Abstract: A driving force switching control apparatus in a vehicle which runs by two-wheel drive or four-wheel drive in accordance with the running state. The apparatus includes a device for determining whether the vehicle runs at a constant speed; and a device for determining a drive system of the vehicle running at a constant speed to be the two-wheel drive or the four-wheel drive according to road surface conditions computed using rolling resistance. A threshold value for switching between the two-wheel drive and the four-wheel drive is changed in a manner such that a determination area where the four-wheel drive is selected increases according to increase in the rolling resistance. Sufficient driving force transmitted to the wheels can be secured even when the road surface condition varies, and accordingly, sufficient driving force is secured also when the running condition is changed from constant speed running to acceleration or deceleration running.

Abstract: A power transmission system for a four-wheel drive vehicle comprises a power transmission mechanism provided in a vehicle arranged such that power is always transmitted to one of two pairs of wheels consisting of a pair of front wheels and a pair of rear wheels, to transmit power to the other pair of wheels, and a differential gear unit arranged between left and right wheels in the other pair, to distribute the power transmitted from the power transmission mechanism to the other pair, between the left and right wheels. The differential gear unit is a torque-sensitive differential gear unit with a differential limiting function for producing a differential limiting force between the left and right wheels, depending on power transmitted thereto, and a power transmission control means controls the power transmitted from the power transmission mechanism to the differential gear unit according to a driving state of the vehicle.

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.

Abstract: In the case of a control device for an at least part-time four-wheel-driven motor vehicle, having a control unit which can variably distribute the driving torque of a drive unit to primary driving wheels, which are permanently connected with the drive unit, and to secondary driving wheels which, if required, can be connected by way of a transfer clutch with the drive unit, wherein the control unit determines a desired clutch torque which is to be set by an actuator device at the transfer clutch, the control unit consists of a main control unit and an additional control unit, the main control unit computing the desired clutch torque as a function of detected and/or determined parameters, which clutch torque is transmitted to the additional control unit, and the additional control unit converting the desired clutch torque to a corresponding electric control signal for the actuator device.

Abstract: The estimated drive torque calculation unit, which is the drive torque estimation device according to the present invention, is configured such that if the running condition determination unit determines that the transmission mechanism is in gear, and if the speed of rotation of the output shaft of the torque converter measured by the rotation speed measurement sensor is equal to or less than a predetermined speed of rotation, and if the rotation speed of the wheels measured by the wheel speed sensor is equal to or greater than a predetermined rotation speed, the torque combination unit calculates the first estimated drive torque as the engine estimated drive torque even if the slip ratio of the torque converter is equal to or less than a predetermined value, and even if the first estimated drive torque calculated by the first drive torque calculation unit is greater than the second estimated drive torque calculated by the second drive torque calculation unit.

Abstract: A driving force distribution control apparatus and driving force distribution control method for a four-wheel drive vehicle which can quickly increase torque distribution to sub-drive wheels after a transmission has been shifted down. According to the apparatus and method, when it is determined that the transmission has been shifted down, an ECU controls a coupling capable of changing the torque distribution to the front wheels and rear wheels such that the torque distribution to the front wheels and rear wheels approaches a uniform state.

Abstract: A differential control system for the center and rear differentials of a four-wheel-drive vehicle comprises a controller (28) which receives signals input from a number of sensors including ride height sensors (42, 44, 46, 48). The controller (28) determines from the ride height signals the degree of articulation of the vehicle suspension and controls the degree of locking of the differentials in response. The degree of locking is increased with increased articulation, and with increased rate of change of articulation.

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 method a operating a traction control system using a traction controller (30) for an automotive vehicle (10) is provided. A slip target is first determined. Then, an operating temperature turning characteristic or slope of the slip curve may, in combination or alone, be used to adjust the slip trigger threshold above the slip target. Traction control mode is entered when the driven wheel speed is above the slip trigger threshold.

