Technical solutions are described for estimating tire-road friction in a vehicle pro-actively, prior to safety systems of the vehicle are engaged. An example method includes computing a slip for the vehicle based on one or more wheel speeds, acceleration, and tire pressure measurement. The method further includes determining a slope () as indicator of tire-road friction for the vehicle based on the acceleration and the slip. Further, the method includes sending the slope to an autonomous controller of the vehicle for adjusting vehicle kinematics according to the estimated friction using the slope.

A vehicle driving force control apparatus is mounted in a vehicle that runs by transmitting power from a plurality of drive sources to a plurality of wheels or a plurality of sets of wheels. The vehicle driving force control apparatus includes: a ratio determination unit; and a command unit. The ratio determination unit determines a target ratio at which a required driving force applied to the vehicle is to be distributed to the plurality of wheels or the plurality of sets of wheels. The command unit commands the plurality of drive sources to output power such that driving force distributed in accordance with the target ratio is generated in the plurality of wheels or the plurality of sets of wheels.

A traction control method and a traction control apparatus for a vehicle are provided. The traction control method includes: estimating driving torque for each wheel and a difference between left and right wheel rotation speeds; determining a situation, in which the difference between the left and right wheel rotation speeds exceeds a first set value, to be a split wheel spin situation; estimating a maximum coefficient of friction between a spinning wheel and a road surface in the split wheel spin situation and estimating a maximum driving torque, at which the road surface is acceptable, by the maximum coefficient of friction; and obtaining a difference between driving torque of the spinning wheel and the maximum driving torque to calculate a road surface limitation excess driving torque and determining entry into traction control when the road surface limitation excess driving torque exceeds a second set value.

Systems and methods are provided herein for operating an electric vehicle in a vehicle yaw mode. The electric vehicle includes a normal driving mode where the electric vehicle is steered by turning the steerable wheels (e.g., left or right) and vehicle yaw mode where the vehicle controls the torque applied to each wheel. In response to receiving input to initiate vehicle yaw mode and yaw direction, the system determines the inner wheels and the outer wheels and provides forward torque to the outer wheels of the vehicle and backward torque to the inner wheels of the vehicle to rotate the vehicle.

A device for operating an all-wheel-drive agricultural commercial vehicle with a driven rear axle and a front axle that can be engaged for performing an all-wheel-drive mode. A control unit determines, during the all-wheel-drive mode, a front wheel slip parameter that characterizes a drive wheel slip occurring on the front axle of the agricultural commercial vehicle. The control unit deactivates the all-wheel-drive mode independent of the driver if this unit detects that the determined front wheel slip parameter is greater than a specified threshold value.

A controller for a driving force transmitting apparatus mounted in a four-wheel-drive vehicle, includes: a driving force controller configured to calculate a command torque indicating a driving force to be transmitted to the sub-drive wheels via the driving force transmitting apparatus based on a traveling state of the four-wheel-drive vehicle and a road surface condition, and to control the driving force transmitting apparatus based on the command torque; and a road surface condition determiner configured to determine that the road surface condition is a high- condition when a duration of a non-slipping state where a vehicle speed is equal to or higher than a prescribed value and a slip ratio of each of both the main drive wheels is lower than a prescribed value has become equal to or longer than a prescribed time.

A vehicle control device separately controls driving powers distributed to right and left wheels. The vehicle control device is configured to execute a vehicle posture control for reducing the driving powers transmitted from a driving source to the wheels by a request from a vehicle side. The vehicle control device includes a slip detection unit and a torque control unit. The slip detection unit is configured to detect a slip in the wheels. The torque control unit is configured to determine whether to perform a torque control after an operation of the vehicle posture control according to a detection result of the slip and a state of a transmission. The torque control is a control to control a torque input to the transmission by a request from the transmission side. The torque control unit is configured to execute the torque control on the basis of a determination result.

A motor vehicle controller configured to reduce net drive torque applied to one or more driving wheels of a first axle of a driveline when an amount of slip of a driving wheel of the first axle exceeds a first predetermined threshold value. The controller controls torque applied to wheels of a second axle and determines when the vehicle is operating in a split-mu condition in which slip of a driving wheel on one side of each of the two axles exceeds that of a driving wheel on an opposite side of the axles by more than a predetermined amount. The controller performs a split-mu mitigation operation by reducing net torque applied to a driving wheel of the axle that is experiencing the greater slip when an amount of slip of that driving wheel exceeds a second predetermined threshold value less than the first predetermined threshold value.

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 computer system comprising processing circuitry configured to handle wheel slip a vehicle is provided. The vehicle comprises a first axle. The first axle comprises at least two wheels. Each of the at least two wheels of the first axle is drivable by at least two hydraulic motors. The processing circuitry is configured to obtain a slip condition of the vehicle. The processing circuitry is configured to, based on the obtained slip condition, trigger an adjustment of pressure and/or flow to be supplied to at least one of the at least two hydraulic motors in the vehicle. Triggering the adjustment comprises triggering an adjustment of pressure and/or flow between at least two hydraulic motors, and/or triggering adjustment of pressure and/or flow supplied by a source.