Abstract: A method for operating a motor vehicle, the motor vehicle including a prime mover (1), a transmission (2), and a driven end (3), wherein the transmission (2) is an automatic or automated transmission and is connected between the prime mover (1) and the driven end (3). The method includes activating a sailing mode of the motor vehicle depending on at least one operating condition of the motor vehicle; performing a gear select interlock in the transmission (2), while maintaining the sailing mode, when the sailing mode is active; and deactivating the sailing mode is subsequently depending on at least one operating condition of the motor vehicle. The gear select interlock is implemented in the transmission (2) depending on a rotational speed of the prime mover (1) and depending on synchronous speeds of the gears of the transmission (2).

Abstract: A cruise control system for a vehicle includes a controller configured to maintain a speed of the vehicle about a setpoint, and in response to predicted brake capacity falling below a threshold based on predicted brake fade, reduce the setpoint and downshift a transmission of the vehicle to increase negative torque to reduce brake fade. Also, a powertrain of a vehicle includes an engine, an automatic transmission coupled with the engine, and a controller. The controller is configured to maintain a speed of the vehicle about a setpoint, and in response to a predicted brake capacity falling below a threshold based on predicted brake fade, reduce the setpoint and downshift the transmission to increase a negative torque.

Abstract: An automatic transmission control apparatus includes an engine generating power by a combustion of fuel; an automatic transmission provided with a friction element including a clutch and a brake and changing the power generated in the engine into a torque required depending on a speed by an engagement and release of the friction element to be output; an accelerator pedal position sensor detecting a position signal of the accelerator pedal; and a controller determining whether a vehicle is in a rapid acceleration state from the position signal of the accelerator pedal detected from the accelerator pedal position sensor and correcting a control hydraulic pressure of the friction element if the vehicle is the rapid acceleration state. Since the friction element control hydraulic pressure is controlled depending on the operation speed of the accelerator pedal, the shift responsiveness may be improved.

Abstract: A vehicle control system is provided which includes a travel controller working to execute a coasting mode to cut transmission of drive power, as produced by an engine to a drive wheel of the vehicle when a given execution condition is encountered while the vehicle is traveling. The travel controller determines a threshold value, as used for comparison with a position of an accelerator, based on the speed of the vehicle. When the position of the accelerator is determined to be smaller than the threshold value, the travel controller executes the coasting mode. This improves the fuel economy in the vehicle without sacrificing traveling of the vehicle according to a driver's operation on the accelerator.

Abstract: A method of operating a transmission having a plurality of gears which can operate in an automatic shifting mode, during which a gear is selected automatically depending on the current driving situation, and also in a manual shifting mode during which a gear is selected depending on a driver's command. When the driver commands a shift, a change takes place from the automatic shifting mode to the manual shifting mode. A specific threshold value of the transmission output speed or an equivalent rotational speed value is associated with each gear and, when the driver commands a downshift, a target gear is determined as a function of the current transmission output speed or the equivalent rotational speed value. The gear selected as the target gear is the gear whose specific threshold value is higher than or equal to the current transmission output speed or the equivalent rotational speed value.

Abstract: During a non-shift operation when a predetermined gear of an automatic transmission is kept, a hydraulic control unit increases an engagement hydraulic pressure to a friction engagement device associated with the gear formation by a predetermined hydraulic pressure with respect to a line hydraulic pressure. Therefore, in comparison with a case where a hydraulic pressure equivalent to the line hydraulic pressure is set as an engagement hydraulic pressure to the friction engagement device for obtaining a hydraulic pressure equivalent to the line hydraulic pressure, shift response (hydraulic pressure response) variations when shifting from a non-shift state (steady state) into a shift state are suppressed by the margin of the predetermined hydraulic pressure. In addition, in comparison with a case where the engagement hydraulic pressure to the friction engagement device is set to a maximum hydraulic pressure to reduce the response variations, power consumption of each linear solenoid valve is suppressed.

