Mazda Motor Corporation

Mitsuru Nagaoka

Kenichi Watanabe

Toshihiro Matsuoka

Yasunari Nakayama

Kaoru Sotoyama

Kazutoshi Nobumoto

Eizi Nishimura

Kazuya Oda

Mitsuo Yasuno

Osamu Kameda

Toru Onaka

Tetsuhiro Yamashita

Shizuo Sumida

Eiji Nishimura

Yasuhiro Harada

Yoshiaki Anan

Shoji Imai

Hideshi Hiruta

Yasuma Nishiyama

An automatic transmission control system for an automatic transmission including a hydraulic pressure control circuit which supplies locking and unlocking pressures selectively to a plurality of friction coupling elements to lock and unlock the selected friction coupling elements, changing a torque transmission path in a transmission gear mechanism to provide available gears, a specific one of which is achieved by locking and unlocking simultaneously specific friction coupling elements.

Automatic control system for automobiles

A rear wheel steering system for a vehicle including a yaw rate sensor for detecting a yaw rate of the vehicle and yaw rate feedback controller for controlling a steering angle of rear wheels so that a yaw rate detected by the yaw rate sensor is made equal to a target yaw rate, the rear wheel steering system further including a side slip angle calculator for estimating a side slip angle of the vehicle, a side slip angle controller for controlling the steering angle of the rear wheels to decrease an absolute value of the estimated side slip angle calculated by the side slip angle calculator and a fuzzy controller for controlling the steering angle of the rear wheels based on fuzzy control to decrease an absolute value of a rate of change in the detected yaw rate. This rear wheel steering system can control the steering angle of the rear wheels in a desired manner even when the lateral acceleration is high and the vehicle is turning sharply, and can improve driving stability.

Rear wheel steering system for vehicle

A running state control system having running state control means for controlling a running state of a vehicle, in which a control target quantity thereof is set different according to a steering angle, comprises steering angle detecting means for detecting the steering angle, and steering angle changing means for changing the steering angle detected by the steering angle detecting means into a filtered steering angle a decrease of which lags behind a decrease of an actual steering angle. Consequently, an abrupt change in a control condition can be prevented even during a slalom run and counter steering of a vehicle, thus enhancing a running stability of the vehicle.

System for controlling the running state of a vehicle in accordance with

A four-wheel drive vehicle has a center differential which transmits the output torque of a power plant to both front and rear wheels in such a manner as to permit the front and rear wheels to rotate at different speeds. A differential control system has a differential rotation limit member which acts on the center differential to limit differential rotation of the front and rear wheels to a degree which is increased as the difference in rotational speed between the front and rear wheels increases. The degree of limitation on the differential rotation of the front and rear wheels is changed according to a predetermined characteristics which nullifies the degree of limitation in a range where the difference in rotational speed is relatively small and provides a gain in a range where the difference in rotational speed is relatively large. The gain is changed according to a factor which governs the running condition of the vehicle.

Differential control system for four-wheel drive vehicle

A four-wheel drive vehicle has a center differential which transmits the output torque of a power plant to both front and rear wheels in such a manner as to permit the front and rear wheels to rotate at different speeds. A differential control system has a differential rotation limit member which acts on the center differential to limit differential rotation of the front and rear wheels to a degree which is determined according to the difference in rotational speed between the front and rear wheels. The degree of limitation on the differential rotation of the wheels is determined according to the difference in rotational speed between the front and rear wheels based on first characteristics when the rotational speed of the front wheels is higher than that of the rear wheels and based on second characteristics when the rotational speed of the rear wheels is higher than that of the front wheels. The first and second characteristics are set separately from each other.

A drive control system of a four-wheel drive vehicle has a differential device interposed between front and rear wheels and a differential restricting device mounted to the differential device. The differential restricting device is subjected to feedback control so as for the wheels to reach a target slip ratio. In this control, a control target value is given by way of slip ratios of the wheels and the target slip ratios are then converted into a wheel speed difference between the front and rear wheels. The feedback control of the differential restricting device is performed by comparing the target wheel speed difference with an actual wheel speed difference between the front and rear wheels.

Drive control system of four-wheel drive vehicle

Disclosed is a four wheel drive vehicle with four wheels drivable, which is provided with a first slip control apparatus for reducing a driving force to the wheels by operating a brake mounted on each of the wheels and with a second slip control apparatus for reducing a driving force to the wheels by reducing the engine output. Operation of only the first slip control apparatus or both the first and second slip control apparatuses is selectively carried out in accordance with the number of wheels which are detected to be slipping in an amount greater than a given degree of slippage. Particularly when such slipping wheels are two, the slip control is conducted by operating only the first slip control apparatus or both the first and second slip control apparatuses in accordance with control modes predetermined on the basis of six combinations in which such two slipping wheels out of the four wheels are combined with each other.

