Hydraulic control system of automatic transmission

A hydraulic control system for an automatic transmission comprising;

• a shift speed mechanism,
• a frictional element hydraulically controlled for switching a power transmitting path in the shift speed mechanism,
• a working pressure controller for controlling an engaging force of the frictional element during a shift operation by adjusting a working pressure applied to the frictional element,
• a target shift time setting device for setting a target shift time based on a speed change amount of an input member of the shift speed mechanism through the shift operation and an input torque introduced to the shift speed mechanism,
• a target acceleration calculator for calculating a target angular acceleration of the input member during the shift operation based on the target shift time and the speed change amount of the input member,
• a hydraulic pressure setting device for setting the working pressure based on the angular acceleration and the input torque calculated by the target acceleration calculator, acceleration detector for detecting an actual angular acceleration of the input member of the shift speed mechanism during the shift operation,
• an angular acceleration detecting device for detecting an actual angular acceleration of the input member of the shift speed mechanism, and
• a learning control compensator for compensating the working pressure for a next shift operation based on a difference between a mean angular acceleration of the input member after the shift operation and the target angular acceleration of the input member by means of the learning control in an up-shift operation where a vehicle is positively driven by an engine output.

A hydraulic control system for an automatic transmission comprising;

• a shift speed mechanism,
• a frictional element hydraulically controlled for switching a power transmitting path in the shift speed mechanism,
• a working pressure controller for controlling an engaging force of the frictional element during a shift operation by adjusting a working pressure applied to the frictional element,
• a target shift time setting device for setting a target shift time based on a speed change amount of an input member of the shift speed mechanism through the shift operation and an input torque introduced to the shift speed mechanism,
• a target acceleration calculator for calculating a target angular acceleration of the input member during the shift operation based on the target shift time and the speed change amount of the input member,
• an inertia torque pressure setting device for setting an inertia torque pressure based on the target angular acceleration,
• an input torque pressure setting device for setting an input torque pressure based on said input torque introduced to the shift speed mechanism,
• a hydraulic pressure setting device for setting the working pressure based on the angular acceleration and the input torque calculated by the target acceleration calculator, acceleration detector for detecting an actual angular acceleration of the input member of the shift speed mechanism during the shift operation,
• an angular acceleration detecting device for detecting an actual angular acceleration of the input member of the shift speed mechanism, and
• a learning control compensator for compensating the working pressure for a next shift operation based on a difference between a mean angular acceleration of the input member after the shift operation and the target angular acceleration of the input member by means of the learning control in an up-shift operation where a vehicle is positively driven by an engine output.

A hydraulic control system for an automatic transmission comprising;

• a shift speed mechanism,
• a frictional element hydraulically controlled for switching a power transmitting path in the shift speed mechanism,
• a working pressure controller for controlling an engaging force of the frictional element during a shift operation by adjusting a working pressure applied to the frictional element,
• a target shift time setting device for setting a target shift time based on a speed change amount of an input member of the shift speed mechanism through the shift operation and an input torque introduced to the shift speed mechanism,
• a target acceleration calculator for calculating a target angular acceleration of the input member during the shift operation based on the target shift time and the speed change amount of the input member,
• an inertia torque pressure setting device for setting an inertia torque pressure based on the target angular acceleration,
• an input torque pressure setting device for setting an input torque pressure based on said input torque introduced to the shift speed mechanism,
• a shift hydraulic pressure setting device for setting the working pressure based-on said input torque, inertia pressure and a compensation coefficient related to a hydraulic temperature determined taking account of a frictional coefficient of the frictional element involved in the shift operation,
• an angular acceleration detecting device for detecting an actual angular acceleration of the input member of the shift speed mechanism,
• an inertia torque pressure inference device for inferring the inertia torque pressure during the shift operation based on a mean angular acceleration of said rotation speed of the input speed of the shift speed mechanism when the shift operation is completed, and
• learning control compensator for compensating the compensation coefficient for a next shift operation by means of a learning control based on said inferred inertia torque pressure, the inertia torque pressure set by the inertia torque pressure setting device and the input torque pressure set by the input torque pressure setting device.