Abstract: A method for controlling preferably an electro-hydraulic automatic transmission of a motor vehicle fitted with a combustion engine provides a gradual kick-down while braking. In particular the kick-down is performed when, in the course of approaching a bend, a condition is activated, which prevents upshifting. The upshift prevention is initiated when the accelerator pedal is released quickly during shearing action. The upshift prevention stops if after an interval, upon detection of tensile action, the vehicle does drive round a bend. The upshift prevention is followed by a gradual adaptation of the gear level to the shift parameter.

Abstract: A change gear control device is provided for an automatic transmission in a motor vehicle propelled by an internal combustion engine which is operated with an air/fuel mixture having air/fuel ratios ranging from a fuel rich air/fuel ratio to a fuel lean air/fuel ratio depending on driving conditions of the motor vehicle. In this device a first detector detects an engine torque of the internal combustion engine and a second detector detects a vehicle speed of the motor vehicle. A processor processes transmission gear ratios for the automatic transmission.

Abstract: The present invention is directed to a device and a method for controlling a shift position of a vehicle in response to a road condition when the vehicle is running on a steeply sloped road or a sharply curved road. The device includes a slope/curve sensor, a steering angle sensor, a throttle valve sensor, a vehicle speed sensor, and a shift controller. A solenoid valve controls a hydraulic pressure and the resulting shift position in response to a control signal applied from the shift controller.

Abstract: An automatic transmission control system for a transmission which is installed in a vehicle and whose torque converter is provided with a lockup mechanism; comprising a vehicle weight estimation device for estimating the weight of the vehicle; a gradient estimation device for estimating a gradient on which the vehicle is running; a standard lockup line selector for storing therein standard lockup lines which correspond respectively to the specified gear shift ratios of a speed change gear included in the transmission, and for selecting that one of the stored standard lockup lines which corresponds to the gear shift ratio in the present state of the vehicle; a lockup line corrector for correcting the selected standard lockup line in accordance with the estimated vehicle weight and the estimated gradient; and a lockup signal output device for deciding a timing of lockup "ON" or lockup "OFF" by the use of the corrected lockup line, and for delivering a lockup signal to the lockup mechanism (a lockup solenoid) at

Abstract: A shift control system for shifting an automatic transmission from a predetermined gear stage to another by draining an oil pressure from predetermined frictional engagement element to release the same frictional engagement element and by feeding the oil pressure to another frictional engagement element to engage the same frictional engagement element while controlling the drain oil pressure of the frictional engagement element to be released and the engaging oil pressure to the frictional engagement element to be engaged. The shift control system includes an engine racing detector for detecting the racing of the engine while the transmission is being shifted in a clutch-to-clutch manner, and a hydraulic control circuit for controlling at least one of the drain oil pressure and the engaging oil pressure, on the basis of the degree of racing of the engine, as detected by the engine racing detector, such that the amount of racing of the engine falls within a predetermined range.

Abstract: An adaptive control system/method for an at least partially automated vehicular mechanical transmission system (10) is provided for determining the value of a control parameter (T.sub.ACCES) indicative of accessory torque when the vehicle is in motion and the value of a control parameter (dES/dt rate) indicative of engine deceleration rate when the vehicle is not in motion. A relationship (dES/dt rate=A+B * T.sub.ACCES) between engine deceleration rate and accessory torque is determined and allows derivation of one parameter from the other parameter during vehicle operating conditions wherein the other parameter may be directly determined from sensed inputs (T.sub.EG, T.sub.BEF, ES).

Abstract: In one aspect of the present invention, a method of effecting shifts in a vehicle is disclosed. The method modifies the transmission shiftpoints in response the wheel power of the vehicle in order to optimize vehicle shifting, while reducing the potential for shift cycling.

