Abstract: A method of controlling gear selection in a vehicle transmission comprises detecting a change in a direction control signal (DCS) from a neutral signal state. If the current TOS is less than or equal to a predetermined neutral shift threshold TOS, the transmission selects one of a plurality of first direction gears if the DCS was changed to a first direction signal state or one of a plurality of second direction gears if the DCS was changed to a second direction signal state. If the current TOS is greater than the predetermined neutral shift threshold TOS, the transmission selects one of the plurality of first direction gears if a machine motion direction parameter indicates that the vehicle is moving in the first direction or one of the plurality of second direction gears if the machine motion direction parameter indicates that the vehicle is moving in the second direction.

Abstract: A control device for a vehicle including (i) a power transmission device, (ii) a shift operation device that is to be operated by a driver of the vehicle to an operation position corresponding to a shift position of the power transmission device, and (iii) a switching device for switching the shift position of the power transmission device through actuation of an actuator. The control device is configured, upon occurrence of a momentary interruption of a control-device electric-power source that is supplied with an electric power from a vehicle electric-power source, to not perform an initial position learning process for setting a reference position of the actuator, until a shift switching operation for switching the shift position of the power transmission device is performed by a driver of the vehicle.

Abstract: A vehicle transmission control device is provided in a vehicle having a gear type transmission capable of selecting a plurality of gear shift patterns, and an electric oil pump for supplying lubricating oil to a gear-shifting mechanism. The vehicle transmission control device includes a transmission controller that selects a path having a small load on the lubricated parts from among the plurality of power transmission paths upon detecting a malfunction has occurred in the oil pump to prevent seizing of lubricated parts and damage to gear-shifting mechanism if a malfunction occurs in the oil pump.

Abstract: A hydraulic control circuit includes: a shift valve configured to be switched between a state of supplying oil pressure to a clearance adjusting chamber of an LR brake and a state of discharging the oil pressure from the clearance adjusting chamber of the LR brake; and a linear SV configured to control the oil pressure supplied to a pressing chamber of the LR brake. The hydraulic control circuit further includes a source pressure oil passage through which oil pressure equal to the oil pressure supplied from the shift valve to the clearance adjusting chamber is supplied to a source pressure port a of the linear SV. By discharging the oil pressure in the clearance adjusting chamber at the time of opening malfunction of the linear SV, the oil pressure in the pressing chamber is also discharged through a drain port of the shift valve.

Abstract: A hydraulic control system for a multiple mode electro-mechanical drive unit of a motor vehicle includes multiple torque transmitting mechanisms each including at least one friction clutch. Multiple clutch control valves are individually in fluid communication with one of the torque transmitting mechanisms and are operable when actuated to change a condition of the torque transmitting mechanisms from a clutch disconnected condition to a clutch engaged condition. Solenoid valves are individually paired with and in fluid communication with one of the clutch control valves. A normally open variable force solenoid valve is in fluid communication with the solenoid valves. Operation of the variable force solenoid valve sets a hydraulic pressure between any of the solenoid valves in an open condition and its paired clutch control valve.

Abstract: A hydraulic control device of an automatic transmission configured such that: a first gear stage is formed by engagement of an LR brake and a low clutch; a third gear stage by engagement of the low clutch and an R35 brake; and a reverse gear stage by engagement of the LR brake and the R35 brake. The hydraulic control device includes a cut valve configured to be switched between a first state where a source pressure port of a third linear solenoid valve (SV) configured to control an oil pressure supplied to the R35 brake is connected to an oil pressure source and a second state where the pressure is discharged from the port. The cut valve becomes the second state when the third gear stage is shifted to the first gear stage, and the oil pressure supplied to the low clutch is less than a predetermined oil pressure.