Abstract: During control of a shift of a first friction engagement element from an engaged state into a disengaged state and a shift of a second friction engagement element from a disengaged state into an engaged state for a gear shift to a first target gear from a second target gear, a desired torque capacity of the first friction engagement element is set based on an actual transmission gear ratio by interpolation from values of the desired torque capacity corresponding to at least first and second reference transmission gear ratios, wherein the first reference transmission gear ratio is a transmission gear ratio at start of an inertia phase of the shift control. When the first reference transmission gear ratio is between the actual transmission gear ratio and the second reference transmission gear ratio, the desired torque capacity is set to the value corresponding to the first reference transmission gear ratio.

Abstract: If a mode-detection value is switched from an automatic shift-mode to a manual shift-mode, a T-ECU changes a shift-stage to a speed lower than a speed that is obtained before the switching of the mode-detection value. The T-ECU determines that a state of the T-ECU returns to a recognizable-state, in which a mode-selection value can be recognized, from an unrecognizable-state, in which the mode-selection value cannot be recognized. The T-ECU sets the shift-stage to a hold value after the return. The T-ECU controls the shift-stage in the automatic shift-mode “D” over a standby-period after the return. The T-ECU controls the shift-stage in the automatic shift-mode “D” until the detection of the operation of the shift-lever after the standby-period passes.

Abstract: An ECU executes a program for implementing a method that includes: a step of performing control so that torque capacity Tch of a frictional engagement device that is brought from an engaged state into a disengage state by a downshift operation is gradually reduced to start an inertia phase when a power-on downshift is performed; and a step of stopping the gradual reduction of the torque capacity Tch when the rate of change in an input shaft rotation speed NI of an automatic transmission has reached a desired rate of change ?N(1). Variation in output torque is kept small, and the shock that can occur at the time of a shift is thus reduced.

Abstract: A converterless, multiple-ratio transmission and ratio shift control method wherein smoothness of power-on upshifts and downshifts and power-off upshifts and downshifts is achieved by closed loop control of slip speed and friction element actuating pressure for an oncoming friction element, the data used during the closed loop control including speed sensor information for multiple friction elements during upshift and downshift events.

Abstract: A method for implementing shifts from a source gear to a target gear of an automatic shift transmission includes storing a respective upshift threshold and a respective downshift threshold for each possible sequential gear shift. The respective upshift threshold and the respective downshift threshold are defined in dependence of an accelerator pedal position, such that a limit value that is valid for a respective upshift or downshift is stored as a vehicle speed value in a control device. The vehicle speed that changes while the motor vehicle is driving and a changing accelerator pedal position are measured. Downshifts are simplified for a driver by configuring at least two downshift thresholds to be substantially horizontally extending in a first region of a possible accelerator pedal position and at least partly step-shaped in a second region of the possible accelerator pedal position.

Abstract: A method of controlling a downshift in a transmission having a main box and a compounder that has at least one gearset and at least one friction element separate from the main box includes initiating an upshift in the compounder including application of at least one friction element (e.g. a clutch) in the compounder, and releasing a friction element (e.g. a clutch) in the main box providing a swap shift. The speed phase in the compounder may trigger the speed phase in the main box, and vice versa. Target fluid volumes in one or both of a clutch being released in the main box and a clutch being applied in the compounder may be controlled and adjusted, if necessary, as a function of specific event timing in prior shifts.

Abstract: An automatic transmission control device with a hydraulic control system controlled by an electric transmission control device. The system including several pressure control valves, actuated electrically by the transmission control device, and several switching valves and pressure regulation valves, actuated by hydraulic pilot pressure, which is adjustable with the pressure control valves. Each shift element is associated with one of the pressure control valve. An engagement prevention valve is actuated by one of a control pressure of the first shift element and a pressure signal equivalent to the control pressure of the first shift element to engage the reverse drive gear. A pressure supply line of the second shift element for obtaining the reversing gear is blocked when the engagement prevention valve is in its first switch position and open when the engagement prevention valve is in its second switch position.

