Nissan Motor Company Limited

Toru Iwata

Minoru Tamura

Takashi Imaseki

Shinji Katayose

Terukiyo Murakami

Yuichi Fukuyama

Sota Yasuda

Hideaki Inoue

Tomohiro Fukumura

A continuously variable transmission of an automobile which varies the drive ratio arbitrarily between an input axis and an output axis is combined with a traction control device for example which performs braking corresponding to vehicle running conditions and irrespective of the accelerator pedal depression. A microprocessor calculates the vehicle speed from the rotation speed of the output axis, calculates the target drive ratio depending on the vehicle speed, and controls the drive ratio of the continuously variable transmission to be equal to the target ratio. When the brake operation device performs braking, fluctuation of the drive ratio based on the rotation variation of the output axis is prevented by the correction of the drive ratio in the upshift direction.

Control device for continuously variable transmission

A slip of drive wheels of a vehicle driven via a continuously variable transmission is suppressed due to fuel cut of a multi-cylinder engine. The speed change response characteristics of the transmission are made to vary according to the engine rotation speed when fuel cut is performed. A speed change ratio command value is calculated from a target speed change ratio based on a first-order delay due to a predetermined time-constant. The response of the transmission is thus delayed for low engine rotation speed than for high rotation speed, and undesirable fluctuation of the speed change ratio when the drive wheels slip is prevented.

Vehicle drive force control device

An engine for a vehicle which selectively performs uniform combustion wherein an air-fuel mixture uniformly spread in the combustion chamber is burnt and stratified combustion wherein an air-fuel mixture converged to a part of the combustion chamber is burnt, is combined with a drive force controller for suppressing a slip of a vehicle drive wheel by reducing the engine output. At the end of drive force reduction control, it is determined whether the engine is in the stratified combustion condition or the uniform combustion condition. When it is in the stratified combustion condition, uniform combustion is first performed for a predetermined time, and then stratified combustion is performed. In this way, the combustion is prevented from becoming instable when the drive force reduction control is terminated.

Drive force controller for a vehicle

In a lean burn engine for a vehicle wherein an ordinary air-fuel ratio and a lean air-fuel ratio are selectively applied, an engine output is reduced when a slip of a drive wheel is detected. By controlling the air-fuel ratio when the engine output is reduced to an ordinary air-fuel ratio, the engine is prevented from becoming unstable even when output is reduced at a lean air -fuel ratio. Preferably, when the engine output reduction has terminated, the air-fuel ratio is returned to the air-fuel ratio prior to the output reduction.

An engine output control apparatus for use with an automotive vehicle supported on a road surface by a pair of driven road wheels and a pair of non-driven road wheels to control an output transmitted from an internal combustion engine to the driven road wheels through an automatic transmission adapted to produce changes up based on engine output and vehicle speed. A traction control signal is produced when the degree of slip of the driven road wheels is equal to or greater than a predetermined value. The engine output is reduced in the presence of the traction control signal. Changes up are produced at higher vehicle speeds in the presence of the traction control signal than in the absence of the traction control signal when the engine output is equal to or less than a predetermined value.

Engine output control apparatus

In order to provide an accurate traction control by closing a second throttle valve provided in series to an accelerator-operated ordinary throttle valve, with a simplified actuator, a control system for reducing a vehicle driving torque employs one or more sensors for sensing a second vehicle operating parameter representing a road surface friction coefficient (.mu.) or a driver's command for acceleration, in addition to sensors for sensing a first vehicle operating parameter representing a drive wheel slip. When the road surface friction coefficient is high or when the driver depresses the accelerator pedal hard, the control system restrains the closing operation of the second throttle valve in accordance with the second parameter even though the closure of the second throttle valve is requested by the first parameter.

System for controlling driving torque of vehicle

A traction control apparatus for use with an automotive vehicle having an internal combustion engine through which an output drive is transmitted to drive road wheels. A demand for first traction control is produced based on a slippage produced on the drive road wheels during acceleration. The first traction control demand includes a normal demand for first traction control continuing for a time shorter than a limit time and an exceptional demand for first traction control continuing over the limit time. A limit value is set for the number of times the exceptional demand is permitted. In response to the first traction control demand, at least one of fuelcut control and ignition control is performed to reduce the engine output drive. The first traction control demand is ignored when the number of times the exceptional demand has occurred reaches the limit value.