Abstract: A mixture pilot control for operating an internal combustion engine, in particular a gasoline engine of a motor vehicle, is provided. The mixture pilot control determines at least one composition of an air-fuel mixture required for a predetermined target air-fuel mixture ratio. The internal combustion engine is also provided with a lambda control with at least one lambda probe arranged in the exhaust gas flow of the internal combustion engine for determining a deviation of the actual air-fuel ratio from the predetermined target air-fuel ratio. Operating-parameter-dependent correction factors for the composition of the air-fuel mixture by the mixture pilot control are determined in dependence on the lambda control deviation, at least one of the load and/or the rotational speed and/or the temperature of the internal combustion engine, and further operating parameters of the vehicle other than the load, rotation speed or temperature of the internal combustion engine.

Abstract: A hydraulic control device for an automatic transmission includes a cut-off valve and a line pressure detector. The cut-off valve has a valve element located at one of a first position and a second position. The first position disables supply of a hydraulic fluid to a frictional engagement mechanism of the automatic transmission. The second position enables supply of the hydraulic fluid to the frictional engagement mechanism. The line pressure detector is configured to detect a line pressure. The cut-off valve is to control a hydraulic fluid passage so that the line pressure is supplied to the line pressure detector in a case where the valve element is at the first position and so that the line pressure is not supplied to the line pressure detector in a case where the valve element is at the second position.

Abstract: The present invention provides a method of selecting and implementing a shift schedule for a transmission in a vehicle that includes an output speed sensor and a controller. The method includes measuring output speed with the output speed sensor and comparing the measured output speed to an output speed threshold. The controller receives throttle percentage and compares the throttle percentage to a throttle threshold. The method also includes calculating output acceleration and transmission gear ratio with the controller. The shift schedule is selected based on the measured output speed, calculated output acceleration, calculated transmission gear ratio, and throttle percentage.

Abstract: A range switching device for performing switching the range of a transmission includes first control valve, a second control valve having a characteristic opposite to the first control, and first, second, third and fourth switching valves for controlling the transmission of oil pressures. The first and second switching valves cooperatively control the transmission of the oil pressure from the first control valve to a forward or reverse driving element (R). The third and fourth switching valve cooperatively control the transmission of the oil pressure from the second control valve to the forward or reverse driving element (R). The third and fourth switching valves each perform a substantially same oil pressure transmission when the state of the second and third actuators is reversed with respect to the first switching and second switching valves, respectively.

Abstract: A mechanism for actuating a transmission having shifting elements. A self-holding valve device is movable into a first position, by a pilot pressure, against a force directed to a second position and held by a pressure holding signal in the first position. Transmission of a pressure signal, to a switching valve, is blocked by the self-holding valve device in the first position but, in the second position, is applied to the switching valve. When the driver sets the switching valve to a first shift position, the pressure signal can be applied to valve devices of at least two of the shifting elements that produce an actuating pressure and, in a second shift position of the switching valve, the onward transmission of the pressure signal, to the valve devices of the shifting elements that produce an actuating pressure, is blocked in the area of the switching valve.

Abstract: A control for a multi-speed automatic vehicle transmission includes electrical and hydraulic components, such as pressure control valve systems in fluid communication with shift valves and electrohydraulic actuators. The control includes electrohydraulic features configured to enable the transmission to respond to an electrical failure whether the transmission is in neutral, a reverse range, or one of a plurality of forward ranges.

Abstract: A control for a multi-speed automatic vehicle transmission is provided. Electrical and hydraulic components are provided, including pressure control or “trim” valve systems in fluid communication with shift valves and electrohydraulic actuators to selectively engage and disengage the transmission clutches or other shift mechanisms. Pressure switches are provided for the trim valves and shift valves. The fluid connections between the trim valve systems and the shift valve systems are configured to reduce the total number of valves and fluid passages required and to reduce the size of at least one of the valves. Clutch blocking features are provided. Power off limp home and reduced engine load at stop features are provided in all forward ranges, and control of double transition shifts is also provided.

