Abstract: A shift control system of an automatic transmission controls operating forces on frictional engaging elements being engaged and disengaged with gear elements during a shift operation by generating a target transmission variable which prevents a rate of change of a corresponding target input rotational speed from inverting at the start of the shift operation and/or at the end of the shift operation. The target transmission variable may be the target input rotational speed, a target gear ratio, or other variable corresponding to a target input rotational speed which has a rate of change gradually changing at the start and end of the shift operation so as to avoid any inversion of the rate of change within a predetermined duration after the start of the shift operation and within a predetermined duration before the end of the shift operation.

Abstract: In order to prevent an increase in engine noise during a kick-down, a timer is set concurrently with a downshifting. When the throttle opening degree becomes equal to or larger than a threshold value YTHNST by a rapid depression of an accelerator pedal before lapse of a predetermined time, a lock-up clutch of a torque converter is brought into an engaged state, thereby preventing a revolution speed of an engine from rising rapidly in order to alleviate the engine noise. After the throttle opening degree TH becomes smaller than the threshold value YTHNST and the engagement of the lock-up clutch is released, the lock-up clutch is not brought into the engaged state even if the throttle opening degree TH again becomes equal to or larger than the threshold value YTHNST. Also, when the throttle opening degree TH becomes equal to or larger than the threshold value YTHNST after lapse of the predetermined time, the lock-up clutch is not brought into the engaged state.

Abstract: A control system and method for a semi-automatic mechanical transmission system (10) is provided for sensing rolling start conditions (OS>REF, GR=N, (CLUTCH MANUAL DISENGAGED=TRUE)) and upon sensing such conditions, allowing operator request for a direct shift into an appropriate rolling start gear ratio (GR.sub.RS) determined as a function of current and/or expected output shaft speed (GR.sub.RS .gtoreq.ES.sub.IDLE /OS).

Abstract: A control system for control of a clutch interposed between a fluid transmission unit and a speed change unit in a vehicular automatic transmission. The control system includes a first R.P.M. detector for detecting clutch input side R.P.M. and a second R.P.M. detector for detecting clutch output side R.P.M. A stop state detector determines if the vehicle is at a standstill and a starting operation detector detects a starting operation by the driver.

Abstract: A control is provided for controlling reengagement of a master clutch (16) in a vehicular automated mechanical transmission system. A nominal reengagement rate (CLU.sub.-- RATE) is determined as a function of engine lag (K.sub.1), throttle position (THL), engine acceleration/deceleration (dES/dt) and/or input shaft acceleration/deceleration (dIS/dr). To provide smoother shifting during braking (BRK=1, THL=0) and/or coasting (THL<30%) downshifts, the clutch is reengaged at a rate slower than the nominal reengagement rate.

Abstract: An automatic transmission system includes a drive device, electronic control and a valve control. An accelerator pedal, a brake pedal, speedometer and a gear will send signals to the electronic control. Based on these signals, the electronic control will control the valve control. Hydraulic fluid is provided to the drive device based upon operation of the valves in the valve control. The drive device contains a plurality of clutches for each of the valves of the valve control. These clutches are sequentially engaged by sequential operation of the valves in order to connect the engine shaft with an axle of the vehicle to thereby drive the vehicle.

Abstract: A control system and method for a vehicular semi-automatic mechanical transmission system (10) is provided for allowing operator request, immediately after bringing a vehicle to rest, for both a direct shift into a preselected start ratio and a direct shift into neutral, under certain predefined conditions, by a single movement of the shift selection lever (1).

Abstract: In a system for controlling the shifting of an automatic transmission, a selector device is controllable from a "D" selected position into one of two shift positions for a stepwise shift limitation, by one gear at a time, manually. The respective upshift or downshift limitation can automatically be eliminated by fulfillment of a presettable condition, for example the expiration of a delay period.

