Abstract: A method for assessing slippage of wheels in a vehicle includes the steps of measuring, via a sensor, an initial value of vehicle speed, determining, via a processor, at least one of a minimum vehicle speed and a maximum vehicle speed, and determining, via the processor, wheel slip using the initial value and the at least one of the minimum vehicle speed and the maximum vehicle speed.

Abstract: The invention is an autonomous dual tracked mobile (10) robot system comprising two or more tracked driving units (12x) configured to travel in tandem and a separate mechanical linkage (16), which joins each of the mobile units to the unit immediately preceding and following it, and enables efficient power transmission between the two driving units. Each of the mechanical linkages comprises one connecting bar (14) and three revolute joints (18y) located on each of the adjacent units and a connecting beam that connects the connecting bar on one of the units with the connecting bar on the adjacent unit.

Abstract: A turning control apparatus for a vehicle that improves turning ability while avoiding degradation of acceleration ability is provided. The turning control apparatus comprises: a driving torque controller (31) for adjusting driving torque between a left and right wheels (14L and 14R); a unit (62) for calculating a necessary yaw momentum value indicating degree of necessary yaw momentum for the turning of the vehicle; and a clipping unit (63) for clipping the necessary yaw momentum value as a target yaw momentum at a maximum yaw momentum value, which is defined according to difference between rotation speeds of inside and outside wheels, if the necessary yaw momentum value is over the maximum yaw momentum value. The controller adjusts driving torque of the left and right wheels to generate target yaw momentum at the vehicle corresponding to the target yaw momentum value obtained by the clipping unit.

Abstract: Children's ride-on vehicles having a drive assembly that is selectively configured between a plurality of drive configurations, such as responsive to user inputs via user input devices, and a ground detection system that is adapted to detect when at least one of a plurality of wheels loses contact with the ground surface. The ground detection system may be adapted to restrict the plurality of drive configurations responsive thereto. This restriction may be automatic responsive to loss of contact of the at least one of the plurality of wheels with the ground surface, and it may be made regardless, or independent, of user inputs that otherwise would select and/or enable one of the restricted drive configurations.

Abstract: A method of reducing wheel slip and wheel locking in an electric traction vehicle includes receiving in a first controller a first signal value representative of a first amount of torque to be applied to at least one wheel of the electric traction vehicle by a motor coupled to the wheel and to the first controller, and a second signal value representative of a reference speed of the electric traction vehicle. The first and second signal values are generated by a second controller in communication with the first controller. The method also includes receiving in the first controller a third signal value representative of a speed of the at least one wheel, determining in the first controller a torque output signal using the first, second, and third signal values; and transmitting the torque output signal from the first controller to the motor.

Abstract: A system and process for controlling propulsion and steering of a track trencher excavation machine powered by an engine includes a multiple mode propulsion and steering control system that performs a plurality of functions depending on a selection of one of a plurality of operational modes. A controller generates a vehicle propulsion hydrostatic drive signal optionally using a track drive hydraulic pressure or a track drive speed as a variable for modifying the propulsion drive signal. The controller optionally uses a hydraulic attachment drive pressure as a variable for further modifying the propulsion drive signal.

Abstract: A turning control apparatus for a vehicle to improve turning ability and to avoid degradation of acceleration ability is provided. The turning control apparatus comprises a first yaw controller for adjusting at least one of driving torque of a left wheel and a right wheel; a second yaw controller for adjusting a speeds difference between a front wheel and a rear wheel; and an integrated yaw controller for controlling yaw momentum of the vehicle by managing the first and second yaw controller, wherein when the yaw of the vehicle should be reduced, the integrated yaw controller controls the first yaw controller so as to decrease the driving torque of a inside wheel, which is one of the right and left wheel and is near to a center axis of turning, and the second yaw controller so as to decrease the speeds difference between the front and rear wheel.

Abstract: Methods and apparatus are provided for integrating a torque vectoring differential (TVD) and a stability control system in a motor vehicle. The integrated system is utilized for more efficiently correcting understeer and/or oversteer slides in a motor vehicle. In correcting these slides, the integrated system utilizes the TVD to rotate two wheels on opposite sides of the motor vehicle at different rates to create a yaw moment at the vehicle's center of gravity until the TVD reaches a saturation point and the understeer or oversteer slide is not corrected. Once the saturation point is reached without correcting the understeer or oversteer slide, the stability control system is employed to selectively apply one or more of the vehicle's brakes in a further effort to correct the understeer or oversteer slide.