Abstract: A shift control device of a vehicular automatic transmission that establishes a plurality of gear steps of different speed change ratios by selectively engaging a plurality of friction engagement devices ends the shift control by making an engagement end determination regarding an engagement-side friction engagement device if it has been determined continuously for a predetermined time that the input shaft rotation speed of the automatic transmission is in the vicinity of the synchronous rotation speed of the post-shift gear step. The predetermined time is set at a first time if the downshift is a power-on downshift due to a shift judgement in a power-on state, and is set at a second time that is shorter than the first time if the downshift is a power-off?on downshift selected in connection with a change to the power-on state during a power-off shift due to the shift judgment in a power-off state.

Abstract: A method for shifting an automatic transmission (8) of a motor vehicle having a hydrodynamic, converter (6), when the vehicle slows from driving to a standstill a predetermined stopping condition of the automatic transmission (8) exists, such that the transmission (8) is shifted into neutral. To avoid disadvantages from shifting into neutral immediately after the motor vehicle is stationary, such as an increase in fuel consumption by a tractional torque operation of the converter, a disengagement impact upon shifting into the standby mode; an unexpected rolling of the vehicle, when stopping occurs on an incline following a shift into neutral. The automatic transmission (8), conforming to predetermined stopping conditions, shifts even during the driving state into neutral.

Abstract: An automatic transmission ratio shift control system and method for a powertrain having an engine and multiple-ratio gearing controlled by friction elements actuated by hydraulic pressure, an electronic controller for establishing torque transitions among the friction elements as the gear ratio changes, the engine speed being controlled by an electronic throttle control. The strategy employs an electronic throttle and closed loop engine speed control and uses fuel and air as an energy source to increase engine speed during a power-off downshift. The engine speed is boosted to a level close to the synchronous speed in conjunction with release of the off-going friction element. The on-coming friction element is then applied as the engine speed approaches a desired speed. The engine speed increase is timed to lead an increase in torque converter speed.

Abstract: A transmission system for a work vehicle, which is capable of reliably mitigating, with relatively simple arrangement, shocks caused by speed changes even in a work vehicle such as a bulldozer in which almost all operations are performed with the engine operating at full load. In the transmission system which converts the output torque of an engine into torque according to work load by operations for shifting speed gears through disengagement/engagement of friction clutches, if a downshift from a higher speed gear to a lower speed gear is effected while the engine operating at full load, the friction clutch controlling valves, controller and friction clutches allows the friction clutch corresponding to the higher speed gear to slide so as to enable power transmission and the engine controlling fuel injection system and controller allows the engine to perform high power operation (overload operation) during the sliding of the friction clutch.

Abstract: A shift control apparatus of an automatic transmission of a motor vehicle to which torque is transmitted from an engine via a fluid coupling device is provided. In the automatic transmission including a plurality of hydraulically operated friction elements, a clutch-to-clutch downshift is carried out during coasting of the vehicle by releasing one of the friction elements and engaging another friction element. A controller of the shift control apparatus detects a difference between input and output rotation speeds of the fluid coupling device, and increases an engine speed by a controlled amount based on the difference between the input and output rotation speeds when the clutch-to-clutch downshift is carried out during coasting of the vehicle, so that the vehicle is brought into a minimal driving state in which the engine speed is slightly higher than the output rotation speed of the fluid coupling device.

Abstract: A method for controlling a gear shift in an automatic transmission of a motor vehicle that is carried out as a deceleration shift of at least one engaging shifting element, without use of a mechanical free-wheeling condition. To increase the ride comfort, it is proposed that during the shifting sequence of the deceleration shift, a free-wheeling condition is simulated by a slip operation or by an opening of a second shift element of the automatic transmission, that is located in the power flow path, preferably using a start-up shift element of the automatic transmission.

