Abstract: A foldable electronic pedal apparatus is proposed. The foldable electronic pedal apparatus has both a foldable function that can pop up and hide the pedal and an electronic pedal function, and can tune necessary pedal effort, stroke, and hysteresis that are different for every kind of vehicle by having a high-load spring module and a hysteresis lever.

Abstract: An idle reduction control device mounted on a vehicle equipped with an engine and a brake comprises: a pumping operation detector that detects a pumping operation of the brake; and an engine controller that controls a start and a stop of the engine. The engine controller stops the engine after elapse of a predetermined time since a stop of the vehicle, when a number of the pumping operations during a deceleration period before the stop of the vehicle is less than a predetermined value.

Abstract: A method of controlling a rolling or coasting function of a vehicle with a drive train having a drive motor, an automatic or automated transmission, a controllable shifting means, a brake device and a drive speed control device. The vehicle speed is regulated by the drive speed control device and the braking device is activated, as needed, when driving on a downhill gradient section. To effectively and reliably use the rolling or coasting function in suitable driving situations, taking into account the influence of the driving speed control device, a rolling or a coasting condition for a downhill gradient taper is checked, when driving on the downhill gradient section, and, when the rolling or coasting condition is satisfied, the transmission controls interrupt the flow of power in the drive train before the vehicle entering a flat area, and/or before the driving speed control device generates an engine torque request.

Abstract: A method for controlling deceleration of a motor vehicle having an internal combustion engine with an automated clutch, in which method, when a deceleration is present, a deceleration fuel cutoff is carried out in order to generate a drag torque as a drive torque if the engine speed is higher than a deceleration fuel cutoff threshold wherein when a braking request is present, the effect of the engine speed is evaluated, a comparison is carried out between the expected engine speed or the current engine speed and the deceleration fuel cutoff threshold, and the internal combustion engine is adjusted to a deceleration mode or a deceleration fuel mode is maintained only if the expected or current engine speed is higher than the deceleration fuel cutoff threshold.

Abstract: In a control apparatus of an internal combustion engine having an electronic throttle system driving an actuator so that a throttle valve provided in the internal combustion engine is at a target opening according to driving conditions, a throttle opening is turned to a limp home opening when abnormality is detected in the driving conditions so as to allow retreat traveling of a vehicle. The control apparatus of the internal combustion engine includes a brake operation detecting unit detecting a brake operation, in which when a brake operation is added subsequently while the accelerator pedal is operated, the control apparatus sets the target opening to the limp home opening based on occurrence of a sequence of the operations, and drives the actuator so that the throttle opening turns to the limp home opening, regardless of whether abnormality is detected or not.

Abstract: A system comprising a controller configured to determine if a brake control of a vehicle is actuated; determine a delay time in response to a speed of the vehicle; determine if the delay time has passed from when the brake control was actuated; and if the delay time has passed, override an engine control of the vehicle.

Abstract: A motor vehicle speed control system for attenuating sudden unintended acceleration and maintaining driver control of a motor vehicle has a brake switch connected in series with a vacuum switch and a relay. A foot pedal when depressed actuates the brake switch to provide electric power to the vacuum switch coupled to the intake manifold of the motor vehicle. Vacuum pressure in the intake manifold actuates the vacuum switch to close the electric circuit to the relay. Relay interposed in the electric ignition or fuel injector circuits is open when both brake and vacuum switch are closed thereby interrupting these circuits and reducing the power or terminating the operation of the motor vehicle's engine.

Abstract: A method for controlling the operating mode of a drive of a vehicle that includes a main drive unit and an auxiliary tractive energy source. The method includes operating the main drive unit, detecting the duration of actuation of an uninterrupted actuation of a brake pedal, and detecting whether the duration of actuation is above a minimum duration by comparing the duration of actuation with a minimum duration. The main drive unit is switched off if it has been detected that the duration of actuation is above the minimum duration. Otherwise, operation of the main drive unit is continued if it has been detected that the duration of actuation is not above the minimum duration. A device for carrying out the method is also described, which includes a timer for detecting the duration of actuation and a comparator for comparing the duration of actuation with a minimum duration.

Abstract: A control device controlling a vehicle's automatic transmission. The automatic transmission engages first and second friction engagement elements by fluid pressure from a pump operating using motive power from the vehicle's motor when a shift position is at a reverse traveling position, places the first friction engagement element on standby at a predetermined pressure that is higher than a stroke starting pressure by which a piston stroke is started and lower than a complete engagement pressure or engages the first friction engagement at the complete engagement pressure when the shift position is at a non-traveling position, and engages a third friction engagement element as a starting shift speed when the shift position is at a forward traveling position.

