Abstract: Aspects of the disclosure relate to controlling a vehicle in an autonomous driving mode. For instance, a trajectory is identified. The trajectory defines a future desired path for the vehicle and includes a control requirement having a corresponding point in time. A command for achieving the control requirement is generated. A fixed delay value corresponding to a delay caused by transmission of the command to an actuator of the vehicle is generated. A variable delay value corresponding to a delay caused by an amount of time to change a physical state of the actuator to a desired state according to the command is generated. The command is then sent to the actuator based on the fixed delay value, the variable delay value, and so that the actuator causes the vehicle to move according to the command.

Abstract: A shift control device has stepless and stepped shift modes in which a transmission gear ratio of a continuously variable transmission is controlled in stepless and stepwise fashions, respectively, and includes a shift controller that switches the shift mode to the stepless shift mode by executing shift control of the transmission if an accelerator-pedal operated amount falls below a switch threshold during the stepped shift mode, a minimum value detector that detects an operated-amount minimum value in a shift process of switching the shift mode to the stepless shift mode, and an upper-limit-value setting unit that sets an upper limit value for engine rotational acceleration based on a difference between the operated amount and the minimum value in the shift process. In the shift process, the shift controller limits the rotational acceleration to the upper limit value or lower by limiting a shift rate when the transmission is downshifted.

Abstract: A shift control apparatus (80) for a vehicle (10; 100) provided with a drive power source (39; MG), and a step-variable transmission portion (20; 110) including a plurality of hydraulically operated coupling devices (CB), the shift control apparatus controlling the step-variable transmission portion to implement a shifting action with an engaging action of the engaging-side coupling device and a releasing action of the releasing-side coupling device, and including a shift control portion (82) to control a shift-down action of the step-variable transmission portion in a predetermined mode of hydraulic control of the engaging-side and releasing-side coupling devices, wherein the shift control portion controls the engaging-side and releasing-side coupling devices in a non-vehicle-driving control mode during the shift-down action of the step-variable transmission portion in a non-driving state of the vehicle, the shift control portion switching the mode of hydraulic control from the non-vehicle-driving control mo

Abstract: The present invention relates to a control device and a control method for a vehicle in which a lockup clutch is disengaged when a rotation speed of an engine falls below a disengagement rotation speed. The device/method changes a speed ratio of a variator on the basis of a shifting map in which a primary pulley rotation speed on a coast line is set higher than a primary pulley rotation speed on a drive line and sets a target input rotation speed of the variator to a predetermined target input rotation speed higher than the primary pulley rotation speed on the drive line when an operation of an accelerator pedal is performed such that an accelerator pedal opening falls to a first predetermined opening or less. As a result, the present invention can suppress drop of fuel efficiency of the engine caused by disengagement of the lockup clutch which is a friction engagement element.

Abstract: A multi-speed automatic transmission having a control circuit for managing a hill climb event is provided. The control circuit may detect the hill climb event, such as by identifying when an upshift from a climb gear to an upshift gear would cause deceleration on a hill. The control circuit may also respond to the hill climb event based on desired performance characteristics, including fuel economy, speed, acceleration, and other performance characteristics. In one embodiment, the control circuit responds to the hill climb event by cycling the multi-speed automatic transmission between the climb gear and the upshift gear.

Abstract: A vehicle includes an accelerator pedal moveable across a plurality of predefined positions and a controller programmed to, responsive to the pedal reaching a tip-in position, command a downshift to a downshift gear from an initial gear. A difference between the initial and downshift gears exceeds a number of predefined positions crossed upon moving to the tip-in position when a rate of change of pedal position exceeds a predefined threshold.

Abstract: A control method of a vehicle includes summing weight values according to shift types through a controller during kickdown shifts of the vehicle, calculating a control constant based on the acquired sum of the weight values and the number of times of kickdown shifting through the controller, after summing of the weight values, and adjusting at least one of a shift pattern and an engine RPM based on the calculated control constant through the controller, after the calculation of the control constant.

Abstract: A method includes: controlling a production of torque by an engine of a vehicle such that a first torque is produced in an nth gear prior to a downshift determined according to a gear shifting pattern of the vehicle, wherein the first torque is 100% of the engine's available torque at a given accelerator pedal position and a given engine revolutions per minute (RPM); calculating a second torque which causes a predefined increase in engine power output based on a first engine power output occurring as the engine produces the first torque at the given accelerator pedal position and the given RPM; and controlling the production of torque by the engine such that the second torque is produced in an (n?1)th gear after the downshift.

