Automated transmission upshift control

• US 6,149,545 A
• Filed: 01/14/1999
• Issued: 11/21/2000
• Est. Priority Date: 01/14/1999
• Status: Expired due to Term

• Current Assignee: Eaton Intelligent Power Limited (Eaton Corporation PLC.)
• Original Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Inventors: Genise, Thomas A., Janecke, Daniel P., Amsallen, Marcel
• Primary Examiner(s): Marmor, Charles A.
• Assistant Examiner(s): PANG, ROGER L
• Application Number:
  US09/232,252
• Time in Patent Office: 677 Days
• Field of Search: 74/335, 74/336 R, 477/123, 477/124
• US Class Current: 477/124
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/11 Stepped gearings
• CPC Class Codes: B60W 10/111 with separate change-speed gear trains arranged in series
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2710/1005 Transmission ratio engaged
• CPC Class Codes: B60W 30/18 Propelling the vehicle
• CPC Class Codes: F16H 2059/366 Engine or motor speed
• 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 59/24 dependent on the throttle opening
• CPC Class Codes: F16H 59/36 Inputs being a function of speed
• CPC Class Codes: F16H 61/0213 characterised by the method for generating shift signals
• 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 61/21 Providing engine brake control
• CPC Class Codes: Y10T 74/19251 Control mechanism

Abstract

A method/system for controlling upshifting in an automated mechanical transmission system (10) utilized on a vehicle preferably having an ECU (28) controlled engine brake (46). When an upshift from a currently engaged ratio (GR) is required (ES>ESU/S), skip upshifts (GRTARGET=GR+N, N>1) and then single upshifts (GRTARGET=GR+1) are evaluated in sequence.

Claims

1. A method for controlling automatic upshifting in a vehicular automated mechanical transmission system (10) for a vehicle comprising a fuel-controlled engine (12) having a maximum torque rotational speed, a multiple-speed mechanical transmission (14), and a controller (28) for receiving input signals (30) including one or more of signals indicative of engine speed (ES), engaged gear ratio (GR) and vehicle speed (OS), and to process said input signals in accordance with logic rules to issue command output signals (32) to transmission system actuators including a transmission actuator (52) effective to shift said transmission, said method characterized by:

(i) establishing a maximum acceptable time (TMAX) for completion of skip upshifts;

(ii) establishing an upshift feasibility criteria whereby upshifts into a target gear ratio are considered feasible only if, under sensed vehicle operating conditions,

(a) substantial synchronization can be obtained above a predetermined engine speed substantially equal to maximum torque rotational speed and

(b) at engagement of the target ratio, the vehicle will be capable of at least a predetermined acceleration (dOS/dt);

(iii) upon sensing a requirement (ES>

ES/U/S) for an upshift from an engaged gear ratio (GR), in sequence;

(a) determining if a skip upshift of two ratios from the currently engaged ratio (GRTARGET=GR+2) is feasible within a time no greater than said maximum acceptable time and, if so, commanding a skip upshift of two ratios from the currently engaged ratio;

if not,

(b) then determining if a single upshift (GRTARGET=GR+1) without using engine brakes is feasible and, if feasible, commanding a single upshift from the currently engaged ratio without using engine brakes.

2. The method of claim 1 wherein said vehicle includes an engine brake operable by command output signals from said controller and comprising the further steps, after step (iii)(b), of:

(c) if a single upshift without using engine brakes is not feasible, then determining if a single upshift with use of engine brakes is feasible and, if so, commanding a single upshift from currently engaged ratio using engine brakes and, if not,

(d) then retaining the transmission engaged in the currently engaged ratio.

3. The method of claim 1 comprising the further step, prior to step (iii)(a), of:

(e) determining if a skip upshift of three ratios from the currently engaged ratio (GRTARGET=GR+3) is feasible within a time no greater than said maximum acceptable time and, if so, commanding a skip upshift of three ratios from said currently engaged ratio and, if not, then proceeding to step (iii)(a).

4. The method of claim 2 comprising the further step, prior to step (iii)(a), of:

(e) determining if a skip upshift of three ratios from the currently engaged ratio (GRTARGET=GR+3) is feasible within a time no greater than said maximum acceptable time and, if so, commanding a skip upshift of three ratios from said currently engaged ratio and, if not, then proceeding to step (iii)(a).

5. The method of claim 1 wherein said transmission (14) is drivingly coupled to said engine (12) by a manually controlled clutch (16).

6. The method of claim 1 wherein said maximum acceptable time is about 1.0 to 2.0 seconds.

7. The method of claim 1 wherein said engine is a diesel engine and said predetermined engine speed is about 1100 to 1300 rpm.