Abstract: A method for controlling a manual transmission of a vehicle includes providing a manual transmission comprising a shift fork actuator and a shifter assembly comprising a shift lever, a shift knob disposed on the shifter lever, a shift lever position sensor and a shifter tactile sensor. The tactile sensor may be used to determine when pressure is applied to the shift knob of the shifter assembly and, when pressure is applied to the shift knob, vehicle operating parameters are monitored. A predicted gear selection is determined based on the monitored vehicle operating parameters. An operator gear selection is then determined based on the shift lever position sensor when the shift lever is moved. The operator gear selection is compared to the predicted gear selection and, when the predicted gear selection is the same as the operator gear selection, the manual transmission is shifted to the predicted gear selection.

Abstract: A method is described for the operation of a transmission device (1) with a plurality of frictional shift elements (A, D, E, F) and at least one interlocking shift element (B, C) for obtaining various gear ratios. When a command is received for a gearshift during which the interlocking shift element (C) has to be changed from an open to a closed operating condition, the interlocking shift element (C) is at least approximately synchronized by increasing the transmission capacity of at least one frictional shift element (A) which does not have to be engaged in the force flow either to obtain the gear ratio that is to be disengaged or to obtain the gear ratio that is to be engaged.

Abstract: A transmission includes first, second, third, and fourth clutches, first and second shift valves, and first, second, third, and fourth trim valves. Each trim valve is operative to control fluid pressure to a respective one of the first, second, third, and fourth clutches. The transmission also includes a controller. The controller is electrically operatively connected to the first and second shift valves and the first, second, third, and fourth trim valves to selectively provide a first clutch configuration for operating in a first mode and a second clutch configuration for operating in a second mode. The transmission also includes a clutch control mechanization for selectively moving the clutch configuration to a default position in the event power to the transmission is lost.

Abstract: To provide a vehicle speed limiting system that is capable of executing a maximum speed limiting control without influencing a driving feeling of a vehicle. A vehicle speed limiting system includes: a three-dimensional map 46a and a throttle valve driving unit 47. A first maximum speed limiter opening degree is calculated by adding a first predetermined opening degree, a second predetermined opening degree, and a current throttle valve opening degree, the first predetermined opening degree being calculated by multiplying a speed difference of the vehicle by a preset P-term coefficient, the second predetermined opening degree being calculated by multiplying an acceleration of the vehicle by a preset D-term coefficient. Once the calculated first maximum speed limiter opening degree falls below the target throttle valve opening degree ?B, the throttle valve motor 30 is driven on a basis of the first maximum speed limiter opening degree.

Abstract: A machine includes a drive train with an electronically controlled transmission in communication with an electronic engine controller. The machine ground speed is limited by executing a vehicle speed limit algorithm in the electronic transmission controller. This algorithm generates an engine control message that is communicated to the electronic engine controller. The power output of the engine is reduced responsive to the engine control message. The machine responds by not exceeding a prescribed speed limit programmed into the electronic transmission controller. This vehicle speed limiting strategy is particularly applicable to machines without a vehicle speed limiting algorithm resident in the electronic engine controller.

Abstract: A method and apparatus for controlling transmission functions in a transmission of a motor vehicle by an electromagnetically actuated control valve. The control valve is controlled by a control device that includes a stored valve characteristic curve to provide a temperature-dependent and a target-current-dependent overlay, so that a symmetrical target value oscillation around a target current value is achieved. The characteristic curve for controlling the control valve is adapted at least partially as a function of a current value and a temperature.

Abstract: A transmission device has at least two change-under-load shift elements with transmission capacities that are varied an actuation device. A method for operating a drive train including transmission and drive engine includes a step that when the transmission is shifted, one of the shift elements, which is engaged in the force flow, is disengaged by the actuation device and the other shift element, which is engaged, is disengaged. The actuation device includes an actuator which applies an actuating force to actuate the shift elements and a coupling device by which the actuator communicates with the shift elements to actuate them, such that an actuating force of the actuator, which is actuating the shift element to be disengaged, can be reduced, while an actuating force of the actuator, which is actuating the shift element to be engaged can simultaneously be increased.