Slip control apparatus for a four wheel drive vehicle

The control apparatus eliminates the adverse effects upon a moving vehicle caused by interference between two control operations taking place at the same time. For example, the control of torque applied to the wheels simultaneously subjected to wheel slip control can cause competing contradictory instructions to be issued to control the rotation of the wheel. When a wheel undergoing slip control is instructed by the torque split control to increase torque, the torque split control is cancelled. When the torque split control decreases the torque applied to a wheel and the wheel continues to slip, the wheel is subjected to slip control and the torque applied is reduced to prevent slip. When a wheel undergoing slip control has increased torque applied, the slip of the wheel is monitored and the torque is reudced to bring the slip below a predetermined limit.

Power train control apparatus

In a four wheel drive vehicle adapted to drive all of the four wheels, a braking force is applied to the wheel which causes slipping while the output torque of the engine is increased in accordance with brake operation. A braking pressure adjusting unit is preferably provided with each of the four wheels which is arranged so as to separately and individually brake the wheel which slips.

Torque distribution control system for a four wheel drive vehicle

A torque distribution control system for a four-wheel drive vehicle has an engine output controller which controls the output of the engine of the vehicle, a braking controller which separately controls the braking forces applied to the left wheels and the right wheels and/or the braking forces applied to the front wheels and the rear wheels. A torque distribution changing system determines the torque distribution to the wheels according to the running condition of the vehicle and controls the braking controller and the engine output controller to apply a braking force to one of the front wheels and the rear wheels or one of the left wheels and the right wheels and to increase the output of the engine by an amount substantially corresponding to the braking force applied to the one of the front wheels and the rear wheels or the one of the left wheels and the right wheels so that the torque distribution determined according to the running condition of the vehicle can be obtained.

Torque distribution control system for four-wheel drive vehicle

A control system for a vehicle engine comprises a first detecting device for detecting a controlled variable on an accelerator, an engine ouput adjusting device, such as a throttle valve, a second detecting device for detecting a situation wherein a vehicle employing therein the vehicle engine is in a travelling condition of traffic jam, and a control device for controlling the engine output adjusting device to cause the vehicle engine to vary its engine output with a predetermined rate of variation in the engine output to the controlled variable on the accelerator when the situation wherein the vehicle is in the travelling condition of traffic jam is not detected by the second detecting device and with a diminished rate of variation in the engine output to the controlled variable on the accelerator when the situation wherein the vehicle is in the travelling condition of traffic jam is detected by said second detecting device so as to have the engine output adjusted in accordance with the controlled variable on the accelerator detected by the first detecting device.

Control systems for vehicle engines

The engine control system of the present invention comprises an engine output changing device for controlling an engine output of at least one of engine power, engine, engine torque and engine speed. At least two controls for controlling the engine output changing device are selected from a direct control device for directing detecting an actual value to which the engine output changing device is operated. A target value for the engine output changing device is set based on an amount an accelerator is operated to thereby adjust the engine output changing device to eliminate a difference between the actual value and the target value. A vehicle speed control device for detecting an actual vehicle speed, setting a target value of vehicle speed based on the amount the accelerator is operated, and for controlling the engine output changing device, and an acceleration control device for detecting a change in an actual vehicle speed, setting a target value of vehicle acceleration based on the amount the accelerator is operated, and for controlling the engine output changing device, are also provided. A selecting device is used to select one of the direct control, vehicle speed control and acceleration control devices in accordance with a vehicle running condition.

Engine control system

A control value of the control apparatus for controlling a device or devices loaded on a vehicle, for example, a slip ratio against a road surface of driven wheels for a slip control apparatus (traction control apparatus) is determined as a final control value based on plural input signals. For every input signal, plural control zones coresponding to its signal value are present. For every combination of the control zones, a basic control value is memorized in a memory; an adaptability for the control zone corresponding to each signal value is determined as a first adaptability; a second adaptability is determined on the basis of the first adaptability obtained for every input signal; and an inference control value is then determined on the basis of the second adaptability and the basic control value. From the numbers of inference control values and second adaptabilities corresponding to the number of all combinations of the control zones, there is determined the final control value.

Control apparatus for controlling device loaded on vehicle

The vehicle slip control apparatus is designed so as to enable the slip control to be done by causing the output torque of the engine to be reduced and operating the brake when an amount of a slip or spinning of the driving wheels is large, on the one hand, and only by causing the output torque of the engine to be reduced without using the brake when an amount of the slip or spinning of the driving wheels is small.

Vehicle slip control apparatus

A vehicle automatic transmission including a hydraulic torque converter, a multiple stage gear mechanism and an electronic controller for controlling the gear mechanism to select an appropriate gear stage in accordance with vehicle operating conditions. The electronic controller has a first gear shift control map for controlling the gear mechanism under normal vehicle operations. It further has a second gear shift control map for operations under a traffic jam so that a better fuel economy is established than in an operation under the first map.

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Hiroshima, Japan

Mitsuru Nagaoka