Abstract: The invention relates to an improved method and an arrangement for implementation of that method for obtaining safer and quicker upshifts while maintaining gear change comfort, using computer-assisted systems for gear change in mechanical gearboxes in motor vehicles, preferably without clutch disengagement between engine and gearbox. In connection with upshift, an exhaust brake is activated, (EB.sub.on) at time t.sub.1 in parallel with the fuel (FUEL) to the engine being reduced to zero quantity. The engine speed n.sub.2 is thereby reduced more quickly to the speed n.sub.1 which is the synchronous engine speed for the next higher gear. The speed reduction is monitored with a view to achieving rapid engine speed bracketing to synchronous speed, and also good gear change smoothness and safe gear engagement. The exhaust brake switch-off point EB.sub.off at time t.sub.2 is adjusted adaptively for subsequent upshift by a connection factor EBA.sub.

Abstract: Shift control system and method are provided for use in a vehicle automatic transmission in which a desired speed range is achieved in accordance with the state of driving of a vehicle. The degree of meandering of a running road on which the vehicle is running is detected. The downhill grade of the running road is also detected. Based on the detection results, it is determined whether or not the running road is a meandering downhill road. When it is determined that the vehicle is running on the meandering downhill road, it is then determined whether or not a downshift is needed. When the downshift has been determined to be necessary, the speed range of the vehicle automatic transmission is shifted from a current speed range to a speed range lower than the current speed range.

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 preestablished 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 preestablished and in response to the average obtained, one of the maps is selected. A gear shifting is controlled based on the selected map. A driver's intention to decelerate is estimated and is compared with a reference value which increases with increasing said average indicative of the grade of hill that the vehicle is descending.

Abstract: A diagnosing apparatus for diagnosing a vehicle automatic transmission system including an automatic transmission having frictional coupling devices, and solenoid-operated valves for controlling the frictional coupling devices to shift the automatic transmission according to shift commands generated by a control device, the apparatus including a speed detector for detecting an engine speed of the vehicle, a device for determining a reference range of the engine speed within which the engine speed is expected to fall when the transmission is placed in a position selected by a shift command, a device for determining whether a predetermined running condition of the vehicle is satisfied, and a defect detector for determining whether there exists a defect associated with the automatic transmission system, depending upon whether the detected engine speed is held within or outside the determined reference range when the predetermined vehicle running condition is satisfied.

Abstract: A method and an arrangement for controlling an automatic transmission of a motor vehicle driven by an internal-combustion engine, in which the position of a throttle valve of the motor vehicle and the acceleration of the vehicle as the reaction thereto are determined and are related to one another. Subsequently, this relationship is compared with the relationship as it occurs during a normal drive on a level surface. As a function of the deviation between the actual relationship and the normal relationship, the ratios of the transmission are displaced in the direction of higher rotational engine speeds, which means that the ratio assigned to a throttle valve position and to a rotational engine speed will now be achieved at a lower rotational engine speed, or the rotational engine speed level is raised. For a stepped transmission, several characteristic shifting diagrams are provided and the displacement of the ratio is carried out by changing the characteristic shifting diagram according to the deviation.

Abstract: An adaptive control system/method for an at least partially automated vehicular mechanical transmission system (10) is provided for determining the current value of a control parameter (T.sub.FW) indicative of engine flywheel torque. Engine flywheel torque (T.sub.FW) is determined as a function of the expression gross engine torque (T.sub.EG) is equal to the sum of flywheel torque (T.sub.FW), base engine friction torque (T.sub.BEF), acceleration torque (T.sub.ACCEL) and accessory torque (T.sub.ACCES). Accessory torque (T.sub.ACCES) is determined, when the vehicle is in motion, as a function of engine deceleration rate (dES/dt rate). Flywheel torque (T.sub.FW), or drivewheel torque (T.sub.DW) determined as a function of flywheel torque (T.sub.FW) and drivetrain parameters such as engaged gear ratio (GR), is utilized as a control parameter for controlling shifting of the transmission system.