Abstract: In a hydraulic control apparatus for a vehicle automatic transmission, a check valve is provided parallel to a first oil passageway switching valve and a third oil passageway switching valve between an output port of a linear solenoid valve and a brake, and the check valve permits pressure oil to flow from the brake to the output port side, and blocks the flow thereof in the opposite direction. Therefore, the pressure oil from the brake when the brake is released is supplied to the output port via the check valve, not via the first or third oil passageway switching valve. Therefore, when the brake is released, the engaging pressure of the brake can be controlled by the linear solenoid valve, and the positions of the first and third oil passageway switching valves are not restricted.

Abstract: An oil pressure control apparatus for an automatic transmission configured with an oil pressure servo that engages and disengages a friction engagement element. The friction element is engaged by first and second hydraulic oil chambers that individually provide low torque, and can provide a higher torque when working in combination. A failure solenoid valve outputs a signal when a failure occurs to stop oil pressure to an oil pressure servo. Valves are configured to determine whether oil pressure is supplied to or discharged from the first and second hydraulic oil chambers. A switching valve is switched on the basis of the failure signal, and an oil pressure can be individually supplied to and discharged from the first and second hydraulic oil chambers based on the status of the switching solenoid valve and the signal from the failure solenoid valve.

Abstract: A shift by wire control for a multi-speed vehicle transmission is provided. The control includes a shift by wire shift valve in fluid communication with other shift valves and clutch trim valves to provide double blocking features in the neutral range and a reverse range. The shift by wire valve is configured with multiple differential areas to provide failure modes for all forward ranges.

Abstract: A method of controlling a vehicle transmission during a gear change thereof, the method comprising operating a plurality of power shift clutches to disengage the power shift input gearing and the power shift output gearing, disengaging the driving connection between the range shift input shaft and the range shift output shaft by means of the range selection gearing, engaging at least two of the power shift clutches to vary the rotational speed of the power shift output shaft and hence the range shift input shaft, and operating the range selection gearing to establish a driving connection between the range shift input shaft and the range shift output shaft.

Abstract: A device for controlling a hydraulically operable switching element (2) of an automatic transmission of a vehicle with a position valve mechanism (3) having a main switch piston (6) which is spring biased into a first switch position and a second switch position with a pilot pressure (P_MV) which is adjustable through an electrically operated actuator (5). An additional switch piston (7) and the main switch piston (6) are axially actuated in a valve housing (8). Depending on the position of the pistons (6, 7), faces (6A, 7A) of the respective pistons are either spaced apart or adjacent. The additional switch piston (7) is adjustable depending on a pilot pressure (p_K) of a switching element which engages a gear for forward drive.

Abstract: A hydraulic control device for a multi-speed automatic transmission includes friction engagement elements, several hydraulic servos that engage and release the friction engagement elements, solenoid valves for engagement control, and a sorting switch valve that allocates engagement pressure from at least one of the solenoid valves for engagement control to two of the hydraulic servos. The sorting switch is switched between a first position that supplies engagement pressure to one of the two hydraulic servos in at least a Reverse, non-drive range and a specific Forward gear range, and a second position that supplies engagement pressure to the two hydraulic servos in other than the Forward range.

Abstract: A hydraulic control system applicable to a power train of a seven-speed automatic transmission for a vehicle having six friction members. Enhanced overall performance is achieved by minimization of shift shock and an enhancement of fuel consumption as a consequence of achieving precise and effective control.

Abstract: A hydraulic control apparatus for a multi-stage automatic transmission includes solenoid valves such as the linear solenoid valves that are formed as normally closed valves. A first clutch apply relay valves that outputs a forward range pressure as a reverse input pressure during an all-solenoid-off mode, and a second clutch apply relay valve that switches between a left half position that inputs a reverse input pressure to a discharge port and a right half position that inputs the reverse pressure to the discharge port are provided. The second clutch apply relay valve is set to the right half position during normal engine startup and locked based on the lock pressure by feeding the line pressure as a lock pressure and is set at the left half position that interrupts the lock pressure after the engine is restarted during all-solenoids-off.

