Abstract: Calibration and simulation techniques for modeled gear shift events of an automatic transmission of a vehicle comprise obtaining a set of parameters for a modeled gear shift event of the transmission and, based on the set of parameters, modeling forward/aft vehicle acceleration caused by the modeled gear shift event. A shift quality rating system is the utilized to obtain a shift quality rating of the modeled gear shift event based on at least one of the set of parameters and the modeled forward/aft vehicle acceleration. Finally, the techniques determine whether the determined shift quality rating satisfies a shift quality rating threshold and, when the determined shift quality rating fails to satisfy the shift quality rating threshold, a gear ratio gradient for the modeled gear shift event is adjusted and the process is repeated until the determined shift quality rating satisfies the shift quality rating threshold.

Abstract: A hydraulic control apparatus may include a first valve bifurcating hydraulic pressures of two pressure control solenoid valves, a second valve selectively supplying one pressure from the first valve to first chambers of first and second actuators and another hydraulic pressure from the first valve to second chambers of first and second actuators, a third valve bifurcating hydraulic pressure from the first valve, a fourth valve selectively supplying one pressure from the third valve to first chambers of third and fourth actuators and selectively supplying another pressure from the third valve to second chambers of third and fourth actuators, and a fifth valve selectively supplying one pressure from the third valve to a first chamber of a fifth actuator and an exhaust port and selectively supplying another pressure from the third valve to a second chamber of the fifth actuator and the exhaust port.

Abstract: A vehicle includes a transmission and a controller. The transmission has clutches that are configured to establish multiple speed ratios, including a first clutch. The first clutch has a measured drag torque distribution. The measured drag torque distribution has a median and a standard deviation. The controller is programmed to increase a pressure at a rate to engage the first clutch and to increase the rate in response to a measured first clutch torque exceeding the median by a predetermined multiple of the standard deviation.

Abstract: A method of controlling shifts in a multi-speed transmission includes beginning an initial shift, which changes the transmission from a starting gear to an initial target gear, and executing an adjusted shift, which changes the transmission to an adjusted target gear having higher speed ratio than the initial target gear, when transition conditions are satisfied. The transition conditions include a threshold increase in torque request, which is sufficient to require the transmission to be placed into the adjusted target gear. The transition conditions also include a common controlling clutch, which is partially engaged during the initial shift and the adjusted shift and is an off-going clutch to place the transmission in the adjusted target gear. Executing the adjusted shift does not include placing the transmission in a neutral mode. Furthermore, executing the adjusted shift does not include completing the initial shift.

Abstract: An electronic controller for a variable ratio transmission and an electronically controllable variable ratio transmission including a variator or other CVT are described herein. The electronic controller can be configured to receive input signals indicative of parameters associated with an engine coupled to the transmission. The electronic controller can also receive one or more control inputs. The electronic controller can determine an active range and an active variator mode based on the input signals and control inputs. The electronic controller can control a final drive ratio of the variable ratio transmission by controlling one or more electronic solenoids that control the ratios of one or more portions of the variable ratio transmission.

Abstract: A method and a vehicle transmission for selecting a starting gear in a vehicle are provided, the method including steps of measuring a starting gear selection parameter, and selecting a starting gear for the next coming vehicle take-off in dependence of the measured starting gear selection parameter, wherein the starting gear selection parameter is the number of vehicle take offs per time unit. Additionally the parameter can be acceleration in movement of an accelerator pedal being depressed by a driver, accelerator pedal position and clutch wear. Benefits are increased clutch endurance for a vehicle that during at least a period has to perform frequent take-offs and at the same time enhancing take-off comfort for a vehicle that during at least a period goes long-distance.

Abstract: A method of controlling an offgoing clutch in a transmission during a power downshift includes detecting the downshift, reducing a pressure command to the offgoing clutch, and introducing a calibrated error value to a pressure command for the offgoing clutch during the inertia phase. The method also includes synchronizing the speed of the offgoing and an oncoming clutch during the torque phase, determining the offgoing clutch pressure and torque after synchronizing clutch speeds, and then recording a clutch gain as a function of the offgoing clutch pressure and torque. The recorded clutch gains are used to control a subsequent power downshift of the transmission. A controller using proportional-integral-derivative (PID) control logic introduces the error as PID error in a pressure control signal, and controls slip across the offgoing clutch. A transmission is also disclosed having an offgoing clutch and controller configured to execute the above method.

