Abstract: A solenoid valve drive system includes a step-up circuit that produces a first high voltage by using a switching device to on/off control supply of current from a battery to a step-up coil and stores the first high voltage in a first capacitor as a high voltage for initial high-voltage driving of a solenoid valve, a second capacitor, and a discriminating circuit for discriminating the level of the charge voltage of the second capacitor. The second capacitor is charged by high voltage from the step-up circuit only when the charge voltage of the second capacitor has not reached a prescribed level. The system can efficiently produce two types of high voltages without enlarging circuit size.

Abstract: An apparatus for driving an electromagnetic load by applying a high voltage at the initial driving stage and thereafter applying a constant hold current is provided with a switch for supplying high-voltage energy to the electromagnetic load from a capacitor for storing high-voltage energy and a control circuit responsive to an electric signal for starting electromagnetic load driving and the output voltage of the capacitor. The control circuit turns the switch on at application of the electric signal and keeps it on until the output voltage reaches a prescribed level. The apparatus of this configuration enables optimum timing of changeover from high-voltage application mode operation to hold mold operation with simple circuitry.

Abstract: In a method for correcting clutch data used for controlling the operation of a friction clutch connected with an electronically controlled transmission system, the clutch data includes meet position data stored in a memory and the stored meet position data is compared with a first learned meet position data obtained after power is applied to the transmission system. The old data stored in the memory is replaced with the first learned meet position data when the difference between the old data and the first learned meet position data is greater than a prescribed value. The old data is corrected by the use of the old data and the learned data when the difference is not greater than the prescribed value even if the learned data is the first learned meet position data.

Abstract: In a method for automatically controlling the gear-shifting operation of a vehicle gear transmission so as to shift the transmission to a calculated target position according to the vehicle operation parameter(s), the stability of the calculated target position is discriminated and the required gear-shifting operation is carried out only when the stability satisfies a prescribed condition, whereby unnecessary gear-shifting operations can be effectively eliminated even if for some reason the calculated target gear position frequently changes.

Abstract: In an automatic transmission system having a selector and a generator responsive to the operation of the selector for generating electric information indicating the operation condition of the selector, the nature of the malfunction or trouble arising in the generator is discriminated on the basis of the change in the electric information. This discrimination may be made as to whether or not there is a malfunction condition wherein no information is obtained for any set position, whether or not there is a malfunction condition wherein the information indicating a specific position is always produced. When there is a malfunction therein, the position set by the selector is assumed by taking into account the nature of the malfunction, making it possible to control the gear-shift operation even if there is malfunction.

Abstract: In a method for correcting clutch data used for controlling the engaging/disengaging operation of a friction type vehicle clutch, the meet position data among the clutch data is updated by a learning operation at each operation of a predetermined operation member of the vehicle, and the updated meet position data is corrected in accordance with the engine speed during the actual operation of the clutch, each time the vehicle is driven off, whereby appropriate correction of the clutch data can be carried out at suitable time intervals.

Abstract: A clutch control apparatus for controlling the operation of a friction type clutch comprises a data generator responsive to an engaging command signal for generating an electric signal corresponding to the time-course in a target clutch stroke pattern for engaging the clutch. The actual clutch stroke of the clutch is adjusted by the use of a clutch actuator coupled with the clutch in response to the electric signal in such a way that the actual clutch stroke is made to coincide with the target clutch stroke at each instant, whereby the actual clutch stroke varies in accordance with the desired time-course pattern for engaging the clutch after the application of the engaging command signal. The initial target clutch stroke of the desired pattern may be corrected in accordance with the amount of operation of an acceleration member to reduce the dead time in the torque transmission through the clutch.

Abstract: In an electronically controlled automatic transmission system including a gear transmission and a clutch, in which a target gear position is determined in accordance with map data for gear-shift control, it is discriminated whether or not the vehicle is in accelerating condition and necessary control for shifting up the transmission to the target gear position is carried out only when the vehicle is not in the accelerating state. Thus, when the driver presses hard on an accelerating member to accelerate the vehicle, a series operations for shifting up is not carried out, whereby the transmission is kept in its present gear position. The operation for shifting up can be carried out after the completion of the acceleration of the vehicle.