Abstract: An apparatus for controlling driving forces supplied to left and right wheels of a vehicle, for effectively inhibiting oversteer and understeer states, includes driving force adjusting device for adjusting driving forces supplied to the left and the right rear wheels, first controlling device for controlling the driving force adjusting device such that a wheel speed difference between the left and the right rear wheels coincides with a target wheel speed difference, and second controlling device for controlling the driving force adjusting device such that a yaw momentum of the vehicle coincides with a target yaw momentum. If the vehicle is in an understeer state, the contribution of the second controlling device is increased relative to that the first controlling device and if the vehicle is in an oversteer state, the contribution of the first controlling device is increased relative to that of the second controlling device.

Abstract: Front and rear wheels Tf, Tr of a motor vehicle driven by an engine 10 are connected through a differential control device 15 which is capable of varying the torque to transmit. When the turning radius of a predetermined one wheel or the motor vehicle is equal to or smaller than a predetermined turning radius, the transmission torque of the differential control device is decreased by a control device to prevent the tight-corner braking phenomenon from occurring. When the motor vehicle is stopped momentarily with the transmission torque being lowered, the control device maintains the transmission torque as it is, and the vehicle is then restarted with the transmission torque being lowered. Thus, when the motor vehicle which was stopped momentarily with a large steering angle is then restarted, the tight-corner braking phenomenon can be prevented from occurring from the beginning of the restarting.

Abstract: In the case of a control device for an at least temporarily four-wheel-driven motor vehicle, having a control unit which can variably distribute the driving torque of a drive unit as a function of operating conditions to primary driving wheels, which are permanently connected with the drive unit, and to secondary driving wheels which, if required, can be connected by way of a transfer clutch with the drive unit, in that the control unit determines a desired clutch torque which is to be set by an actuator device at the transfer clutch, one operating condition is the vehicle speed. The control unit is further developed such that, when the desired clutch torque is determined, at least one defined high-speed range is taken into account and in that a speed-range-related clutch torque assigned to the high-speed range is defined as a maximally permissible limit torque.

Abstract: In the case of a control device for an at least partially four-wheel-driven motor vehicle, having a control unit which can variably distribute the driving torque of a drive unit to primary driving wheels, which are permanently connected with the drive unit, and to secondary driving wheels which, if required, can be connected by way of a transfer clutch with the drive unit, in that the control unit determines a desired clutch torque which is to be set by means of an actuator device at the transfer clutch, the control unit receives at least one input signal for detecting an accelerator pedal position and is further developed such that, when the desired clutch torque is determined, a basic pilot control fraction is taken into account, which is defined as a function of the accelerator pedal position and is corrected as a function of additional parameters which are detected or determined by the control unit.

Abstract: A control system limits reactive torque in a powertrain that is generated when braking force is applied to traction wheels during a sudden stop or other sudden braking event. The reactive torque generated at the traction wheels is prevented from being transmitted upstream through the driveline and powertrain by using a slip type clutch in the driveline to limit the upstream transfer of the reactive wheel torque. The clutch is directly actuated by the reactive torque and therefore does not require special controls or monitoring systems to sense the braking event. The clutch pressure may be automatically adjusted in response to certain operating conditions or events, thereby adjusting the point at which the clutch begins to slip due to reactive wheel torque.

Abstract: In the case of a control system for a vehicle with at least part-time four-wheel drive, having a control unit which detects or determines quantities proportional to the wheel speeds of all wheels and the vehicle speed, and by means of which the driving torque of a drive unit can be variably distributed to primary driving wheels, which are permanently connected with the drive unit, and to secondary driving wheels which, if required, can be connected with the drive unit, for the distribution of the driving torque, a clutch torque of a transfer clutch arranged between the drive unit and the secondary driving wheels is set by means of the control unit, and the control unit is further developed such that the clutch torque is increased if a difference is detected between the wheel speed of a wheel and the vehicle speed and/or if a difference is detected between the two wheels speeds of the wheels of at least one vehicle side.