Abstract: The purpose of the present invention is to provide a work vehicle that does not slip. The work vehicle has an engine (10) generating a rotational power, a hydraulic stepless transmission (HST) (20) having a hydraulic pump (22) and a hydraulic motor (24) and changing the speed of rotation generated by the engine (10) and transmitting it to drive wheels (40), an actuator (73) for adjusting the transmission ratio of the HST (20) by changing the tilt angle of a movable swash plate (22a) of the hydraulic pump (22), a shift lever (speed setting means) (50) for setting the speed of a motor output shaft (25) changed by the HST (20), and a control device (60) for controlling operation of the actuator (73) so that the speed of the motor output shaft (25) changed by the HST (20) changes at a predetermined rate of change (?) until it reaches the speed (preset speed) set by the shift lever (50).

Abstract: Traction control for a motorcycle including a driving wheel speed sensor and a driven wheel speed sensor. An ECU controls an engine on the basis of a corrected slip signal obtained by subtracting a low frequency component of a pre-correction slip signal from the pre-correction slip signal. The pre-correction slip signal is obtained by subtracting a speed of a front wheel detected by the driven wheel speed sensor from a speed of a rear wheel detected by the driving wheel speed sensor.

Abstract: A vehicle control apparatus is used to control a driving force to be given to a vehicle. A driving force calculating device calculates the driving force to be given to the vehicle, on the basis of a deviation between a vehicle speed of the vehicle and a target speed. A driving force correcting device performs correction of increasing the driving force calculated by the driving force calculating device, when the vehicle speed reduces to a predetermined value or less. Specifically, the driving force correcting device performs the correction of increasing the driving force, when the vehicle speed reduces to the predetermined value or less as the vehicle comes in contact with an obstacle, such as a bump. By this, it is possible to reduce a stop time length of the vehicle due to the contact with the obstacle, to thereby quickly make the vehicle run over the obstacle.

Abstract: The objective of the present invention is to provide a vehicle motion control device capable of controlling the driving force distribution to the wheels with superior stability and response while effectively utilizing the tire grip.

Abstract: A method of controlling a vehicle includes determining a desired sideslip angle in the moving road plane, determining an actual sideslip angle in the moving road plane, a desired yaw rate in the moving road plane, and an actual yaw rate in the moving road plane. A controller controls the vehicle system in response to the desired slip angle, the actual sideslip angle, the desired yaw rate and the actual yaw rate in the moving road plane.

Abstract: A control system (18) for an automotive vehicle (10) has a first roll condition detector (64A), a second roll condition detector (64B), a third roll condition detector (64C), and a controller (26) that uses the roll condition generated by the roll condition detectors (64A-C) to determine a wheel lift condition. Other roll condition detectors may also be used in the wheel lift determination. The wheel lift conditions may be active or passive or both.

Abstract: A process for increasing the stability of a vehicle upon acceleration on a roadway with a non-homogenous coefficient of friction, whereby a drive wheel is acted on by a braking force on a side with a low coefficient of friction by means of a drive slip regulation. A value (pASR) is determined which corresponds to the braking force (FB,ASR) set by the drive slip regulation (ASR). The value determined (pASR) is used for the determination of a disrupting yaw momentum (MZ), and a control portion (??Z) of a supplemental steering angle (??) is determined in dependence on the disrupting yaw momentum (MZ). An apparatus for the implementation of the process is also provided.

Abstract: This invention relates to a method for controlling a motor vehicle drivetrain system which has a drivetrain as well as a combustion engine for driving this drivetrain and an electronic engine control unit as well as an electronic transmission control unit, whereby, if the electronic transmission control unit fails or when the electronic engine control unit loses communication with the electronic transmission control unit, the permissible engine torque of the combustion engine is limited, as well as a safety system for a motor vehicle by means of which the method is controlled, as well as a motor vehicle with such a safety system.

Abstract: A driving force control device for an electric vehicle in which a left wheel is driven by a left in-wheel motor and a right wheel is driven by a right in-wheel motor includes a driving force difference setting section. The driving force difference setting section is configured to set a driving force difference between a driving force outputted from the left in-wheel motor and a driving force outputted from the right in-wheel motor when a lateral acceleration is detected acting on the vehicle, the driving force difference being set to generate a restoring moment against the vehicle corresponding to the lateral acceleration.