Abstract: A speed changing control apparatus for use in a vehicle includes: a driving power source configured to generate driving power for running; a transmission having a synchromesh mechanism configured to synchronize an input shaft revolution number with an output shaft revolution number and an actuator configured to automatically carry out a shift operation; and an automatic clutch disposed between the driving power source and the transmission. The speed changing control apparatus is configured to start a shift disengaging operation for the transmission after a speed change is requested and before the automatic clutch turns into a decoupled state, so as to suppress torsional vibration at the time of decoupling the automatic clutch. Such control enables the synchromesh mechanism to carry out revolution synchronization with the input shaft revolution number of the transmission in a lowered state, and diminishes a revolution difference subjected to synchronization.

Abstract: A method for adjusting the point of engagement of a friction clutch of a step-variable transmission for a motor vehicle, in particular a friction clutch of a dual clutch transmission. The friction clutch is controllably actuated by means of a clutch actuator and at least one synchronizer shifting clutch is controllably actuated by means of a shift actuator for the engagement and disengagement of a gear ratio of the spur-gear transmission. A set-point of the clutch actuator for the point of engagement of the friction clutch is adjusted as a function of a speed gradient value, which ensues from a transitional state with the friction clutch actuated and the shifting clutch actuated, once the shifting clutch is opened. The transitional state is established by setting the clutch actuator and the shift actuator to a respective transitional value substantially at the same time or, at least in sections, in parallel.

Abstract: A method of controlling an offgoing clutch in a transmission during a power downshift includes detecting the downshift, reducing a pressure command to the offgoing clutch, and introducing a calibrated error value to a pressure command for the offgoing clutch during the inertia phase. The method also includes synchronizing the speed of the offgoing and an oncoming clutch during the torque phase, determining the offgoing clutch pressure and torque after synchronizing clutch speeds, and then recording a clutch gain as a function of the offgoing clutch pressure and torque. The recorded clutch gains are used to control a subsequent power downshift of the transmission. A controller using proportional-integral-derivative (PID) control logic introduces the error as PID error in a pressure control signal, and controls slip across the offgoing clutch. A transmission is also disclosed having an offgoing clutch and controller configured to execute the above method.

Abstract: A method for performing gear shifting by engaging a coupling element with a gear wheel includes moving the coupling element relative to the gear wheel from a disengaged position to an engaged position, in which a particular gear is selected. A speed of the coupling element relative to a speed of the gear wheel is controlled during movement of the coupling element so that a speed difference is maintained until the coupling element reaches the engaged position.

Abstract: A tractor has a control system configured for disengaging the clutch a first time, selecting a first transmission ratio of the change speed gearbox, engaging the clutch a first time to drive the PTO shaft determining the speed of the PTO shaft, disengaging the clutch a second time when the PTO shaft attains a predetermined first speed, selecting a second transmission ratio of the change speed gearbox and engaging the clutch a second time to drive the PTO shaft up to a desired second speed.

Abstract: The present invention provides a control system for a dual clutch automatic transmission having a torque converter. The transmission provides seven forward speeds or gear ratios and reverse. The control system includes a hydraulic pump, a pressure regulator assembly and control valves that provide and release pressurized hydraulic fluid to the torque converter, a pair of input clutches and eight synchronizer clutches. A first pair of control valves are high flow rate valves which are capable of rapidly engaging and disengaging the input clutches. A second pair of high flow rate valves, control valves and spool valves provide a branching control circuit which controls engagement and disengagement of the synchronizer clutches. A control valve linked to the shift lever blocks hydraulic fluid flow to the first pair of high flow rate valves to inhibit input clutch activation when the shift lever is in Park or Neutral.

Abstract: In a stepwise automatic transmission, a mass is concentrated in a longitudinal direction thereof. The stepwise automatic transmission includes an input shaft, an intermediate shaft, an output shaft, a first clutch which is connected and disconnected in accordance with a rotation speed of the input shaft, first and second power transmission mechanisms, and a second clutch which is connected and disconnected in accordance with rotation speed of the intermediate shaft. The intermediate shaft is disposed rearward of the input shaft. When the first clutch is connected, the first power transmission mechanism transmits rotation of the input shaft to the intermediate shaft. The second clutch is provided on the intermediate shaft. When the second clutch is connected, the second power transmission mechanism transmits rotation of the intermediate shaft to the output shaft. A front end of the second clutch is located forward of a rear end of the first clutch as viewed from an axial direction of the input shaft.

