Abstract: A power Off upshift control method for an automatic transmission includes the steps of: a) determining if a vehicle is under conditions requiring power Off upshift control; b) starting power Off upshift duty control if the conditions are satisfied; c) calculating average turbine rpm change rate; d) measuring turbine rpm changing period and determining if the turbine rpm changing period is greater than a predetermined value; e) calculating a shift finish point if the turbine rpm changing period is greater than the predetermined value; f) determining if the turbine rpm change rate is less than a value obtained by adding a mapping value to the turbine rpm change rate; g) determining if the turbine rpm value is greater than or equal to the shift finish point, if the turbine rpm change rate is greater than the mapped value in the previous step; h) producing a shift finish point duty rate if the turbine rpm value is greater than or equal to the shift finish point; i) determining if the turbine rpm is less than a ta

Abstract: A speed change mechanism (1) constructed by connecting in tandem a hydraulic type speed change unit (17) having a plurality of hydraulic clutches (57, 58, 59) to be alternatively engaged and a hydraulic type speed change unit (20) having a plurality of hydraulic clutches (66, 67, 68) to be alternatively engaged, wherein a time-varying region (common slip region) is secured in which the two clutches slip in common such that during speed change, when the working hydraulic pressure in a clutch to be engaged is on its way to gradual increase, the working hydraulic pressure in a clutch to be disengaged lowers. This common slip region is made smaller during shift-down than during shift-up by a change in time-difference between the pressure increase start time for the clutch to be engaged and the pressure decrease start time for the clutch to be disengaged or by a change in the pressure decrease property of the clutch to be disengaged.

Abstract: When a reshift request for a second shift to a second gear ratio is produced during a first shift operation to a first gear ratio in an automatic transmission, a reshift control apparatus performs a reshift operation in response to the reshift request in a first reshift control mode by terminating the first shift operation at an intermediate state without completing the first shift operation, and instead initiating the second shift operation from an intermediate state.

Abstract: A shift control apparatus that advances activation of an engagement element to be engaged during a shift requiring engagement and release of four engagement elements, thereby reducing the shift time. The automatic transmission achieves a sixth-to-fourth-to-third shift by controlling servo pressures for the four engagement elements. The control apparatus starts, during the time of the sixth-to-third shift, supply of the hydraulic pressure for activating the engagement element to be engaged at the time of the fourth-to-third shift, thereby advancing the establishment of the engagement stand-by state at the time of the fourth-to-third shift. Accordingly, the reduction in the servo pressure of the engagement element to be released at the time of the fourth-to-third shift can be advanced, thereby reducing the time for the sixth-to-third shift.

Abstract: In a process wherein a before-shifting gear ratio Gx changes to a gear ratio of the target gear position, an actual shift time is measured by regarding as a shift starting point an earlier one between a time point when the present gear ratio G has repeated decreasing by a value equal to or larger than a predetermined unit gear ratio &Dgr;G a predetermined number of times N and a time point when the present gear ratio reaches a first gear ratio G1 that is set to a value smaller than the gear ratio Gx by a predetermined value. If the gear ratio changes rapidly, the start of shifting can be detected at a time tsl when the present gear ratio G reaches the gear ratio G1, and if the gear ratio changes slowly, the start of shifting can be detected at a time ts4 when the gear ratio has repeated decreasing by a value equal to or larger than a predetermined unit gear ratio a predetermined number of times N.

Abstract: An automatic transmission includes a low reverse brake and a reverse clutch that are engaged at different timings to determine a selected gear position, the reverse clutch being engaged immediately before the low reverse brake to be engaged last. It is determined whether or not a piston for actuating the reverse clutch has completed its stroke up to the position where it can start actual engagement. Before determination that the piston of the reverse clutch has completed its stroke up to the position where it can start actual engagement, it is prevented to determine whether or not a piston for actuating the low reverse brake has completed its stroke up to the position where it can start actual engagement.