Abstract: A vehicle includes an engine, dual-clutch transmission (DCT), and controller. The controller executes a method to detect a requested power-on downshift of the DCT from an attained gear to a desired gear. Offgoing and oncoming clutches are identified for the power-on downshift from the input clutches, and the controller determines whether engine speed has reached a target synchronous speed. The controller increases oncoming clutch torque at a calibrated ramp rate when a fork for the desired gear has engaged and releases the offgoing clutch at another calibrated ramp rate. If engine flare is present, the controller adjusts the oncoming clutch ramp rate, uses engine torque management to control the flare, and allows the offgoing clutch to continue disengaging. The power-on downshift is completed when the oncoming clutch reaches full torque capacity of the engine and the offgoing clutch is completely exhausted.

Abstract: An inverter converts input DC power into AC power and supplies the AC power to a motor generator. An inverter control unit executes shutdown control for stopping power conversion by the inverter, when operation of the motor generator is not requested. A transmission control unit controls the transmission. When a state quantity related to a rotation speed of the motor generator increases to a prescribed quantity during execution of the shutdown control, the inverter control unit continues the shutdown control and the transmission control unit executes shift control for controlling the transmission to reduce the rotation speed of the motor generator.

Abstract: An actuating device for performing gearshifts in a transmission and for switching functional elements includes substantially two control levers which are connected to, and arranged so as to rotate conjointly with, the steering wheel. One control lever is designed as a so-called gearshift paddle and is arranged above a further control lever for the functional elements. The lower control lever is designed so as to be movable relative to the upper gearshift paddle control lever.

Abstract: A control apparatus for an automatic transmission including three frictional engagement elements is configured to set engagement pressures of first and second frictional engagement elements at the time when a predetermined shift speed is established such that a torque capacity of a third frictional engagement element becomes smaller than torque capacities of the first and second frictional engagement elements in the case where an engagement pressure is generated in the third frictional engagement element at the time when the predetermined shift speed is established.

Abstract: A method of controlling a transmission includes detecting an occurrence of a downshift in the transmission from a first gear ratio to a second gear ratio. A determination is made whether the vehicle is operating within a freeway speed range, and whether an accelerator pedal is depressed at least a minimum percentage of a fully depressed position. When the downshift from the high gear ratio to the low gear ratio is detected, the vehicle is operating within the freeway speed range, and the accelerator pedal is depressed at least the minimum percentage of the fully depressed position, a countdown timer is started to count down from a pre-defined time to zero. An upshift of the transmission from the second gear ratio to the first gear ratio is restricted while the countdown timer defines a time that is greater than zero.

Abstract: A vehicle includes an internal combustion engine, an engine control module (ECM) programmed to estimate engine torque as a function of throttle request, and a transmission assembly. The transmission assembly includes a plurality of gear sets and clutches, including an offgoing clutch and an oncoming clutch for a power downshift, and a transmission control module (TCM). The TCM includes a processor and memory on which is recorded a shift line for the downshift, and instructions for executing the downshift. The TCM communicates an estimated throttle level at the shift line to the ECM, receives an estimated engine torque for the estimated throttle level at the shift line from the ECM, and decreases offgoing pressure to the offgoing clutch to a threshold pressure level prior to executing the downshift. The TCM then decreases the offgoing clutch pressure to a calibrated pressure at the shift line to execute the downshift.

Abstract: A vehicle driving force control device includes: a brake unit configured to generate a brake force of a vehicle; a stroke amount detecting unit configured to detect a stroke amount of a brake pedal of the vehicle; a monitoring unit configured to monitor whether generation of the brake force of the brake unit is abnormal; and a creep torque controlling unit configured to increase a reduction amount of a creep torque of the vehicle as the stroke amount increases, when the monitoring unit determines that the generation of the brake force in the brake unit is abnormal.

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: An automatic transmission device for a wheel loader includes: a shift mechanism; a work detection device that detects that the wheel loader is performing an excavation work; and a shift control device that executes control so as to downshift a speed stage at the shift mechanism if the work detection device detects that the wheel loader is performing the excavation work.