Differential limit torque control apparatus

A control system for controlling an acceleration slip of a wheeled vehicle by performing a fuel cut control and an ignition timing control is designed to prevent a temperature increase of an engine system and to prevent a heating of a catalyst in an exhaust system when an engine output reduction control is continued. When a predetermined engine operating condition such as a high engine load condition or a high engine speed condition or a high engine temperature condition is detected during the engine torque reduction control, the control system further reduces the engine output gradually, or alternatively the control system inhibits the ignition timing control to reduce the engine output and instead increases the number of fuel cut cylinders.

Fuel cut and ignition timing control system for controlling acceleration

In order to prevent a traction control system and an auxiliary steering or the like from combining stabilizing effects in a manner which causes excessive understeer, when the traction control is functioning in a predetermined manner, a signal is issued to the auxiliary steering control and reduces the gain with which the control thereof is implemented. As a result excessive understeer is avoided while maintaining suitable vehicle stability.

Traction control for automotive vehicle

A control system, such as a traction control system, for a wheel vehicle comprises a detecting section for detecting a hydroplaning condition by comparing a difference between a sensed undriven wheel speed, and a filter signal obtained by passing the sensed undriven wheel speed signal through a low-pass filter, and a controlling section for performing a control action adapted to the hydroplaning condition. This control system can detect the hydroplaning condition accurately, and control the vehicle adequately to negotiate the hydroplaning condition.

System for detecting hydroplaning of vehicle

An automobile total traction control system comprises a primary traction control system utilizing at least one of a fuel-cut control and an ignition-timing control, a secondary traction control system utilizing a driving-force reduction control different from the fuel-cut control and the ignition-timing control, sensors for detecting a wheel speed of each road wheel to derive a slip rate of each drive wheel and detecting an engine condition such as engine load and engine speed, and a controller for determining an acceleration-slip state of the vehicle based on the derived slip rate. During acceleration-slip, the controller determines the control allocation between the primary and secondary traction control systems based on the detected engine load, such that the control allocation of the primary traction control system to the secondary traction control system is decreased in accordance with an increase in the detected engine load.

Automobile traction control system

An automotive traction control system comprises a master cylinder, an external brake fluid pressure source, a brake fluid pressure control actuator being applied commonly to an acceleration-slip control and a deceleration-slip control, a first switching valve for establishing and blocking a communication between the master cylinder and the pressure control actuator, a second switching valve for establishing and blocking a communication between the external brake fluid pressure source and the pressure control actuator, and a control unit for deriving a pressure reducing control time necessary to reduce the wheel cylinder pressure to a designated brake fluid pressure, based on a pressure intensifying control time, during the acceleration-slip control. The control unit is arranged for switching the second switching valve just after the pressure reducing control time has elapsed, and for switching the first switching valve and a pressure intensifying valve and a pressure reducing valve both included in the pressure control actuator with a predetermined time lag after shifting of the second switching valve, in a transient state transiting from the acceleration-slip control mode to the normal braking operational mode.

Traction control system for automotive vehicles

An automotive brake control system includes a master cylinder, an external brake fluid pressure source, a wheel-cylinder pressure control actuator applied commonly to a traction control (TCS control) performed for suppressing excessive driving force exerted on driven wheels during quick acceleration and an anti-skid brake control (ABS control) performed for preventing brakes from locking vehicle wheels during quick braking, or braking on a low frictional road, and a fluid pump for supplying the brake fluid stored in a fluid reservoir to a pressure accumulator, and a controller for controlling the pump, such that the pump is driven for a first setting time in an ABS pressure reducing mode and drives the pump for a second setting time substantially at a time point where one cycle of the TCS control ends, so as to feed the brake fluid from the reservoir to the accumulator.

Automotive brake control system

An improved traction control system and method for an automotive vehicle are disclosed in which both deceleration slip brake control system (ABS) and acceleration slip brake control system (TCS) are mounted and a switching condition of control from the deceleration slip brake control to the acceleration slip brake control is different from a switching condition from the acceleration slip brake control to the deceleration slip brake control, the deceleration slip brake control having a higher priority that the acceleration slip brake control so as to prevent occurrence of control hunting.

Traction control system for automotive vehicle and traction control

A traction control system monitors wheel slippage and variation of wheel slippage for detecting road friction condition. The traction control system selects brake control characteristics depending upon the detected road friction condition.

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Kanagawa, Japan

Toru Iwata