Abstract: In a gear shift module for an automatic transmission of a motor vehicle including a series of gear shift elements for example in the form of gear shift forks, which are operated for the shifting of gears, a gear shift module is provided which has a module baseplate forming part of the cylinders of piston-cylinder units and at least part of a housing of a countershaft brake and a central clutch disengager of a starting clutch. These parts can be manufactured jointly providing for lower manufacturing and assembly costs.

Abstract: The hydraulic pressure control apparatus includes an upstream control valve, a downstream control valve, a hydraulic pressure sensor, and a controller. The upstream control valve is provided between a hydraulic pressure source and a hydraulic pressure device. The downstream control valve is disposed between the upstream control valve and the hydraulic pressure device. The hydraulic pressure sensor is configured and arranged to detect the hydraulic pressure on a downstream side of the downstream control valve. The controller is configured to control the upstream control valve and the downstream control valve based on an upstream pressure command value and a downstream pressure command value, respectively. The controller is further configured to detect an abnormality in the upstream control valve based on the hydraulic pressure detected by the hydraulic pressure sensor when the downstream pressure command value is set to be equal to or greater than the upstream pressure command value.

Abstract: A control system is provided for a multiple clutch transmission (10) having at least three synchronizers (74, 76, 78, 80) with opposed acting alpha and beta pressure chambers (106, 104) to selectively synchronize alpha or beta gears with a rotating shaft. The control system includes a pressure source (124), a sump (120), a first multiplex valve (160) having a first position allowing fluid communication of alpha and beta chambers for two synchronizers (74, 76) with the pressure source (122) and diverting alpha and beta pressure chambers (106, 104) of remaining synchronizers (80, 78) to sump (120). The first multiplex valve (160) has a second position reversing the above action. A second multiplex valve (164) connected with the first multiplex valve (160) having a first position connecting alpha and beta chambers (106, 104) of a given synchronizer with the pressure source (122) and alpha and beta chambers (106, 104) of the other synchronizer with the sump (120).

Abstract: The present invention is a transfer case incorporating the use of a single actuator having an input member selectively engagable to a primary output member, an actuator operatively associated with a clutch assembly and a range selector, a first one-way clutch operably associated with the actuator, and a second one-way clutch operably associated with the actuator. When the actuator is actuated in a first direction, the first one-way clutch will activate the range selector to couple the input member and the primary output member to have either of a direct drive ratio, or a reduced gear ratio. When the actuator is actuated in a second direction, the actuator will actuate the second one-way clutch to engage the clutch assembly, transferring rotational force from the primary output member to a secondary output member.

Abstract: Engagement of a clutch is at least partially controlled based upon the difference in rotational speed between the drive side of the clutch and the driven side of the clutch. As the rotational speed difference varies, the approach rate of the drive side and the driven side also varies for at least part of the total distance defined between the drive side and the driven side when the clutch is disengaged.

Abstract: A control apparatus of an automatic transmission having first and second frictional engagement elements that achieve higher and lower speed gear stages respectively, includes a target value determination section setting a rotation speed difference between input and output sides of the frictional engagement element, a total torque capacity calculation section calculating a total torque capacity, a distribution ratio determination section setting a distribution ratio of the total torque capacity to the first and second frictional engagement elements, an individual torque capacity calculation section calculating individual torque capacities respectively required of the first and second frictional engagement elements, and an engagement control section controlling engagement conditions of the first and second frictional engagement elements in accordance with the individual torque capacity.

Abstract: A hydraulic pressure control system for an automatic transmission is comprised of an engagement element engaged when the vehicle runs and a first engagement control actuator controlling the engagement element by supplying the controlled hydraulic pressure to the engagement element when the vehicle starts running. An effective cross sectional area of the engagement element is set at a minimum area which has an engagement capacity capable of transmitting a maximum torque inputted from the engine when the engagement element receives a maximum pressure controlled by the first engagement control actuator.

Abstract: A check valve is installed in a hydraulic line for hydraulic oil to be fed to a forward movement hydraulic clutch, while an accumulator for accumulating some amount of the hydraulic oil fed to the hydraulic clutch is installed between the check valve and the hydraulic clutch. Further installed is a control spool that is operated by the hydraulic oil fed to the forward movement hydraulic clutch and that cooperates with the check valve to hold the hydraulic oil accumulated in the accumulator. According to this arrangement, even if the oil pressure drops momentarily due to a speed gear shift, the pressure for the hydraulic clutch before the gear shift is held by the hydraulic oil accumulated in the accumulator. Thus, a delay in torque restoration due to a slip of the hydraulic clutch can be eliminated, so that an operator can be freed from having a feeling of torque loss or a shock, and a feeling of uneasiness such as a feeling of reversing on an uphill slope, during the gear shift.