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 method for controlling a vehicles drivetrain including an engine and automatic transmission, such that transmission ratios are shifted within a range of transmission ratios in a continuous and/or stepped manner as function of preset target speeds that are adjustable via a vehicle speed control and actual vehicle inclinations in relation to the vehicles longitudinal axis. When the actual speed of the vehicle differs from a preset threshold speed, a request to change an actual ratio of the transmission is generated, if it has been determined that the output torque is smaller than a threshold value or an output torque required to adjust the preset threshold speed of the vehicle. The ratio of the transmission is shifted so the torque applied to the output is modified toward the output torque required to adjust the threshold speed.

Abstract: A method for executing a downshift in a transmission includes starting disengagement of a second control element after starting disengagement of a first element. Disengagement of the second element starts before starting engagement of a fourth element. A third element is forced to synchronous speed by beginning engagement of the fourth element before engaging the third element. Engagement of the third and fourth elements is completed at the end of the downshift.

Abstract: An automatic transmission calculates a current thermal load state of the frictional element, predicts (S24, 531), prior to the start of the shift, a heat generation amount of the frictional element during the shift, predicts (S25, S32) a thermal load state of the frictional element upon shift completion on the basis of the current thermal load state and the predicted heat generation amount, and when the predicted thermal load state upon shift completion is inside a predetermined region, either performs (S28, S38) the shift after modifying a shift mode such that the heat generation amount of the frictional element is smaller than that of a case in which the predicted thermal load state upon shift completion is outside the predetermined region, or prohibits (S39) the shift, wherein the predetermined region is set at a different region depending on whether the shift is an upshift or a downshift.

Abstract: An automatic transmission calculates a current thermal load state of the frictional element, predicts (S41), prior to the start of the shift, a heat generation amount of the frictional element during the shift, predicts (S42) a thermal load state of the frictional element upon shift completion on the basis of the current thermal load state of the frictional element and the predicted heat generation amount, determines (S43, S44, S45) whether to permit or prohibit the shift on the basis of the predicted thermal load state upon shift completion, and halts the determination as to whether to permit or prohibit the shift, made on the basis of the predicted thermal load state upon shift completion, when a shift mode of the shift is a second shift mode in which the heat generation amount is smaller than that of a first shift mode.

Abstract: A shift control method and apparatus of an automatic transmission for controlling a shift from one speed, achieved by engagement of a first and a second frictional element, to another speed, achieved by engagement of a third and a fourth frictional element. The method includes detecting a rotation speed of a turbine, detecting a rotation speed of at least one operating member of at least one planetary gear set of the automatic transmission, and controlling the shift according to the rotation speeds of the turbine and the operating member. The control includes overlapping a first shift, from the one speed to an additional speed, with a second shift, from the additional speed to the other speed. The additional speed has a gear ratio that is near a gear ratio of the one speed.

Abstract: A shift control method of an automatic transmission for controlling a shift from an nth speed, achieved by engagement of first and second frictional elements to an (n?3)th speed, achieved by engagement of third and fourth frictional elements. The method includes (a) beginning release control of the first element; (b) beginning release control of the second element after step (a) and after the shift is completed; (e) beginning engagement control of the third element; and (d) beginning engagement control of the fourth element after step (c). An alternative method includes (a) beginning release control of the first element; (b) beginning engagement control of the third element after step (a); (c) beginning actual engagement of the third element; (d) beginning actual release of the first element after step (c); (e) beginning engagement control of the fourth element after step (d); (f) beginning release control of the second element after step (e).

Abstract: An apparatus and method for controlling line pressure of an automatic transmission. A driving information detection unit obtains information. A shift control unit determines if a power-on downshift is requested based on the information of the driving information detection unit, and controls the line pressure based on if the power-on downshift is requested. An actuator forms the line pressure according to a control signal of the shift control unit. A pressure supply control unit controls supply of the line pressure to on-coming and off-going frictional elements of the transmission. The method outputs a first value of a line pressure control duty if the power-on downshift is requested; subsequently outputs a second, lower value of the line pressure control duty if a first shifting is started during outputting of the first value; and subsequently outputs the first value if a turbine speed is greater than or equal to a predetermined speed.

