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.

A hybrid all-wheel-drive vehicle includes an engine, first and second motor generators, a first clutch between the second motor generator and a front wheel, a second clutch between the second motor generator and a rear wheel, and a control unit that controls, based on a vehicle traveling state, the engine, the motor generators, and the clutches. The first motor generator is coupled to the engine and the front wheel in a manner capable of transmitting torque. During regeneration, the control unit engages the first clutch and disengages the second clutch. When the all-wheel-drive vehicle shifts from motor traveling to hybrid traveling, the control unit restarts the engine by operating the first motor generator and regulates engagement forces of the clutches and output torque of the second motor generator to compensate driving torque of the front wheel by the second motor generator while maintaining driving torque of the rear wheel.

A control method controls an electric four-wheel-drive vehicle to switch a drive torque distribution between a first distribution prioritizing energy efficiency and a second distribution prioritizing driving performance. The distribution is set to the second distribution where wheel slip is detected during a trip, and returned to the first distribution once the vehicle has stopped. When wheel slip is detected at least during acceleration, the distribution is switched from the first distribution to the second distribution. When wheel slip is detected during deceleration, a slip experience flag is set. The slip experience flag is maintained at least until starting off in a subsequent trip. Where the slip experience flag has been set, the distribution is maintained as the second distribution when the vehicle has stopped, and where the slip experience flag has not been set, the distribution is returned to the first distribution upon the vehicle being stopped.

A vehicle includes a main drive unit, a sub drive unit, and a control unit. The control unit includes a driving force distribution ratio setting unit and is configured to control the main drive unit and the sub drive unit. A drive mode of the main drive unit includes an electric power drive mode and an engine drive mode. The driving force distribution ratio setting unit is configured to set the driving force distribution ratio based on a vehicle speed, a required driving force, and the drive mode. When the drive mode is the engine drive mode, the driving force distribution ratio setting unit is configured to set the driving force distribution ratio so that a distribution ratio of the main driving force is 90% or more.

A vehicle includes a main drive unit, a sub drive unit, and a control unit. The main drive unit includes a main drive rotary electric machine. The sub drive unit includes a sub drive rotary electric machine. The control unit includes a driving force distribution ratio setting unit configured to set a driving force distribution ratio between the main driving force and the sub driving force and is configured to control the outputs of the main drive unit and the sub drive unit so that the main driving force and the sub driving force have the driving force distribution ratio set by the driving force distribution ratio setting unit. The driving force distribution ratio setting unit is configured to set the driving force distribution ratio to minimize electric power loss of the vehicle based on a vehicle speed of the vehicle and a required driving force of the vehicle.

It is determined whether fuel efficiency of a vehicle is improved by operating a first rotating machine to generate electricity to such an extent that an electrical path amount becomes a desired electrical path amount for controlling an operating point of an engine to a desired operating point and driving and operating a second rotating machine as a second power source, the electrical path amount being a magnitude of electric power in an electrical path through which the electric power is transferred between the first rotating machine and the second rotating machine. When the electronic control device determines that the fuel efficiency of the vehicle is improved, the first rotating machine is operated to generate electricity to such an extent that the electrical path amount becomes the desired electrical path amount and the second rotating machine is driven and operated as the second power source.

A control device executes caster angle change control for controlling a driving force applying device or each of the driving force applying device and a braking force applying device to reduce a caster angle of a steered tire-wheel assembly when a steering request is received in a stopped state or in a creeping state without exceeding a predetermined vehicle speed at a point starting from the stopped state. In the caster angle change control, the control device applies, to one tire-wheel assembly out of a front tire-wheel assembly and a rear tire-wheel assembly, a driving force in a direction toward the other tire-wheel assembly and applies, to the other tire-wheel assembly, a braking force or a driving force in a direction toward the one tire-wheel assembly to achieve the stopped state or the creeping state in response to a request for acceleration or deceleration.

A vehicle control device includes: a control portion that makes, of a plurality of shock absorbers included in a vehicle, a first damping force of at least one shock absorber that is located on a first direction side on which acceleration acts in a longitudinal direction of the vehicle larger than a second damping force of at least one shock absorber of the plurality of shock absorbers that is located on a second direction side opposite to the first direction in the longitudinal direction of the vehicle before acceleration acting on the vehicle is detected by an acceleration sensor due to acceleration or deceleration of the vehicle.

A vehicle body speed estimation method applied to a four-wheel drive vehicle includes: acquiring an estimated vehicle body speed based on wheel speeds or a longitudinal acceleration of the vehicle; determining whether an operation condition that includes at least a condition that the estimated vehicle body speed is higher than an operation determination speed is satisfied; performing torque limitation to reduce a torque of a portion of wheels of the vehicle when the operation condition is satisfied; determining whether a stop condition that includes a condition that the estimated vehicle body speed is lower than or equal to a stop determination speed or a condition that a duration of a state where a wheel acceleration of the portion of the wheels is higher than zero is longer than or equal to a set period of time; and stopping the torque limitation when the stop condition is satisfied.

A vehicle driving apparatus includes: an engine; a first rotary electric machine; first and second output shafts; a power distribution device for distributing a power between the first and second output shafts; and a control device for controlling an electric-power generation torque of a second rotary electric machine such that a power distribution ratio between the first and second output shafts becomes a target distribution ratio, and controlling a total torque of the engine and the first rotary electric machine such that a requested drive torque is obtained. The control device executes an electric-power consuming control to supply at least a part of a generated electric power generated by the second rotary electric machine, to the first rotary electric machine without via a power storage device, and to drive the first rotary electric machine, such that an operation state of the engine is brought close to a fuel-economy optimum state.