Abstract: A fly-by-wire control for a multi-speed vehicle transmission is provided. Electronic and hydraulic components are provided, including trim valve systems that are multiplexed by logic valves. The trim valves and logic valves are self-diagnosing via a plurality of pressure switches. The control enables single and double range shifts among the multiple forward speed ratios, including shifts to and from sixth and higher forward ratios, reverse and neutral. The control also includes a reduced engine load at stop feature. In addition, a power off/limp home feature provides a plurality of failure modes, including a failure mode for sixth and higher forward speed ratios.

Abstract: A transmission shift system includes a first control path having a first electrically actuated valve system, and is configured to selectively direct hydraulic pressure to a first plurality of clutches for selecting only an output speed. A second control path independent of the first control path includes a second electrically actuated valve system, and is configured to selectively direct hydraulic pressure to a second plurality of clutches for selecting only an output direction. A shifter has a plurality of switches, each switch being in direct electrical connection with a corresponding of the first electrically actuated valve system and the second electrically actuated valve system for operating the first control path and the second control path controllerlessly, wherein the plurality of switches are operated manually using the shifter.

Abstract: A hydraulic control system of a six-speed automatic transmission provides an enhanced overall performance by achieving precise and effective control by providing a fail-safe function in at least two ways.

Abstract: A hydraulic control apparatus for controlling a vehicular automatic transmission including hydraulically operated frictional coupling devices which are selectively engaged and released to selectively establish gear positions having respective different speed ratios, and linear solenoid valves operable to regulate fluid pressures of the respective frictional coupling devices, each linear solenoid valve including a spool and a solenoid and being operable between a pressure-regulating state in which the spool is movable to a position of equilibrium of forces for regulating an output fluid pressure according to an electromagnetic force produced by the solenoid, and a non-pressure-regulating state in which the spool is held at a stroke end thereof at which no output fluid pressure is generated from the linear solenoid valve, each linear solenoid valve in the pressure-regulating state being operable to regulate a fluid pressure of the corresponding frictional coupling device according to the electromagnetic force,

Abstract: A motor vehicle for controlling an automatic gearshift stepped variable speed transmission that can be driven by a drive engine, in which, depending on an accelerator pedal position and an engine speed, upshifts or downshifts between the gear steps are triggered automatically and in which a kick-down switch is present. In a first speed range below a first boundary speed (n1) actuation of the kick-down switch triggers a downshift. For one or more upper gear steps in a second engine speed range above a second boundary speed (n_KD_Schw), even at high loads, no downshifts is triggered and an upshift is only triggered by actuation of the kick-down switch.

Abstract: In a conventional abnormality detecting apparatus, it is impossible to judge a breakdown before the breakdown actually takes place. An abnormality detecting apparatus for an automatic speed changer includes a speed change controlling unit for controlling the automatic speed changer; a learn controlling device for optimizing an rpm change at the time of speed change control by the speed change controlling device; and an abnormality detection controlling device for judging whether a learned value of the learn controlling device falls within a range between an upper limit and a lower limit and if the learned value falls out of the range, storing the condition as abnormal. Thus, it is possible to detect the abnormal condition of constituents such as a clutch in the automatic speed changer before the actual breakdown.

Abstract: Many vehicles designed for running on rough terrain include an automatic transmission for performing speed change by connecting or disconnecting an oil hydraulic clutch provided alongside each speed change gear. However, depending on the posture of the driver, it may be impossible to step on the brake. As a result, it may be impossible to achieve creep prevention with a creep preventive mechanism dependent on a brake signal. Therefore, a creep preventive mechanism which operates independently from a brake signal is required. The present invention provides an oil pressure control system operating independently from a brake signal. The system includes an oil pressure supply source with a linear solenoid valve for supplying working oil or interrupting the supply of the working oil to the oil hydraulic clutches. The supply of the working oil to the clutches is interrupted when the vehicle is stopped under an idling condition of an engine.