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: The present disclosure is directed toward a method for dissipating power through a machine. The method may include directing power into a power system of the machine. The method may further include controlling a parasitic load of the power system to increase dissipation of the power system, the controlling of the parasitic load being a function of a power dissipation limit of the power system.

Abstract: A method for executing a downshift in a transmission includes starting disengagement of a second control element after starting disengagement of a first element. Disengagement of the second element starts before starting engagement of a fourth element. A third element is forced to synchronous speed by beginning engagement of the fourth element before engaging the third element. Engagement of the third and fourth elements is completed at the end of the downshift.

Abstract: In a shift control device and a shift control method of a vehicular automatic transmission that performs a coast downshift by engagement switch between a release-side engagement element and an element-side engagement element at a time of deceleration of a vehicle, it is determined whether or not there is a driver's intention to decelerate the vehicle during the coast downshift. If an affirmative determination is made regarding the intention to decelerate the vehicle, the rise of engagement pressure of the engagement-side engagement element is stopped so as to cause the coast downshift not to progress. If a negative determination is made regarding the intention to decelerate the vehicle while the rise of the engagement pressure has been stopped, the engagement pressure of the engagement-side engagement element is raised again so as to cause the coast downshift to progress.

Abstract: In performing a down-shift based on a driver's intention of deceleration, an engine output increasing control is started at a time when a transfer torque capacity of the releasing clutch becomes small or zero and the actual oil pressure decreases to an initial oil pressure, not causing an acceleration feeling even upon the engine output increase. For estimating a time when which the real pressure of the releasing clutch decreases to a level of not higher than the initial pressure, the response of the real pressure relative to an oil pressure command value for the releasing clutch is approximated using a transfer characteristic of “first order lag+time delay.” An estimated real oil pressure obtained based on the transfer characteristic is compared with the initial pressure. It is determined a start timing of the engine output increasing control has been reached upon decrease of the estimated pressure to the initial pressure.

Abstract: A control apparatus and control method of an automatic transmission that establishes a plurality of speeds of different speed ratios by selectively engaging and/or releasing a plurality of engagement devices, detects abnormal engagement of at least one of the engagement devices which causes tie-up to occur in the automatic transmission; establishes a predetermined specific speed set in advance in order to prevent tie-up from occurring in the automatic transmission, when abnormal engagement of the at least one of the engagement devices is detected; and places the automatic transmission in a neutral state when an engine speed will exceed a predetermined allowable speed if the predetermined specific speed is established.

Abstract: In performing a down-shift based on a driver's intention of deceleration, an engine output increasing control is started at a time when a transfer torque capacity of the releasing clutch becomes small or zero and the actual oil pressure decreases to an initial oil pressure, not causing an acceleration feeling even upon the engine output increase. For estimating a time when which the real pressure of the releasing clutch decreases to a level of not higher than the initial pressure, the response of the real pressure relative to an oil pressure command value for the releasing clutch is approximated using a transfer characteristic of “first order lag+time delay.” An estimated real oil pressure obtained based on the transfer characteristic is compared with the initial pressure. It is determined a start timing of the engine output increasing control has been reached upon decrease of the estimated pressure to the initial pressure.

Abstract: The present invention provides a method and apparatus for adaptively controlling a closed throttle downshift in an automatic transmission wherein a transmission aberration during a shift is diagnosed and corrected during subsequent closed throttle downshifts. The invention is carried out by monitoring transmission characteristics including input speed, output speed and shift duration during a closed throttle downshift, and identifying departures from acceptable patterns. Each type of departure calls for a particular remedy, and a suitable adjustment is calculated based on the times and/or the commanded pressures at certain times, the adjustment being implemented by changing one or more initial conditions for the next shift of the same type. The adjustments may have to be large to make a full or significant partial correction at the next shift. Conversely small increments may be necessary to avoid over-correction.

Abstract: An automotive automatic transmission control system is provided which is designed to increase the output of an engine in response to a driver's request to downshift a transmission for setting up the engine braking and to load the amount of working fluid to an on-coming clutch quickly during the downshift. The system works to determine whether the loaded amount of working fluid is excessive or lacking using the speeds of an input shaft of the transmission and the engine to correct the amount of working fluid to be used upon a subsequent downshift request. The use of the two speeds enables the fact that the loaded fluid amount is excessive which arises from a rise in the speed of the input shaft caused by the engine output increasing control, not by completion of the loading of the working fluid to the on-coming clutch to be found accurately.