Abstract: An automatic transmission control system for an automobile, comprising a vehicle weight estimation unit which estimates a vehicle weight of the automobile a torque estimation unit which estimates an output torque, an acceleration input unit which accepts an acceleration signal; a load estimation unit (110) which estimates a running load from the estimated vehicle weight, the estimated output torque and the accepted acceleration; a memory which stores a plurality of shift schedules therein; and a gear position determination unit (109) which includes the memory, and which selects one of the shift schedules in accordance with the vehicle weight and the estimated running load, so as to determine a gear position of an automatic transmission of the automobile in conformity with the selected shift schedule. An exact shift operation conformed to the vehicle weight and the running load can be performed, and an enhanced fuel consumption can be attained.

Abstract: A control method/system for controlling engagement of a target gear ratio (GR.sub.T)in a vehicular automated mechanical transmission system (10) is provided. The control causes engine speed (ES) to be alternately greater than and then less than synchronous engine speed (ES=IS=OS*GR.sub.T) to cause torque reversals across the engaging positive jaw clutch associated with the target gear ratio to minimize or prevent partial engagement caused by torque lock conditions.

Abstract: A control system and method for a semi-automatic mechanical transmission system (10) is provided for allowing operator request for a direct downshift or upshift into a preselected start ratio, under certain predefined conditions. The preselected start ratio is that ratio actually utilized in the immediately preceding vehicle start from stop operation.

Abstract: A control device of an automatic transmission capable of controlling the operation so as to suit the gearshift operation to a driver's pedalling operation for acceleration and deceleration. The control device selects a gearshift pattern corresponding to a result obtained by comparing a displacement per unit time of an accelerator pedal with a predetermined displacement per unit time of the accelerator pedal. Further, the device includes a microcomputer to monitor the driver's pedalling operation for acceleration and deceleration when the gearshift is carried out and to compensate the predetermined displacement per unit time of the accelerator pedal in such a manner that the driver's unnatural pedalling operation would not be required.

Abstract: A system/method of resetting the value of a control parameter (GCW.sub.CP indicative of vehicular gross combined weight and determined as a filtered/averaged value, to a predetermined default value, or to a test value, upon sensing vehicle operating conditions (OS=Oand t>REF) deemed indicative of a change in vehicle loading is provided. A vehicle automated system, such as an automated mechanical transmission system, is controlled as a function of the value of the control parameter.

Abstract: A control system/method for determining vehicular gross combined weight (GCW) is provided. GCW is determined immediately after upshifts of a transmission (10) and requires only input signals indicative of engine or driveline torque (DL), vehicle acceleration (dOS/dt) and currently engaged gear ratio (GR).

Abstract: An adaptive control system/method for an at least partially automated mechanical transmission system (10) is provided for determining if selected upshifts into a target gear ratio are feasible (208) or not feasible (210) under current vehicle operating conditions and for prohibiting the initiation of not feasible selected upshifts. If upshifts determined to be feasible are not completed by the system, the logic rules by which upshift feasibility is determined are modified to render such rules less aggressive.

Abstract: A control system/method for controlling a vehicular, at least partially automated system (110) separate from the vehicular transmission system (10), such as a CTIS or ABS, is provided. The at least partially automated system is controlled as a function of a value (GCW) approximating vehicle gross combined weight and determined as a function of information on the vehicle electronic data link (DL).

Abstract: A control system (104)/method for a vehicular automated mechanical transmission is provided, which will compare input signals indicative of input shaft speed (IS) to the product of input signals indicative of output shaft speed multiplied by engaged gear ratio (OS*GR) to develop control parameters indicative of drivetrain torque magnitude and/or phase requiring a driveline torque transducer.

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 preestablished 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 preestablished and in response to the average obtained, one of the maps is selected. A gear shifting is controlled based on the selected map. The actual vehicle acceleration is corrected by the altitude where the vehicle is traveling so as to compensate for the engine output decrease due to the charging efficiency drop.

