Techniques for managing wheel slip in a through-the-road hybrid vehicle comprise detecting a front wheel slip event based on measured rotational speeds of front wheels, determining a likelihood of a subsequent rear wheel slip event, when the front wheel slip event has ended and the likelihood of the subsequent rear wheel slip event satisfies a calibratable threshold, adjusting a front/rear axle torque split and pre-loading at least one of an engine and a belt-driven starter generator (BSG) unit coupled to a crankshaft of the engine to compensate for a torque drop that is predicted to occur during the rear wheel slip event, and re-adjusting the front/rear axle torque split and pre-unloading at least one of the engine and the BSG unit such that a drop in torque output at a front axle aligns with an end of the rear wheel slip event.

Techniques for managing wheel slip in a through-the-road hybrid vehicle comprise detecting a front wheel slip event based on measured rotational speeds of front wheels, determining a likelihood of a subsequent rear wheel slip event, when the front wheel slip event has ended and the likelihood of the subsequent rear wheel slip event satisfies a calibratable threshold, adjusting a front/rear axle torque split and pre-loading at least one of an engine and a belt-driven starter generator (BSG) unit coupled to a crankshaft of the engine to compensate for a torque drop that is predicted to occur during the rear wheel slip event, and re-adjusting the front/rear axle torque split and pre-unloading at least one of the engine and the BSG unit such that a drop in torque output at a front axle aligns with an end of the rear wheel slip event.

A control apparatus configured to control a four-wheel drive vehicle configured to drive right and left front wheels and right and left rear wheels includes an electronic control unit. The electronic control unit calculates a vehicle body speed based on rotation speeds of the wheels and a cumulative value of accelerations in a longitudinal direction of the vehicle. The accelerations are detected by an acceleration sensor. The electronic control unit calculates the vehicle body speed based on the cumulative value of the accelerations. The electronic control unit calculates a correction value based on a lowest rotation speed among the rotation speeds of the wheels under a predetermined condition. The electronic control unit performs correction by using the correction value to make the vehicle body speed closer to a vehicle body speed conversion value of the lowest rotation speed.

A control apparatus configured to control a four-wheel drive vehicle configured to drive right and left front wheels and right and left rear wheels includes an electronic control unit. The electronic control unit calculates a vehicle body speed based on rotation speeds of the wheels and a cumulative value of accelerations in a longitudinal direction of the vehicle. The accelerations are detected by an acceleration sensor. The electronic control unit calculates the vehicle body speed based on the cumulative value of the accelerations. The electronic control unit calculates a correction value based on a lowest rotation speed among the rotation speeds of the wheels under a predetermined condition. The electronic control unit performs correction by using the correction value to make the vehicle body speed closer to a vehicle body speed conversion value of the lowest rotation speed.

A vehicle control device mounted on a four-wheel drive vehicle including a driving force transmission system includes an electronic control unit. The electronic control unit calculates a command torque based on vehicle information. The electronic control unit estimates a temperature of a heat generating location in the driving force transmission system based on the command torque. The electronic control unit estimates the temperature of the heat generating location based on an estimated value of a driving force input to an input rotating member, when it is not possible for the driving force corresponding to the command torque to be transmitted to auxiliary drive wheels due to a magnitude of the driving force generated by a drive source or occurrence of a wheel slip.

A vehicle control device mounted on a four-wheel drive vehicle including a driving force transmission system includes an electronic control unit. The electronic control unit calculates a command torque based on vehicle information. The electronic control unit estimates a temperature of a heat generating location in the driving force transmission system based on the command torque. The electronic control unit estimates the temperature of the heat generating location based on an estimated value of a driving force input to an input rotating member, when it is not possible for the driving force corresponding to the command torque to be transmitted to auxiliary drive wheels due to a magnitude of the driving force generated by a drive source or occurrence of a wheel slip.

A four-wheel drive vehicle includes: a drive-power distribution device for transmitting a drive power of an engine toward main and auxiliary drive wheels, at a drive-power distribution ratio between the auxiliary drive wheels and the main drive wheels; and a control apparatus for executing a drive-power distribution control for adjusting the drive-power distribution ratio, and executing an engine automatic-start control for causing the engine to be started upon satisfaction of an engine-start condition. Upon execution of the engine automatic-start control, the control apparatus changes a target engine rotational speed from a predetermined engine-start rotational speed to a changed engine rotational speed, such that a difference of the changed engine rotational speed from a resonance rotational speed that causes resonance of a drive system to which the engine is connected in a power transmittable manner, is larger than a difference of the predetermined engine-start rotational speed from the resonance rotational speed.

A four-wheel drive vehicle includes: a drive-power distribution device for transmitting a drive power of an engine toward main and auxiliary drive wheels, at a drive-power distribution ratio between the auxiliary drive wheels and the main drive wheels; and a control apparatus for executing a drive-power distribution control for adjusting the drive-power distribution ratio, and executing an engine automatic-start control for causing the engine to be started upon satisfaction of an engine-start condition. Upon execution of the engine automatic-start control, the control apparatus changes a target engine rotational speed from a predetermined engine-start rotational speed to a changed engine rotational speed, such that a difference of the changed engine rotational speed from a resonance rotational speed that causes resonance of a drive system to which the engine is connected in a power transmittable manner, is larger than a difference of the predetermined engine-start rotational speed from the resonance rotational speed.

Aspects of the present invention relate to a control system for controlling torque distribution between a first axle (110) and a second axle (120) in a vehicle (100), the control system comprising one or more controllers. The control system is configured to detect that the vehicle is in overrun and detect the vehicle speed. When the vehicle is in overrun and the vehicle speed is below a first speed threshold then the torque distribution is controlled to reduce overrun torque to the first axle and to increase overrun torque to the second axle. The vehicle may be a hybrid vehicle comprising an internal combustion engine (ICE) (201), a belt integrated starter generator (B-ISG) (205) and an electric rear axle drive (ERAD) (204).

Aspects of the present invention relate to a control system for controlling torque distribution between a first axle (110) and a second axle (120) in a vehicle (100), the control system comprising one or more controllers. The control system is configured to detect that the vehicle is in overrun and detect the vehicle speed. When the vehicle is in overrun and the vehicle speed is below a first speed threshold then the torque distribution is controlled to reduce overrun torque to the first axle and to increase overrun torque to the second axle. The vehicle may be a hybrid vehicle comprising an internal combustion engine (ICE) (201), a belt integrated starter generator (B-ISG) (205) and an electric rear axle drive (ERAD) (204).