Vehicle automatic transmission control system
First Claim
1. A system for controlling a vehicle automatic transmission with a plurality of gears having different gear ratios, comprising;
- control means for determining operating conditions of the vehicle including engine speed, degree of throttle opening, change in the throttle opening degree, vehicle speed, change in the vehicle speed and gear currently engaged, said control means further comprisingmeans for predicting, with respect to gears to which it is possible to shift to from the gear currently engaged, changes in vehicle operating conditions, including change in reserve motive force available and a first ratio between change in engine output power estimated to be desired by the driver on the basis of the detected throttle opening and the change therein and actual change in engine output power, which would occur upon shifting to each of such gears not currently engaged;
means for establishing a membership function for the determined values and the predicted values of operating conditions in accordance with a plurality of predetermined fuzzy production rules defining a plurality of respective gearshift conclusions;
means for carrying out fuzzy reasoning based on the fuzzy production rules to determine a gear to be engaged; and
actuator means for driving a gear shift valve mechanism in response to the determined gear to be engaged.
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Accused Products
Abstract
A system for controlling automatic transmissions equipped with a motor vehicle utilizing fuzzy logic. In the system, fuzzy production rules have been prepared based upon an expert driver'"'"'s judgments and operation made on a vehicle with a manually shifted transmission. Various operating conditions including opening degree of a throttle valve and road speed of the vehicle are detected and from the detected value, various predictions are made such as an appropriateness of vehicle response to a gearshift intended by the driver and engine output change that would occur should the transmission be shifted to a given gear. These measured or estimated values are put on a common scale named universe of discourse and each membership values degree of the aforesaid rules is successively calculated. Among the rules, one rule is finally selected and according to a gear position indicated in the selected rule, the current gear is shifted up or down or is held at the present position.
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Citations
17 Claims
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1. A system for controlling a vehicle automatic transmission with a plurality of gears having different gear ratios, comprising;
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control means for determining operating conditions of the vehicle including engine speed, degree of throttle opening, change in the throttle opening degree, vehicle speed, change in the vehicle speed and gear currently engaged, said control means further comprising means for predicting, with respect to gears to which it is possible to shift to from the gear currently engaged, changes in vehicle operating conditions, including change in reserve motive force available and a first ratio between change in engine output power estimated to be desired by the driver on the basis of the detected throttle opening and the change therein and actual change in engine output power, which would occur upon shifting to each of such gears not currently engaged; means for establishing a membership function for the determined values and the predicted values of operating conditions in accordance with a plurality of predetermined fuzzy production rules defining a plurality of respective gearshift conclusions; means for carrying out fuzzy reasoning based on the fuzzy production rules to determine a gear to be engaged; and actuator means for driving a gear shift valve mechanism in response to the determined gear to be engaged. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A system for controlling a vehicle automatic transmission with a plurality of gears having different gear ratios, comprising;
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control means for determining operating conditions of the vehicle including engine speed, degree of throttle opening, change in the throttle opening degree, vehicle speed, change in the vehicle speed and gear currently engaged, said control means further comprising means for predicting, with respect to gears to which it is possible to shift to from the gear currently engaged, changes in vehicle operating conditions, including PS ratio and reserve motive force available, which would occur upon shifting to each of such gears not currently engaged; means for establishing a membership function for at least one of the determined values and the predicted values of operating conditions in accordance with a plurality of predetermined fuzzy production rules defining a plurality of respective gearshift conclusions; means for carrying out fuzzy reasoning based on the fuzzy production rules to determine a gear to be engaged; and actuator means for driving a gear shift valve mechanism in response to the determined gear to be engaged.
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17. A system for controlling a vehicle automatic transmission with a plurality of gears having different gear ratios, comprising
control means for determining operating conditions of the vehicle including engine speed, degree of throttle opening, change in the throttle opening degree, vehicle speed, change in the vehicle speed and gear currently engaged, said control means further comprising means for predicting, with respect to gears to which it is possible to shift to from the gear currently engaged, changes in vehicle operating conditions, including control toughness and change in reserve motive force available, which would occur upon shifting to each of such gears not currently engaged; -
means for establishing a membership function for at least one of the determined values and the predicted values of operating conditions in accordance with a plurality of predetermined fuzzy production rules defining a plurality of respective gearshift conclusions; means for carrying out fuzzy reasoning based on the fuzzy production rules to determine a gear to be engaged; and actuator means for driving a gear shift valve mechanism in response to the determined gear to be engaged.
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Specification