Abstract: In the case of a control device for an at least partially four-wheel-driven motor vehicle, having a control unit which can variably distribute the driving torque of a drive unit to primary driving wheels, which are permanently connected with the drive unit, and to secondary driving wheels, which, if required, can be connected by way of a transfer clutch with the drive unit, wherein the control unit determines a desired clutch torque which is to be set by an actuator device at the transfer clutch. The control unit is further configured such that, when the desired clutch torque is determined, at least one degree of stress to the transfer clutch and/or at least one degree of stress to the actuator device are taken into account. In this case, the taking into account of a short-duration degree of stress to the transfer clutch is particularly important with a view to a closing which is as fast as possible for preventing a slip.

Abstract: In a power distribution control system for a four-wheel-drive vehicle, a 4WD controller is electronically connected to a friction clutch for controlling a torque distribution ratio. The 4WD controller determines whether a past-history condition, a command torque, and a reversal-of-torque condition that an input direction of torque inputted into the friction clutch is reversed is satisfied. The 4WD controller outputs a countermeasure-of-noise command torque decreased from the current command torque as a command signal for the friction clutch, when the past-history condition, the command torque condition, and the reversal-of-torque condition are all satisfied.

Abstract: A motor vehicle powertrain system according to this invention controls the magnitudes of torque produced by multiple power sources that drive the vehicle wheels. The system includes a source of pressurized fluid, and a pump/motor driveably connected to the wheels, which is driven in a motoring mode by fluid from the fluid source and has a variable volumetric displacement that changes in response to displacement of the accelerator pedal. An engine, driveably connected to the wheels, includes a throttle that opens and closes in response to displacement of the accelerator pedal. A controller controls operation of the engine and pump/motor such that they produce torque at various magnitudes.

Abstract: In a vehicular brake force control apparatus, an engine brake force Feb is calculated; a road surface friction coefficient ? and a rear wheel degree of grip ?r is calculated; and a threshold value Ke is calculated such that the threshold value Ke increases as the road surface friction coefficient ? becomes smaller. When the rear wheel degree of grip ?r is smaller than the threshold value Ke, it is determined that vehicle behavior of a vehicle is liable to become unstable when the engine brake force Feb acts. In this case, a sum of the engine brake force Feb and a target friction brake force Fbv based upon a steering operation amount of a driver is distributed to each wheel in accordance with a distribution that stabilizes the vehicle behavior of the vehicle. Based on this distribution result, a friction brake force and an output torque of the engine are controlled.

Abstract: A vehicle driving force control apparatus is provided for a vehicle having a drive source configured to drive a generator and an electric motor configured to drive an electric motor driven wheel by electricity from the generator. The vehicle driving force control apparatus basically has a driving force detection section and a driving force control section. The driving force detection section is configured to detect at least one of a requested acceleration amount and a vehicle traveling speed. The driving force control section is configured to set a target generator driving force from the drive source based on at least one of the requested acceleration amount and the vehicle traveling speed. The vehicle driving force control apparatus is configured to provide a batteryless electric motor four-wheel drive vehicle that can ensure stability when starting from a stop on a low friction coefficient road, while maintaining vehicle acceleration performance.

Abstract: A torque transfer mechanism includes a multi-plate clutch assembly that is operably disposed between a first rotary and a second rotary member. A control system determines a desired quantity of torque to deliver to the second rotary member and controls the clutch to produce the desired torque.

Abstract: In a specific control state, confirmation is made whether or not the present torque limiter value exceeds a maximal value of an allowed torque value in the specific control state, and in the event that the present torque limiter value exceeds the maximal value of the allowed torque value in the specific control state, the torque limiter value is slowly lowered by subtracting a constant A1 from the present torque limiter value, while in the event of transition from the specific control state to an ordinary control state, the torque limiter value is slowly raised to the maximal torque limiter value in the ordinary control state by adding a constant A2 to the present torque limiter value. Thus, excessive change of torque at transition of a control state can be suppressed, and adverse effects on driving stability and driving performance under the specific control state can be minimized.

Abstract: A temporary indicated torque is obtained by taking a conventional dead zone area for a first slip control area, and the value proportional to the slip quantity for a maximum value, this temporary indicated torque is corrected by a correction value according to the tight cornering brake quantity to be the indicated torque of the transfer clutch, and occurrence of any tight cornering brake phenomenon is prevented thereby. In a slip control area after passing a dead zone area (a second slip control area), the slip control is smoothly transferred from the first slip control area to the second slip control area by performing the slip control with a value of the indicated torque according to the slip quantity added to the indicated torque in the first slip control area as the indicated torque, abrupt torque change is prevented, and the vehicle behavior is stabilized thereby.