Abstract: Disclosed is a method for increasing a braking effect in a motor vehicle with a hydraulic brake system. An energy supply unit, which is used to increase the brake pressure in at least one wheel brake, is switched on when the brake pressure adjusted by the driver in a master brake cylinder exceeds an activation threshold, which is determined depending on a detected vehicle deceleration. A check is made whether an unbraked trailer is coupled to the vehicle, and in that the activation threshold PAT is raised, if the presence of an unbraked trailer that is coupled to the vehicle is detected.

Abstract: A vehicle anti-rollback system and method can be incorporated into a vehicle that includes a pair of front wheels, a pair of rear wheels, a power unit, and a transmission connecting the power unit to at least one wheel of the front and rear wheels. The transmission can include a plurality of forward drive ratios and at least one reverse drive ratio and a two speed final drive ratio transmission configured to select between a high range drive ratio and a low range drive ratio when the transmission is in one of the plurality of forward drive ratios. A controller can be provided that senses a vehicle rollback condition. When the rollback condition is detected, the controller can decrease torque distributed from the power unit of the vehicle to the at least one wheel, and can actuate a brake. While the vehicle is braked and torque transfer is reduced, the controller can execute drive ratio changeover in a stable manner from the high range drive ratio to the low range drive ratio.

Abstract: An on-board diagnostic system of a vehicle comprises disabling diagnostic operation, such as a misfire monitor, based on road roughness. In one example, the disabling of the diagnostic operation is based on brake actuation and degradation of an anti-lock braking system.

Abstract: An engine of a working vehicle in which an adverse effect of oil temperature rise is avoided, by decreasing a load applied to an accelerator when the working vehicle moves while lifting a boom and approaches a place where the load in a bucket is to be dumped during dump approach and, reducing heat generated through operation of a brake, and deterioration in work efficiency of the working vehicle is avoided by preventing the lifting speed of a boom from decreasing. A hydraulic pump controller and a method for controlling the hydraulic pump are also provided.

Abstract: Engine surge includes oscillations in engine torque resulting in bucking or jerking motion of a vehicle that may degrade driver experience. The present application relates to increasing reformate entering an example engine cylinder in response to engine surge.

Abstract: A safety system for a motor vehicle which prohibits the sudden acceleration of the vehicle as a result of hydraulic brake pressure. The throttle-control system of the vehicle is bypassed by providing an ignition switch connecting a starter to a battery, the battery providing voltage for an internal combustion engine of the motor vehicle. A brake pressure switch is connected to the ignition switch and to a brake master cylinder for receiving brake fluid under hydraulic pressure upon actuation of a brake pedal. An ignition coil means transforms and increases the voltage for the engine. Finally, a limiter set at a specific revolutions per minute (RPM) to limit output of the engine is connected to the brake pressure switch and to the ignition coil, the limiter reacting to the voltage when the brake pressure switch is closed by the hydraulic pressure from the brake pedal.

Abstract: Vehicle operation is controllable and/or regulatable by specifying a driver request describing a setpoint rotational speed or a setpoint torque via an accelerator pedal, detecting the instantaneous position of the accelerator pedal and controlling and/or regulating the internal combustion engine such that the setpoint rotational speed or setpoint torque is achievable. To provide for a sustained-action brake to be easily operated in the vehicle, and increase the vehicle's range of use, one of possible braking actions of the vehicle is specified by selecting a determined position of the pedal. As a function of an instantaneously detected position of the accelerator pedal, the operation of the vehicle is controlled and/or regulated such that braking power specified via the accelerator pedal is achieved. A variation in the braking power specified via the accelerator pedal is also converted as continuously as possible to a corresponding braking power by suitably activating additional components or devices.

Abstract: In a device for securing the standstill of a motor vehicle with a distance-related longitudinal dynamic control module, which is contained in at least one electronic control unit and by which the motor vehicle is decelerated down to a standstill while maintaining a defined distance from a target object, at least until reaching the standstill, a nominal brake torque is defined by the longitudinal dynamic control module for a brake control module. At a defined first time after a detected standstill of the motor vehicle, the longitudinal dynamic control module transmits a transfer signal to the brake control module. Thereupon, independently of the predefinition of a nominal brake torque by the longitudinal dynamic control module, the brake control module alone builds up and/or holds a wheel brake torque in the sense of a parking brake function.