Abstract: In a constitution that a transmission torque capacities of friction engagement elements are determined based on an input shaft torque of a speed change mechanism and a torque sharing ratio, a change velocity of the torque sharing ratio of when the transmission torque capacity of a release side friction engagement element is changed from a value greater than a critical transmission torque capacity to a value smaller than the critical transmission torque capacity, is abruptly altered when the input shaft torque is equal to or less than predetermined value.

Abstract: A control system for executing an upshift from an off-going speed ratio to an on-coming speed ratio by controlling the release of the hydraulic pressure from the frictionally engaging element used for the off-going speed ratio and by controlling the supply of the hydraulic pressure to the frictionally engaging element used for the on-coming speed ratio comprises first and second off-going pressure releasing valves 70 and 80, which release the hydraulic pressure of the frictionally engaging element used for the off-going speed ratio, and a linear solenoid valve 60, which controls the operation of the off-going pressure releasing valves. The linear solenoid valve 60 controls the operation of the off-going pressure releasing valves in correspondence to the throttle opening of the engine. In this case, the smaller the throttle opening of the engine, the earlier the timing for releasing the hydraulic pressure from the frictionally engaging element used for the off-going speed ratio is set.

Abstract: In a control unit of an automotive vehicle, it is possible to securely prevent a tie-up due to a miss-recognition of a disengage timing of a disengage side friction device, securely prevent an early disengage due to an erroneous recognition of the disengage timing and realize a control of accurately and reliably shifting the clutch.

Abstract: A hydraulic control device for an automatic transmission capable of preventing engine racing and tie-up by controlling disengagement side oil pressure in accordance with an input torque and an oil temperature. Gear-change execution controller U4 controls drain timings T1 and T3 and a drain gradient &dgr;P of the disengagement side oil pressure acting on the frictional engagement elements of the disengagement side according to the magnitude of the input torque and elevation of the oil temperature in torque phase control wherein both the engagement side oil pressure and the disengagement side oil pressure are controlled.

Abstract: During an upshift in a full-throttle state, the output of a shift command (Us1) from a control unit is followed by a delay in initiation of an actual shift, due to a delay in increase in oil pressure, a rise in the clutch torque load, etc. A shift initiation (Uj) is determined by comparing the input rotational speed (Ni) with the product of multiplication of the output rotational speed (vehicle speed) (No) by the pre-shift gear ratio. The shift point (Mp1) is learning-corrected based on the shift initiation-time engine rotational speed (NeI). Therefore, false learning is avoided even if the engine races during a shift.

Abstract: A method for controlling an automatic transmission in a drive train of a motor vehicle having a transmission controller selecting and shifting gears of the transmission includes determining a new gear by reference to gear shift characteristic curves and generating a gear shift instruction as soon as a working point of the drive train exceeds a gear shift characteristic curve. The transmission controller determines a new gear that is expected to be engaged shortly. If the new gear differs from the current gear, an initial phase of the gear shift is carried out and the gear shift is completed as soon as the gear shift instruction has been generated. The initial phase is carried out as soon as the working point drops below a predefined distance from the gear shift characteristic curve.

Abstract: An apparatus and method for controlling a plurality of clutches in a powershift transmission. The transmission is coupled to an engine of an off-road vehicle. The method includes receiving a shift command having a shift direction. Clutch timing is selected based on the shift direction. Using the selected shift timing, on-coming clutches are engaged in sequence with disengagement of off-going clutches to achieve smooth shifting.

Abstract: An automatic transmission ratio shift control system and method for a powertrain having a throttle-controlled engine and multiple-ratio gearing, torque flow paths through the gearing being established and disestablished by pressure-operated friction elements, an electronic controller for establishing torque transitions between the friction elements as ratio changes occur in the multiple-ratio gearing, the engine throttle being controlled by an electronic throttle control that is decoupled from the driver-controlled accelerator pedal, the transmission torque output being controlled by means of a friction element capacity control strategy including a feed-forward torque term determined by changes in commanded torque, the slip duration during a ratio change being controlled by means of closed-loop engine torque control.