Abstract: A four wheel drive assembly 10 including a torque transfer assembly 60 which operates under the control of the controller 62 and which receives and selectively transfers a certain desired amount of torque to a front axles 14, 15 and to the rear axles 14 17. The amount of transferred torque varies depending upon the occurrence of a sensed slip condition the use of a pre-emptive slip control mode of operation in which the controller 62 determines that it is likely that a slip may occur. Particularly, controller 62 is allowed to enter the preemptive mode of operation only after an actual slip has occurred and the controller 62 exits this preemptive mode of operation upon the occurrence of a certain event or condition or upon the passage of a certain amount of time.

Abstract: A fault detecting apparatus for a four-wheel drive vehicle is provided for avoiding without fail any erroneous detection due to a response delay associated with an operation for switching a speed increasing system and due to sudden fluctuations in wheel speed, to highly accurately detect a fault in the speed increasing system. The speed increasing system is configured to transmit a driving force of a prime mover directly to main driving wheels and to sub-driving wheels through associated clutches, and to increase rotational speed of the sub-driving wheels above rotational speed of the main driving wheels when a speed increase instruction signal is outputted. The fault detecting apparatus comprises an S-AWD•ECU for detecting a fault in the speed increasing system, and for disabling the fault detection until a predetermined time has elapsed after a speed increase instruction signal was outputted or after the output of the speed increase instruction signal was stopped.

Abstract: The present invention relates to a method for improving an anti-lock control system, in particular for improving driving stability during braking on laterally different coefficients of friction. According to the method, a desired yaw rate is determined using at least one steering angle signal of a steering angle sensor and an actual yaw rate is determined using at least one yaw rate sensor, and the instability is evaluated using a parameter that serves for a qualitative and quantitative judgment of a deviation between the actual yaw rate and the desired yaw rate. Both yaw rate deviation and the time derivative of the yaw rate deviation are used to determine the parameter.

Abstract: A method of replicating a real-world vehicle rollover of a vehicle having wheels utilizing a vehicle testing apparatus having a support. The method includes positioning the vehicle on the support. Static properties of the vehicle are then determined. An initial set of forces and moments to be applied to the support are determined based upon at least the static properties. The support is actuated based upon the initial set of forces and moments to replicate the vehicle rollover. An actual response of the vehicle to the initial actuating of the vehicle testing apparatus is measured to determine dynamic properties of the vehicle. So long as all of the wheels remained on the support during the actuating of the vehicle testing apparatus, sets of forces and moments are continuously determined. The vehicle testing apparatus can be repeatedly actuated based upon the sets of forces and moments to further replicate the vehicle rollover.

Abstract: A CPU computes a throttle opening degree increasing speed V?h and a steering wheel angular velocity V? based on a throttle opening degree ?h and a steering wheel angle ?. Based on the throttle increasing speed V?h and the steering wheel angular velocity V?, the CPU selects one of a first drive mode and a second drive mode. The CPU controls the power transmission ratio of a power transmitting device according to the selected drive mode. Therefore, the power transmission ratio of the power transmitting device is properly controlled in accordance with the degree of intention for acceleration of the driver, which is computed based on the throttle increasing speed V?h, and the turning speed of the steering wheel, which is computed based on the steering wheel angular velocity V?. Therefore, the drive mode is properly switched in accordance with the driving state of a four-wheel drive vehicle.

Abstract: A four-wheel drive apparatus for a vehicle with front wheels driven by an engine comprises a generator connected to the engine for generating an electric current; a motor driven by the electric current supplied from the generator and supplying power for driving rear wheels; a battery charged by the electric current supplied from the generator; a first relay switch for switching electric contact between the generator and the motor; a second relay switch for switching electric contact between the battery and the generator, wherein, the current generated by the generator is alternatively supplied to the motor or the battery.