Abstract: A deceleration control device for a vehicle including an automatic transmission capable of changing the gear ratio by a shift operation of a driver. The control device controls the load of a brake actuator or engine so that the vehicle is decelerated, when the driver performs a shift operation, under conditions that it is determined that the driver has the intention to decelerate and the automatic transmission is not downshifted.

Abstract: A method of controlling fuel injection in an engine of a vehicle comprising of deactivating a fuel injector of the engine during a deceleration condition of the vehicle; and reactivating the fuel injector when a rate of change of a powertrain shaft deceleration is greater than a threshold.

Abstract: A method of controlling fuel injection in an engine of a vehicle comprises reactivating fuel injectors based on release or decrease of driver braking during deceleration fuel shut off operation. According to another aspect, a method of controlling fuel injection in an engine of a vehicle comprises reactivating fuel injectors based on release or decrease of driver braking during deceleration fuel shut off; and increasing air flow to a cylinder before reactivation of fuel injectors in response to said release or decrease of driver braking to enhance torque response. The methods allow an engine to exit DFSO earlier by making use the brake input and effort, which provides time to reactivate the fuel injection and stabilize torque control prior to tip-in.

Abstract: An electronic transmission range selection (ETRS) system for shifting a transmission range of a transmission includes an electro-mechanical park inhibit assembly that operates to disallow the ETRS system from shifting from an Out-of-Park mode to a Park mode under certain circumstances. The park inhibit assembly includes a follower having a recess defined thereon and slidably disposed within a follower bore. In one embodiment a selectively energizable solenoid assembly is mounted substantially perpendicular to the follower and operates to bias a ball into the recess when energized thereby locking the ETRS system in the Out-of-Park mode. In another embodiment the park inhibit assembly includes a selectively energizable motor assembly mounted substantially perpendicular to the follower. The motor assembly operates to enforce the Park and Out-of-Park mode of the ETRS system.

Abstract: A control system for a hybrid vehicle includes a regenerative braking module that controls regenerative braking of the hybrid vehicle. Regenerative braking is controlled when an accelerator device is not engaged. A throttle-by-wire control module controls a throttle valve. The throttle-by-wire control module opens the throttle valve and/or holds the throttle valve open in response to regenerative braking module signals when a transmission of the hybrid vehicle is in gear.

Abstract: A rotary throttle assembly is disclosed for operating a power unit such as an engine or a motor in either a first power setting or a second power setting. The rotary throttle assembly may be used in a concrete vibrator to operate the vibrator in either an idle power setting or a desired power setting. The throttle assembly includes a rotatable throttle handle, a linkage mechanism contained in a casing, and means for urging the throttle assembly selectively to adopt a first position or a second position.

Abstract: In a driving condition control system, a sensing unit is configured to sense a first physical quantity indicative of a rotation of the first rotatable axle assembly and a second physical quantity indicative of a rotation of the second rotatable axle assembly. A correcting unit is configured to correct the torque according to the sensed first and second physical quantities of the rotations of the first and second rotational axle assemblies. This allows the torque to be precisely obtained.

Abstract: Method and apparatus for distributing brake torque between at least one first and one second brake device on a motor vehicle including at least two wheel pairs. The first brake device is a friction brake which acts on at least one wheel pair and the second brake device acts on at least the driven wheel pair via the transmission and is disposed before the clutch device of the transmission. Brake torque is distributed between the first and the second brake device in a manner that compensates for the loss of brake torque which occurs when the second brake device is disengaged by the clutch device of the transmission.

Abstract: A method and an arrangement for controlling the drive unit of a vehicle are suggested which prevent a lost motion and a dead path in the interpretation of the position of the accelerator pedal for forming a desired acceleration. An acceleration command is derived from a position of an operator-controlled element (1), especially of an accelerator pedal, and a desired value for an output quantity of the drive unit is formed in dependence upon the acceleration command. A minimum value and/or a maximum value for the acceleration of the vehicle is determined in dependence upon an instantaneous running resistance. The minimum value and/or the maximum value are assigned to respective boundaries of an adjustment range for the position of the operator-controlled element (1).

Abstract: In a control apparatus for a vehicle, when a coast downshifting is performed in response to a downshifting command from a vehicle operator during braking operation under the fuel cut control, the braking force of the wheel brake is increased so as to increase the deceleration. This makes it possible to achieve a predetermined deceleration with a good response to the deceleration request of the vehicle operator represented by the downshifting command. The control apparatus is structured to decrease the braking force of the wheel brake such that the increase in the engine braking force is offset by the inertia caused by the rise in the engine speed resulting from downshifting upon the coast downshifting due to the vehicle speed increase. The control apparatus for the vehicle, thus, reduces the shock caused by the sharp increase in the engine braking force.

