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US 6,887,183 B2Granted
System and method of controlling automatic transmission
AssigneeJATCO Ltd
InventorTakashi Murasugi
Life of this patent
Estimating the term…
Abstract
In a system for controlling an automatic transmission, an ECU is constructed to carry out changeover control in accordance with shift determination from second speed to first speed to achieve release of a second engaging element and engagement of a first engaging element, detect a magnitude of a torque signal before a predetermined time of shift determination when the changeover control is carried out, and control release of the second engaging element in accordance with the magnitude of the torque signal.
Claims15
A system, comprising:
- an automatic transmission which achieves a first speed by engagement of a first engaging element and a second speed by engagement of a second engaging element;
- a device which generates a torque signal corresponding to input torque to the automatic transmission;
- and
- an electronic control unit (ECU) which controls the automatic transmission with reference to a shift line of a throttle opening versus a vehicle speed, the ECU being programmed to:
- determine shift from the second speed to the first speed when the throttle opening crosses the shift line;
- carry out changeover control in accordance with the determined shift to achieve release of the second engaging element and engagement of the first engaging element;
- detect a magnitude of the torque signal before a predetermined time of the determined shift when the changeover control is carried out;
- compare the magnitude of the torque signal with a preprogrammed switch determination value;
- carry out a first control of the second engaging element when the magnitude of the torque signal is larger than the preprogrammed switch determination value;
- carry out a second control of the second engaging element when the magnitude of the torque signal is equal to or smaller than the preprogrammed switch determination value, the second control requiring shorter time than the first control;
- and
- control the release of the second engaging element in accordance with one of the first and second controls.
9 more elements
A system, comprising:
- an automatic transmission which achieves a first speed by engagement of a first engaging element and a second speed by engagement of a second engaging element;
- means for generating a torque signal corresponding to input torque to the automatic transmission;
- and
- means for controlling the automatic transmission with reference to a shift line of a throttle opening versus a vehicle speed, the controlling means comprising:
- means for determining shift from the second speed to the first speed when the throttle opening crosses the shift line;
- means for carrying out changeover control in accordance with the determined shift to achieve release of the second engaging element and engagement of the first engaging element;
- means for detecting a magnitude of the torque signal before a predetermined time of the determined shift when the changeover control is carried out;
- means for comparing the magnitude of the torque signal with a preprogrammed switch determination value;
- means for carrying out a first control of the second engaging element when the magnitude of the torque signal is larger than the preprogrammed switch determination value;
- means for carrying out a second control of the second engaging element when the magnitude of the torque signal is equal to or smaller than the preprogrammed switch determination value, the second control requiring shorter time than the first control;
- and
- means for controlling the release of the second engaging element in accordance with one of the first and second controls.
9 more elements
A method of controlling an automatic transmission which achieves a first speed by engagement of a first engaging element and a second speed by engagement of a second engaging element, the automatic transmission being controlled with reference to a shift line of a throttle opening versus a vehicle speed, the method comprising:
- generating a torque signal corresponding to input torque to the automatic transmission;
- determining shift from the second speed to the first speed when the throttle opening crosses the shift line;
- carrying out changeover control in accordance with the determined shift to achieve release of the second engaging element and engagement of the first engaging element;
- detecting a magnitude of the torque signal before a predetermined time of the determined shift when the changeover control is carried out;
- comparing the magnitude of the torque signal with a preprogrammed switch determination value;
- carrying out a first control of the second engaging element when the magnitude of the torque signal is larger than the preprogrammed switch determination value;
- carrying out a second control of the second engaging element when the magnitude of the torque signal is equal to or smaller than the preprogrammed switch determination value, the second control requiring shorter time than the first control;
- and
- controlling the release of the second engaging element in accordance with one of the first and second controls.
6 more elements
Dependencies are inferred from the claim text.