Output torque rate limiting based on a request busyness indicator that considers the recent time history of the output torque request

• US 8,560,144 B2
• Filed: 06/17/2011
• Issued: 10/15/2013
• Est. Priority Date: 06/17/2011
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: McGrogan, Sean W.
• Primary Examiner(s): Black, Thomas
• Assistant Examiner(s): PAIGE, TYLER D
• Application Number:
  US13/162,767
• Publication Number:
  US 20120323401A1
• Time in Patent Office: 851 Days
• Field of Search: 701/22, 477/86, 477/87, 731/150.1
• US Class Current: 701/1
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60L 2240/443 Torque
• CPC Class Codes: B60L 2240/463 Torque
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 20/15 Control strategies specially adapted for achieving a particular effect
• CPC Class Codes: B60W 2540/106 Rate of change
• CPC Class Codes: B60W 2710/105 Output torque
• CPC Class Codes: B60W 2710/1055 Output torque change rate
• CPC Class Codes: B60W 50/06 Improving the dynamic response of the control system, e.g. improving the speed of regulation or avoiding hunting or overshoot
• CPC Class Codes: F02D 2250/26 by applying a torque limit
• CPC Class Codes: F02D 29/02 peculiar to engines driving vehicles; peculiar to engines driving variable pitch propellers
• CPC Class Codes: F02D 41/1497 With detection of the mechanical response of the engine
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

A method for controlling torque in a vehicle including monitoring a plurality of factors associated with an output torque request in response to an output torque request rate of change exceeding a predetermined threshold, and controlling rate limiting of a delivered output torque to achieve the output torque request rate of change based on the plurality of factors associated with the output torque request.

Claims

1. Method for controlling torque in a vehicle including a control module, the control module configured to execute the following steps, comprising:

monitoring one of an accelerator pedal position and a brake pedal position to determine an output torque request;

monitoring a plurality of factors associated with the output torque request in response to an output torque request rate of change, the output torque request rate of change corresponding to a rate of change between the output torque request that is one of increased and decreased from an output torque request of a previous iteration; and

controlling rate limiting of a delivered output torque to achieve the output torque request rate of change based on the plurality of factors associated with the output torque request, the controlled rate limiting of the delivered output torque comprising one of the output torque delivered at a rate faster than the output torque request rate of change and the output torque delivered at a rate slower than the output torque request rate of change.

2. The method of claim 1 wherein the plurality of factors associated with the output torque request comprises:

an elapsed time beginning when the output torque request rate of change exceeded the predetermined threshold; and

a magnitude of change in the output torque request, the magnitude of change comprising a magnitude of torque between the output torque request and the output torque request from the previous iteration.

3. The method of claim 2 wherein the plurality of factors associated with the output torque request further comprises:

an output torque request time rate of change corresponding to a time rate of change between the output torque request and the output torque request of the previous iteration.

4. The method of claim 3 wherein controlling rate limiting of the delivered output torque comprises:

when the monitored elapsed time is less than a threshold time, applying no rate limiting to the delivered output torque to achieve the output torque request rate of change.

5. The method of claim 2 wherein controlling rate limiting of the delivered output torque comprises:

applying rate limiting in proportion to the magnitude of change in the output torque request.

6. The method of claim 3 wherein controlling rate limiting of the delivered output torque comprises:

when the output torque request time rate of change exceeds an output torque request time rate of change threshold, decreasing rate limiting of the delivered output torque resulting in the output torque delivered at a rate faster than the output torque request rate of change; and

when the monitored output torque request time rate of change does not exceed the output torque request time rate of change threshold, increasing rate limiting of the delivered output torque resulting in the output torque delivered at a rate slower than the output torque request rate of change.

7. The method of claim 1 further comprising:

when a magnitude of the output torque request rate of change is at least an output torque request rate of change threshold, decrementing a timer associated with monitoring a time history of the output torque request rate of change.

8. The method of claim 1 wherein the output torque request rate of change corresponds to an accelerator pedal tip-in.

9. The method of claim 1 wherein the output torque request rate of change corresponds to an accelerator pedal tip-out.

10. Method for controlling torque in a vehicle powertrain in response to an operator torque request rate of change, the vehicle including a control module configured to execute the following steps, comprising:

monitoring one of an accelerator pedal position and a brake pedal position to determine an output torque request;

when the output torque request is one of increased and decreased from an output torque request of a previous iteration, monitoring a request busyness indicator corresponding to recent steadiness of the operator torque request rate of change corresponding to a rate of change between the output torque request and the output torque request of the previous iteration comprising;

monitoring an elapsed time beginning when the output torque request rate of change was detected;

monitoring a magnitude of change of the operator torque request, the magnitude of change comprising a magnitude of torque between the output torque request and the output torque request from the previous iteration;

monitoring an operator torque request time rate of change; and

controlling rate limiting of a delivered output torque to achieve the operator torque request rate of change based on the request busyness indicator, the controlled rate limiting of the delivered output torque comprising one of the output torque delivered at a rate faster than the output torque request rate of change and the output torque delivered at a rate slower than the output torque request rate of change.

11. The method of claim 10 wherein controlling the rate limiting of the delivered output torque comprises:

when the elapsed time is less than an elapsed time threshold, controlling the rate limiting of the delivered output torque using a rate corresponding to the operator torque request rate of change.

12. The method of claim 10 wherein controlling the rate limiting of the delivered output torque comprises:

controlling the rate limiting of the delivered output torque proportionally to the magnitude of change of the operator torque request.

13. The method of claim 12 wherein controlling the rate limiting of the delivered output torque comprises:

when the operator torque request time rate of change exceeds an output torque request time rate of change threshold, decreasing the controlled rate limiting of the delivered output torque resulting in the output torque delivered at a rate faster than the output torque request rate of change; and

when the time rate of change of the torque request does not exceed the output torque request time rate of change threshold, increasing the controlled rate limiting of the delivered output torque resulting in the output torque delivered a rate slower than the output torque request rate of change.

14. The method of claim 10 wherein the operator torque request rate of change comprises an accelerator pedal input.

15. The method of claim 10 wherein the operator torque request rate of change comprises a brake pedal input.

16. The method of claim 10 further comprising:

monitoring a threshold output torque capability comprising one of a maximum and minimum amount of output torque capability of the powertrain;

comparing the threshold output torque capability to the operator torque request; and

if the operator torque request exceeds the threshold output torque capability, constraining the operator torque request to the threshold output torque capability until the threshold output torque capability is adjusted to carry out the operator torque request.

17. Apparatus for controlling torque in a vehicle in response to an operator torque request rate of change, comprising:

a control module configured to execute the following steps, comprising;

monitoring one of an accelerator pedal position and a brake pedal position to determine an output torque request;

when the output torque request is one of increased and decreased from an output torque request of a previous iteration, monitoring a request busyness indicator corresponding to recent steadiness of the operator torque request rate of change corresponding to a rate of change between the output torque request and the output torque request of the previous iteration comprising;

monitoring an elapsed time beginning when the output torque request rate of change was detected;

monitoring a magnitude of change of the operator torque request, the magnitude of change comprising a magnitude of torque between the output torque request and the output torque request from the previous iteration; and

monitoring an operator torque request time rate of change; and

controlling rate limiting of a delivered output torque to achieve the operator torque request rate of change based on the request busyness indicator, the controlled rate limiting of the delivered output torque comprising one of the output torque delivered at a rate faster than the output torque request rate of change and the output torque delivered at a rate slower than the output torque request rate of change.