Control apparatus and method for an automatic transmission of a vehicle

A hydraulic control apparatus of an automatic transmission having pressure-adjust command generating means for changing a transmission speed by engaging and disengaging a specified friction coupling device in said automatic transmission connected to an engine, and adjusting an oil pressure acting on said friction coupling device when changing the transmission speed, comprising:

• speed change command signal generating means for generating a speed change command signal representing a speed chance ratio;
• transmission output shaft revolution speed detector means for detecting a revolution speed of an output shaft of said automatic transmission;
• transmission input shaft revolution speed detector for detecting a revolution speed of an input shaft of said automatic transmission;
• revolution ratio calculating means for calculating an output shaft revolution ratio of said transmission by using two revolution speeds obtained by said two revolution speed detectors;
• target revolution ratio setting means for one of storing and calculating a target value of said revolution ratio, and
• oil pressure correction value calculating means for correcting an oil pressure acting on said friction coupling device so that an actual revolution ratio calculated by said revolution ratio calculating means follows up said target revolution ratio after a speed change command signal is generated by said speed change command signal generating means further comprising initial oil pressure command value storing means for setting a target oil pressure command value for a specified period lust after a speed change command signal is generated by said speed chance command signal, wherein an initial oil pressure command value output from said storing means is calculated by using a transmission input shaft torque and a transmission input shaft revolution speed as parameters.

A hydraulic control apparatus of an automatic transmission having pressure-adjust command generating means for changing a transmission speed by engaging and disengaging a specified friction coupling device in said automatic transmission connected to an engine, and adjusting an oil pressure acting on said friction coupling device when changing the transmission speed, comprising:

• speed change command signal generating means for generating a speed change command signal representing a speed change ratio;
• transmission output shaft revolution speed detector means for detecting a revolution speed of an output shaft of said automatic transmission;
• transmission input shaft revolution speed detector for detecting a revolution speed of an input shaft of said automatic transmission;
• revolution ratio calculating means for calculating an output shaft revolution ratio of said transmission by using two revolution speeds obtained by said two revolution speed detectors;
• target revolution ratio setting means for one of storing and calculating a target value of said revolution ratio, and
• oil pressure correction value calculating means for correcting an oil pressure acting on said friction coupling device so that an actual revolution ratio calculated by said revolution ratio calculating means follows up said target revolution ratio after a speed chance command signal is generated by said speed change command signal generating means, further comprising target engine torque calculating means for controlling the engine torque so that an actual revolution ratio calculated by said revolution ratio calculating means follows up said target revolution ratio after a speed change command signal is generated by said speed change command signal generating means.

A hydraulic control apparatus of an automatic transmission having pressure-adjust command generating means for changing a transmission speed by engaging and disengaging a specified friction coupling device in said automatic transmission connected to an engine, and adjusting an oil pressure acting on said friction coupling device when changing the transmission speed, comprising:

• speed change command signal generating means for generating a speed change command signal representing a speed chance ratio;
• transmission output shaft revolution speed detector means for detecting a revolution speed of an output shaft of said automatic transmission;
• transmission input shaft revolution speed detector for detecting a revolution speed of an input shaft of said automatic transmission;
• revolution ratio calculating means for calculating an output shaft revolution ratio of said transmission by using two revolution speeds obtained by said two revolution speed detectors;
• target revolution ratio setting means for one of storing and calculating a target value of said revolution ratio, and
• oil pressure correction value calculating means for correcting an oil pressure acting on said friction coupling device so that an actual revolution ratio calculated by said revolution ratio calculating means follows up said target revolution ratio after a speed change command signal is generated by said speed change command signal generating means further comprising initial oil pressure command value storing means for setting a target oil pressure command value for a specified period lust after a speed change command signal is generated by said speed change command signal, further comprising hydraulic pressure changing means for inputting said oil pressure command value, after control has been performed so that an actual revolution ratio calculated by said revolution ratio calculating means follows up said target revolution ratio, into said initial oil pressure command value storing means to update the stored value of said initial oil pressure command value storing means.

A hydraulic pressure control method of an automatic transmission of changing a transmission speed by engaging and disengaging a specified friction coupling device

• in which an oil pressure acting on said friction coupling device is adjusted when changing the transmission speed,
• generating a speed change signal representing a gear ratio of said automatic transmission;
• detecting a revolution speed of a transmission output shaft;
• detecting a revolution speed of a transmission input shaft;
• calculating an actual revolution ratio of said transmission between said input and output shafts of said automatic transmission based on the detected revolution speeds of the input and output shafts;
• one of storing and calculating a target value of said revolution ratio between said input and output shafts of said automatic transmission;
• and
• correcting the oil pressure acting on said friction coupling device so that said output shaft revolution ratio follows up said target value of said revolution ratio after the speed change command signal is generated and before actual shifting starts in response to said speed change command signal.

A hydraulic control apparatus of an automatic transmission having pressure-adjust command generating means for changing the transmission speed by engaging and disengaging a specified friction coupling device in said automatic transmission connected to an engine, and adjusting an oil pressure acting on said friction coupling device when changing the transmission speed, comprising;

• speed change command signal generating means for generating a speed change command signal representing a speed change ratio of said automatic transmission;
• transmission output shaft revolution speed detector for detecting a revolution speed of an output shaft of said automatic transmission;
• transmission input shaft revolution speed detector for detecting a revolution speed of an input shaft of said automatic transmission;
• revolution ratio calculating means for calculating an actual revolution ratio of said automatic transmission based on said transmission output shaft revolution speed and said transmission input shaft revolution speed;
• target revolution ratio setting means for one of storing and calculating a target revolution ratio between said input and output shafts;
• and
• output shaft torque control means for controlling an output shaft torque of said automatic transmission, wherein said output shaft torque control means controls said output shaft torque so that said revolution ratio follows said target revolution ratio after the speed change command signal is generated and before actual shifting starts in response to said speed chance command signal.

A hydraulic control apparatus of an automatic transmission having pressure-adjust command generating means for changing the transmission speed by engaging and disengaging a specified friction coupling device in said automatic transmission connected to an engine, and adjusting an oil pressure acting on said friction coupling device when changing the transmission speed, comprising;

• speed change command signal generating means for generating a speed change command signal representing a speed change ratio of said automatic transmission;
• transmission output shaft revolution speed detector for detecting a revolution speed of an output shaft of said automatic transmission;
• transmission input shaft revolution speed detector for detecting a revolution speed of an input shaft of said automatic transmission;
• revolution ratio calculating means for calculating an output shaft revolution ratio of said automatic transmission according to said transmission output shaft revolution speed and said transmission input shaft revolution speed;
• target revolution ratio setting means for one of storing and calculating a target value of said revolution ratio;
• and
• output shaft torque control means for controlling an output shaft torque of said automatic transmission, wherein said output shaft torque control means controls said output shaft torque so that said revolution ratio follows said target revolution ratio, further comprising initial oil pressure command value storing means for setting at least target oil pressure command value for a specified period after said speed change command signal is generated, wherein an oil pressure command stored in said initial oil pressure command value storing means is changed in accordance with a control amount for controlling said output shaft torque such that said revolution ratio follows said target revolution ratio.