Fujitsu Corporation

Isuzu Motors Limited

Izuzu Motors Limited

Yasuyoshi Asagi

Toshihiro Hattori

Hitoshi Kasai

Makoto Uriuhara

Noriaki Ogawa

Masaki Ishihara

Katsuya Shishido

Shigeki Moride

Hideo Saito

Nobuichi Uchiyama

Jyunzo Kuroyanagi

A method of controlling the gear changing operation in an automatic transmission having a gear transmission actuatable by a gear changing actuator assembly controlled by an electronic control system. When operating the gear changing actuator assembly for a gear changing operation, an interval of time, which elapses after the gear changing actuator assembly is operated, is measured with a timer. The measured interval of time is compared with a preset interval of time. When a lock is detected as being caused at the time the gear changing operation is not completed within the preset interval of time, the gear changing actuator assembly is operated to a gear position different from a gear position which the gear changing actuator assembly has originally been operated to select.

Method of controlling gear changing operation in automatic transmission

Herein disclosed is a signal processing system for a motor vehicle with high responsiveness to the will of a driver. The output voltage of an acceleration sensor using a potentiometer is converted into a digital value by an analog-digital converter. The nonlinearity of the output voltage is corrected by polynominally calculating the digital value. This digital value is controlled by a central processing unit which processes the digital value to generate an acceleration signal having a linear relationship to the changes in the resistance of the potentiometer during actuation of an accelerator. The central processing unit further includes a memory for storing the acceleration signal at an idling position to determine a calibrated acceleration signal using a ratio of an actual acceleration signal obtained from the accelerator pedal to the stored value thereof.

Signal processing system for vehicular acceleration sensor

A method of controlling a synchromesh type automatic transmission of a vehicle such as an automobile, including the steps of releasing a clutch for connecting an engine and the transmission in response to a speed change command, shifting the transmission from one speed position to a neutral position, shifting the transmission from the neutral position to a subsequent speed position, and applying the clutch. The double-clutching operation is conducted if a load upon synchronization during the speed changing operation exceeds a predetermined level, to once apply the clutch and subsequently release the clutch again while the transmission is in the neutral position. Thus, the synchronization load can be dropped to prevent any so-called 'under-synchronization' in the transmission. The synchronization load is detected in terms of the difference between the r.p.m. of the input shaft of the transmission and the product of the vehicle speed or the r.p.m. of the output shaft of the transmission and the reduction ratio.

Method of controlling automatic transmission

A method of controlling a shifting operation of a synchro mesh type automatic transmission in a vehicle, such as an automobile. The method includes the steps of (i) detecting the running state of the vehicle, (ii) determining an optimum gear position from the vehicle running condition, (iii) determining if the optimum gear position is higher than a gear position of the transmission, (iv) determining if the engine torque is greater than or equal to a predetermined value and reducing the engine torque below the predetermined value, if the optimum gear position is higher than the gear position of the transmission, (v) disengaging a clutch to disconnect an engine and the transmission, (vi) shifting the transmission to the optimum gear position, and (vii) engaging the clutch. Moreover, the engine torque is reduced before the clutch is released--by reducing the fuel supply to the engine--so that abrupt decelerations and declutching shocks caused by conventional shifting methods are not felt by the driver.

Method of controlling automatic transmission in accordance with engine

An automatic clutch control system and method for controlling a clutch for an automatic transmission when a clutch stroke sensor fails. The apparatus includes a clutch actuator for controlling a clutch stroke, a plurality of solenoid valves for controlling the clutch actuator, a clutch stroke sensor for measuring the clutch stroke, a control unit for feeding back a stroke signal detected by the clutch stroke sensor when requests for clutch engagement or disengagement are received and for controlling the solenoid valves so as to obtain a clutch moving speed defined by an engine rotational speed and other driving conditions. The control unit further includes a clutch engagement control section and a clutch disengagement control section for controlling solenoid valves for operating the clutch independently of the stroke signal when the stroke sensor fails. The control unit detects a failure of the stroke sensor by defining an upper limit value and a lower limit value for the stroke signal and when the stroke signal exceeds the upper limit value or is lower than the lower limit value it is determined that the stroke sensor has failed. The method includes the steps of setting the upper and lower limit values for the stroke signal, detecting a clutch stroke sensor failure by determining if the value of the stroke signal exceeds the upper limit or is less than the lower limit and operating the clutch at a predetermined speed if a stroke sensor failure is detected.

Automatic clutch control system

A method of controlling the gear changing operation of an automatic transmission includes determining an optimum gear position based on a car speed and an extent of depression of an accelerator pedal to control a gear transmission to select the optimum gear position, and selecting neutral when the determined optimum gear position is lower than a selected gear position at the time the accelerator pedal is released, to interrupt the gear changing operation until the accelerator pedal is depressed.

Method of controlling automatic transmission in accordance with

A diagnostic processing system for the automatic transmission of an automobile to cooperate with an instruction element for producing an actuation signal for driving the transmission gears and clutch. The system is chiefly comprised of a gear position sensor which senses the gear position of the transmission gears and a diagnostic check element which determines, based on a gear position signal from the sensor and other information regarding the automobile's operation, the validity of the actuation signal.

Diagnostic processing system for automatic transmission of an automobile

A failure diagnostic processing system including a checking element for achieving a diagnostic check with respect to sensors to produce first and second diagnostic signals regarding each sensor. The first and second diagnostic signals indicate whether or not a failure condition stands, respectively. Also included are counting element for achieving a count up and a count down selectively in response to the first and second diagnostic signals, respectively; an alarm element for providing an alarm indication in accordance with the count number of the counting element; and a recording element for creating a history of failure by recording the count number of the counting element where the count number exceeds a predetermined reference number for starting the record.

Failure diagnostic processing system

An electronic control method for vehicles, wherein, when exercising control to start a vehicle from rest, the vehicle engine and clutch are controlled in a very low speed control mode, if the amount by which an accelerator pedal is depressed is less than a set value. If, however, the amount of accelerator pedal depression is greater than the set value, the engine and clutch are controlled in an ordinary start control mode. When the vehicle is travelling and the speed thereof is less than a set value, the clutch is controlled in a start control mode. When the travelling speed of the vehicle is greater than the set value, the clutch is controlled in a shift mode.

Method for automatic control of a motor vehicle clutch

An automatic clutch control system, for use in automobiles, using a microcomputer. Included in the system are an accelerator pedal sensor for detecting accelerator position; an engine speed sensor for detecting engine speed; a clutch stroke sensor for detecting clutch stroke; and an automobile speed sensor for detecting automobile speed. The microcomputer is included in a controller for controlling opening or closing of solenoid valves, gear change of a transmission, and opening or closing of a throttle actuator, based on predetermined stored data and based on signals transmitted from the sensors. The automatic clutch control system consequently can automatically control the clutch moving time and clutch moving speed for easy driving under all driving conditions. Moreover, while the clutch control system is fully automatic, it can use dry-type single-plate clutches and sliding-mesh-type transmissions as in manual and semiautomatic transmissions.

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Kawasaki, Japan

Yasuyoshi Asagi