The invention provides a
road surface attachment coefficient and
road surface gradient synchronous real-
time estimation system and method for a hub-motor-driven vehicle. The
road surface attachment coefficient and road
surface gradient synchronous real-
time estimation system comprises a wheel trackslip rate calculating module, a wheel side-
slip angle calculating module, a wheel
vertical force calculating module, a Dugoff tire model module for deformation treatment, an air resistance calculating module, a
fading memory UKF parameter
estimation algorithm module, a wheel longitudinal lateral force calculating module, a wheel rotating dynamics module and a longitudinal force feedback and correction module. According to the road surface attachment coefficient and road
surface gradient synchronous real-
time estimation method, through
fading memory weighting
processing on a traditional UKF
algorithm, obsolete measured data of the
algorithm are rejected in time, the weight of newly measured data is increased, and accordingly the
estimation precision of parameters is improved; and the
advantage that the torque of all wheels of the hub-motor-driven vehicle can be measured precisely is fullycombined, and accurate wheel longitudinal force information obtained by the wheel rotating dynamics module is utilized to correct wheel longitudinal force information obtained by a Dugoff tire model,so that the accuracy of longitudinal normalized force is ensured, and accordingly the
estimation precision of the road surface attachment coefficient is improved indirectly.