Abstract: A motor vehicle has a manual transmission and means for indicating to the operator a point in operation for upshifting to the next higher gear from the present gear. A method of determining the shift point is provided based upon actual operating parameters of the motor vehicle effecting current wheel torque and predicted wheel torque in the next higher gear. Calibration to a single value representing the ratio of predicted wheel torque to current wheel torque allows simple balancing between fuel economy and performance.

Abstract: A system and method for controlling the bypass clutch of an automatic transmission includes an electronic microprocessor, an electronic memory accessible to the microprocessor, solenoid-operated bypass valve, pressure actuated bypass clutche, a variable force solenoid-operated bypass valve, a torque converter bypass friction clutch, and control algorithms that produce output signals to control the state of the solenoid-operated valve. The vehicle speed at which the bypass clutch engages and disengages, according to a reference schedule, is compensated for loss of engine torque at conditions that differ from the conditions at which the reference schedule is defined. Vehicle speed is compensated for torque variation with reference to the ratio of current calculated engine torque divided by current engine output torque.

Abstract: A change gear control device is provided for an automatic transmission in a motor vehicle propelled by an internal combustion engine which is operated with an air/fuel mixture having air/fuel ratios ranging from a fuel rich air/fuel ratio to a fuel lean air/fuel ratio depending on driving conditions of the motor vehicle. In this device a first detector detects an engine torque of the internal combustion engine and a second detector detects a vehicle speed of the motor vehicle. A processor processes transmission gear ratios for the automatic transmission.

Abstract: The invention is directed to a method for controlling the gear-shifting comfort in motor vehicles having automatic transmissions. The method provides for pressure controllers for controlling clutches affecting the gear-shifting operations of the transmission. The preset values for the torque and/or the torque curves of the clutches are stored in dependence upon the particular gear-shifting operations and the transmission rpms in a characteristic field. The actual acceleration of the motor vehicle is detected with the aid of an acceleration sensor and a very low desired acceleration is used as a guide quantity for the torque control at the clutches. The preset values for the clutches corrected by this control are stored in the characteristic field.

Abstract: An apparatus is provided for use in a vehicle having an engine driven transmission which includes a plurality of gear ratios. The apparatus includes a sensor adapted to sense an operating parameter and responsively produce a parameter signal. A memory device includes a custom shiftpoint map for storing data which relates transmission gear ratio to the parameter signal. A programming device for allowing the custom shiftpoint map to be reprogrammed during vehicle operation. A controller is adapted to receive the vehicle speed signal, retrieve data from the custom shiftpoint map, and process the retrieved data and the parameter signal to produce a transmission control signal. An actuator is adapted to receive the transmission control signal and responsively control the transmission gear ratio.

Abstract: An automatic transmission control method and apparatus for a vehicle includes a first gear change mechanism in which an input shaft is connected to an output shaft of a fluid coupling and a rotational speed of the output shaft of the first gear change mechanism is changed by selectively controlling hydraulic oil supplied to and discharged from a plurality of first frictional engaging elements. It further includes a second gear change mechanism in which an input shaft is connected to the output shaft of the first gear change mechanism, the output shaft is connected to a driving wheel member and an output shaft rotational speed of the second gear change mechanism is controlled by selectively controlling the hydraulic oil supplied to and discharged from a plurality of second frictional engaging elements.

Abstract: A control for a motor vehicle drive having an automatic transmission includes a circuit configuration for generating an output signal adapting shifting points to a load state of the motor vehicle from an evaluation of a power takeoff rpm of the transmission or of a variable equivalent to it. The circuit configuration ascertains a deviation between a calculated and a measured power takeoff rpm in successive time intervals and forms a correction term by multiplication with a factor. At least one characteristic curve memory stores shifting points of the transmission. The at least one characteristic curve memory receives the correction term as an output signal for adapting a characteristic curve to the load state. In a method for controlling a vehicle drive having an automatic transmission, shifting points or characteristic curves for shifting are varied as a function of driving parameters.