Abstract: A powertrain module for a vehicle. The powertrain module comprises a support member. An energy source is disposed within the support member. A motor-driven wheel is rotatably attached to the support member and coupled to the energy source, and a tire is mounted to the motor-driven wheel. The powertrain module is configured to be attached as a unit to a corner portion of a vehicle to provide the vehicle with motive power.

Abstract: A method is provided for controlling a powertrain of a vehicle comprising wheels, and an accelerator pedal actuated by a driver. The method comprises controlling wheel slip to a first amount during a first road condition, the first amount independent of a driver requested output; and controlling the wheel slip to a second amount during a second road condition, the second amount based on the driver requested output, the second road condition having higher friction than the first road condition.

Abstract: A device for controlling an automated transmission of a motor vehicle engine-transmission unit capable of delivering a torque setpoint signal to be applied to the motor vehicle wheels, including two static and dynamic components, produced based on input data delivered by an input unit including a recorded list of parameters representing the driver's wishes, the motor vehicle state, and the motor vehicle surroundings. The device includes a first unit capable of calculating a dynamic torque component not adapted to a cornering situation; a second unit capable of calculating a static torque component, connected to the input of the first unit; and a unit for adaptation to the come in situation delivering a static torque component adapted to the cornering situation in accordance with a list of predetermined input parameters.

Abstract: A method, system, and computer program product for calculating a torque overlay command in a steering control system is provided. The method includes receiving a current hand wheel angle, receiving a change in vehicle yaw moment command, and calculating a lateral force in response to the change in vehicle yaw moment command. The method also includes determining a new tire side slip angle from the lateral force and calculating a commanded hand wheel angle from the new tire side slip angle. The method further includes calculating an error signal as a difference between the commanded hand wheel angle and the current hand wheel angle, and generating a torque overlay command from the error signal.

Abstract: In a throttle valve control device, an engine required output setting section sets an engine required output corresponding to an accelerator opening degree by means of selecting a characteristic which is varied depending on a road surface friction coefficient or by means of interpolation calculation based on a road surface friction coefficient. An engine required torque setting section sets an engine required torque based on an engine speed and the engine required output. A throttle opening degree setting section sets a throttle opening degree based on the engine speed and the engine required torque and outputs a signal corresponding to the throttle opening degree to a throttle motor.

Abstract: A method of calculating a cornering force to be applied to each wheel provided to a vehicle which is cornering, comprising the steps of: obtaining a magnitude of a centrifugal force to the vehicle in a direction substantially orthogonal to a vehicle traveling direction, a contact length of each wheel during the cornering of the vehicle, and an amount of deformation in a wheel width direction at the contact portion of each wheel of the vehicle, calculating a difference between the obtained amount of the deformation and an amount of deformation in the wheel width direction under a straight forward travel condition of the vehicle for each wheel, and calculating a cornering force for each wheel based on the magnitude of the centrifugal force, the contact length, and the difference between amounts of deformation in the wheel width direction.

Abstract: System and method to diagnose shock absorbers (7) on a vehicle (2) and where at least one of the vehicle's wheel axles are air suspended. A control unit (5) with at least one measuring device (4) connected thereto is provided and in which the measuring device (4) measures a signal that corresponds to the oscillations of the vehicle's wheel suspension. The control unit (5) analyzes the characteristic resonance frequency of the vehicle's wheel suspension.

Abstract: A running vehicle has front and rear driving wheels, and a sensor for measuring the acceleration of the running vehicle. The vehicle determines a distribution rate of torque to each of the driving wheels in accordance with the found acceleration, and changes driving torque to each of the front and rear driving wheels based on the found distribution rate to control driving motors.

Abstract: A control system for a vehicle having first and second wheels is provided that includes a differential apparatus adapted to distribute torque between the first and second wheels and a traction controller for controlling operation of the differential apparatus from vehicle launch up to a predetermined vehicle speed. The traction controller is configured to engage the differential apparatus in a first operating state according to at least one vehicle operating parameter indicative of a low traction operating condition and to further control engagement of the differential apparatus in a second vehicle operating state during the low traction operating condition according to a difference between an actual vehicle yaw rate and a predetermined target vehicle yaw rate. The control system also includes a stability controller for controlling engagement of the differential apparatus at or above the predetermined vehicle speed.

