Robust vehicle speed over ground estimation using wheel speed sensors and inertial measurement units

A vehicle motion management, VMM, system for a heavy-duty vehicle, the system comprising:

• at least one wheel speed sensor configured to output a wheel speed signal indicative of a rotation speed of a respective wheel on the vehicle,
• at least one inertial measurement unit, IMU, configured to output an IMU signal indicative of an acceleration of the vehicle,
• a motion estimation function configured to estimate a vehicle motion state(s) comprising vehicle speed over ground, SOG, based on the at least one wheel speed signal and on the at least one IMU signal,
• where the motion estimation function is arranged to estimate a respective SOG error associated with the wheel speed signal as an increasing function of an applied torque to the wheel, and a respective SOG error associated with the IMU signal as an increasing function of a time duration elapsed since last calibration of an integrator of the IMU signal,
• where the motion estimation function is configured to estimate the vehicle SOG, based on a weighted combination of the at least one wheel speed signal and the at least one IMU signal, where the weights of the weighted combination are determined based on the SOG error associated with the wheel speed signal and on the SOG error associated with the IMU signal.