Abstract: During downshift operation of an automotive automatic transmission in which a lower-speed clutch for establishing a lower-speed gear is engaged while a higher-speed clutch, which has established a higher-speed gear, is disengaged, to increase the turbine rotational speed Nt toward a synchronous rotation speed Ntj associated with the lower-speed gear, speed change control is carried out according to the same control method regardless of whether the engine is in a power-on or power-off state. A target change rate (Nir)' of turbine rotational speed associated with the higher-speed clutch and a target change rate (Nia)' of turbine rotational speed associated with the lower-speed clutch are set, and a change rate (Nt)' of the turbine rotational speed is detected.

Abstract: A reengagement control system/method (200) for a semi-automatic mechanical transmission system (104) of the type requiring manual synchronization of the transmission to enable automatic implementation of a selected shift into a target gear ratio is provided. The reengagement control will cause immediate engagement of an engageable ratio, based upon vehicle speed, if the transmission is shifted to neutral and is then unable to engage in the target gear for greater than a predetermined time (REF.sub.2) as vehicle acceleration (dOS/dt) exceeds an acceleration reference value (REF.sub.1).

Abstract: A control system (104)/method for semi-automatically executing automatically and manually selected upshifts and downshifts of a mechanical transmission system (10) is provided. The control system includes a central processing unit (106) for receiving input signals indicative of transmission input shaft (16) and output shaft (90) speeds and from a driver control console (108) and processing the same in accordance with predetermined logic rules to issue command output signals to a transmission actuator (112, 70, 96) to implement the selected shifts. The control is effective to initiate a shift by automatically preselecting a shift from the currently ratio into neutral and to then await a manually caused torque break of the transmission to complete the shift to neutral. The control is effective to minimize wear by issuing repetitive shift prompts if transmission neutral is not sensed within predetermined times from preselection of a shift frown a currently engaged ratio (GR) into neutral(N).

Abstract: A control apparatus for an engine and an automatic transmission controls a starting timing, a terminating timing, or methods of torque reduction of the engine during gear shifts. Using stored information such as a turbine speed signal, a gear shift signal, a degree to which a throttle valve is opened, a vehicle speed, an engine speed and so on, the control apparatus calculates an appropriate torque reduction which is performed by either retarding ignition timing or cutting fuel supplied to fuel injection valves. According to one embodiment of the invention, by detecting a variation ratio or differential value of turbine speed, a period of the torque reduction is started, ended, and kept within a proper timing. According to another embodiment of the invention, based on a "chasing" state of an input torque of the transmission against the variation of engine load, the timing of torque reduction is changed.

Abstract: An automatic transmission control system for a transmission which is installed in a vehicle and whose torque converter is provided with a lockup mechanism; comprising a vehicle weight estimation device for estimating the weight of the vehicle; a gradient estimation device for estimating a gradient on which the vehicle is running; a standard lockup line selector for storing therein standard lockup lines which correspond respectively to the specified gear shift ratios of a speed change gear included in the transmission, and for selecting that one of the stored standard lockup lines which corresponds to the gear shift ratio in the present state of the vehicle; a lockup line corrector for correcting the selected standard lockup line in accordance with the estimated vehicle weight and the estimated gradient; and a lockup signal output device for deciding a timing of lockup "ON" or lockup "OFF" by the use of the corrected lockup line, and for delivering a lockup signal to the lockup mechanism (a lockup solenoid) at

Abstract: When a vehicle is traveling on a descending slope, the gearshift position of an automatic transmission is set to a position selected in accordance with driver's intention to accelerate the vehicle based on the accelerator opening. A decision is preferably made as to whether the gearshift position should be set to a low-speed gearshift position where an engine brake can be applied, in accordance with the magnitude comparison between a threshold value and at least one value of a gradient of a road and a timedependent change in vehicle speed. The threshold value may be changed to a value that causes the low-speed gearshift position to be easily selected if the frictional resistance of the road surface is judged to be low. Further, the threshold value may be preset corresponding to the degree of gradient and/or winding of the road.

