A vehicle control device includes sensors that detect pulse signals corresponding to rotation of front wheels and of rear wheels of a vehicle, and a controller that increases a count at a rise and a fall of the pulse signals. The controller estimates a road surface friction coefficient based on a time rate of change of a difference between a value counted up using the front wheels and a value counted up using the rear wheels.

A method is described for controlling the automatic starting of a motor vehicle comprising an electronically controllable locking differential, uphill in a split mu situation. The method comprises the following steps: determining the positive gradient of the underlying surface; defining an initial locking torque on the basis of the determined positive gradient and on the basis of a component of the torque which the vehicle requires to travel uphill with only the first driven wheel powered; calculating the slip ratio SR.sub.xx for the first driven wheel xx according to SR.sub.xx=(V.sub.xxV.sub.Ref)/V.sub.Crit if the reference velocity V.sub.Ref is between 0 and a critical velocity V.sub.Crit, and according to SR.sub.xx=(V.sub.xxV.sub.Ref)/V.sub.Ref if the reference velocity V.sub.Ref is higher than the critical velocity V.sub.Crit; and defining the locking torque of the electronically controllable locking differential on the basis of the slip ratio of the first driven wheel.

A driving force control system for a vehicle configured to eliminate slippage of a wheel without changing a driving torque or a braking torque abruptly. The driving force control system comprises a drive unit and a controller. The drive unit includes a differential mechanism connected to a right wheel and a left wheel to distribute torque of a torque generating device, and a differential restricting device that restricts a differential rotation between the right wheel and the left wheel. The controller restricts a differential rotation between the right wheel and the left wheel less than a predetermined value by the differential mechanism. If a slip ratio of one of the wheels smaller than that of the other wheels is greater than an acceptable value, the controller executes a slip-eliminating control.

A vehicle control ECU determines a road surface state of a forward road of a vehicle based on a front image. The vehicle control ECU changes, in accordance with a determined result, a split determination threshold value which is used to determine whether to perform a vehicle behavior stabilization control for stabilizing a behavior of the vehicle.

A vehicle control device including a first driving force controller and a second driving force controller. The first driving force controller executes the first driving force control or the second driving force controller executes the second driving force control, on the basis of the speed of the vehicle, the first vehicle speed limit, and the second vehicle speed limit. The first vehicle speed limit and the second vehicle speed limit change independently of each other.

A vehicle speed control system operable to cause a vehicle to operate in accordance with a target speed value, the system being further operable automatically to control cross-axle locking means of an axle of the vehicle to cause an increase in resistance to relative rotation of wheels of the axle. Thus, the speed control system may be operable automatically to command the cross-axle locking means to increase the resistance to relative rotation of wheels of the axle without a driver being required to intervene to command assumption of this condition.

A system and to a method executed in a vehicle control unit for controlling wheel slip of a vehicle, wherein the vehicle comprises at least two wheels driven by at least primary actuator via an open differential. The primary actuator is controlled to rotate at a speed resulting in a slip .sub.em of the primary actuator. A signed wheel slip limit .sub.lim is determined by adding a configurable value to the slip .sub.em of the primary actuator, such that .sub.lim>.sub.em. The at least two wheels are controlled to rotate at wheel speeds resulting in respective wheel slips .sub.l, .sub.r below the signed wheel slip limit .sub.lim, wherein each one of .sub.l, .sub.r and .sub.em are signed numerical values.

A wheel slip control method for a vehicle is provided, and includes estimating equivalent inertia information of a driving system based on operation information of the driving system while a vehicle travels, determining whether the slip of a drive wheel occurs from the estimated equivalent inertia information of the driving system, determining whether the drive wheel is in an uneven wheel slip state where the slip occurs only in one of a left wheel and a right wheel of the drive wheel from a left wheel speed and a right wheel speed detected by a sensor, if it is determined that the slip of the drive wheel occurs, and controlling an operation of a braking device such that a braking force is applied to the vehicle wheel in which the slip occurs, if it is determined that the vehicle wheel is in the uneven wheel slip state.

An electrified axle system includes a pair of wheels, a super positioning torque vectoring differential coupled between the wheels, and a controller. The super positioning torque vectoring differential includes a traction motor and a vectoring motor. The controller operates the vectoring motor in speed control mode to reduce a speed difference between the wheels responsive to the difference exceeding a threshold, and operates the vectoring motor in torque control mode responsive to the difference falling within a target range and an accelerator pedal position achieving a value that depends on lateral acceleration associated with the system.

A vehicle speed calculating device includes a vehicle speed calculating unit configured to calculate a control vehicle speed that is acquired by estimating a vehicle body speed that is a speed at which a vehicle is actually traveling, as a state variable used to control an onboard device configured to operate to realize various functions provided in the vehicle. The vehicle speed calculating unit is configured to include an extraction function of extracting at least one wheel speed acquired from at least one wheel that is assumed to be rotating in a state in which an influence causing a difference from the vehicle body speed is likely to be small, out of wheel speeds of a plurality of wheels, and a calculation function of calculating the control vehicle speed based on the at least one wheel speed extracted by the extraction function.