Abstract: A hydrostatic propulsion system includes a hydrostatic circuit fluidly connecting left front and right front motors in parallel with an outlet of a pump, left rear and right rear motors in parallel with an inlet of the pump, left front motor and right rear motor in series, and the right front motor and left rear motor in series. A valve system has a first relief valve line providing flow from a right rear motor inlet side to a left rear motor inlet side, and a second relief valve line providing flow from a left rear motor inlet side to a right rear motor inlet side. A first check valve line provides flow from a right rear motor outlet side to the right rear motor inlet side, and a second check valve line provides flow from a left rear motor outlet side to the left rear motor inlet side.

Abstract: A method of controlling the handling of vehicles having a controllable longitudinal clutch and/or a controllable main-axle lateral lock in the case of all-wheel systems and a controllable lateral lock in the case of vehicles with a single-axle drive. The input quantities are first detected and processed, and subsequently, a comparison takes place of the desired driving direction, which is defined by way of the steering angle (LW), and the actual moving direction (BR) of the vehicle. If the two values deviate from one another by a definable reference value (RW), the coupling between the front axle and the rear axle of the vehicle is increased for increasing the yaw damping, or, when a controllable main-axle lateral lock is present, the locking torque of the lateral lock is increased, or the two measures are initiated simultaneously.

Abstract: A motor assembly includes a keyed on-off switch and at least one 12-volt battery coupled to the existing DC electrical system of the vehicle. A D.C. speed control unit regulates the current to a DC drive motor. A housing is positionable adjacent to a front or rear portion of the vehicle and includes a D.C. motor connected to the DC speed control unit and a 12-volt D.C. alternator. An A.C. generator is operably connected to at least one AC breaker box via the electrical system. A converter is electrically coupled to the existing electrical system and the A.C. breaker box. The system further includes a plurality of electrical outlets and a power switch operably connected thereto and to the A.C. breaker box wherein the outlets conveniently allow a user to supply power to an external device.

Abstract: A vehicle power take off system provides power for a variety of systems including a source of alternating current power for conventional electrical equipment to be powered by the vehicle. In a preferred electrical implementation, the power take off system is energized from the vehicle direct current electrical power system and generates alternating current of the desired voltage using a derectifier and step up transformer. Management of the system is implemented through modularized units which may be connected to communicate with another over a vehicle's controller area network. Load management may be monitored by an existing on board computer.

Abstract: To provide a vehicular two-wheel drive and four-wheel drive switching system the power consumption of which can be reduced. A vehicular two-wheel drive and four-wheel drive switching system is provided with a switching unit for transmitting power or disconnecting the transmission of power. The switching unit is provided with a driving shaft connected to the drive side, a driven shaft fitted to the driving shaft via an annular clearance gap. A plurality of connecting/disconnecting members are provided in a clearance between the driving shaft and the driven shaft for connecting or disconnecting the driving shaft and the driven shaft by being fitted or disconnected to/from respective opposite surfaces. A switching mechanism is provided for selectively positioning the connecting/disconnecting members in a position in which the driving shaft and the driven shaft are connected and in a position in which the driving shaft and driven shaft are disconnected.

Abstract: The present invention provides a method, a computer usable medium including a program, and a system for monitoring inflation in a plurality of vehicle tires. The method and computer usable medium include the steps of determining a direct pressure in at least one primary tire and determining a rolling radius for the primary tire and at least one secondary tire. A pressure difference is determined based on the determined rolling radius for the primary and secondary tires. The determined pressure difference is adjusted based on the determined direct pressure of the primary tire. The determined pressure difference is compared to at least one threshold value. The system includes means for achieving the method steps of the invention.

Abstract: A torque distribution control device for a four-wheel drive vehicle having a torque distribution device for distributing the drive power transmitted from an engine to either of the front wheels or the rear wheels as prime drive wheels, to other wheels as sub-drive wheels determines a pre-torque in a feed forward sense based on the vehicle speed, the throttle opening degree and the gear shift step of a transmission. A compensation torque is determined in a feedback sense based on the vehicle speed and the rotational speed difference between the drive wheels and the sub-drive wheels. A torque transmission clutch is controlled based on a command torque which is obtained by the addition of the pre-torque and the compensation torque, so that the command torque is distributed to the sub-drive wheels.