Abstract: An engine deceleration control system for an internal combustion engine of a vehicle is arranged to prohibit correcting an air quantity supplied to the engine when an elapsed time period from a moment of turning off of an accelerator of the engine is within a first predetermined time period, or when an elapsed time period from a moment of turning off of a lockup clutch of a torque converter is within a second predetermined time period or when a shifting of a transmission connected to the engine is being executed, and to cancel prohibiting the correction of the supplied air quantity when a braking operation is executed.

Abstract: A method and system to control engine shutdown in a hybrid electric vehicle (HEV) are provided. Tailpipe emissions are reduced during the many engine shutdowns and subsequent restarts during the course of an HEV drive cycle, and evaporative emissions are reduced during an HEV “soak” (inactive) period. The engine shutdown routine can ramp off fuel injectors, control engine torque (via electronic throttle control), control engine speed, stop spark delivery by disabling the ignition system, stop purge vapor flow by closing a vapor management valve (VMV), stop exhaust gas recirculation (EGR) flow by closing an EGR valve, and flush the intake manifold of residual fuel (vapor and puddles) into the combustion chamber to be combusted. The resulting exhaust gas byproducts are then converted in the catalytic converter.

Abstract: One embodiment of the present invention is an apparatus including an internal combustion engine for powering a ground travelling vehicle, a throttle control arrangement including a device for sensing position of an operator-adjustable pedal to provide a throttle control signal, a first sensor to sense rotational speed of the engine, a second sensor to sense brake status of the vehicle, a way to determine failure of the throttle control signal, and a way to operate the engine in a limp-home mode in response to the failure, which includes fueling the engine during the limp-home mode of operation in accordance with idle position of the pedal, rotational speed of the engine, and the brake status.

Abstract: The braking force control apparatus for a vehicle which has a function of applying a braking force to the vehicle by rotational resistance of the engine, by stopping the fuel supply to the engine during coasting of the vehicle and by controlling a torque capacity of a torque capacity control device that is provided between the engine and a wheel so that the torque capacity becomes equal to or higher than a predetermined value, and of decreasing the torque capacity of the torque capacity control device when a predetermined condition is satisfied, and has a function of applying the braking force to the vehicle by a function of an electric power generator which is coupled with the wheel such that power can be transmitted. The braking force control apparatus includes braking force control means which increases a braking force that is generated by the function of the electric power generator when the torque capacity of the torque capacity control device is decreased.

Abstract: A method and an arrangement for ensuring the standstill of a vehicle, especially in combination with a control of the speed of the vehicle, are suggested, wherein a braking force is built up to realize a parking brake when standstill of the vehicle is detected and/or a transmission is switched into the park position. The brake force or the transmission position is also maintained when the supply voltage for the electrical systems of the vehicle is switched off.

Abstract: It is known in the art to apply a counterforce, which opposes the actuating force, onto an accelerator pedal of a vehicle in the event that the vehicle, with respect to a vehicle parameter, sufficiently deviates from the nominal value. The parameter can be the speed or the measured distance from vehicles driving ahead.

Abstract: A brake negative pressure control apparatus and method, and an engine control unit for an internal combustion engine are provided for ensuring a negative pressure within a brake booster and a stable combustion while avoiding a complicated control. The brake negative pressure control apparatus comprises a negative pressure sensor for detecting a negative pressure within the brake booster, and an ECU for disabling the combustion mode to be set to the stratified combustion when the detected negative pressure is lower than a first predetermined negative pressure. The ECU controls a throttle valve opening in accordance with a target throttle valve opening in a homogeneous combustion mode when the ECU disables the combustion mode to be set to the stratified combustion.

Abstract: A method and system to control engine shutdown for a hybrid electric vehicle (HEV) is provided. Tailpipe emissions are reduced during the many engine shutdowns and subsequent restarts during the course of an HEV drive cycle, and evaporative emissions are reduced during an HEV “soak” (inactive) period. The engine shutdown routine can ramp off fuel injectors, control engine torque (via electronic throttle control), control engine speed, stop spark delivery by disabling the ignition system, stop purge vapor flow by closing a vapor management valve (VMV), stop exhaust gas recirculation (EGR) flow by closing an EGR valve, and flush the intake manifold of residual fuel (vapor and puddles) into the combustion chamber to be combusted chamber to be combusted. The resulting exhaust gas byproducts are then converted in the catalytic converter.

