Shift control method/system
AssigneeEaton Corporation
InventorsThomas A. Genise, Ronald K. Markyvech
Life of this patent
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Abstract
A control system/method for an at least partially automated mechanical transmission system (10) is provided for determining if selected upshifts into a target gear ratio are feasible (208) or not feasible (210) under current vehicle operating conditions and for prohibiting the initiation of not feasible selected upshifts.
Claims20
A control system for controlling at least partially automated implementation of selected shifts of a vehicular mechanical change gear transmission system comprising a controlled fuel throttle controlled engine (E), a multi-speed change gear mechanical transmission (10) having an input shaft (16) and an output shaft (90) adapted to drive vehicular drive wheels, said input shaft having a determinable expected acceleration during a gear ratio change operation, a master friction clutch (C) drivingly interposed between the engine and the transmission, a first sensor (98) for providing a first input signal indicative of transmission input shaft (16) rotational speed, a second sensor (100) for providing a second input signal indicative of vehicle speed, a third sensor (DL) for providing an input signal indicative of engine torque and a transmission actuator (112, 70, 96) for controlling shifting of the transmission, said control system characterized by;
- means for determining selection of a shift from a currently engaged transmission ratio to a target gear ratio,
- means for determining as a function of at least said input signals indicative of (i) current engine torque and (ii) current vehicle acceleration, the expected vehicle acceleration (A.sub.0) under current vehicle operating conditions and at zero engine torque to the drive wheels;
- means for determining as of function of (i) expected vehicle acceleration (A.sub.0) under current vehicle operating conditions and zero engine torque to the drive wheel, (ii) the gear ratio of the selected target gear ratio and (iii) the expected input shaft acceleration during a shift into the target gear ratio, feasibility or infeasibility of achieving substantially synchronous conditions for engagement of the target ratio if the selected shift is implemented, and
- means for causing the initiation of a selected shift only upon a determination of feasibility of achieving substantially synchronous conditions for engagement of the target gear ratio.
The control system of claim 4 wherein said means for determining the expected vehicle acceleration under current vehicle operation conditions and zero engine torque to the drive wheel comprises:
- means effective, while remaining in the currently engaged ratio, for causing a change in engine torque from a first torque value (T.sub.1) to a second torque value (T.sub.2) and means for determining the vehicle accelerations (A.sub.1, A.sub.2) at both said first and second engine torque values.
The control system of claim 5 wherein said change in engine torque values is no greater than about ten percent (10%) of said first torque value and occurs for a period of time no greater than about one second.
A control method for controlling at least partially automated implementation of selected shifts of a vehicular mechanical change gear transmission system comprising a controlled fuel throttle controlled engine (E), a multi-speed change gear mechanical transmission (10) having an input shaft (16) and an output shaft (90) adapted to drive vehicular drive wheels, said input shaft having a determinable expected acceleration during a gear ratio change operation, a master friction clutch (C) drivingly interposed between the engine and the transmission, a first sensor (98) for providing a first input signal indicative of transmission input shaft (16) rotational speed, a second sensor (100) for providing a second input signal indicative of vehicle speed, a third sensor (DL) for providing an input signal indicative of engine torque and a transmission actuator (112, 70, 96) for controlling shifting of the transmission, said control method characterized by;
- determining selection of a shift from a currently engaged transmission ratio of a target gear ratio,
- determining as a function of at least said input signals indicative of (i) current engine torque and (ii) current vehicle acceleration, an expected vehicle acceleration (A.sub.0) under current vehicle operating conditions and at zero engine torque to the drive wheels;
- determining as of function of (i) the expected vehicle acceleration (A.sub.0) under current vehicle operating conditions and at zero engine torque to the drive wheels, (ii) the gear ratio of the selected target gear ratio and (iii) the expected input shaft acceleration during a shift into the target gear ratio, feasibility or infeasibility of achieving substantially synchronous conditions for engagement of the target ratio if the selected shift is implemented, and
- causing the initiation of a selected shift only upon a determination of feasibility of achieving substantially synchronous conditions for engagement of the target gear ratio.
A control method for controlling at least partially automated implementation of automatically selected upshifts of a vehicular mechanical change gear transmission system comprising a controlled fuel throttle controlled engine (E), a multi-speed change gear mechanical transmission (10), having an input shaft (16) and an output shaft (90) adapted to drive vehicular drive wheels a master friction clutch (C) drivingly interposed between the engine and the transmission, a first sensor (98) for providing a first input signal indicative of transmission input shaft (16) rotational speed, a second sensor (100) for providing a second input signal indicative of vehicle speed, a third sensor (DL) for providing an input signal indicative of current engine torque, means for storing data indicative of expected deceleration rates of the transmission input shaft upon defueling of the engine with the master clutch engaged and the transmission shifted to neutral, a non-manually controllable transmission actuator (112, 70, 96) for controlling shifting of the transmission, said control method characterized by, upon selection of an upshift from a currently engaged gear ratio to a target gear ratio;
- means for determining as a function of at least (i) curent engine torque (T) and (ii) current vehicle acceleration (A), an expected vehicle acceleration (A.sub.O) under current vehicle operating conditions with the transmission shifted to neutral;
- means for determining, as a function of at least (i) expected vehicle acceleration (A.sub.0) under current vehicle operating conditions with the transmission shifted to neutral, (ii) the gear ratio of the selected target gear ratio and (iii) the expected deceleration rate of the transmission input shall upon refueling of the engine with the master clutch engaged and the transmission shifted to neutral, the feasibility or infeasibility of achieving substantially synchronous conditions for jaw clutch engagement of the target gear ratio if the selected upshift is initiated, and
- means for causing initiation of the selected upshift only upon a determination of feasibility of achieving said substantially synchronous conditions.
A control method for controlling the at least partially automated implementation of automatically selected upshifts of a vehicular mechanical change gear transmission system comprising a controlled fuel throttle controlled engine (E), a multi-speed change gear mechanical transmission (10), having an input shaft (16) and an output shaft (90) adapted to drive vehicular drive wheels a master friction clutch (C) drivingly interposed between the engine and the transmission, a first sensor (98) for providing a first input signal indicative of transmission input shaft (16) rotational speed, a second sensor (100) for providing a second input signal indicative of vehicle speed, a third sensor (DL) for providing an input signal indicative of current engine torque, means for storing data indicative of expected deceleration rates of the transmission input shaft upon defueling of the engine with the master clutch engaged and the transmission shifted to neutral, a non-manually controllable transmission actuator (112, 70, 96) for controlling shifting of the transmission, said control method characterized by, upon selection of an upshift from a currently engaged gear ratio to a target gear ratio;
- determining as a function of at least (i) curent engine torque (T) and (ii) current vehicle acceleration (A), an expected vehicle acceleration (A.sub.0) under current vehicle operating conditions with the transmission shifted to neutral;
- determining, as a function of at least (i) expected vehicle acceleration (A.sub.0) under current vehicle operating conditions with the transmission shifted to neutral, (ii) the gear ratio of the selected target gear ratio and (iii) the expected deceleration rate of the transmission input shaft upon defueling of the engine with the master clutch engaged and the transmission shifted to neutral, feasibility or infeasibility of achieving substantially synchronous conditions for jaw clutch engagement of the target gear ratio if the selected upshift is initiated, and
- causing initiation of the selected upshift only upon a determination of feasibility of achieving said substantially synchronous conditions.
Dependencies are inferred from the claim text.