Abstract: A system for controlling slip of vehicle drive members is disclosed. The system includes a power train including a plurality of drive members and a hydraulic transmission configured to supply torque to at least one of the drive members. A magnitude of the torque is related to fluid flow in the hydraulic transmission. The system further includes a controller configured to control the fluid flow in the hydraulic transmission. The controller is configured to receive a signal indicative of a steering command and a signal indicative of a parameter related to pressure in the hydraulic transmission. The controller is further configured to control slip of the at least one drive member based on the signal indicative of a steering command and the signal indicative of a parameter related to pressure.

Abstract: The turning control apparatus for a vehicle has a driving torque controlling mechanism adjusting driving torque of left and right wheels. The apparatus includes a maximum-yaw momentum value calculating means having means for estimating an outside-wheel gripping capacity, which is capacity of adhesive friction between the outside-wheel and a road surface, and an inside-wheel gripping capacity, which is capacity of adhesive friction between the inside-wheel and the road surface, and means for calculating a torque adjustment limiting value indicating an adjustment amount of driving torque by the driving torque controlling mechanism so that the adjustment amount does not exceed the gripping capacity. The maximum-yaw momentum value calculating means sets the maximum-yaw momentum value indicating possible yaw momentum, which is estimated if the driving torque is adjusted along with the torque-adjustment-limit value calculated by the torque adjustment limiting value calculating means.

Abstract: A method for operating a drive train of a vehicle with a drive engine, a brake system, at least two vehicle cross-shafts of a first vehicle axle with at least two wheels. The cross-shafts being actively connected via a transverse distributor gear and being driven by the engine. The vehicle also possibly having a second vehicle axle with at least two wheels. Frictional shift elements of the first vehicle axle, between the wheels of the first vehicle axle and the transverse distributor gear, are provided for variable distribution, to the first vehicle axle, of the fraction of the drive torque from the engine in the transverse direction of the vehicle between the two wheels. A desired yaw torque is determined. The drive engine, brake system and shift elements are controlled such that the desired yaw torque is produced essentially without changing the positive forward drive of the vehicle.

Abstract: In a driving-force distribution control unit, a first transfer-torque calculation unit calculates an input-torque sensitive transfer torque, a second transfer-torque calculation unit calculates a steering-angle/yaw-rate sensitive transfer torque, and a third transfer-torque calculation unit calculates a tack-in preventing transfer torque. In the third transfer-torque calculation unit, tack-in prevention control is performed during turning at a high speed not only when the accelerator opening is substantially reduced and the current accelerator opening becomes small, but also when the torque amount to be reduced by a traction control unit is more than a preset value. Further, when at least one of a side-slip prevention control unit and an ABS is started, tack-in prevention control is prohibited.

Abstract: In a rollover stability method for a vehicle in a situation which is critical with respect to the driving dynamics, a critical rollover situation is detected by analyzing a control variable and the stabilization intervention is activated or de-activated as a function of the control variable. The regulation intervention is maintained even in driving situations featuring relatively low transverse acceleration if the control variable or a characteristic property of the stability algorithm is calculated as a function of the steering angle and/or the longitudinal vehicle velocity.

Abstract: A system for controlling slip of a machine is disclosed. The system has a power source configured to produce a power output, at least one driven traction device, and a transmission operably connected to transmit the power output from the power source to the at least one driven traction device. The system further has at least one sensor configured to detect an acceleration of the machine and to generate a corresponding signal, and a controller configured to receive the signal and to reduce a magnitude of power or torque transmitted to the at least one driven traction device when the detected acceleration indicates slip of the at least one driven traction device.

Abstract: A system for estimating vehicle side-slip in the linear vehicle operating region that includes updating front and rear cornering stiffness signals. The system includes a first state observer processor that employs a bicycle model with state feedback for generating yaw acceleration and lateral acceleration signals. The system further includes a subtractor that receives the yaw acceleration and lateral acceleration signals and measured yaw rate and lateral acceleration signals, and generates yaw acceleration and lateral acceleration error signals. A parameter estimation processor calculates an updated front cornering stiffness and rear cornering stiffness signals. The updated front and rear cornering stiffness signals are sent back to the first state observer processor, and are used by second state observer processor for generating the estimated vehicle side-slip.