Abstract: An automatic gearbox includes a control device for selecting a gearbox driving position, which device includes at least one spool valve via which at least one pressure connection may be connected to at least one consumer, and having at least one shift valve via which at least one pressure connection from at least one pressure supply of the control device may be shifted to the spool valve in order to actuate the spool valve. The control device includes a retaining device via which, if the shift valve should fail, the spool valve may be fixed in at least one control position and the selected gearbox driving position may be retained.

Abstract: A shift control method for an automatic transmission improves shift feel and acceleration characteristics by determining if 4→3 shifting is required during lift-foot-up 3→4 shift control, and if so, the method controls a number of solenoid valves and friction elements with input from a plurality of sensors that stop the lift-foot-up 3→4 shift when the accelerator pedal is again depressed after being released.

Abstract: An electro-hydraulic control system for an automatic transmission comprises a manual selector valve for operator direction of line pressure fluid to a drive passage when drive is selected or to a reverse passage when reverse is selected. A drive/reverse passage connects the drive passage and the reverse passage. A first check ball is disposed between the drive passage and the drive/reverse passage and a second check ball is disposed between the reverse passage and the drive/reverse passage wherein the check balls operate to pressurize the drive/reverse passage when either drive or reverse is selected.

Abstract: A hydraulic control system includes switching mechanisms for receiving as a signal pressure a hydraulic pressure which is output from each shifting mechanism when all units of the shifting mechanisms are caused to output a hydraulic pressure, and being responsive to the reception of the signal pressure to be switched to a predetermined state for blocking a hydraulic-pressure supply path to specific hydraulic servos, thereby achieving a specific speed out of a plurality of speeds; and supply switching mechanisms provided in a hydraulic-pressure supply path to a hydraulic servo which is not included in the specific hydraulic servos, for switching between supply and cut-off of the hydraulic pressure to the hydraulic servo so as to assure two speeds in the event of the signal failure in a hydraulic control system for individually controlling engaging elements in an automatic transmission by using electric signals.

Abstract: Disclosed is a shift control method for an automatic transmission that improves shift feel and acceleration characteristics by determining if 4→3 shifting is required during lift-foot-up 3→4 shift control, and if so, the method controls a number of solenoid valves and friction elements with input from a plurality of sensors that stop the lift-foot-up 3→4 shift when the accelerator pedal is again depressed after being released.

Abstract: A hydraulic control for an automatic shifting transmission has a plurality of shift logic valves, a high ratio control valve, a low ratio control valve and respective pressure control valves for controlling the bias pressure on the ratio control valves. The shift logic valves control the distribution of fluid to a plurality of torque transmitting mechanisms from the proper ratio control valve. During an upshift sequence, the high ratio control valves establishes the engagement pressure in the oncoming torque transmitting mechanism and the low ratio control valve establishes the engagement pressure in the offgoing torque transmitting mechanism. The pressure from the high ratio control valve is also delivered to a control port on the low ratio control valve to force the exhausting of the offgoing torque transmitting mechanism when the oncoming torque transmitting mechanism reaches its critical torque capacity.

Abstract: A hydraulic control system for 4-speed automatic transmissions in which line pressure, drive pressure, reverse pressure and low pressure are selectively supplied from a manual valve to an underdrive clutch, an overdrive clutch, a low-reverse brake, a reverse clutch, and a second brake to realize four forward speeds and a reverse speed.

Abstract: An apparatus for controlling an automatic transmission is disclosed. A 2nd speed is established in which hydraulic pressure is supplied only into an engaging chamber of a 2-4 brake by a first duty solenoid valve so that the brake is applied. A 3rd speed is established in which the hydraulic pressure is supplied into a releasing chamber of the brake and a hydraulic chamber of a 3-4 clutch by a second duty solenoid valve under the condition of the hydraulic pressure being supplied into the engaging chamber of the brake so that the brake is released and the 3-4 clutch is engaged. When the 2nd speed is changed to the 3rd speed, a controller increases the hydraulic pressure supplied into the releasing chamber of the brake and the hydraulic chamber of the 3-4 clutch in a case where a failure, in which the first solenoid valve is fixed under a condition that the first solenoid valve supplies the hydraulic pressure into the engaging chamber, is detected.