Abstract: A control method/system for controlling engagement of a target gear ratio (GR.sub.T)in a vehicular automated mechanical transmission system (10) is provided. The control causes engine speed (ES) to be alternately greater than and then less than synchronous engine speed (ES=IS=OS*GR.sub.T) to cause torque reversals across the engaging positive jaw clutch associated with the target gear ratio to minimize or prevent partial engagement caused by torque lock conditions.

Abstract: An apparatus for controlling a lock-up clutch disposed between an engine and an automatic transmission of a motor vehicle, including a slip control device for controlling a slip control pressure to be applied to the lock-up clutch to control the amount of slip of the lock-up clutch, a shift detector for detecting a shifting action of the transmission during deceleration of the vehicle, and a pressure changing device which commands the slip control device, upon detection of a shifting action of the transmission during vehicle deceleration, to change the slip control pressure a predetermined time prior to completion of the shifting action, for reducing an engaging force of the lock-up clutch to a value lower than a value corresponding to the amount of slip of the lock-up clutch established when the transmission is not in the process of a shifting action, to reduce the shifting shock of the transmission.

Abstract: In the present invention a solenoid is used on a ratchet shifter and is controlled through a relay by an electronic controller. This controller can be an analog, digital, or microprocessor driven device. The power supplied to the solenoid most conveniently is the existing battery of the vehicle. This power source is the only source needed, unlike pneumatic cylinders that require a bottle of compressed gas, e.g., air or CO.sub.2. The electronic controller is reset when the hold button is activated at the starting line. When the hold button is released, the vehicle launches violently at or above the rpm lock up of the transmission converter. This is sometimes referred to as "converter flash". If the rpm lock up of the converter is close to the rpm level setting for the first shift, or tire spin occurs, the rpm level will be reached prematurely causing the vehicle to shift early. The electronic controller has a preset time delay, disabling a shift, that begins when the hold button is released.

Abstract: A control for a motor vehicle drive having an automatic transmission includes a circuit configuration for generating an output signal adapting shifting points to a load state of the motor vehicle from an evaluation of a power takeoff rpm of the transmission or of a variable equivalent to it. The circuit configuration ascertains a deviation between a calculated and a measured power takeoff rpm in successive time intervals and forms a correction term by multiplication with a factor. At least one characteristic curve memory stores shifting points of the transmission. The at least one characteristic curve memory receives the correction term as an output signal for adapting a characteristic curve to the load state. In a method for controlling a vehicle drive having an automatic transmission, shifting points or characteristic curves for shifting are varied as a function of driving parameters.

Abstract: A control system for sensing unintended range section (14) not-engaged conditions in an automated mechanical range-type compound transmission (10), and for causing engagement of the selected range section ratio (86, 88), is provided.

Abstract: A control system/method (104) for controlling execution of selected shifts of a mechanical transmission system (10) is provided. The control system includes a central processing unit (106) for receiving input signals indicative of engine or input shaft (11/98) speeds and of output shaft or vehicle speed (VS) speeds and from a driver control console (108) indicative of manual or automatic selection of upshifts or downshifts from a currently engaged gear ratio and processing the same in accordance with predetermined logic rule to issue command output signals to a transmission actuator (112, 70, 96) to implement the selected shifts upon a manually or automatically caused torque break of the transmission and manually or automatically caused substantial synchronization of the transmission thereafter. The predetermined logic rules include a strategy for sensing conditions indicative of a potentially dangerous downhill free-wheeling situation and for immediately causing the forced engagement of a gear ratio (GR.sub.

Abstract: A hydraulically operated continuously variable transmission associated with the engine of a motor vehicle has a clutch for controlling the transfer of power through the transmission and a hydraulic servo unit for selectively connecting and disconnecting the clutch.

Abstract: A multistage transmission has a plurality of gear stages and an additional gear stage which may be engaged to transmit part of the input shaft torque before disengagement of an engaged gear stage. A friction clutch is used to engage the additional stage. Alternatively, a variable-ratio pulley connection may be used for the additional stage. Synchronization of the transmission input shaft with a gear stage to be engaged is attained by controlling the change in input shaft speed in accordance with a selected speed gradient.