Abstract: A method of controlling, in response to a shift command, a commanded shift of a powershift transmission of an engine-driven vehicle includes monitoring speeds transmission component selected according to the commanded shift and monitoring a speed ratio therefrom. If the input section will speed up during the commanded shift, the speed clutches are swapped, and then the output clutches are swapped when the monitored speed ratio matches a stored speed ratio. Also, the input speed of an input shaft of the transmission is monitored, and the pressure of the off-going output clutch is controlled to limit the deceleration of the input shaft speed to desired limits. If the input section will slow down during the commanded shift, the output clutches are swapped, and then the speed clutches are swapped when a monitored speed ratio matches a stored speed ratio. If a particular shift requires swapping of only speed clutches, then a speed ratio is monitored for the pair of the speed clutches to be swapped.

Abstract: A control apparatus and a control method for an automatic transmission, improved over those devised to minimize torque fluctuations which, if left unchecked, give vehicle passengers a disagreeable feeling upon a gear shift. The inventive control apparatus and method, aimed at suppressing such torque fluctuations during a shift of the transmission thereby to improve robustness and provide good shift characteristics, involve recognizing an inertia phase in which the engine speed starts to drop during the shift. At the beginning of the inertia phase, hydraulic pressures supplied to frictional engaging devices in the transmission are kept constant to suppress the torque fluctuations.

Abstract: An apparatus for controlling a vehicle automatic transmission, wherein a moment at which the supply of a pressurized fluid to a hydraulic cylinder for engagement of a frictional coupling device to effect an upshift of the transmission during running of the vehicle in a power-off state is initiated is determined by comparing an estimated synchronizing time required for the transmission input speed to reach a synchronizing speed of a higher-gear position to which the transmission is shifted, with a stored predetermined stroking time required for the piston of the hydraulic cylinder to reach its engaging stroke end.

Abstract: Described is a method for the control of a transmission of a motor vehicle, especially an automatic transmission, with hydraulically activated shifting elements. The shifting elements are shifted to engage or disengage by means of specified pressure pattern (pkab, pkzu) which have been input into an electronic control unit. In the said method, an applied pressure (pkab) on a disengaged shifting element, by the release of a force flow generated by a holding pressure (pkab-h), is reduced to a shift pressure (pkab-sd) and a transmission input speed of rotation (nt) experiences a change dependent upon the applied pressure (pkab) on a disengaged shifting element.

Abstract: Described is a method for controlling a transmission of a motor vehicle, especially of an automatic transmission or of an automated manual mechanical transmission. The transmission has hydraulically actuatable shifting elements which, during gear shifts, are engaged or disengaged via pressure curves (p_kzu, p_kab) stored in an electronic control unit. For one gear shift are carried out at least one adaptation of the pressure curves (p_kzu, p_kab) of the shifting elements for compensation of tolerances of components and alternative to this one adaptation for compensation of influences determinant of shifting quality for different shifting strategies and/or shifting kinds, the filling parameters of the engaging shifting elements being determined during the gear shift itself or by preset test pressure curves outside the gear shift.

Abstract: An improved control for an automatic transmission upshift, wherein the engine output torque and on-coming clutch pressure are coordinated during the shift based on an inverse dynamic model of the transmission to achieve a desired output torque trajectory. The desired output torque trajectory is influenced by operator demand, and an initial value of the desired output torque trajectory is used along with the engine output torque to develop an input acceleration trajectory. The inverse dynamic model of the transmission is used (1) to determine an engine torque command that will achieve both the input acceleration trajectory and the desired output torque trajectory, and (2) to determine a feed-forward pressure command for the on-coming clutch that will produce the input acceleration trajectory, given the engine torque command.

Abstract: An improved control for an automatic transmission closed-throttle downshift, wherein closed-throttle engine torque is used to raise the transmission input speed to the synchronous speed of the target speed ratio, and wherein the on-coming clutch is controlled in a manner to complete the shift with minimum driveline torque disturbance in spite of clutch control variability. The invention includes a primary on-coming clutch control for completing the downshift when the input speed reaches the synchronous speed, and a contingent on-coming clutch control that is initiated if shift completion is not achieved by the primary control, the contingent control being effective to re-establish input speed synchronization and thereupon engage the on-coming clutch to complete the shift.

