Abstract: A method to control a road vehicle for the execution of a multiple downshift in a drivetrain provided with a servo-assisted transmission; the control method comprises the steps of: detecting a condition of slowing down of the road vehicle and, simultaneously, detecting a driver's request for a multiple downshift; carrying out, in succession, a plurality of downshifts while the road vehicle is slowing down and in an autonomous manner regardless of further interventions of the driver; determining a duration of a shift time interval; and carrying out each downshift following a first downshift when said shift time interval has exactly elapsed since the previous downshift.

Abstract: A drive device for a motor vehicle, with a first drive assembly, a second drive assembly, and an auxiliary drive having at least one auxiliary assembly. The auxiliary drive being coupled to or can be coupled to, respectively, the first drive assembly and the second drive assembly via an epicyclic gear transmission. The auxiliary drive is coupled to a first transmission element of the epicyclic gear transmission. In this case, a second transmission element of the epicyclic gear transmission is coupled by a gearshift transmission, which is shifted in a speed-dependent manner, to a secondary drive shaft, which is coupled to or can be coupled to the first drive assembly.

Abstract: A control system of a vehicle includes an engine, a continuously variable transmission, drive wheels, a clutch, and an electronic control unit. The electronic control unit is configured to release the clutch and stop the engine when a predetermined execution condition is satisfied during traveling, such that the vehicle performs coasting. The electronic control unit is configured to keep the continuously variable transmission at a speed ratio established at start of the coasting, during the coasting of the vehicle. The electronic control unit is configured to restart the engine that has been stopped and perform downshift of the continuously variable transmission, when a predetermined return condition is satisfied during the coasting. The electronic control unit is configured to engage the clutch after the downshift is started, such that the vehicle returns from the coasting.

Abstract: A coast stop vehicle, includes an engine, a transmission arranged between the engine and drive wheels and having a plurality of gear positions, a coast stop starting unit which automatically stops the engine when a coast stop start condition holds during travel, a coast stop releasing unit which automatically starts the engine when a coast stop release condition holds during a coast stop, and a downshifting unit which starts engagement of a frictional engagement element, which realizes a lower gear position than the one when the coast stop release condition holds, before complete explosion of the engine and causes a downshift of the transmission when the coast stop release condition holds.

Abstract: A transmission 20 includes an input shaft 12, an output shaft 13, a primary sheave 23 that rotates together with the input shaft 12, a secondary sheave 24 that rotates together with the output shaft 13, and a belt 25 wound around both the primary sheave 23 and the secondary sheave 24. The transmission 20 includes a motor 22 that shifts a transmission ratio by driving a movable sheave 23a of the primary sheave 23. A control device (ECU 5) of the transmission 20 includes a secondary sheave rotation speed sensor 28 that detects rotation of the belt 25, and a control portion 55 of the ECU 5 performs a sheave position control (normal control of the transmission ratio) after rotation of the belt 25 is detected after starting.

Abstract: A transmission shift control system includes a transmission shift control module that executes an upshift or a closed-throttle downshift, a shift stage determination module, and a clutch control module. The stage determination module determines a stage of the upshift or the closed throttle downshift when a downshift is requested. The clutch control module determines a downshift type based on the stage of the upshift or the closed throttle downshift and selectively executes a downshift before the upshift or the closed throttle downshift is completed.

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

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

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

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

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

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

Abstract: The oil supply device for a change-under-load transmission having a high-pressure circuit and a low-pressure circuit is designed in such a manner that the high-pressure feed line to the consumer devices of the transmission system incorporates an inlet aperture of small size, the low-pressure feed line is connected between the inlet aperture and the consumer device, and the low-pressure feed line can be cut off from the high-pressure feed line by a one-way valve.

Abstract: A method and apparatus for controllably shifting into a lower gear of a manual transmission is disclosed. A high downshift speed value is established and stored in a memory. The downshift speed variable of the manual transmission is set equal to the high downshift speed value for a duration time in response to a control signal. The manual transmission is controllably shifted into a lower gear when an engine speed becomes equal to or less than the downshift speed variable.

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: The invention relates to an improved method and arrangement for implementing that method, for obtaining in motor vehicles with mechanical stepped gearboxes with automatic gear changing a gentle and quiet engine adjustment during downshifts in normal operating situations and automatically in operating situations where a need for quicker downshifts requires quicker engine synchronisation. In normal operating situations, downshifts involve using only a limited fuel quantity, preferably corresponding to 20% of full-load fuel quantity, in order to raise the engine speed to the synchronous speed for the next gear, resulting in quieter engine adjustment without the occurrence of obvious disturbance of comfort, risk of losing downshifts or safety disadvantages.

Abstract: This invention relates to a shift control system and method for a vehicle automatic transmission, in which control of a downshift on a downhill road is performed by fuzzy inference. When a vehicle has been determined to be running on a downhill road by a driving state determining device, a speed range setting device sets as an optimal speed range a speed range lower than a current speed range. In the automatic transmission, the state of engagement of a desired engaging element is changed over to achieve the optimal speed range. When the vehicle has been determined to be running on the downhill road by the driving state determining device so that the speed range lower than the current speed range has been set as the optimal speed range and also when no change has been determined in engine load by an engine load detecting device, an engagement state control device reduces engaging force to be produced upon changing over the state of engagement of a desired engaging element for achieving the optimal speed range.

Abstract: The present invention is directed to a hydraulic pressure control system of an automatic transmission for a vehicle includes a damper clutch control part for controlling a damper clutch to increase power train efficiency, a pressure regulating part for regulating line pressure generated from a hydraulic pump, and a shift control part for selectively supplying hydraulic pressure regulated at the pressure regulating part to friction members for applying more than one of the friction members in accordance with each speed ratio.