Abstract: A high acceleration time shift control apparatus and method for a vehicle is provided. The high acceleration time shift control apparatus includes a transmission which achieves plural shift speeds whose gear ratios are different from each other; and a high acceleration time upshifting control device which changes a shift speed of the transmission to a higher speed based on a predetermined determination rotational speed such that an input rotational speed of the transmission substantially reaches a target maximum rotational speed when a request for high acceleration is made by a driver.

Abstract: In a shift control apparatus for an automatic transmission, there is provided a target speed change permitting means which; at the time of a dual changeover shift which is a shift from an Nth speed achieved by bringing a first friction element and a second friction element to an engagement state, to an (N-?)th speed achieved by engaging a third friction element and a fourth friction element, and which has at least one intermediate speed, between the Nth speed and the (N-?)th speed, achieved by engaging the second friction element and the third friction element; checks a driver's shift intention again at the time of attainment of the gear ratio corresponding to the intermediate speed, and permits the target speed to be changed to the speed according to the driver's intention when the target speed is different from the (N-?)th speed.

Abstract: In a vehicle in which a moderate throttle opening degree control of maintaining a degree of throttle opening that is less than a degree of throttle opening that corresponds to an accelerator operation is performed for a predetermined period following a beginning of the accelerator operation, if it is determined that a clutch-to-clutch downshift judgment has been made, the reduction of the engaging pressure of a disengage-side friction engagement device is restrained until it is determined that the moderate throttle opening degree control has ended. Therefore, even if the turbine torque is returned to a normal value at the end of the moderate throttle opening degree control, insufficient engaging torque is avoided, and the takeover of engaging torque for the clutch-to-clutch downshift is smoothly performed while the turbine torque is stable. Hence, occurrence of a shock related to the end of the moderate throttle opening degree control is suitably prevented.

Abstract: When a current downshift is determined to be a multiple downshift, it is determined whether or not a torque down during a first downshift is in a condition of interfering with learning performed for stabilizing the downshift operation during a second downshift is executed. If the torque down during the first downshift is determined to be in the condition of interfering with the learning, the learning is prohibited.

Abstract: A downshift control determines whether a commanded downshift is a downshift oriented toward minimum shock or a downshift oriented toward responsiveness, based on inputs from various sensors. The oil pressure on the hydraulic servo which controls the releasing-side friction engagement element is controlled based on the determined downshift type (DT), so that the releasing-side friction engagement element is released in accordance with a selected one of a plurality of release patterns, i.e., release patterns corresponding to different downshift type indexes (Dt). The releasing speed of the releasing-side friction engagement element is changed in accordance with the downshift type. By properly determining the type of downshift, it becomes possible to realize a shift of a type in accordance with the driver's intention.

Abstract: In a vehicle in which a moderate throttle opening degree control of maintaining a degree of throttle opening that is less than a degree of throttle opening that corresponds to an accelerator operation is performed for a predetermined period following a beginning of the accelerator operation, if it is determined that a clutch-to-clutch downshift judgment has been made, the reduction of the engaging pressure of a disengage-side friction engagement device is restrained until it is determined that the moderate throttle opening degree control has ended. Therefore, even if the turbine torque is returned to a normal value at the end of the moderate throttle opening degree control, insufficient engaging torque is avoided, and the takeover of engaging torque for the clutch-to-clutch downshift is smoothly performed while the turbine torque is stable. Hence, occurrence of a shock related to the end of the moderate throttle opening degree control is suitably prevented.

Abstract: At the time of the 6→3 speed shift, an automatic transmission achieves a 6→4→3 speed shift by controlling the servo pressures of four engageable elements. A control apparatus controls the servo pressure of one engageable element in accordance with the servo pressures of other engageable elements. The engagement and release timings are adjusted by determining and controlling the oil pressures of the hydraulic servos, taking into consideration the 6→4 shift state (torque sharing) during a shift transitional period. Therefore, engine blow and prolongation are prevented during the 6→3 shift control.

