Shaft Torque and Backlash Estimation for Longitudinal Motion Control of All-Wheel-Drive Vehicles

With automated driving, new challenges for vehicle longitudinal motion control arise. The precise control of speed and acceleration requires knowledge of the torques acting at the wheels. In this work we present an observer that estimates the shaft torques of an all-wheel-drive vehicle and pay attention to the especially challenging use case of driving over large obstacles like curb stones. The performance of our observer is compared with two other approaches and verified using realworld measurement data. The results show that the observer provides good estimates and cooperates well with the switching system. The all-wheel-drive specific, fundamental reallocation of drive torque due to the differential lock in the transfer case is also covered.