Acceleration prediction responsive adaptive upshift control

• US 5,241,476 A
• Filed: 07/14/1992
• Issued: 08/31/1993
• Est. Priority Date: 05/08/1990
• Status: Expired due to Term

• Current Assignee: Chrysler Group LLC (Stellantis NV)
• Original Assignee: Chrysler Corporation (Stellantis NV)
• Inventors: Leising, Maurice B., Benford, Howard L.
• Primary Examiner(s): Harvey, Jack B.
• Assistant Examiner(s): PIPALA, EDWARD J
• Application Number:
  US07/914,509
• Time in Patent Office: 413 Days
• Field of Search: 364/424.1, 74/861, 74/866
• US Class Current: 701/58
• CPC Class Codes: F16H 2059/142 of driving resistance calculated from weight, slope, or the like
• CPC Class Codes: F16H 2061/0216 Calculation or estimation of post shift values for different gear ratios, e.g. by using engine performance tables
• 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 59/48 Inputs being a function of acceleration
• CPC Class Codes: F16H 61/0213 characterised by the method for generating shift signals
• CPC Class Codes: F16H 61/10 Controlling shift hysteresis

Abstract

A method of adaptively scheduling an upshift. The method determines whether the vehicle can maintain speed in a high gear and, if it cannot, to inhibit the lower to higher gear upshift. This is accomplished by observing vehicle acceleration in the lower gear, determining whether the vehicle will be capable of providing a predetermined value of acceleration after an upshift of the gear assembly to a higher gear. If the vehicle will not be capable of providing the predetermined value of acceleration, then the upshift will be prevented.

Claims

1. In a fully automatic transmission system associated with an engine, a method of adaptively scheduling a third to fourth gear upshift of the gear assembly, said method comprising the steps of:

sensing an output speed of the transmission in third gear over a predetermined time period;

determining a current acceleration in third gear based on a change in sensed output speed;

determining a predicted acceleration in fourth gear;

comparing the predicted acceleration with a required acceleration;

determining whether the predicted acceleration is less than the required acceleration based on the comparison;

if the predicted acceleration is not less that the required acceleration, enabling the upshift to occur; and

if the predicted acceleration is less than the required acceleration, delaying the upshift of the gear assembly until the predicted acceleration is greater than or equal to the required acceleration.

2. In an automatic electronically controlled transmission system of a vehicle, a method of adaptively scheduling an upshift of a gear assembly of the transmission system, comprising the steps of:

sensing a speed value which is indicative of vehicle speed over a predetermined time period;

determining a current acceleration value for the vehicle from the sensed speed value while the gear assembly of the transmission is operating in a gear which is lower than a highest available gear;

determining whether the vehicle will be capable of providing a predetermined value of acceleration after an upshift of the gear assembly to a higher gear;

enabling an upshift of the gear assembly to a next higher gear if the vehicle will be capable of providing the predetermined value of acceleration; and

preventing an upshift of the gear assembly to the next higher gear if the vehicle will not be capable of providing the predetermined value of acceleration.

3. The method according to claim 2, wherein the step of determining whether the vehicle will be capable of providing the predetermined value of acceleration includes the steps of calculating a predicted acceleration value for the vehicle in the current gear which indicates capability for achieving the predetermined value of acceleration in the next higher gear and comparing the current acceleration value with the predicted acceleration value to determine whether the vehicle will be capable of providing said predetermined value of acceleration after an upshift of the gear assembly to a high gear.

4. The method according to claim 3, wherein the predicted acceleration value is based at least in part upon a continually updated atmospheric pressure value.

5. The method according to claim 2, wherein the predetermined value of acceleration is greater than or equal to zero.

6. The method according to claim 2, wherein the predetermined value of acceleration is initially set to a nominal value, and thereafter the predetermined value of acceleration is adjusted in response to predicted vehicle acceleration in the higher gear of operation.

7. The method according to claim 2, where the speed value sensed is an output speed of the transmission system.