Abstract: When a reshift request for a second shift to a second gear ratio is produced during a first shift operation to a first gear ratio in an automatic transmission, a reshift control apparatus performs a reshift operation in response to the reshift request in a first reshift control mode by terminating the first shift operation at an intermediate state without completing the first shift operation, and instead initiating the second shift operation from an intermediate state.

Abstract: An improved control for an automatic transmission garage shift, wherein a dynamic model of the transmission is used to estimate the transmission input torque during the shift and to schedule the on-coming clutch pressure in accordance with the estimated input torque to achieve a desired input shaft trajectory. The transmission input torque is estimated based on two different methodologies —one suited to steady-state engine idle conditions, and the other suited to engine output torque transient conditions. A fuzzy summation of the input torques provided by the two methodologies is utilized in transitions between the two conditions. Shift quality variations due to variations in mechanical and/or hydraulic stiffness are minimized by a pause or hold interval inserted between the end of the fill period and the initiation of on-coming clutch pressure control, which results in a reasonably consistent degree of perceived transmission-to-transmission hydraulic and mechanical compliance.

Abstract: When a contradictory event in which raising of the engine rotation speed is detected and the inertia phase start time is early occurs (8), a learn correction is made to engagement hydraulic pressure (ON side). If the raising of the engine rotation speed cannot be canceled still after the learn correction is made, release hydraulic pressure (OFF side) is increased for correction.

Abstract: A shift control apparatus comprises clutches driven by shift solenoids and whether or not the raising of the rotation speed occurs in an internal combustion engine is determined. If the raising of the engine rotation speed is detected, a hydraulic pressure learn correction is made to engagement hydraulic pressure and a time learn correction is made to the hydraulic pressure supply preparation time. The correction ratio of the energization-hydraulic pressure characteristic (I-P characteristic) of clutch clearance and the shift solenoid is set so as to become an appropriate distribution ratio and the learning is started based thereon.

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: In a control unit of an automotive vehicle, it is possible to securely prevent a tie-up due to a miss-recognition of a disengage timing of a disengage side friction device, securely prevent an early disengage due to an erroneous recognition of the disengage timing and realize a control of accurately and reliably shifting the clutch.

Abstract: With a specific shift pattern, a chronological aging of a clutch used in a friction engagement is judged and an obtained judgement result is reflected to other shifts to which the clutch contributes. A control apparatus for an automatic transmission and a control method for an automatic transmission are provided so that even when the clutch used in the friction engagement is presented with chronological aging, in all shift operations, a good shift characteristic can be obtained.

Abstract: An improved control for an automatic transmission upshift, wherein the on-coming clutch pressure (Ponc) is scheduled during the torque and inertia phases of the shift in accordance with the summation of feed-forward and feed-back control terms, the feed-forward control term being developed using an inverse dynamic model of the transmission. The feed-forward control term is determined by developing a desired acceleration trajectory of the input shaft, and periodically applying the acceleration trajectory to the inverse dynamic model to obtain an estimate of the required on-coming clutch pressure, given the transmission input torque. The feed-back control term is based on a comparison of the expected input speed response with the actual input speed response, and corrects for modeling errors in the feed-forward control, providing disturbance rejection and improved command following.

Abstract: An improved transmission upshift control in which the off-going clutch is controlled to emulate the behavior of an ideal free-wheel device to thereby achieve nearly ideal timing of the off-going clutch disengagement relative to the on-coming clutch engagement. During the preparation phase of the shift, the off-going pressure is reduced in proportion to the estimated volume of fluid supplied to the on-coming clutch such that the off-going pressure is at a calibrated value when the on-coming clutch is filled. However, the calibrated value is adjusted upward in direct relation to the transmission input torque above a given level so as to emulate the reaction torque that would be exerted by an ideal free-wheel device for maintaining the current speed ratio. The torque phase of the control commences when the estimated volume indicates that the on-coming clutch is completely filled.