Abstract: A control system/method for an at least partially automated mechanical transmission system (10), inclading a controller (106) operated engine brake (EB), is provided. The control system/method is effective to determine if selected upshifts into a target gear ratio are feasible (212, 214) or not feasible (216) under current vehicle operating conditions and to prohibit the initiation of not feasible selected upshifts. The transmission system includes an engine brake actuator (23A) operable by the system controller (106). selected upshifts are evaluated and will be implemented, if feasible, in a sequence wherein feasibility is a function of engine deceleration (dES/dt), and engine deceleration is assigned expected values at minimum to progressively greater engine braking.

Abstract: A manually-shifted synchronized compound transmission (10) is provided with a relatively simple and inexpensive mechanism for warning the operator that an inappropriate gear ratio has been selected. Sensors (110, 112, 114) provide input signals (116) to a logic unit (118) indicative of the rotational speed of the transmission input shaft (118) and the logic unit will issue command signals (120) to an alarm member (122) if sensed input shaft speed is not within an acceptable range to warn the vehicle operator that reengagement of the vehicle master clutch (C) in the currently engaged ratio (GR) will result in undesirable overspeeding and/or underspeeding of the vehicle engine (E).

Abstract: A gear shift control apparatus for use with an automotive vehicle to control gear shift operation in the automatic transmission. An estimated engine load is calculated as a function of engine load and engine load rate of change to reflect a driver's expectation for gear shift operation on the gear shift control. A shift pattern is used to select an appropriate gear position based upon the vehicle speed and the estimated engine load.

Abstract: An operation mode control system for an automatic automotive power transmission includes a manually operable mode selection switch for selecting an operation mode from among economy, power, and hold modes. When an acceleration demand magnitude is larger than a criterion value while the hold mode is selected, the execution of the hold mode is suspended. This suspension of the hold mode execution is automatically released without operating the manually operable mode selection switch when certain conditions are reached. The power mode may be executed in place of the hold mode during the suspension of the hold mode execution.

Abstract: A control method/system for controlling upshifting in an automated mechanical transmission system (10) provided with an engine compression brake (50) is provided. A control unit (54) is effective to operate the engine compression brake during a transmission upshift such that at initiation of an upshift the engine compression brake applies a minimum retarding torque to the engine, the retarding torque is then gradually increased to a maximum retarding torque value and, upon sensing that engine speed (ES) is within a predetermined value (REF.sub.1) of the synchronous value thereof, the retarding torque applied by the engine brake is caused to gradually decrease until such time as engine speed reaches the synchronous window therefor.

Abstract: In an automatic transmission control system provided for an internal combustion engine having an automatic transmission system equipped with a traction control system in which a throttle valve is adjusted towards a closed state from a throttle position corresponding to an operation of an accelerator pedal when wheel slippage occurs, a detection unit detects a degree of operation of the accelerator pedal. A shift point changing unit changes a shift point so that gear shifting occurs on the basis of the degree of operation of the accelerator pedal in a normal state and gear shifting occurs at an engine speed lower than a predetermined engine speed at which gear shifting normally occurs when the degree of operation of the accelerator pedal is equal to or greater than a predetermined value.

Abstract: A method is provided for use in a vehicle including an automatic transmission having at least one load carrying friction element, such as clutch, of optimizing the line pressure in the transmission by slipping the weakest friction element by a small amount. The method includes the steps of decreasing the line pressure from a predetermined base pressure to allow for incipient slip across the weakest friction element and then increasing the line pressure to obtain a temporary pressure at which the weakest friction element is no longer slipping. The method also includes the step of further increasing the line pressure from the temporary pressure to obtain an operating line pressure. Preferably, the operating line pressure provides the weakest friction element with additional capacity for transmitting torque without slip for normal driving conditions, i.e. sensed vehicle throttle positions within a predetermined hysteresis band.

