The present invention relates to a vehicle recovery system (1) for a vehicle having at least one driven wheel. The vehicle recovery system (1) is operable to self-recover the vehicle from terrain having a deformable surface affording insufficient traction at the at least one driven wheel to mobilise the vehicle. A recovery controller (2) is provided to maintain at least substantially continuous rotation of said at least one driven wheel at a target recovery speed or within a target recovery speed range to increase the available traction at each driven wheel. The present invention also relates to a vehicle having a vehicle recovery system (1).

A drive torque control device of a vehicle that includes a drive source for generating a drive source torque, a brake mechanism for generating a braking torque, and a drive wheel for driving the vehicle. The drive torque control device includes a target drive wheel torque calculator configured to calculate a target drive wheel torque, a drive source torque control unit configured to estimate a drive source torque limit value, calculate a target drive source torque based on the target drive wheel torque and the drive source torque limit value, and control the generation of the drive source torque by the drive source based on the target drive source torque, and a braking torque control unit configured to calculate a target braking torque based on the target drive wheel torque and the target drive source torque, and control the generation of the braking torque by the brake mechanism based on the target braking torque.

The vehicle control device includes a speed calculation unit, a speed estimation unit, a motion feedback calculation unit, and a slip estimator. The speed calculation unit calculates a speed in a predetermined direction of a vehicle on the basis of a feature quantity. The speed estimation unit estimates a speed in the predetermined direction on the basis of a speed or acceleration detected by a motion detector. The motion feedback calculation unit performs feedback calculation in which a value obtained, through a proportional gain, from a deviation between a calculation speed calculated by the speed calculation unit and an estimation speed estimated by the speed estimation unit, is added to the feature quantity. The slip estimator compares the calculation speed with the estimation speed, and estimates that the vehicle is in a slip state in the predetermined direction, when the estimation speed exceeds the calculation speed.

A control apparatus of a self-driving vehicle with a self-driving capability including a slip detector detecting a slip generated at four drive wheels, a direction detector detecting a direction of a vehicle body, and a microprocessor and a memory. The microprocessor is configured to perform: calculating target torques of the four drive wheels in accordance with an action plan; correcting the target torques so as to decrease the target torque of the first drive wheel when the slip of the first drive wheel is detected, and thereafter so as to increase the target torque of the second drive wheel and decrease the target torque of the fourth drive wheel when a deviation of the detected direction from a target traveling direction is greater than or equal to a predetermined deviation; and controlling a driving part in accordance with the corrected target torque.

A control apparatus of a self-driving vehicle with a self-driving capability including a slip detector detecting a slip generated at four drive wheels, a direction detector detecting a direction of a vehicle body, and a microprocessor and a memory. The microprocessor is configured to perform: calculating target torques of the four drive wheels in accordance with an action plan; correcting the target torques so as to decrease the target torque of the first drive wheel when the slip of the first drive wheel is detected, and thereafter so as to increase the target torque of the second drive wheel and decrease the target torque of the fourth drive wheel when a deviation of the detected direction from a target traveling direction is greater than or equal to a predetermined deviation; and controlling a driving part in accordance with the corrected target torque.

A method and system for controlling the stability and yaw response of a vehicle being equipped with a front axle (24), a rear axle (26), a controllable differential (22) and a control unit (50) arranged for locking and unlocking the differential (22), the method includes: selectively locking or unlocking the differential (22) depending on the operation of the vehicle; measuring at least the longitudinal vehicle speed (v); comparing the measured vehicle speed (v) with a predetermined first reference speed (v.sub.H); and locking the differential (22) if the measured vehicle speed (v) exceeds the first reference speed (v.sub.H).

A method includes switching a vehicle to a 4WD state by connecting a disconnector, maintaining the disconnector in the connected state for a predetermined maintenance time, determining whether a condition to be switched to a 2WD state is satisfied when the predetermined maintenance time period elapses, and disconnecting the disconnector when the condition to be switched to the 2WD state is satisfied.

A method includes switching a vehicle to a 4WD state by connecting a disconnector, maintaining the disconnector in the connected state for a predetermined maintenance time, determining whether a condition to be switched to a 2WD state is satisfied when the predetermined maintenance time period elapses, and disconnecting the disconnector when the condition to be switched to the 2WD state is satisfied.

A method includes switching a vehicle to a 4WD state by connecting a disconnector, maintaining the disconnector in the connected state for a predetermined maintenance time, determining whether a condition to be switched to a 2WD state is satisfied when the predetermined maintenance time period elapses, and disconnecting the disconnector when the condition to be switched to the 2WD state is satisfied.

A method includes switching a vehicle to a 4WD state by connecting a disconnector, maintaining the disconnector in the connected state for a predetermined maintenance time, determining whether a condition to be switched to a 2WD state is satisfied when the predetermined maintenance time period elapses, and disconnecting the disconnector when the condition to be switched to the 2WD state is satisfied.