Abstract: An apparatus (10) for controlling the road speed of a motor vehicle has an accelerator pedal (12), which is biased counter to its actuating direction into an inoperative position and is movable from the inoperative position into a neutral position, from which a further movement of the accelerator pedal (12) counter to the spring bias leads to an increase of the drive torque of the motor vehicle drive. A device for detecting the inoperative position of the accelerator pedal (12) is connected to a braking-force generator (40) and in the inoperative position of the accelerator pedal (12) causes the braking-force generator (40) to make a predetermined braking force available.

Abstract: A vehicle deceleration controller which is able to relatively reliably satisfy the intended deceleration of the driver irrespective of changes in the vehicle speed, the gradient of the driving road surface and the total weight of the vehicle includes a deceleration determining device that determines a required deceleration in accordance with the vehicle speed and the gradient of the driving road surface with reference to stored characteristic information, and an operation mode determining device that determines the required operation mode in accordance with the required deceleration determined by the deceleration determining device and the vehicle speed and the total vehicle weight with reference to stored characteristic information. An outputting device operates a braking force generating device with the required operation mode when it is determined that the accelerator has been released.

Abstract: A travel speed controller for use in an electrically powered light weight vehicle with a battery-powered motor and a control circuit. If an operator applies some accelerating force or a physical force, to the vehicle body, the control circuit receives a plus signal from a rotation transmission means attached to its wheel, corresponding to the accelerating force, and calculates an acceleration based on operation treatment of variation of time intervals of the pulse signal, memorizes the acceleration, and supplies to the motor a driving electric current corresponding to the memorized acceleration. If a higher acceleration is calculated, the memorized acceleration is renewed and a driving electric current is supplied to the motor, corresponding to the renewed acceleration.

Abstract: An engine control system for a hybrid vehicle having an internal combustion engine and an electric motor as driving force sources, for permitting stopping and restarting of the engine in accordance with predetermined drive conditions. The engine control system includes a fuel cutter for cutting fuel supply to the engine when the vehicle decelerates and an engine speed detector for detecting an engine speed. Stopping of the engine is initiated by cutting the fuel supply by the fuel cutter, and when the engine speed becomes equal to or lower than a predetermined speed, the engine is stopped by operating the motor as a generator and by cutting the fuel supply.

Abstract: A method and apparatus is configured for calibrating a fluid retarder 155 in a transmission system. The transmission system may include an engine 120 connected to a transmission 135 through a driveshaft 118, or power input shaft. The driveshaft is mechanically connected to the fluid retarder 155. The fluid retarder includes a rotor 162 mechanically connected to the driveshaft 118, and a retarder valve 175 adapted to enable fluid flow across the rotor 162. The method includes the steps of delivering a valve command to the retarder valve, determining a speed of the engine, and calibrating the retarder valve in response to the engine speed, and the valve command.

Abstract: Abrupt deceleration of a vehicle is detected based on a depression amount or a depression speed of a brake pedal. If abrupt deceleration of the vehicle has been detected during fuel-cut control, a command is issued to make forcible restoration of control out of the fuel-cut control. Then a lock-up clutch is disconnected and fuel injection for an engine is resumed so as to restore a rotational speed of the engine. As a result, the engine is prevented from stalling due to the undershooting of the engine rotational speed.

Abstract: A control unit for an automatic transmission provides improved responsiveness to a speed reduction operation by the driver. The control unit includes a speed reduction requirement judging logic which judges whether or not there is a speed reduction requirement. An up-shift is inhibited and prevented when a judgement is made that there is a speed reduction requirement, based at least in part on release of the accelerator. Accordingly, it is possible to prevent a vehicle from being accidentally accelerated by an up-shift operation and to smoothly perform a down-shift to effect an engine brake.

Abstract: An automatic engine-stop control apparatus for a vehicle includes a vehicle speed sensor and a brake pedal depression sensor which are coupled to a control unit. The control unit is programmed to decide that the vehicle speed detected by the vehicle speed sensor is smaller than or equal to a predetermined stop expected speed when the brake pedal depression sensor detects that the brake pedal is depressed, and to decide that the vehicle is stopped when a predetermined time period elapses from a moment that the vehicle speed becomes smaller than or equal to the predetermined stop expected speed and when the depression of the brake pedal is continued.

