A stability control system of a vehicle utilizing an electronic control unit that minimizes rollback of a vehicle as a result of wheel slip immediately following a hill start assist operation. The electronic braking control module controls actuation and de-actuation of vehicle brakes on an inclined surface. Immediately following a hill start assist operation on the inclined surface after each wheel brake is de-actuated for allowing forward movement of the vehicle up the hill, a split-mu road surface condition is detected in response to sensing wheel slip for each of the wheels. The electronic control unit determines a respective undriven, or non-dominant driven, wheel having the highest coefficient of friction among the undriven, or less dominant driven wheels, as determined by the wheel speeds. The electronic braking control module actuates the vehicle brake of the undriven, or less dominant, driven wheels having the highest coefficient of friction relative to a tire/road surface interface for reducing rollback of the vehicle. The braking of the undriven, or less dominant, driven wheel is in addition to any standard stability control braking that may already be occurring.

A method for controlling propulsion of a heavy-duty vehicle, where the heavy-duty vehicle comprises a differential drive arrangement arranged in connection to a drive axle with a left wheel and a right wheel is provided. The method includes determining a nominal shaft slip corresponding to a desired wheel force to be generated by the drive axle wheels, wherein the nominal shaft slip is indicative of a difference between a current vehicle velocity and a vehicle velocity corresponding to the shaft speed, determining a difference between a speed of the left wheel and a speed of the right wheel, adjusting the nominal shaft slip in dependence of a magnitude of the wheel speed difference to a target shaft slip, and controlling the shaft speed based on the target shaft slip.

A method is described for computing a friction estimate between a road surface and a tire of a vehicle when the vehicle is in motion along a course, the tire being arranged on a steerable wheel of the vehicle, and the vehicle including two front wheels and two rear wheels and an axle rack pivotably attached to a linkage arm connected to the steerable wheel such that a translational motion of the axle rack causes the linkage arm to rotate about a kingpin element such that the linkage arm causes a turning motion of the steerable wheel. A corresponding system and vehicle are also described.

A method is described for determining a friction estimate between a road surface and a tire of a vehicle, the tire being arranged on a steerable wheel of the vehicle, and the vehicle having an axle rack pivotably attached to a linkage arm connected to the steerable wheel such that a translational motion of the axle rack causes the linkage arm to rotate about a kingpin element such that the linkage arm causes a turning motion of the steerable wheel. The method includes acquiring a plurality of rack force values; acquiring a plurality of lateral wheel force values; mapping a relation between the plurality of rack force values and the lateral wheel force values to a model; and determining the lateral friction estimate based on the mapping.

A method for controlling propulsion of a heavy-duty vehicle, where the heavy-duty vehicle comprises a differential drive arrangement arranged in connection to a drive axle with a left wheel and a right wheel is provided. The method includes determining a nominal shaft slip corresponding to a desired wheel force to be generated by the drive axle wheels, wherein the nominal shaft slip is indicative of a difference between a current vehicle velocity and a vehicle velocity corresponding to the shaft speed, determining a difference between a speed of the left wheel and a speed of the right wheel, adjusting the nominal shaft slip in dependence of a magnitude of the wheel speed difference to a target shaft slip, and controlling the shaft speed based on the target shaft slip.

A method for controlling propulsion of a heavy-duty vehicle includes. configuring a nominal shaft slip of the drive shaft in dependence of a desired longitudinal wheel force to be generated by the driven axle, wherein a shaft slip is indicative of a difference between a current vehicle velocity and a vehicle velocity corresponding to the rotation speed of the drive shaft, obtaining a rotation speed of the left wheel and a rotation speed of the right wheel, as function of a current shaft slip of the driven axle, estimating a peak shaft slip value associated with an open differential peak longitudinal force of the driven axle, based on the current shaft slip and on the corresponding obtained speeds of the left and right wheels, and controlling propulsion of the heavy-duty vehicle unit by setting the current shaft slip of the drive shaft based on the configured nominal shaft slip adjusted in dependence of the estimated peak shaft slip value.