摘要:
A control system and method for an automated mechanical transmission system (310) operable in a hold mode of operation (H) is provided. When operating in the hold mode of operation, if override conditions (ES>ES.sub.MAX, ES
摘要:
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).
摘要:
An electronic engine control monitors engine speed, vehicle speed and determines various engine RPM values and RPM ranges used in fueling a motor vehicle engine to achieve desired engine speeds prior to and during an automatic gear shift sequence. The engine is coupled to a manual/automatic transmission that includes manually selectable gear ratio operation modes and automatically selectable gear ratio operation modes. In order to verify engagement of the automatically selectable gear ratio operation modes, a predetermined reverse torque is introduced into the drivetrain by fueling the engine to certain predetermined levels after an automatic gear shift sequence begins and monitoring engine speed to test whether engine speed is within calculated synchronous engine speed ranges corresponding to the gear ratio of the desired automatically selectable gear ratio operation mode.
摘要:
A reengagement control system/method (200) for a semi-automatic mechanical transmission system (104) of the type requiring manual synchronization of the transmission to enable automatic implementation of a selected shift into a target gear ratio is provided. The reengagement control will cause immediate engagement of an engageable ratio, based upon vehicle speed, if the transmission is shifted to neutral and is then unable to engage in the target gear for greater than a predetermined time (REF.sub.2) as vehicle acceleration (dOS/dt) exceeds an acceleration reference value (REF.sub.1).
摘要:
A control system (104)/method for semi-automatically executing automatically and manually selected upshifts and downshifts of a mechanical transmission system (10) is provided. The control system includes a central processing unit (106) for receiving input signals indicative of transmission input shaft (16) and output shaft (90) speeds and from a driver control console (108) and processing the same in accordance with predetermined logic rules to issue command output signals to a transmission actuator (112, 70, 96) to implement the selected shifts. The control is effective to initiate a shift by automatically preselecting a shift from the currently ratio into neutral and to then await a manually caused torque break of the transmission to complete the shift to neutral. The control is effective to minimize wear by issuing repetitive shift prompts if transmission neutral is not sensed within predetermined times from preselection of a shift frown a currently engaged ratio (GR) into neutral(N).
摘要:
A control system for controlling automatic shifting of a manual/automatic transmission is disclosed including a cruise control system and an auto-shift mode for controlling automatic upshift and downshift operations between the top two gears of a heavy duty truck transmission. Certain failures of equipment or incorrect driving habits of operators are corrected for with algorithms which prevent undesirable operating conditions which compromise the acceptability of an electronically controlled heavy duty truck transmission equipped vehicle. The mechanism by which auto-shift operation of the transmission is requested is also compared with parameters such as vehicle speed and engine speed in order to determine whether gears should be engaged or disengaged, the gears being those subject to auto-shift control of the system controller.
摘要:
In a powershift transmission having electro-hydraulic clutches for selectively connecting an input shaft in driving relationship with an output at any one of a plurality of output to input shaft speed ratios, creeper gear speeds, less than those obtained by selecting the lowest output to input shaft speed ratio, are obtained by placing the transmission in the lowest gear (forward or reverse) and controlling the output shaft speed by automatically controlling clutch slippage. Any one of a plurality of forward or reverse creeper gear speeds may be selected by operation of a gearshift lever. The speeds of the input and output shafts are sensed and a microprocessor responds to the sensed shaft speeds and the selected creeper gear speed to control slipping of the clutch. In one embodiment the output shaft speed is controlled to a specific speed value independent of the input shaft speed. In a second embodiment, the output shaft speed is controlled to obtain a specific ratio of output to input shaft speed.
摘要:
A control method/system (200) for a control system (104) for semi-automatically executing automatically selected upshifts and downshifts of a mechanical transmission system (10) is provided. The control system includes a central processing unit (106) for receiving input signals indicative of transmission input shaft (16) and output shaft (90) speeds (IS, OS) 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 by automatic shifting into neutral upon a naturally or manually caused torque reversal of the transmission and remaining in neutral until the vehicle operator causes substantially synchronous conditions to occur. The method/system (200) includes calculating a first and second reference value (REF-UP, REF-DN) as functions of input shaft speed and only preselecting upshifts of output shaft acceleration (dOS/dt) exceeds the first reference (REF-UP) and only preselecting downshifts if output shaft acceleration (dOS/dt) is less than the second reference value (REF-DN). The first and second reference values vary with the value of input shaft speed over ranges (150-154, 152-160) thereof.
摘要:
A system for controlling the selection of the operative ratio of a vehicle powershift transmission driven from an engine via a main clutch. The system includes a clutch status sensor for sensing engaged and disengaged conditions of the main clutch. A selector is provided for selecting the operative ratio of the transmission. Also, a control circuit is provided which includes a ratio-change modulating function which, when the main clutch is engaged and a change to a non-adjacent ratio is selected, invokes a serial routine which ensures that each intermediate ratio between the current ratio and the selected ratio is engaged for a moment to ensure a smooth substantially jerk-free progression between the current ratio and the selected ratio. When the main clutch is disengaged and a change to a non-adjacent ratio is selected, the control circuit invokes a direct routine which permits changes from a current ratio to a non-adjacent selected ratio without engagement of any intermediate ratio.
摘要:
An automatic selector device for multi-gear change-speed gearbox includes a multi-way valve which can be driven into several valve positions each associated with one gear by a stepper motor whose operation depends on an electronic control unit. Each of the valve positions causes the appropriate gear to be selected. The multi-way valve is connected kinematically to a selector unit which can be actuated manually in order to block gears through the intermediary of a stop and an opposing stop.