Abstract: A transmission control system, includes:

Abstract: A first switch (2) which can select a manual mode, and a second switch (5, 6) which can select one of an upshift and a downshift, are provided. A microprocessor (1) varies a speed ratio of an automatic transmission (10) according to the specification of the second switch (5, 6) when the first switch (2) has previously selected the manual mode, and the second switch (5, 6) subsequently specifies one of the upshift and the downshift (S20, S21, S33, S40, S41, S34, S36, S37, S53, S54, S55). On the other hand, variation of the speed ratio of the automatic transmission (10) according to the specification of the second switch (5, 6) is prohibited when the second switch (5,6) specifies one of the upshift and the downshift at a timing not later than a timing at which the manual mode is selected by the first switch (2) (S20, S22, S33, S40, S38, S34, S36, S38, S53, S54, S56).

Abstract: A control strategy for a multiple-ratio transmission for an automotive vehicle comprising a shift valve system that responds to shift valve signals developed by a microprocessor controller, the controller being in communication with engine sensors indicating engine operating variables and transmission sensors indicating transmission operating variables, the shift valve system responding to shift signals developed by the microprocessor during coasting downshift of the vehicle from one gear ratio to a lower gear ratio with a closed engine throttle whereby torque reversals are avoided during coast-down, thereby eliminating inertia torque changes to improve the smoothness of coasting downshifts during cold engine operation.

Abstract: Under a condition where a manual mode is selected by a selecting lever, when a down-shift switch is turned ON and down-shift is requested, an engine speed NED after the down shift is calculated (step S12), and if this engine speed exceeds the overspeed NOV, the down-shift is made to stand by, and a down-shift elapsed time T1 is incremented. When the incremented elapsed time is within a down-shift effective time TD (predetermined time) which is set on the basis of a gear position, throttle opening degree, vehicle speed, deceleration, etc., a down-shift command is sent (step S18) when the engine speed NED reaches the overspeed NOV or lower, whereas when the down-shift elapsed time T1 reaches the down-shift effective time TD or longer, the down-shift stand-by condition is released (step S17).

Abstract: When a vehicle driving state of an automatic transmission is changed to a power-off state from a power-on state during a down shift involving the disengagement of one friction element and the engagement of another friction element, a disengagement side pressure PA is reduced rapidly by a feedback control based on the change in gear ratio because of a reduction of an input torque. The disengagement side pressure control is unable to complete change of the gear ratio to complete the down shift. When the disengagement side pressure is reduced to a value less than a return spring load pressure PG or when the gear ratio change has not achieved a basic value in a predetermined time, the down shift control is changed from primary control by the disengagement side pressure control to primary control by an engagement side control so that the gear ratio change is completed by control of the engagement side pressure.

Abstract: A shift control method for an automatic transmission not equipped to undergo skip shifting. Various skip shifting patterns are realized by detecting changes in turbine RPM, and delaying shifting if it is determined that turbine RPM are irregular, thereby achieving a normal shift pattern.

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 controlling an automatic transmission equipped with a torque converter which is locked and unlocked through a lockup clutch has a lockup release control device which releases locking of the torque converter at different release rates between a downshift resulting from an increase in engine load and a downshift resulting not from an increase in engine load.

Abstract: A slip detecting device detects slipping of a selected hydraulically engaged element of an automatic transmission during non-shifting, and a determining device determines a hydraulically engaged element larger in driving-force transmitting capacity than the hydraulically engaged element which is in its engaged state. A transmission control element then brings the hydraulically engaged element having the larger driving force transmitting capacity, into its engaged state, in place of the hydraulically engaged element which was in its engaged state. Thus, the slipping of the hydraulically engaged element during non-shifting is prevented.

Abstract: During transmission shifts, a band brake is used in either a self-loosening direction in which an engaging force thereof is not sensitive to variations in hydraulic pressure or a self-tightening direction in which the engaging force is sensitive to variations in hydraulic pressure. In the self-loosening direction, a second regulated hydraulic pressure generated by a second pressure regulating valve (B-4 control valve) in accordance with a control hydraulic pressure generated by a second (throttle-pressure-control) linear solenoid valve in a margin control region thereof is supplied to a hydraulic servo of the fourth brake (band brake). In this clutch-to-clutch shift, a first regulated hydraulic pressure generated by a first pressure regulating valve (a shift-pressure control valve) in accordance with a control hydraulic pressure generated by a first (pressure-regulation) linear solenoid valve is supplied to a hydraulic servo of a third (UD direct) clutch.