Abstract: An apparatus for clutch braking in a multi-speed transmission comprising a prime mover, a transmission system, an output shaft and a torque converter. The transmission comprises a first stage and a second stage wherein the first stage comprises at least two range clutches and the second stage comprises at least two direction clutches. The range and direction clutches are slipped, locked and/or engaged to brake the system.

Abstract: The invention pertains to a motor vehicle with overspeed protector. The clutch in the power train of the motor vehicle can be operated in dependency upon the engine speed in such a way that it is disengaged or operates with slip when the engine speed exceeds a preselected limit while the clutch is engaged. The threshold value of the engine speed is ascertained on the basis of the prevailing (instantaneous) engine speed and the prevailing (instantaneous) or desired increase of transmission ratio. Gear shifting errors and overspeeding of the vehicle are thus prevented in a manner which is more reliable than by following prior proposals.

Abstract: A strategy for overcoming a tooth butt condition includes changing a target closed clutch position over time. When a tooth butt condition exists, a controller selectively closes a clutch to provide limited engagement between the engine and the transmission. A first target closed clutch position is used on the first attempt. If the tooth butt condition is not resolved, the controller then changes the target closed clutch position to provide a different level of engagement between the engine and the transmission. This process is repeated until the tooth butt condition is resolved, a preselected period of time expires, a maximum number of attempts has been completed or the maximum desirable closed clutch position has been used.

Abstract: A strategy for overcoming a tooth butt condition includes changing a target closed clutch position over time. When a tooth butt condition exists, a controller selectively closes a clutch to provide limited engagement between the engine and the transmission. A first target closed clutch position is used on the first attempt. If the tooth butt condition is not resolved, the controller then changes the target closed clutch position to provide a different level of engagement between the engine and the transmission. This process is repeated until the tooth butt condition is resolved, a preselected period of time expires, a maximum number of attempts has been completed or the maximum desirable closed clutch position has been used.

Abstract: An interlock mechanism is provided for a transmission system having a gear unit with a plurality of selectable gear ratios. A manually operated clutch control pedal is manually movable from a clutch engaged position to a clutch disengaged position. The transmission has a pair of shift rails movable to select gear ratios. The shift rails have detent grooves which interact with a pair of detent balls. An interlock member is normally in a lock position wherein the interlock member engages both detent balls and holds them in the detent grooves to prevent movement of either or both shift rails. The interlock member is movable to a release position wherein the interlock member is disengaged from the both detent balls whereby the detent balls will allow one of the shift rails to be moved. An interlock spring is biased to urge the interlock member to the lock position.

Abstract: A control apparatus for controlling a shift operation sets an output Mout from a reference model M(s), which is ideally changed, as a target slip amount of a feedback controller Cpi(s). The controller Cpi(s) controls torque transmitted to an off-going friction engagement element for matching a control slip amount sp with the target slip amount. The characteristics of the controller Cpi(s) is determined for optimally performing a clutch-to-clutch shift operation during a lock-up clutch being engaged. When the lock-up clutch has been disengaged, an input shaft rotation speed is filtered by a notch filter NF for removing a frequency component in a predetermined frequency domain, wherein the control slip amount sp is obtained based upon the filtered input shaft rotation speed.

Abstract: A control apparatus of an automated manual transmission includes an input shaft provided with a plurality of drive gears, an output shaft provided with a plurality of driven gears engaged with the drive gears, and a reverse idler gear engaging with gears for backward movement respectively provided at the input and output sides when a backward moving stage is selected, as a mechanism for backward moving. Further, there is provided with a bypass clutch capable of selectively transmitting or shutting a power of the input shaft to the output shaft. When the backward moving stage is selected (S1), the bypass clutch is engaged (S3) so as to stop a rotation of the input shaft (S4), and thereafter, the reverse idler gear and the backward moving gears are engaged with each other (S5). Thus, a shift operation to a reverse mode can be securely and smoothly executed for a short time.

Abstract: A method for the control of a bi-directional overrunning clutch assembly (10) disposed within a vehicle transmission, including the steps of initiating a drive function control routine (112) within an electronic control unit and sensing the commanded gear ratio within the transmission. The method steps further include determining whether a first gear function (132) should be initiated based on the commanded gear ratio and determining whether a second gear function (150) should be initiated based on the commanded gear ratio. The method also includes sensing whether the reverse engagement members (24B) and the forward engagement members (24A) of the bi-directional clutch (10) are engaged when neither the first gear function (132) nor the second gear function (150) are initiated.

