Control system for vehicle automatic transmission
First Claim
1. A system for controlling an automatic transmission of a vehicle, having an internal combustion engine connected to said automatic transmission for driving one or more wheels of said vehicle, comprising:
- a hydraulic control circuit connected to said automatic transmission,an electronic control means for controlling said automatic transmission through said hydraulic control circuit;
a load detecting means for detecting an operating load on said engine and sending a first output signal representing the engine load to said electronic control means; and
a vehicle speed detecting means for detecting the vehicle speed and sending a second output signal representing the vehicle speed to said electronic controls means,wherein said electronic control means computes an index indicative of a running resistance of the vehicle based on said first signal, and compares said index with a pre-determined reference value stored in a memory in said electronic control means to determine if the vehicle is hill climbing or hill descending;
said electronic control means actuating said hydraulic control circuit for carrying out gear shifting control including changing the gear shifting characteristics of said transmission to be suitable for either hill climbing or hill descending based on said determination, andwherein said electronic control means discontinues gear shifting control for hill climbing or hill descending whenever a pre-determined condition of the operation of said vehicle is detected.
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Accused Products
Abstract
A control system of a vehicle automatic transmission in which an engine load and a vehicle speed are detected and used to determine a vehicle acceleration in accordance with the pre-established characteristics. An actual vehicle acceleration is at the same time calculated in response to the detected vehicle speed. The difference therebetween is then calculated and the calculated value is added to a difference calculated earlier to obtain an average therebetween. Five gear shifting scheduling maps, for example, one for moderate hill climbing, one for level-road running, one for steep hill descent, are pre-established and in response to the average obtained, one of the maps is selected. A gear shifting is controlled based on the selected map. In a pre-determined condition, such as when the engine load changes abruptly, braking is in progress and so on, the map selection is suspended and the control is carried out using the map selected earlier.
49 Citations
41 Claims
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1. A system for controlling an automatic transmission of a vehicle, having an internal combustion engine connected to said automatic transmission for driving one or more wheels of said vehicle, comprising:
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a hydraulic control circuit connected to said automatic transmission, an electronic control means for controlling said automatic transmission through said hydraulic control circuit; a load detecting means for detecting an operating load on said engine and sending a first output signal representing the engine load to said electronic control means; and
a vehicle speed detecting means for detecting the vehicle speed and sending a second output signal representing the vehicle speed to said electronic controls means,wherein said electronic control means computes an index indicative of a running resistance of the vehicle based on said first signal, and compares said index with a pre-determined reference value stored in a memory in said electronic control means to determine if the vehicle is hill climbing or hill descending;
said electronic control means actuating said hydraulic control circuit for carrying out gear shifting control including changing the gear shifting characteristics of said transmission to be suitable for either hill climbing or hill descending based on said determination, andwherein said electronic control means discontinues gear shifting control for hill climbing or hill descending whenever a pre-determined condition of the operation of said vehicle is detected. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A system for controlling an automatic transmission of a vehicle, having an internal combustion engine connected to said automatic transmission or driving one or more wheels of said vehicle, comprising:
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a hydraulic control circuit connected to said automatic transmission, an electronic control means for controlling said automatic transmission through said hydraulic control circuit; load detecting means for detecting an operating load on said engine and sending a first output signal representing the engine load to said electronic control means; and vehicle speed for detecting means for detecting the vehicle speed and sending a second output signal representing the vehicle speed to said electronic control means; wherein said electronic control means predicts an acceleration of the vehicle as a function of said first output signal and said second output signal, determines an actual acceleration of said vehicle as a function of the detected vehicle speed, compares the actual acceleration with the predicted acceleration, changes a gear shifting characteristic in response to the comparison result, and actuates said hydraulic control circuit for performing gear shifting control in accordance with the changed gear shifting characteristic, and wherein said electronic control means discontinues changing the gear shifting characteristic when the vehicle is in the pre-determined mode of operation. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A system for controlling an automatic transmission of a vehicle, having an internal combustion engine connected to said automatic transmission or driving one or more wheels of said vehicle, comprising:
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a hydraulic control circuit connected to said automatic transmission, an electronic control means for controlling said automatic transmission through said hydraulic control circuit; load detecting means for detecting an operating load on said engine and sending a first output signal representing the engine load to said electronic control means; and vehicle speed for detecting means for detecting the vehicle speed and sending a second output signal representing the vehicle speed to said electronic control means; wherein said electronic control means predicts an acceleration of the vehicle as a function of said first output signal and said second output signal, wherein said electronic control means determines an actual acceleration of said vehicle as a function of said second output signal representing the detected vehicle speed, compares the actual acceleration with the predicted acceleration cyclically at a prescribed interval, changes a gear shifting characteristic in response to the comparison result, and actuates said hydraulic control circuit for performing gear shifting control in accordance with the changed gear shifting characteristic, wherein said electronic control means calculates a difference between the actual acceleration and the predicted acceleration and adds a difference to a value calculated at a preceding cycle to obtain a weighted average therebetween and compares the weighted average with a reference value; and wherein said electronic control means changes a coefficient of the weight when the vehicle operation is in a pre-determined mode. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32, 33, 34)
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35. A system for controlling an automatic transmission for a vehicle, having an internal combustion engine connected to said automatic transmission or driving one or more wheels of said vehicle, comprising:
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a hydraulic control circuit connected to said automatic transmission; an electronic control means for controlling said automatic transmission through said hydraulic control circuit; load detecting means for detecting an operating load on said engine and sending a first output signal representing the engine load to said electronic control means; and vehicle speed for detecting means for detecting the vehicle speed and sending a second output signal representing the vehicle speed to said electronic control means; wherein said electronic control means predicts an acceleration of the vehicle as a function of said first output signal and said second output signal, wherein said electronic control means determines an actual acceleration of the vehicle as a function of said second output signal representing the detected vehicle speed with respect to the same gear, wherein said electronic control means compares the actual acceleration with the predicted acceleration to obtain a difference therebetween cyclically at a prescribed interval and adds the difference to a difference obtained at a preceding cycle, for calculating an average therebetween, and wherein said electronic control means compares the average with a reference value to change a gear shifting characteristic and actuates said hydraulic control circuit for performing gear shifting control in accordance with the changed gear shifting characteristic. - View Dependent Claims (36, 37, 38, 39, 40, 41)
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Specification