Abstract: A shift control apparatus for an automatic transmission of a motor vehicle is disclosed. The shift control apparatus includes a shift control device for automatically shifting the transmission according to a predetermined shift control pattern, on the basis of a speed of the engine and a currently required output of the engine. When a vehicle driver operates to re-accelerate the vehicle after deceleration with the transmission shifted down to the low-speed gear position, the transmission is shifted up from the lower-speed gear position to the high-speed gear position having the smaller speed reduction ratio than the lower-speed gear position, if a predetermined period of time has not elapsed after the low-speed gear position is established.

Abstract: In a speed change control method for setting the gearshift position of an automatic transmission for vehicles with a plurality of gearshift positions, to a position selected on the basis of vehicle speed and engine load, in accordance with a preset shift pattern for a first control mode, one of the gearshift positions is selected by fuzzy inference in accordance with at least one of parameter values which represent operating conditions of the vehicle, parameter values which represent driver's driving intention, and parameter values which represent road conditions. Further, the gearshift position of the automatic transmission is set to the position selected by the fuzzy inference only if the gearshift position selected by the fuzzy inference provides a lower speed than that provided by the gearshift position selected in accordance with the shift pattern for the first control mode.

Abstract: A control device of a transmission fluid pressure for an electronically controlled automatic transmission comprising: a rotational number change detecting means for detecting a rotational number change of either an engine or a rotational member of an automatic transmission; a transmission fluid pressure controlling means for arbitrarily controlling a transmission fluid pressure for a transmission fluid pressure controlling device of the automatic transmission; and a control device for controlling a target value of the transmission fluid pressure for the transmission fluid pressure controlling device by a negative feed back control dependent at least on the rotational number change of either the engine or the rotational member of the automatic transmission, said control device determining whether the engine is in a constant speed or acceleration mode, and temporarily discontinuing the negative feed back control or reducing a control quantity thereof when the engine shifts from a deceleration/closed throttle mo

Abstract: A system for scheduling gear ratio changes in an automatic transmission and controlling operation of a torque converter bypass clutch includes a microprocessor; electronic memory containing control algorithms, lookup tables, functions and constants; solenoid-operated shift valves, a variable force solenoid, friction clutches, brakes and sensors, and planetary gear units. A table of calibrated performance weighting factors (PWF) is used to alter reference schedules of gear ratio changes based on the extent to which high performance operation is desired rather than economy operation. The PWFs are used to adjust gear shift points based on inferences drawn from engine throttle position and time rate of change of throttle position. Hydraulic pressure supplied to the friction elements and the schedule of unlocked and modulated operation of the torque converter are adjusted from reference schedules and pressures on the basis of PWF values.

Abstract: An apparatus automatically shifts a vehicle transmission, according to a shift pattern and on the basis of a detected parameter of the pattern. The shift pattern or the detected parameter is compensated by a compensating coefficient determined from an actual intake air quantity of the engine, and a required intake air quantity calculated from the throttle opening and the engine speed. The apparatus includes an arrangement for adjusting the compensating coefficient so as to prevent busy shifting actions of the transmission upon changing of the throttle opening, or an arrangement for determining the compensating coefficient so as to reflect the driver's desire for accelerating the vehicle, preferably depending upon the vehicle running condition.

Abstract: A particular engine control system is used with an engine equipped with an automatic transmission. The automatic transmission is changeable between an economy operation mode, in which the automatic transmission is placed more frequently in higher gears so as to create a travel mode giving priority to fuel economy, and a power operation mode, in which the automatic transmission is placed more frequently in lower gears so as to create a travel mode giving priority to powerful running. The system controls the engine so as to provide a gentle increase in engine output in the economy mode.

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.