Abstract: A drive power from an engine is transferred to front wheel drive systems and rear wheel drive systems via a central differential. A torque distribution ratio between front and rear wheels defined by the central differential is set to one for the front wheels being made too much thereof, with a motor generator being coupled to the rear wheel drive systems. In response to detection signals from various sensors for detecting the running conditions, a drive power control unit controls the additional torque from the motor generator toward the drive torque or regenerative braking torque side, thereby changing the torque distribution ratio between the front and rear wheels. Thus, a degree of flexibility in making a change in the torque distribution between front and rear wheels or between right and left wheels is increased, thereby realizing an all-wheel drivable hybrid vehicle which provides further improved running performance.

Abstract: The aim is to stably control the lateral movement of a vehicle even on a road where the frictional coefficient is extremely small, such as on a frozen road, thereby improving the turnability and travelling stability. The device includes a frictional force adding means for increasing the frictional force of wheels to a road surface by scattering particulates and a controller which calculates the target lateral movement value and the actual lateral movement value based on the signals from wheel speed sensors, a steering angle sensor and a yaw rate sensor and actuates the right or left frictional force adding means according to the difference between these two values to increase the frictional force, thereby stabilizing the lateral movement.

Abstract: The two-wheel/four-wheel drive switching device including a switching unit provided in either a power transmitting mechanism interposed between an engine and front wheels or a power transmitting mechanism interposed between the engine and rear wheels for switching between the continuation and interruption of power transmission in the power transmitting mechanism, and a control unit for controlling the switching unit. The control unit detects a drive current supplied to the switching unit and performs variable duty control to maintain the drive current at a given value. As a result, the two-wheel/four-wheel drive switching device reduces the generation of noise and greatly suppresses the consumption of power.

Abstract: Method of controlling the vehicle handling of vehicles having a controllable longitudinal clutch and/or a controllable main-axle lateral lock in the case of all-wheel systems and a controllable lateral lock in the case of vehicles with a single-axle operation wherein at least the driving speed (v), the lateral acceleration (aq) and the actual steering angle (LW(act)) are detected. From the filed characteristic diagram, which extends along the driving speed (v) and the lateral acceleration (aq), the pertaining steering angle (LW(KF)) is determined for the respective driving speed (v) and the lateral acceleration (aq) and is then compared with the actual steering angle (LW(act)). If the two steering angles deviate from one another by at least a definable amount, the lateral acceleration is adapted by changing the locking torque for a stable vehicle handling.

Abstract: A method of automatic location of the right and left wheels of a motor vehicle of the type comprising a step of automatic measurement of the centripetal acceleration of a wheel, the method being characterized in that it consists in comparing the theoretical centripetal acceleration (Ai) of a wheel in a straight line with the measured centripetal acceleration (Aiv) of this same wheel when cornering for a given vehicle speed (V), and for a given steering wheel angle (T), so as to determine whether the wheel is on the right or on the left of the vehicle.

Abstract: A method of detection of the limited slip differential device, wherein it is detected whether a vehicle is mounted with a limited slip differential device on the basis of a relationship between a lateral directional acceleration of a vehicle calculated by using rotational information obtained from tires attached to the vehicle or on the basis of a turning radius of the vehicle, and a specified judged value. It is possible to improve performance and safety of the vehicle since it is possible to accurately judge decrease in internal pressure of a tire.

Abstract: A system is provided, which controls a starting and the subsequent vehicle acceleration procedure of a motor vehicle. The system compares a predetermined variable that grows continuously during the starting procedure to a threshold value. It determines a first desired value of torque in response to operator demand, and a second desired value torque in response to acceleration slip. The system performs a feed-forward 4WD control in response to the first desired value of torque when the predetermined variable is lower than or equal to the threshold value. The system determines whether or not driving situation justifies a change from performing the feed-forward 4WD control to performing a feed-back 2/4WD control in response to the second desired value of torque.

