Adaptive shift control method/system for modifying engine delay rate or vehicle coast deceleration during upshifts

• US 5,489,247 A
• Filed: 04/12/1994
• Issued: 02/06/1996
• Est. Priority Date: 07/06/1992
• Status: Expired due to Term

• Current Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Original Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Inventors: Graves, Roger A. Jr., Markyvech, Ronald K.
• Primary Examiner(s): Ta, Khoi Q.
• Application Number:
  US08/226,749
• Time in Patent Office: 665 Days
• Field of Search: 74/335, 477/120, 477/124, 477/904
• US Class Current: 477/120
• CPC Class Codes: B60W 2510/0652 Speed change rate
• CPC Class Codes: B60W 2510/1045 Output speed change rate
• CPC Class Codes: F16H 2059/142 of driving resistance calculated from weight, slope, or the like
• CPC Class Codes: F16H 2061/161 by checking feasibility of shifts, i.e. determine if requested shift can be successfully completed and post shift values are in an acceptable range
• CPC Class Codes: F16H 59/14 Inputs being a function of torque or torque demand
• CPC Class Codes: F16H 59/46 dependent on a comparison between speeds
• CPC Class Codes: F16H 59/48 Inputs being a function of acceleration
• CPC Class Codes: F16H 59/52 dependent on the weight of the machine, e.g. change in weight resulting from passengers boarding a bus
• CPC Class Codes: F16H 61/0248 Control units where shifting is directly initiated by the driver, e.g. semi-automatic transmissions generation of movements for final actuating mechanisms F16H61/28
• CPC Class Codes: F16H 61/0403 Synchronisation before shifting
• CPC Class Codes: F16H 61/16 Inhibiting or initiating shift during unfavourable conditions, e.g. preventing forward reverse shift at high vehicle speed, preventing engine over speed unintentional control input F16H61/18
• CPC Class Codes: F16H 61/702 using electric or electrohydraulic control means
• CPC Class Codes: Y10S 477/904 Control signal is acceleration

Abstract

An adaptive 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. If upshifts determined to be feasible are not completed by the system, the logic rules by which upshift feasibility is determined are modified to render such rules less aggressive.

Claims

1. An adaptive 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 an upshift into a target gear ratio, a master friction clutch (C) drivingly interposed between the engine and the input shaft, 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/152) 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 including means for:

determining selection of an upshift from a currently engaged transmission ratio to a target gear ratio;

determining as a first function of at least said input signals indicative of (i) current engine torque and (ii) current vehicle acceleration, an expected vehicle acceleration (A₀) under current vehicle operating conditions and at zero engine torque to the drive wheels;

determining as a second function of (i) the expected vehicle acceleration (A₀) 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 an upshift into the target gear ratio, feasibility or infeasibility of achieving substantially synchronous conditions for engagement of the target ratio if the selection of an upshift is implemented; and

causing the initiation of a selected upshift only upon a determination of feasibility of achieving substantially synchronous conditions for engagement of the target gear ratio; and

means effective, after initiation of a selected upshift and upon sensing failure to achieve substantially synchronous conditions for engagement of the target gear ratio, for modifying at least one of said first function and said second function to cause at least one of an increase in the expected input shaft acceleration during a gear ratio change operation and a decrease in the expected vehicle acceleration under current vehicle operating conditions and at zero engine torque to the drive wheels for subsequent selections of upshifts.

2. The system of claim 1 wherein expected vehicle deceleration under current vehicle operating conditions and at zero engine torque is also determined as a function of vehicle gross combined weight and said means for modifying modifies by decreasing the value of vehicle gross combined weight utilized in said first function by a predetermined amount.

3. The system of claim 2 wherein said predetermined amount is about 6 percent.

4. The system of claim 1 wherein the means for modifying at least one of said first and second functions causes a modification of about 6 percent.

5. The system of claim 1 wherein said means for modifying after modifying one of said first and second functions, causes said first and second functions to revert to original values thereof.

6. The system of claim 1 wherein said expected vehicle acceleration (A₀) is determined as a function of the expression

7. The system of claim 6 wherein a value for the expression C·

W is determined as a function of the expression

space="preserve" listing-type="equation">(T.sub.1 -T.sub.2)/(A.sub.1 -A.sub.2)

where;

A₂ is a value representative of vehicle acceleration at a second torque value (T₂) and

T₂ is a known second torque value where T₂ does not equal T₁.

8. An adaptive 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 an upshift into a target gear ratio, a master friction clutch (C) drivingly interposed between the engine and the input shaft, 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/152) 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 including the steps of:

determining selection of an upshift from a currently engaged transmission ratio to a target gear ratio;

determining as a first function of at least said input signals indicative of (i) current engine torque and (ii) current vehicle acceleration, an expected vehicle acceleration (A₀) under current vehicle operating conditions and at zero engine torque to the drive wheels;

determining as a second function of (i) the expected vehicle acceleration (A₀) 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 an upshift into the target gear ratio, feasibility or infeasibility of achieving substantially synchronous conditions for engagement of the target ratio if the selection of an upshift is implemented; and

causing the initiation of a selected upshift only upon a determination of feasibility of achieving substantially, synchronous conditions for engagement of the target gear ratio; and

after initiation of a selected upshift, upon sensing failure to achieve substantially synchronous conditions for engagement of the target gear ratio, modifying at least one of said first function and said second function to cause at least one of an increase in the expected input shaft acceleration during a gear ratio change operation and a decrease in the expected vehicle acceleration under current vehicle operating conditions and at zero engine torque to the drive wheels for subsequent selections of upshifts.

9. The method of claim 8 wherein expected vehicle deceleration under current vehicle operating conditions and at zero engine torque is also determined as a function of vehicle gross combined weight and said modification comprises decreasing the value of vehicle gross combined weight utilized in said first function by a predetermined amount.

10. The method of claim 9 wherein said predetermined amount is about 6 percent.

11. The method of claim 8 wherein the step of modifying at least one of said first and second functions results in a modification of about 6 percent.

12. The method of claim 8 further comprising the step of, after modifying one of said first and second functions, causing said first and second functions to revert to original values thereof.

13. The method of claim 8 wherein said expected vehicle acceleration (A₀) is determined as a function of the expression

14. The method of claim 13 wherein a value for the expression C·

W is determined as a function of the expression

space="preserve" listing-type="equation">(T.sub.1 -T.sub.2)/(A.sub.1 -A.sub.2)

where;

A₂ is a value representative of vehicle acceleration at a second torque value (T₂) and

T₂ is a known second torque value where T₂ does not equal T₁.