Abstract: An improved traction control system in which a wheel spin condition is detected based on measured vehicle acceleration instead of measured wheel speeds. An electronic controller detects a wheel spin condition by computing the acceleration of the vehicle drive shaft and comparing the computed acceleration to an acceleration threshold stored as function of vehicle speed and wheel torque. If the computed acceleration exceeds the threshold for more than a predetermined time, the engine torque is reduced in relation to the amount by which the computed acceleration exceeds the threshold. When the computed acceleration falls below the threshold, the torque reduction is gradually removed. The wheel torque, vehicle speed and drive shaft acceleration are easily determined and filtered, and the incremental cost of the traction control function is primarily related to the memory requirements to accommodate the acceleration threshold look-up table.

Abstract: A circuit interfaces the brake, the drivetrain, and an accessory driven from the engine through a power take-off with the engine control so as to disallow application of the brake from discontinuing running of the engine at running speed set by the throttle control input whenever there is concurrence of a first input selecting placement of the accessory device in driven relationship to the power shaft, of a second input distinguishing that the transmission is in non-neutral position, and of a third input indicating vehicle speed is below a certain limit. The circuit allows a driver of the vehicle to apply the brake and operate the accessory without interrupting the set running speed of the engine so long the vehicle speed is below the certain limit.

Abstract: In an automobile having a pair of front wheels, a pair of rear wheels, a brake system for selectively braking each of the pairs of front and rear wheels, an engine, a transmission system including a speed change gear device for selectively providing a plurality of transmission gear ratios, a center differential device, a front differential device, and a rear differential device, the traction control device detects slipping conditions of each of the pairs of front and rear wheels, and controls the brake system so as to brake at least one of the pairs of front and rear wheels for execution of traction controls according to one of at least two separate traction control programs which are automatically changed over for execution according to selections of the transmission gear ratios of the speed change gear device for a relatively high speed driving or a relatively low speed driving.

Abstract: A system and method for increasing engine idle during operation of an anti-lock brake system includes car-speed sensing means, in which the state of an electronic signal, outputted according to a driving speed of an automobile, is changed; engine revolution sensing section means, which varies the state of an electronic signal outputted according to the engine's revolutions; operation control means, which, when the ABS operation is realized, outputs a control signal for increasing the revolutions of the engine so that it matches the speed the automobile is travelling; a solenoid valve, which controls the state of pressure applied to change the operational degree of the acceleration pedal; switching means, which, according the state of the signal applied from the operation control means, controls the operational state of the solenoid valve; a vacuum pump, which is linked with the operation of the alternator and creates pressure, and, according to an opening state of the solenoid valve, supplies pressure; and an

Abstract: A system to control the operation of a vehicular transmission embodying the concepts of the present invention utilizes a controller, at least one pulse width modulation solenoid valve and a torque transfer device operatively controlled by each of the solenoid valves so as to regulate a transmission system. The controller operatively imposes not only a varying modulation frequency on each of the solenoid valves, but also a varying modulation duty cycle on each of the solenoid valves. The controller also operatively varies the modulation rate of said frequency and said duty cycle of the fluid pressure operating the plurality of torque transfer devices, thus controlling the operation of each solenoid valve such that it does not impose a torque spike on the operation of the transmission as each solenoid valve applies fluid pressure to the appropriate torque transfer device. Accordingly, the controller provides smooth and quiet operation of the transmission.

Abstract: An electronically controlled hydrodynamic retarder interconnects with the output shaft of a vehicle transmission to selectively apply a braking torque thereto. The retarder includes a solenoid valve, the operating duty cycle of which controls the retarder capacity and resultant braking torque. A control unit, interconnecting the transmission and the retarder, regulates the duty cycle of the solenoid valve to regulate the retarder operation as a function of excessive deceleration or overheating, while also regulating such operation during downshift to assure efficient, effective, and comfortable operation of the transmission/retarder. The retarder is adaptive to accommodate variations resulting from age, wear, and the like.

Abstract: A traction control system for a motor vehicle having driving wheels and driven wheels includes a device for detecting the speed of each of the driving wheels of the vehicle, a device for detecting the speed of each of the driven wheels of the vehicle, a device for calculating a slip value of the driving wheels based on the detected speeds of the driving and driven wheels, a traction control device for controlling the driving wheel so that the slip value of each driving wheel is equal to a predetermined desired slip value when the slip value of each driving wheel is greater than the predetermined desired slip value, and a device for estimating a friction coefficient of a road surface which is employed when the predetermined desired slip value is determined.