A vehicle includes an all-wheel-drive powertrain having an electric machine configured to power wheels. A controller is programmed to output a first calculated vehicle speed derived from integrating a measured longitudinal acceleration of the vehicle and output a second calculated vehicle speed based on the measured longitudinal acceleration and a speed of one of the wheels. The controller is further programmed to, responsive to a flag being present, command a speed to the electric machine that is based on the first vehicle speed to reduce wheel slip, and responsive to a flag not being present, command a speed to the electric machine that is based on the second vehicle speed to reduce wheel slip.

Aspects of the present invention relate to a method and to a control system for a vehicle, the vehicle comprising an internal combustion engine configured to provide torque to a first axle of the vehicle for generating first axle wheel torque, and an electric machine configured to provide torque to a second axle of the vehicle for generating second axle wheel torque, the method comprising: outputting a torque request for the engine and a torque request for the electric machine, the torque requests having a first ratio dependent on a required torque split between the first axle wheel torque and the second axle wheel torque, wherein received first axle wheel torque and received second axle wheel torque have a second variable ratio dependent on a difference between wheel torque response capabilities of the engine and of the electric machine; determining that a trigger condition is satisfied; and controlling, in dependence on satisfaction of the trigger condition, determination of the torque request for the electric machine such that deviation of the second ratio from the first ratio is inhibited.

One axle of a hybrid vehicle is powered by an electric motor while a second axle of the vehicle is powered by a powertrain that includes an internal combustion engine. The electrically driven axle can be controlled in a speed control mode or in a torque control mode based on a driver demanded torque. The speed control mode is used when slip is detected at the electrically driven axle. The torque control mode is used when the electrically driven axle has traction. During a transition between these modes, the rate of change of torque is controlled to a predetermined level to mitigate noise, vibration, and harshness.

A method includes at least the following phases: a first phase wherein a path to be followed is generated, the path being subdivided into a series of sections of which the starting point forms an intermediate position; a second phase wherein, at the current intermediate position of the vehicle: a non-zero curvature is defined for each of the next n prediction horizon sections, the curvature varying progressively from one section to the next; a prediction is made, before the vehicle engages a movement, as to whether the path can be followed to the prediction horizon, as a function of imposed constraints and of the estimated lateral and/or longitudinal slips; a third phase wherein, if the path can be followed, the steering lock angle of the front wheels and the linear traction speed of the vehicle are controlled as a function of the state of the vehicle and of the lateral and/or longitudinal slips to line up the centre of the axle of the rear wheels on the path; if the path cannot be followed, the vehicle is realigned towards the target position and a new reference path is generated according to the first phase.

A system control a vehicle using a friction function describing a friction between a type of surface of the road and a tire of the vehicle as a function of a slip of a wheel of the vehicle. The parameters of each friction function include an initial slope of the friction function defining a stiffness of the tire and one or combination of a peak friction, a shape factor and a curvature factor of the friction function. Upon estimating a slip and a stiffness of the tire, the system selects from the memory parameters of the friction function corresponding to the current stiffness of the tire, determines a control command using a value of the friction corresponding to the slip of the tire according to the friction function defined by the selected parameters, and submits the control command to an actuator of the vehicle.

A vehicle drive system includes a slip acquisition unit that acquires that an excessive slip of front wheels or rear wheels has occurred, an addition slip point calculating unit that calculates addition slip points in a time-discrete manner, based on the slip acquisition unit having acquired that the excessive slip has occurred, a cumulative slip point calculating unit that accumulates the addition slip points and calculates a cumulative slip point over time, a drive state switching unit that, switches between 2WD and AWD based on cumulative slip points, and an increase forbidding determination unit that forbids addition or accumulation of the addition slip points, or increase of the cumulative slip points, in a case where a lateral acceleration correlation value that has correlation with lateral acceleration of the vehicle exceeds a lateral acceleration threshold value.

An ECU is formed of an ABS control device for controlling operation of a braking device when a slip ratio of wheels FR to RL becomes greater than a threshold, an automatic brake control device that controls operation of the braking device based on information on surroundings of the vehicle, and the threshold changing device that changes the threshold at which the braking device is activated by the ABS control device so that the threshold when the braking device is being operated by the automatic brake control device is smaller than the threshold when the braking device is not being operated by the automatic brake control device.

A method for validating a model of vehicle dynamics for use in autonomous driving. The method comprising setting a wheel slip limit on an operation of at least one vehicle torque device, obtaining a model of vehicle dynamics based on the set wheel slip limit, and validating the model of vehicle dynamics based on the set wheel slip limit.

A method is provided for controlling a drivetrain of a vehicle, wherein the drivetrain comprises a multi-clutch transmission. The gear shift of the multi-clutch transmission is adapted to be performed either by power cut shift or by power shift dependent on predetermined vehicle shift conditions. The method includes detecting at least one of a plurality of indications of slippery road conditions and setting a slip risk factor, wherein the slip risk factor is dependent on the indication of slippery road conditions. If the slip risk factor is above a first predetermined threshold value the method further comprises controlling the multi-clutch transmission such that an upcoming gear shift is performed as a power-shift independently of if upcoming shift was determined to be performed as a power-cut shift or as a power shift.

A system including a first drive axle, a second drive axle, a first sensor, a second sensor, and a controller. The first sensor is configured to measure a first speed of the first drive axle. The second sensor is configured to measure a second speed of the second drive axle. The controller is in communication with the first and second sensors. The controller configured to determine an actual axle speed difference value based on the measured first speed and the measured second speed, determine an expected axle speed difference value based on a vehicle speed and a vehicle torque, compare the actual axle speed difference value and the expected axle speed difference value to obtain an error value, and generate an output signal in response to the error value being above a predetermined threshold value.