Abstract: A control for a vehicle drive line system (10) including an automated vehicle master clutch (14) drivingly interposed in between a fuel-controlled engine (12) and the input shaft (20) of a mechanical transmission. At sensed idle conditions (THL<REF and OS<REF), the engine (12) is commanded to generate an output torque (T.sub.FW) equal to a selected idle drive torque (T.sub.IDLE) at idle speed (ES=IDLE), the engine is commanded to rotate at idle speed and the clutch, preferably a wet clutch, is caused to engage with a torque capacity equal to the idle drive torque.

Abstract: A mechanical transmission system (10) is provided with a detent mechanism (156/172, 186/196) for applying a selectively variable detent resistance to disengagement of an engaged gear ratio. To provide resistance to shift lever (31) induced jumpout when no intent to shift is sensed, a greater detent resistance is provided, and to provide improved shift quality upon sensing an intent to shift, a lesser detent resistance is provided. The mechanism also may be utilized to maintain the transmission in neutral.

Abstract: A method/system for controlling downshifting in an automated mechanical transmission system (10) utilized on a vehicle. When a downshift from a currently engaged ratio (GR) is required (ES<ES.sub.D/S), skip downshifts (GR.sub.TARGET =GR-N, N>1) and then single downshifts (GR.sub.TARGET =GR-1) are evaluated in sequence.

Abstract: A control for determining the state of adjustment or misadjustment of a master friction clutch (14) in a vehicular automated mechanical transmission system (10). A system controller (24) receives input signals (26) indicative of the engaged or disengaged condition of the master clutch, the rotational speed of the transmission input shaft (IS) and the engaged or disengaged condition of the mechanical transmission (16). When the master clutch and the transmission both are disengaged, the rate of change of input shaft speed (dIS/dt) is compared to a predetermined reference value, and if the rate of deceleration of the input shaft speed is less than said reference value, significant master clutch misadjustment is determined and corrective action is initiated. Corrective action may include causing a display (48) to signal the operator that the master clutch is improperly adjusted and/or operating an input shaft brake (50) in a fault-tolerant mode.

Abstract: A control system/method for controlling engine (12) flywheel (T.sub.FW) torque in a vehicular powertrain system (10) including an electronically controlled engine and a torque load limited drivetrain system (11) is provided. The control will sense values of a control parameter (GR, OS) indicative of potential overloading of the drivetrain at maximum engine flywheel torque and will cause engine flywheel torque to be limited to a value less than the maximum value thereof. Flywheel torque is determined as a function of torque values available on the vehicle electronic data link (DL).

Abstract: A control for enhanced manual shifting in a computer-assisted (48) vehicular splitter-type compound transmission (16) having a nonsynchronized, enlarged backlash main section (16A) shifted by a manually operated shift lever (31) and a controller (42). The splitter section (16E) is provided with a three-position (L, H, N) actuator (46) and is commanded to a splitter-neutral position upon sensing a main section shift to neutral to reduce the inertia of the main shaft assembly and reduce the need to synchronize the main section.

Abstract: A control for enhanced range shifting in a computer (48) assisted vehicular compound transmission having a main section (16A) shifted by a manually operated shift lever (31) and a range section (16B) shifted in response to operation of a range shift selector, such as sensing shift lever (31) passing through a predetermined actuation point (AR) in the shift pattern. During a compound shift, if the main section is engaged prior to completion of the range shift, the engine is fueled to a synchronous speed for engaging the target ratio (ES=OS*GR.sub.T) and the range section shift is completed without undue wear or damage to the range section synchronized clutch (130).

Abstract: A control for providing a smooth, high quality torque converter lockup event in an automated mechanical transmission system (10) including a fuel-controlled engine (12) and a mechanical transmission (14) drivingly coupled by a torque converter and torque converter lockup clutch assembly (16). To achieve smooth torque converter lockup, engine torque is smoothly ramped down to a relatively low value and maintained at that value until the torque converter lockup clutch is effectively engaged.

Abstract: A control for a drive line (10) including an automated clutch (14) utilizing an electronic data link (DL) to identify the value of a clutch control parameter (PWM) corresponding to the clutch touch point.

Abstract: An improved control system/method for controlling input shaft retarding device (28/32) assisted upshifting in an at least partially automated vehicular mechanical transmission system (10). The input shaft (18) deceleration (dIS/dt) during an upshift is varied as a function of sensed gear ratio and/or throttle pedal position (THL).