Abstract: A hydraulic control system of an automatic transmission for a vehicle includes a line pressure control part for converting line pressure from a hydraulic pump into constant hydraulic pressure. A torque pressure generating part converts the constant hydraulic pressure fed from the line pressure control part via a manual valve into torque pressure in accordance with the operation of a transmission control unit. A torque pressure switching part switches the supply direction of the torque pressure fed from the torque pressure generating parts in accordance with the operation of the transmission control unit. A shift part primarily feeds the torque pressure fed from the torque pressure switching part to friction members and secondly feeds drive pressure to the friction members after converting the line pressure fed from the line pressure control means into drive pressure.

Abstract: A hydraulic control system of an automatic transmission for an automotive vehicle includes a hydraulic pump, a pressure regulating valve, a torque converter, a converter clutch, first, second and third solenoid valves, first through eighth friction elements, second and third speed clutch valves, a band valve and a manual value. The pressure regulating valve varies a hydraulic pressure when shifting, and the converter clutch regulator valve actuates a damper clutch to improve transmission efficiency of the torque converter. The first, second and third solenoid valves supply or obstruct the supply of hydraulic pressure from the pressure regulating valve to a respective one of a first, second and third clutch shift valve to displace valve spools of a respective one of the first, second and third clutch shift valves. The second speed and third speed clutch shift valves as well as the fourth speed band valve, selectively supply hydraulic pressure to the friction elements to perform shifting.

Abstract: A shift timing detecting system for detecting the start of a shift of an automatic transmission A in terms of a change in the R.P.M. of a predetermined rotary member after a shift command has been outputted. The shift timing detecting system comprises: a detector for detecting a change in the output R.P.M. of the automatic transmission; an arithmetic processor for arithmetically processing the change in the output R.P.M. with different coefficients to determine two processed values: a comparator for comparing the two processed values: and a shift start decider 5 for deciding the start of the shift on the basis of the result of the comparison. Since the shifting situation can be grasped from the change in the output torque accompanying the start of the shift and the change in the output R.P.M. caused by the former change, the start of the shift can be accurately detected without any time delay.

Abstract: A speed change control method and apparatus for a vehicular automatic transmission having a first-speed clutch for establishing a first speed and a second-speed clutch for establishing a second speed, includes subjection of at least a duty ratio Dr of a second-speed solenoid valve for supplying oil pressure to the second-speed clutch to feedback control, so that the first-speed clutch is engaged while disengaging the second-speed clutch. This thereby increases a turbine rotational speed Nt toward the first-speed synchronous rotational speed. Further, an upper limit value Dmax of the duty ratio Dr is set, and the duty ratio Dr is subject to feedback control within a resultant duty ratio range. This thereby prevents the duty ratio Dr from being set at an excessive value caused by a delay in the rise of the oil pressure. As a result, even if a depression of an accelerator pedal is suddenly increased during a downshifting process, an interlock problem can be prevented, thereby ensuring smooth speed change.

Abstract: A control system is provided for servo hydraulic pressure in an automatic transmission having planetary gear mechanisms. First and second frictional engagement devices, whose servo pressures are reversed in feed/drain relationship between desired two high speed stages, are controlled by a shift valve and a directional control valve. The shift valve is switched by a first solenoid. The directional control valve is interposed in a servo hydraulic pressure feed/drain line communicating the shift valve with the first frictional engagement device and is controlled by a second solenoid. The first and second solenoids are controlled by an electronic control unit in accordance with a shift position detected by a detector, whereby the timings of feed or drain of the servo hydraulic pressures to or from the first and second frictional engagement devices are changed by predetermined relative amounts, respectively.