism configuration, the wheel position and orientation (relative to the vehicle) can be calculated, eliminating the need for position sensors. Through the continuous calculation of the position and orientation, the inertia force and moment can be estimated, which is used in the Newton-Euler formulation for wheel force calculation. Experimental results show the root mean square error of three-axis wheel forces ≤8.26 N and mean error of three-axis wheel forces ≤4.06 N, which validates the feasibility of the proposed method.