Abstract: A semi-automatic shift implementation system (100) for a lever-shifted mechanical transmission (10) includes an intent-to-shift sensor (122), such as an intent-to-shift button (120). Upon sensing an intent to shift, a controller (146) will cause the engine to be fueled to minimize torque-lock conditions at jaw clutches to be disengaged.

Abstract: A semi-automatic shift implementation system (100) for a manually shifted transmission (10) having gear ratios selectively engaged and disengaged by means of jaw clutches (48, 50) selectively positioned by a shift lever (57). The system will sense a transmission neutral condition, operation of a manually actuated switch (120), and a target gear ratio (GR.sub.T) and, upon sensing a transmission neutral condition and continued actuation of said switch, will automatically cause the system engine (102) to achieve a substantially synchronous speed (ES=IS=((OS*GR.sub. T).+-.E) for engaging the target ratio.

Abstract: A shifting mechanism for a mechanical transmission includes a selector shaft having associated shift forks for engaging or disengaging a selected gear ratio and a control rod directionally coupled to the selector shaft for positive rotation while allowing a predetermined relative axial translation. A cylinder assembly is operatively associated with the selector shaft and control rod to provide a fluid coupling which applies a force on the selector shaft in response to the relative translation between the selector shaft and the control rod to reduce the operator effort required to complete a gear shift.

Abstract: A robust control (10) for a pressurized-fluid-operated, three-position shift actuator piston assembly (12). The system requires only a single controlled source of pressurized fluid (44) to provide movement to and retention in a selected one of three axially displaced positions (D, N, OD). A solenoid-controlled valve (42) is controlled by pulse width modulation. Current applied to the solenoid coil is controlled (46), voltage (V) applied to the solenoid coil is sensed and used as a control parameter and/or a relatively light detent (48, 50) biases the assembly to a neutral (N) position to provide a robust control.

Abstract: A partially automated mechanical transmission system (92) having a mechanical transmission (10) with a lower group (first-eighth) of manually shifted ratios and an upper group (ninth-tenth) of ratios with automatic shifting between ratios in the upper group and requiring manual shifting between groups. Control logic is provided to sense a driver intention to retain the transmission engaged in a current engaged upper group ratio until the occurrence of an event, such a manual shift into transmission neutral. In one embodiment, the on/off switch (184) from the cruise control control panel (125) is utilized to provide a signal indicative of operator intent to temporarily suspend automatic upper ratio shifting.

Abstract: A control for enhanced manual shifting in a computer (48) -assisted vehicular compound transmission having a main section (16A) shifted by a manually operated shift lever (31) and an engine fuel controller (36). Engine fueling will be in accordance with the operator-set throttle pedal position (THL) unless the control logic determines that such fueling will prevent acceptable engagement of a target gear ratio (GR.sub.T), in which case engine fueling will be automatically controlled to complete the shift.

Abstract: A control system for controlling jaw clutch (88) engagement for completing upshifts. The synchronous window ((OS*GR.sub.T).+-.offset) for commanding jaw clutch engagement is increased upon sensing relative great vehicle deceleration (dOS/dt<REF.sub.1) or relatively great vehicle acceleration and relative small engine deceleration (dOS/dt<REF.sub.1) and (dES/dt>REF.sub.2).

Abstract: A launch control for a vehicle drive line (10) including a selectively engaged clutch (14) and an electronically controlled engine (12). Throttle position (THL) is sensed to determine a target engine speed (ES.sub.T), the engine is commanded to achieve the target engine speed, and the clutch is engaged as a function (82) of sensed engine speed (ES), known maximum torque engine speed (84), and the known maximum engine torque (80) at the sensed engine speed.

Abstract: A control for controlling splitter clutch (88) engagement for compound shifts in a controller (48) assisted manually shifted splitter-type vehicular transmission system (10). The controller has logic rule for sensing an attempted compound shift of the splitter-type transmission (16) and will retain the splitter clutch in a disengaged condition (N) until engagement of a main transmission section (16A) ratio from main transmission section neutral is sensed.

Abstract: A first ball ramp actuator having a control ring acting with an activation ring to supply an axial clutch clamping force in a vehicle driving mode and a second ball ramp actuator using the control ring acting with a clutch pressure plate to supply an axial clutch clamping force in a vehicle coast mode where one side of a one-way clutch is attached to the control ring and another side is attached to a support bracket that is frictionally coupled to a transmission input shaft to maintain an energized rotational relationship with the activation ring when in the coast mode.