8. The method of claim 1 wherein determining feasibility of an upshift into a target ratio includes:

determining as a function of at least the currently engaged gear ratio and said input signals indicative of (i) current engine torque and (ii) current vehicle acceleration, an expected required drivewheel torque (T0) to maintain at least said minimum vehicle acceleration (A0) under current vehicle operating conditions;

determining as a function of (i) the expected required drivewheel torque (T0) to maintain at least said minimum vehicle acceleration (A0) under current vehicle operating conditions, (ii) the gear ratio of the selected target gear ratio and (iii) the expected maximum available torque to the drivewheels in the target transmission ratio (206), if said expected maximum available torque will at least equal said expected required drivewheel torque upon engagement of the target transmission ratio if the selected shift is implemented, and

causing the initiation of a selected shift, only upon a determination of said maximum available torque, that will at least equal said expected required drivewheel torque upon engagement of the target transmission ratio.

9. The method of claim 1 wherein determining feasibility of an upshift into a target ratio includes:

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 (A0) under current vehicle operating conditions and at zero engine torque to the drive wheels;

determining as of 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 a shift into the target gear ratio, the feasibiliity or infeasibility of achieving substantially synchronous conditions for engagement of the target ratio if the selected shift is implemented.

10. The method of claim 1 wherein said vehicle includes an engine brake operable by command output signals from said controller, and step (iii)(a) comprises:

(a-1) determining if a skip upshift of two ratios from the currently engaged ratio (GRTARGET=GR+2) without using engine brakes is feasible within a time no greater than said maximum acceptable time and, if so, commanding a skip upshift of two ratios from the currently engaged ratio;

if not,

(a-2) determining if a skip upshift of two ratios from the currently engaged ratio (GRTARGET=GR+2) using engine brakes is feasible within a time no greater than said maximum acceptable time and, if so, commanding a skip upshift of two ratios from the currently engaged ratio.

11. A control system for controlling automatic upshifting in a vehicular automated mechanical transmission system (10) for a vehicle comprising a fuel-controlled engine (12) having a maximum torque rotational speed, a multiple-speed mechanical transmission (14), and a controller (28) for receiving input signals (30) including one or more of signals indicative of engine speed (ES), engaged gear ratio (GR) and vehicle speed (OS), and to process said input signals in accordance with logic rules to issue command output signals (32) to transmission system actuators including a transmission actuator (52) effective to shift said transmission, said control system including logic rules for:

(i) establishing a maximum acceptable time (TMAX) for completion of skip upshifts;

(ii) establishing an upshift feasibility criteria whereby upshifts into a target gear ratio are considered feasible only if, under sensed vehicle operating conditions,

(a) substantial synchronization can be obtained above a predetermined engine speed substantially equal to said maximum torque rotational speed and

(b) at engagement of the target ratio, the vehicle will be capable of at least a predetermined acceleration (dOS/dt);

(iii) upon sensing a requirement (ES>

ES/U/S) for an upshift from an engaged gear ratio (GR), in sequence;

(a) determining if a skip upshift of two ratios from the currently engaged ratio (GRTARGET=GR+2) is feasible within a time no greater than said maximum acceptable time and, if so, commanding a skip upshift of two ratios from the currently engaged ratio;

if not,

(b) then determining if a single upshift (GRTARGET=GR+1) without using engine brakes is feasible and, if feasible, commanding a single upshift from the currently engaged ratio without using engine brakes.

12. The control system of claim 11 wherein said vehicle includes an engine brake operable by command output signals from said controller and further comprising logic rules, after step (iii)(b), for:

(c) if a single upshift without using engine brakes is not feasible, then determining if a single upshift with use of engine brakes is feasible and, if so, commanding a single upshift from currently engaged ratio using engine brakes and, if not,

(d) then retaining the transmission engaged in the currently engaged ratio.

13. The control system of claim 11 further comprising logic rules, prior to step (iii)(a), for:

(e) determining if a skip upshift of three ratios from the currently engaged ratio (GRTARGET=GR+3) is feasible within a time no greater than said maximum acceptable time and, if so, commanding a skip upshift of three ratios from said currently engaged ratio and, if not, then proceeding to step (iii)(a).

14. The control system of claim 12 further comprising logic rules, prior to step (iii)(a), for:

(e) determining if a skip upshift of three ratios from the currently engaged ratio (GRTARGET=GR+3) is feasible within a time no greater than said maximum acceptable time and, if so, commanding a skip upshift of three ratios from said currently engaged ratio and, if not, then proceeding to step (iii)(a).

15. The control system of claim 11 wherein said transmission (14) is drivingly coupled to said engine (12) by a manually controlled clutch (16).

16. The control system of claim 11 wherein said maximum acceptable time is about 1.0 to 2.0 seconds.

17. The control system of claim 11 wherein said engine is a diesel engine and said predetermined engine speed is about 1100 to 1300 rpm.