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

Abstract: An automatic control strategy for use with a multiple-ratio transmission in an automotive vehicle driveline in which the crankshaft of an internal combustion engine is connected directly to torque input elements of multiple-ratio gearing without an intervening hydrokinetic torque converter. The strategy is adapted especially for use with a wet auto clutch to provide forward or reverse drive engagement during vehicle launch and during transient damping of driveline disturbances. The strategy makes it possible to control the clutches to achieve maximum vehicle acceleration by controlling the engine speed so that it operates at maximum torque throughout the useful engine speed range for any given engine throttle position. The entry and exit conditions for each drive mode are determined by the strategy so that optimum drive-away performance and optimum shift control, as well as soft clutch engagement and full clutch engagement, can be achieved.

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: In a constitution that a transmission torque capacities of friction engagement elements are determined based on an input shaft torque of a speed change mechanism and a torque sharing ratio, a change velocity of the torque sharing ratio of when the transmission torque capacity of a release side friction engagement element is changed from a value greater than a critical transmission torque capacity to a value smaller than the critical transmission torque capacity, is abruptly altered when the input shaft torque is equal to or less than a predetermined value.

Abstract: A shift control system executing a shift of an automatic transmission with a manual shift mode from a first speed position to a second speed position. A controller of the shift control system controls a first valve for varying a pressure applied to a first friction element and a second valve for varying a pressure applied to a second friction element. The controller delays an operation of the second valve as compared with an operation of the first valve when a transmission oil temperature is lower than a predetermined temperature.

Abstract: An automatic transmission comprises a friction engaging means having a plurality of first plates spline-fitted to a hub and a plurality of second plates spline-fitted to a drum and disposed in an interleaving relation to the first plates, an one-way clutch provided in the hub and having a plurality of sprags for locking the rotation of the hub when the hub rotates in a locking direction and a control means for temporarily releasing the friction engaging means for a specified timespan when the friction engaging means is in an engagement condition and when the hub rotates in a locking direction.

Abstract: Quick shifting is achieved while preventing a shift shock when shifting is caused by grip change of four engagement elements. The automatic transmission requires activation of the four engagement elements when shifting from a first shifting position (sixth speed) to a second shifting position (third speed) is performed. This shifting control apparatus includes shift control means for starting disengagement of a second engagement element after starting disengagement of a first engagement element; completing engagement of a fourth engagement element after completing engagement of a third engagement element; and starting disengagement of the second engagement element before completing engagement of the third engagement element.

Abstract: To relatively precisely detect the start of torque phase for relatively precisely restraining speed shift shock caused by torque interference in clutch to clutch speed shift, an output from an input shaft rotational speed sensor at a reduction gear unit is passed through a secondary Butterworth high pass filter which is a digital filter having a cutoff frequency of 1.0 Hz to remove a change component caused by acceleration of the vehicle. A filter output Ni_fil which is a change component by generation of transmission torque of an engaged side clutch is thus provided. When this filter output Ni_fil falls to less than a first threshold value of −ref1 and thereafter becomes less than a second threshold value of −ref2 without recovering to be equal to or higher than the first threshold value of −ref1, it is determined to be the start of the torque phase.

Abstract: A power Off upshift control method for an automatic transmission includes the steps of: a) determining if a vehicle is under conditions requiring power Off upshift control; b) starting power Off upshift duty control if the conditions are satisfied; c) calculating average turbine rpm change rate; d) measuring turbine rpm changing period and determining if the turbine rpm changing period is greater than a predetermined value; e) calculating a shift finish point if the turbine rpm changing period is greater than the predetermined value; f) determining if the turbine rpm change rate is less than a value obtained by adding a mapping value to the turbine rpm change rate; g) determining if the turbine rpm value is greater than or equal to the shift finish point, if the turbine rpm change rate is greater than the mapped value in the previous step; h) producing a shift finish point duty rate if the turbine rpm value is greater than or equal to the shift finish point; i) determining if the turbine rpm is less than a ta