Abstract: In the oil temperature detecting method, an oil temperature sensor detects the temperature of oil in an automatic transmission. A controller receives the detected temperature and signals indicating a first and second potential. The first potential represents the ground potential of the automatic transmission, and the second potential represents the ground potential of a body of the vehicle. Based on the first and second potentials and the sensed oil temperature, the controller controls an operation of the automatic transmission.

Abstract: Disclosed is a hydraulic control system used in an automatic transmission for a vehicle which includes a plurality of friction elements associated with respective transmission speeds, a hydraulic pressure source, a hydraulic pressure regulating controller for controlling hydraulic pressure from the hydraulic pressure source to constant line pressure, a damper clutch controller for actuating a damper clutch of the torque converter by supplying hydraulic pressure fed from the pressure regulating controller to the torque converter, shift controller for selecting a shift mode by converting hydraulic pressure from the pressure regulating controller into drive pressure corresponding to each speed stage, a hydraulic pressure controller for controlling the drive pressure from the shift controller, and a hydraulic pressure distributor for suitably distributing hydraulic pressure from the hydraulic pressure controller to each friction element for each speed, wherein the hydraulic pressure distributor includes a shift t

Abstract: A control system for an automatic transmission, in which a first frictional engagement element and a second frictional engagement element are released according to a shift from a running range to a non-running range. The shift from the running range to the non-running range is detected, and the reduction in the oil pressure of the second frictional engagement element is controlled on the basis of the reduction in the oil pressure of the first frictional engagement element when the shift from the running range to the non-running range is detected.

Abstract: An automatic transmission for an automotive vehicle which includes a hydraulic pump for pressurizing fluid; a pressure regulating valve for varying hydraulic pressure supplied from the hydraulic pump; seven friction elements for forward driving and two friction elements for reverse driving activated according to spool positions of a manual valve, first and second shift control sections having at least two shift valves for supplying hydraulic pressure to the friction elements selectively, and a torque pressure converting section for supplying torque pressure to the first shift control section.

Abstract: Transmission output speed and engine throttle position are inputs to a control which determines acceleration and input speed. Fuzzy logic has acceleration and throttle membership functions and a set of upshift and downshift values, and rules for weighting each of the values in accordance with the degree of membership of acceleration and throttle position in certain of the functions to determine a downshift point and an upshift point. The input speed is compared to the shift points to decide whether to order a shift. Two or more sets of shift values are stored and are selectable for different performance options. The shift values are stated in terms of a percentage of engine governed speed to allow different engines to be coupled to the transmission. Lockup clutch apply and release logic controls converter lockup to maintain converter mode when significant torque multiplication is occurring and generally to maintain lockup mode when the transmission range is at or above the lowest allowable lockup range.

Abstract: A hydraulic control system for an automatic transmission includes a hydraulic pressure source, a line pressure controller for constantly controlling hydraulic pressure from the hydraulic pressure source, a reducing pressure controller for generating reduced pressure, a damper clutch controller for supplying hydraulic pressure fed from the line pressure controller to a torque converter, a shift controller for converting hydraulic pressure from the line pressure controller into drive pressure corresponding to each speed stage, a hydraulic controller for controlling drive pressure from the shift controller; and a pressure distributer for distributing hydraulic pressure from the hydraulic controller to each friction member for each speed stage by being controlled by drive pressure from the shift controller.

Abstract: The hydraulic control system for an automatic transmission having a plurality of friction elements includes a pressure regulator which regulates hydraulic pressure produced by an oil pump, a plurality of valves selectively supplying hydraulic pressure to the plurality of friction elements, and a pressure controller controlling and selectively supplying hydraulic pressure to a plurality of pressure control lines operationally connected to the plurality of valves and at least one of the plurality of valves. The plurality of valves include a first valve operationally controlled by hydraulic pressure in a first one of the pressure control lines to pass the hydraulic pressure output by the pressure controller to at least one of the plurality of friction elements in each operational range except a first speed stage of a drive range.