Abstract: A downshift control determines whether a commanded downshift is a downshift oriented toward minimum shock or a downshift oriented toward responsiveness, based on inputs from various sensors. The oil pressure on the hydraulic servo which controls the releasing-side friction engagement element is controlled based on the determined downshift type (DT), so that the releasing-side friction engagement element is released in accordance with a selected one of a plurality of release patterns, i.e., release patterns corresponding to different downshift type indexes (Dt)). The releasing speed of the releasing-side friction engagement element is changed in accordance with the downshift type. By properly determining the type of downshift, it becomes possible to realize a shift of a type in accordance with the driver's intention.

Abstract: An apparatus for controlling an automatic transmission of an automotive vehicle, which is shifted to a selected one of operating positions by an engaging action of a frictional coupling device, wherein an overshoot engagement control device is provided to shift the automatic transmission to the selected one operating position such that a shifting action of the automatic transmission is initiated while an input speed of the automatic transmission is lower than a synchronizing speed of the selected operating position. The overshoot engagement control device is arranged to control an engaging force of the frictional coupling device such that the input speed is first raised above the synchronizing speed and is then lowered down toward the synchronizing speed.

Abstract: A control unit for an automatic transmission provides improved responsiveness to a speed reduction operation by the driver. The control unit includes a speed reduction requirement judging logic which judges whether or not there is a speed reduction requirement. An up-shift is inhibited and prevented when a judgement is made that there is a speed reduction requirement, based at least in part on release of the accelerator. Accordingly, it is possible to prevent a vehicle from being accidentally accelerated by an up-shift operation and to smoothly perform a down-shift to effect an engine brake.

Abstract: A forced downshift control method for automatic transmissions, wherein, if shift signals of a forced 4-2 downshift are input, a first shift control solenoid valve (SCSV-A) is controlled to OFF; a second shift control solenoid valve SCSV-B is maintained in an OFF state for a predetermined period of time (t1) then controlled to ON; a third shift control solenoid valve (SCSV-C) is continuously maintained in an ON state, then is immediately controlled to OFF and first and second pressure control solenoid valves (PCSV-A) and (PCSV-B) are duty controlled.

Abstract: A method of shifting a transmission having both a hydrostatic portion, including a variable pump (15), and a hydraulic motor (29), and a mechanical transmission (33) portion, including a shift cylinder (37). The method includes relieving the output torque of the motor (29), shifting the mechanical transmission to neutral, and controlling the. displacement of the pump (15) to synchronize motor output speed with the required input speed to the desired gear ratio of the mechanical transmission (33). Then fluid flow to the shift cylinder (37) occurs to shift to the desired gear ratio. The shifting method includes a series of steps in which the feasibility of the prospective shift is determined, and only when the prospective shift can be completed, without detriment to the operation of the vehicle, will the shift be completed. As a result, the shifting between low gear and high gear can occur without bringing the vehicle to a stop each time.

Abstract: At downshifting, hydraulic pressure of hydraulic clutch on engaging side (ON clutch pressure) is increased when an input and output speed ratio ("Gratio") has fallen below a predetermined value YGDNS. YGDNS is variably set depending on the vehicle speed and the engine temperature so that it becomes a lower value at a high vehicle speed than at a low vehicle speed, and a higher value at a low engine temperature than at a high temperature. When a downshifting command to a still lower speed stage is issued during downshifting control (when FTBD=1), a downshifting completion processing is performed in the course of the downshifting control (step in S111). Oil pressure in a hydraulic engaging element on the disengaging side QDNOFF and oil pressure in a hydraulic engaging element on the engaging side QDNON are switched to the oil pressures at the time of completion of downshifting, to thereby complete the first step downshifting control at an early time.

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: In an automatic transmission of the type wherein a stage intermediate between a higher speed stage and a lower speed stage is achieved through a clutch-to-clutch operation, a power-ON skip downshift is executed via the intermediate stage. First, when the skip downshift has been judged, the hydraulic pressure of the clutch (C4) of the higher speed stage is lowered. Next, when the input speed(r.p.m.) of the transmission have reached the synchronous r.p.m. (SS3) of the intermediate stage, the hydraulic pressure (P3) of the clutch (C3) of the intermediate stage is raised and adjusted so that the rise rate of the input r.p.m. may become a specific value d/dt(NT1). When the input r.p.m. have exceeded the synchronous r.p.m. (SS2) of the lower speed stage, the hydraulic pressure of the intermediate-stage clutch (C3) is adjusted so that the input r.p.m. may keep specific r.p.m. higher than the synchronous r.p.m.