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

Abstract: A drive line assembly for a work machine is disclosed. The drive line assembly includes an engine driving an engine output shaft and an engine speed sensor which generates engine speed signals indicative of a speed of the engine output shaft. The drive line assembly further includes a fuel injector operable to regulate fuel flow to the engine and a transmission driven by the engine output shaft and having a first on-coming clutch. The drive line assembly yet further includes a controller operable to determine the engine speed from the engine speed signals and determine the fuel flow through the fuel injector. The controller is further operable to determine an engine load based on the fuel flow and a predetermined maximum fuel flow for the engine at the engine speed and control engagement of the first on-coming clutch based on the engine load. A method for controlling a drive line assembly is also disclosed.

Abstract: Disclosed is a shift control method for automatic transmissions.

Abstract: A torque-based clutch engagement controller for achieving smooth friction clutch engagement in a multiple-ratio transmission for an automotive vehicle driveline comprising a torque measuring circuit that determines torque inputs for the controller as a function of measured engine torque and turbine acceleration, means for determining the torque commanded by the vehicle operator as a function of engine throttle position, means for comparing the desired torque commanded by the operator to the input torque values, and means for converting the torque values to a pressure value as a function of the difference between the desired torque and the input torque whereby the pressure developed by the system applies a friction clutch so that engagement of the clutch occurs rapidly with optimum smoothness.

Abstract: A method for controlling the fill time of an oncoming transmission clutch of a vehicle within a predetermined range of speed conditions is disclosed, the method including the steps of: (a) sensing an engine speed within the predetermined range; (b) reading an incremental pulse time value corresponding to the speed sensed in step (a); and (c) determining an adjusted pulse time value using the incremental pulse value read in step (b) and a predetermined nominal pulse time value.

Abstract: Control apparatus having improved characteristics at an early stage of changing the gear position which make it possible to clearly discriminate the change in the transmission input shaft revolution speed caused by a rise in the engine torque by depressing the accelerator pedal from changes attending on the disengagement of the disengaging side clutch. For the above purpose, the control apparatus adopts a configuration capable of correcting the oil pressure acting on the friction coupling device by an arrangement that the transmission output shaft revolution ratio, obtained from the transmission output shaft revolution speed and the transmission input shaft revolution speed, follows up the target value of the revolution ratio after a speed change signal is issued.

Abstract: In a control unit of an automotive vehicle, it is possible to securely prevent a tie-up due to a miss-recognition of a disengage timing of a disengage side friction device, securely prevent an early disengage due to an erroneous recognition of the disengage timing and realize a control of accurately and reliably shifting the clutch.

Abstract: An automatic transmission control system controls locking pressure for locking a specific friction coupling element to a target level previously determined according to engine output torque and appropriately changes the target level such that, when an increase in engine output torque occurs, a delay of a locking pressure change relative to an engine output torque change becomes greater after the target level has reached near an appropriate level than before it has reached near the appropriate level.

Abstract: The present invention provides a method for shifting from a first gear state to a second gear state which holds one element at a predetermined level until the second reaches its fill volume. In this method, one element is applied while the other element is released. The element which reaches its fill volume first is held at a control limit. This control limit is defined by a volume between the first clutch element and a predetermined point above the fill volume of the first clutch element. This clutch element is then maintained at within the control limit until the other clutch element reaches its fill volume. The maintained clutch element is then released shortly after the other clutch element has reached its fill volume. This method ensures that neither fighting or slipping occurs between the two elements.

Abstract: A throttle controller is provided so as to reduce a load imposed on the drive and transmission system in the stall state in which both the accelerator and brake are depressed.

Abstract: By determining the abrasion of a gear clutch during the operation of a construction machine and ascertaining the present abrasion state, it is possible to systematically predict the replacement time of a clutch disc and also to ascertain the presence of an abnormally worn clutch disc.