Abstract: A method of operating a machine having a lockable differential includes monitoring a first operating parameter indicative of wheel slip, and monitoring a second operating parameter different from the first parameter, the method further including controlling locking and unlocking of the differential responsive to the second operating parameter. A machine is provided having an electronic controller including software control logic for controlling locking and unlocking of a differential, the electronic controller being configured to lock the differential where the machine is in an operating mode where wheel slip is likely, such as a digging/dozing mode. Satisfaction of criteria for locking may be recognition by the controller of a predetermined pattern of sensor inputs corresponding with a likely wheel slip condition, or actual slip detection.

Abstract: A method of controlling tractive force of a vehicle comprising determining a tractive force request of a driver of the vehicle, determining an actual tractive force of the vehicle, and modifying the actual tractive force of the vehicle to be equal to the tractive force request.

Abstract: A method of operating an articulated machine includes sensing an articulation angle and a wheel steering angle of the machine, and controlling a locking state of a differential responsive to a steering radius of the machine. An articulated frame wheeled machine is further provided, and includes a front frame unit with a wheel steering apparatus, a back frame unit and an articulation apparatus coupled between the front and back frame units. First and second sensors are operable to sense a wheel steering angle and an articulation angle of the machine, and an electronic control is provided which is configured to selectively lock or unlock a differential of the back frame unit responsive to a steering radius of the machine.

Abstract: In one example, a traction control system for a vehicle is shown. The system adjusts a relationship between powertrain output and pedal actuation in response to at least one of road grade and direction of wheel spin.

Abstract: An active vibration insulator includes an electromagnetic actuator, a controller, and a bad-roads processor. The electromagnetic actuator generates vibrating forces depending on electric-current supplies. The controller carries out vibrating-forces generation control. In the vibrating-forces generation control, the electric-current supplies are made variable so as to actively inhibit vibrations generated by an on-vehicle vibration generating source of a vehicle from transmitting to a specific part of the vehicle based on cyclic pulsating signals output from the on-vehicle vibration generating source. Thus, the controller lets the electromagnetic actuator generate the vibrating forces. The bad-roads processor stops the vibrating-forces generation control effected by the controller when the vehicle travels on bad roads.

Abstract: A control system for a vehicle includes an ECU, a front wheel speed sensor, a rear wheel speed sensor, and an engine. The ECU detects an actual slip speed and an actual slip ratio of a rear wheel on the basis of respective detected values of a front wheel speed sensor and a rear wheel speed sensor. Slip speed traction control is started when the actual slip speed exceeds a threshold value of a slip speed when a vehicle is at a low speed, and slip ratio traction control is started when the actual slip ratio exceeds a threshold value of a slip ratio when it is at an intermediate or high speed. An output of the engine is adjusted depending on the actual slip speed in the slip speed traction control, while being adjusted depending on the actual slip ratio in the slip ratio traction control.

Abstract: A method for classifying a road surface condition by estimating the maximum tire/road surface coefficient of friction and actively inducing acceleration or deceleration. In one embodiment, the induced acceleration/deceleration is provided by applying torque to the driven wheels of the vehicle. The speeds of the driven and non-driven wheels are measured. The tire/road surface coefficient of friction and the driven wheel slip ratio are calculated from the wheel speeds. The tire/road surface coefficient of friction and the wheel slip ratio are used to determine the slope of the wheel slip/coefficient of friction curve, which is used to classify the road surface condition.

Abstract: A procedure to operate a hybrid-electric power train and a device to implement the procedure are proposed. The hybrid-electric power train contains at least one internal combustion engine and at least one electromotor, which together supply a drive torque, respectively a driving power output, for a motor vehicle. At a power output demand on the hybrid-electric power train, which corresponds at least to a lower power output threshold, the internal combustion engine is operated constantly at least approximately at the full load.

Abstract: A method, computer usable medium including a program, and a system for braking a vehicle during brake failure. The method and computer usable medium include the steps of determining a brake force lost corresponding to a failed brake, and determining a brake force reserve corresponding to at least one non-failed brake. At least one commanded brake force is determined based on the brake force lost and the brake force reserve. Then at least one command brake force is applied to the at least one non-failed brake wherein at least one of an undesired yaw moment and a yaw moment rate of change are limited to predetermined values. The system includes a plurality of brake assemblies wherein a commanded brake force is applied to at least one non-failed brake.