Abstract: A vehicle driving force control apparatus is configured for a four-wheel drive vehicle that switches between a four-wheel drive state and a two-wheel drive state. The driving force control apparatus improves the response when a vehicle shifts into a four-wheel drive state while starting to move from a state of rest and, simultaneously, avoids the occurrence of shock when the clutch is connected. When the rotational speeds of the motor and the rear wheels reach or fall below their respective minimum detectable rotational speeds, the controller calculates estimated times until the motor and the rear wheels will stop based on the rotational speeds detected up until the minimum detectable rotational speed was reached and begins counting down from those estimated times. Since the clutch is connected after both estimated times have reached zero, the clutch is connected while reliably avoiding the occurrence of shock.

Abstract: The invention relates to a device for increasing the security of a motor vehicle comprising an automatic transmission, which is impinged upon by an electrical transmission control system and a detection unit for detecting a critical driving situation and for generating a corresponding signal. In order to increases driving security, an evaluation device is provided which checks whether the generated signal has reached a specific value or exceeded a specific threshold. If said value has been reached or the threshold has been exceeded, the evaluation device causes the transmission control system to interrupt the positive engagement of the transmission.

Abstract: A torque-biasing system (10) including a torque-biasing device (12) and a control unit (14) for use in a vehicle (16). The torque-biasing system is preferably installed and used in a vehicle having a first wheel (18) with a first rotational speed and a second wheel (20) with a second rotational speed, and an engine (22) with a torque output. The control unit (14) calculates an error value based on a different between the first rotational speed and second rotational speed and derives a control signal based upon proportional and integral terms of the error value with a forgetting factor. The control unit then sensor the control signal to the torque-biasing device (12).

Abstract: In a differential limiting torque control section, a target differential rotation speed between front and rear drive shafts is established according to a dial position inputted by a driver of a variable dial. Further, an actual differential rotation speed between front and rear drive shafts is calculated and a deviation between the target differential rotation speed and the actual differential rotation speed is calculated. Based on the deviation, a first differential limiting torque and based on a dial position of a variable dial a second differential limiting torque are calculated. Further, a third differential limiting torque is calculated based on the dial position and a throttle opening angle. A final differential limiting torque between front and rear drive shafts is obtained by summing up these first, second and third differential limiting torques.

Abstract: A drive-force distribution controller controls a drive-force transmission apparatus of a vehicle in order to control transmission of drive force to rear wheels or front wheels of the vehicle in accordance with a designated drive-force transmission ratio. The drive-force transmission ratio is changed on the basis of vehicle speed, differential rotational speed (speed difference between the front and rear wheels), and throttle opening. Alternatively, the drive-force transmission ratio is changed on the basis of vehicle speed, throttle opening, and throttle open speed. The change speed of current which is supplied to the drive-force transmission apparatus in order to control the drive-force transmission ratio is adjusted in accordance with a command current filter value which is determined on the basis of vehicle speed and a command current filter map of a vehicle-speed responsive type.

Abstract: A method of controlling a four-wheel drive vehicle permits reverse travel on a low-? road without engaging shock. In a four-wheel drive vehicle in which two-wheel drive and four-wheel drive can be changed over by means of a rotation transmission device having a two-way clutch and an electromagnetic coil for controlling engagement of the two-way clutch, the traveling direction of the vehicle is detected with rotation sensors for detecting the rotational direction of the front and rear wheels. If the traveling direction of the vehicle is different from the traveling direction of the range, the two-way clutch is engaged.

Abstract: There is disclosed a driving force control system for a four-wheel drive vehicle, which is capable of properly controlling the execution and cancellation of a lock mode in which the engagement forces of clutches for distributing a driving force to auxiliary drive wheels are made maximum, thereby reducing frequency and duration of the lock mode. Further, there is disclosed a driving force control system for a four-wheel drive vehicle, which is capable of properly controlling the engagement forces of clutches for distributing a driving force of the main drive wheels to auxiliary drive wheels, thereby causing the clutches to efficiently operate without waste of power.