Abstract: A method for the control of a bi-directional overrunning clutch assembly (10) disposed within a vehicle transmission, including the steps of initiating a drive function control routine (112) within an electronic control unit and sensing the commanded gear ratio within the transmission. The method steps further include determining whether a first gear function (132) should be initiated based on the commanded gear ratio and determining whether a second gear function (150) should be initiated based on the commanded gear ratio. The method also includes sensing whether the reverse engagement members (24B) and the forward engagement members (24A) of the bi-directional clutch (10) are engaged when neither the first gear function (132) nor the second gear function (150) are initiated.

Abstract: A check valve is installed in a hydraulic line for hydraulic oil to be fed to a forward movement hydraulic clutch, while an accumulator for accumulating some amount of the hydraulic oil fed to the hydraulic clutch is installed between the check valve and the hydraulic clutch. Further installed is a control spool that is operated by the hydraulic oil fed to the forward movement hydraulic clutch and that cooperates with the check valve to hold the hydraulic oil accumulated in the accumulator. According to this arrangement, even if the oil pressure drops momentarily due to a speed gear shift, the pressure for the hydraulic clutch before the gear shift is held by the hydraulic oil accumulated in the accumulator. Thus, a delay in torque restoration due to a slip of the hydraulic clutch can be eliminated, so that an operator can be freed from having a feeling of torque loss or a shock, and a feeling of uneasiness such as a feeling of reversing on an uphill slope, during the gear shift.

Abstract: A clutch-actuator device is equipped with a position-detecting device for detecting at least one of the different possible positions of engagement, disengagement and partial engagement of a clutch that serves to control the amounts of torque being transmitted between two rotary components of a torque-transmitting mechanism. The position-detecting device performs its detecting function independently of any measurement of the clutch position which may be performed by a displacement-measuring device.

Abstract: A method of regulating the position of a clutch actuator in a vehicle employs the concept of adapting the servo-loop parameters of a position controller of the clutch to different operating conditions of the vehicle, as well as the concept of applying and continuously adapting a bias current of the actuator motor in order to avoid or minimize the incidence of a hunting or after-regulation behavior of the control loop and to thereby minimize the energy consumption of the actuator motor.

Abstract: A semi-automatic transmission comprises an input shaft; a countershaft; constantly meshed gears arranged between the input shaft and the countershaft; and an electrically controlled dog clutch operatively disposed on one the input shaft and the countershaft. The dog clutch is of a type which is free of a synchronizing mechanism and fastens one of the meshed gears to a corresponding one of the input shaft and the countershaft when operated, thereby to establish a given torque transmission path from the input shaft to the countershaft. An electromagnetic multiple disc clutch is employed, which has an input part adapted to be driven by an engine and an output part connected to the input shaft. A control unit is further employed, which controls the dog clutch in accordance with information signals applied thereto.

Abstract: A method and device for a coupling (2) in a motor vehicle, transmission (1) are proposed in which the coupling is controlled and regulated during three operational states via a first regulating circuit (3). The regulated quantity corresponds to the actual value of a differential rotational speed of the coupling (2). The first state corresponds to a starting operation, the second state to the operation with constant ratio and the third state exists when a gear shift under load or a change of ratio from a first to a second ratio step of an automatic transmission (1) is initiated.

Abstract: In a power transmission apparatus for a vehicle having a gear transmission capable of transmitting power from a crankshaft of an engine to driving wheels by selectively establishing a plurality of shift stages of gear trains and a clutch for cutting power transmission from the crankshaft to the gear transmission in operating to shift the power transmission, when the clutch is operated to cut or connect in cooperation with the shift operation of the gear transmission, shift operability is promoted while avoiding an increase in weight. A gear transmission is shifted by a first actuator and a clutch is driven by a second actuator which is independent of the first actuator.

Abstract: An integrated control system for both an electronically-controlled engine and a steplessly variable automatic transmission, comprises a speed-change ratio arithmetic processing section for calculating the speed-change ratio as a ratio of the transmission input speed to the transmission output speed, a target driving torque arithmetic processing section for retrieving a target driving torque, based on both the accelerator operating amount and the vehicle speed, from a first predetermined characteristic map, and a target speed-change ratio arithmetic processing section for retrieving a target speed-change ratio, based on both the accelerator operating amount and the vehicle speed, from a second predetermined characteristic map. Also provided is a target engine output torque arithmetic processing section for calculating a target engine output torque, based on all of the target driving torque, the speed-change ratio, and a speed ratio of the transmission input speed to the engine speed.