Abstract: In a method and a device for predicting movement trajectories of a vehicle to prevent or reduce the consequences of an imminent collision, in which for predicting the movement trajectories, only those trajectories are considered for which, because of a combination of steering intervention and braking intervention, the forces occurring at the wheels of the vehicle are within the range corresponding to the maximum force transferable from the wheel to the road. Particularly for systems which provide an automatic braking and/or steering intervention for avoiding a collision or reducing the severity of a crash with another object, an automatic braking and/or steering intervention is carried out as a function of the pre-calculated movement trajectories.

Abstract: A vehicle includes an internal combustion engine that drives a first set of wheels, a generator, wherein the generator is powered by the internal combustion engine, a inverter connected to an output of the generator, an AC motor connected to an output of the inverter, and a controller, wherein the controller controls the generator, the inverter and the AC motor. The AC motor drives a second set of wheels. Power output by the generator is controlled according to a desired torque output for the second set of wheels. The controller calculates a potential power based upon the current status of the generator and controls the AC motor by the inverter based on the smaller of the desired torque and the potential power output of the generator.

Abstract: A drive force control method for a four-wheel drive vehicle including a torque distributing mechanism capable of changing a drive force distribution ratio between front and rear wheels and a drive force distribution ratio between right and left front wheels or between right and left rear wheels. This method includes the steps of increasing the drive force distribution ratio of the rear wheels to the front wheels according to an increase in absolute value of a lateral G signal, and increasing the drive force distribution ratio of a turning outer wheel as one of the right and left front wheels or one of the right and left rear wheels to a turning inner wheel as the other. A lateral G sensor signal is corrected by an estimated lateral G signal calculated according to a steering angle and a vehicle speed to obtain a control lateral G signal, which is used as the lateral G signal.

Abstract: A vehicle lateral control system that integrates both vehicle dynamics and kinematics control. The system includes a driver interpreter that provides desired vehicle dynamics and predicted vehicle path based on driver input. Error signals between the desired vehicle dynamics and measured vehicle dynamics, and between the predicted vehicle path and the measured vehicle target path are sent to dynamics and kinematics control processors for generating a separate dynamics and kinematics command signals, respectively, to minimize the errors. The command signals are integrated by a control integration processor to combine the commands to optimize the performance of stabilizing the vehicle and tracking the path. The integrated command signal can be used to control one or more of front wheel assist steering, rear-wheel assist steering or differential braking.

Abstract: A lateral G sensor breakdown detection device configured to carry out a breakdown determination control that determines that the lateral G sensor has a breakdown when the difference between the actual lateral G acting on a four wheel drive vehicle measured by the lateral G detection sensor installed on the vehicle and the estimated lateral G estimated and calculated from predetermined parameters that express the condition of the vehicle; while the vehicle is turning when the rotation speed of the outer wheel is equal to or less than the rotation speed of the inner wheel and when the actual lateral G is less than the estimated lateral G and the difference is greater than a predetermined value, the breakdown determination control is suspended.

Abstract: A vehicle dynamics control (VDC) apparatus for an automotive vehicle with a differential limiting device capable of limiting at least one of a differential motion between front and rear wheel axles and a differential motion between left and right wheel axles, includes a VDC system that controls a braking force of at least one of road wheels to control vehicle cornering behavior depending on a vehicle's turning condition independently of a driver's braking action. The VDC system advances a VDC initiation timing used in a differential limited state in which at least one of the front-and-rear wheel axle differential motion and the left-and-right wheel axle differential motion is limited, in comparison with a VDC initiation timing used in a differential non-limited state in which the front-and-rear wheel axle differential motion and the left-and-right wheel axle differential motion are allowed.

Abstract: A braking system for a lift truck performs all service braking using truck traction drive motors. Mechanical, spring applied, electrically released brakes are coupled to wheels on opposite sides of the truck with the mechanical brakes applying unequal braking forces to the wheels. The mechanical brakes perform park braking and, in the event an electrical system problem arises, backup braking as well that can be modulated by an operator of the truck regardless of the operating condition of the truck.

Abstract: To maintain operating safety by driving force distribution control system when an abnormal state arises and to smoothly transition from a normal state to an abnormal state without sudden changes in vehicle behavior. The driving force distribution control part calculates the transfer torque for the transfer clutch for the center differential device and the torque movement for the hydraulic motor for the rear wheel final reduction gear. When the control state detection part detects an abnormal state, there is control of the hydraulic motor in the direction that torque movement is lost on the one hand, and the transfer torque for the transfer clutch is controlled in the direction of front and rear distribution; after a preset time and after this control is carried out, the transfer torque drops.