Abstract: Vehicle automatic transmission control system in which based on the determined operating parameters of the vehicle including degree of throttle opening, vehicle speed or the like, a plurality of sets of membership functions of the parameters are established in accordance with a plurality of sets of predetermined fuzzy production rules. Fuzzy reasoning is carried out on the sets of the rules to determine a target gear ratio to shift to. The plural sets of the rules are predetermined hierarchically. One category of rules is directed toward the entire area of shift control, whereas another category of rules is directed toward a specific shift control area such as hill climbing. Further an additional category of rules is provided to presume the driver's intentional condition such as an intention to decelerate. Based on the last category of rules, fuzzy reasoning is carried out to determine the intentional condition.

Abstract: A system for controlling automatic, multi-step or continuously variable, transmission 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 determined from the reserve motive force with respect to a gear ratio shift intended by the driver and engine output change that would occur should the transmission be shifted to the gear ratio. These measured or estimated value are put on a common scale named universe of discourse and membership values of the rules are sucessively calculated.

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.

Abstract: A system for controlling automatic transmissions equipped 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 the reserve motive force and engine output change that would occur should the current ratio be shifted to a given gear ratio. These measured and estimated values are put on a common scale named universe of discourse and membership values degree of the aforesaid rules are successively calculated. Among the rules, one rule is finally selected and according to a gear ratio indicated in the selected rule, the current gear ratio is shifted up or down or is held at the present ratio.

Abstract: A system for controlling automatic, multi-step or continuously variable, transmission 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 value are put on a common scale named universe of discourse and membership values of the rules are successively calculated.

Abstract: Throttle control system for a vehicular internal combustion engine equipped with a stepper motor connected to a throttle valve provided at an engine air intake passage, wherein the position (the opening degree) of the throttle valve is controlled by the stepper motor in response to the vehicular engine operation. In one embodiment, various throttle positions are once determined including positions for engine idling and vehicle cruising and the largest of the positions is selected for optimally satisfying the whole operating condition. In another embodiment, when the engine is idling, the throttle valve is controlled such that engine speed converges toward a target speed. In the other embodiment, the stepper motor is varied its pulse rate and chopping duty for optimally control the throttle position according to the vehicular engine operation.

Abstract: A vehicle control system embodied as an autocruise control. Fuzzy Logic is introduced in the system such that an expert driver's operation or judgment made on an non-automated vehicle is able to be incorporated in the system as fuzzy production rules. In the system, the control is effected in accordance with the rules which can be expressed linguistically in a simple manner and has a predictive nature therein. Operating condition of the vehicle is detected through parameters such as a vehicle speed, a vehicle acceleration and a change of vehicle acceleration which are then assigned on a scale named universe of discourse. The satisfaction degree is evaluated so that one rule is selected. A control value is determined from the selected rule which is output to an actuator to be controlled.

Abstract: A method of indicating when a shift operation of a manual gearbox is to be preformed includes a step for comparing a detected vehicle speed with a reference vehicle speed which is determined and changed on the basis of a detected engine operational parameter and a step for indicating that the shift operation should be performed on the basis of a result of the comparison. The reference vehicle speed is corrected to a lower speed in response to an increase of a total running time of the vehicle, thereby to maintain the driveability of the vehicle when the running time of the vehicle is short.

Abstract: An air/fuel ratio control system for an internal combustion engine provides a mixture leaner than a predetermined reference value when a detected engine load is in a light load range. In order to produce a required engine power during a transitional period, the system detects the speed of variation of an operating parameter used for the calculation of air/fuel ratio and controls the air/fuel ratio toward the reference level even though the magnitude of the detected engine load is in the light load range. Preferably, an EGR rate is also made smaller upon occurrence of a rapid change of the operating parameter so as to prevent the power down of the engine during the transitional period.