Virtual power steering switch

• US 6,173,696 B1
• Filed: 12/17/1998
• Issued: 01/16/2001
• Est. Priority Date: 12/17/1998
• Status: Expired due to Term

• Current Assignee: FCA US LLC (Stellantis NV)
• Original Assignee: Daimler Chrysler Corporation (Mercedes-Benz Group AG)
• Inventors: Fett, Dennis W., Ellies, Benjamin D., Adams, Joseph B.
• Primary Examiner(s): SOLIS, ERICK R
• Application Number:
  US09/213,975
• Time in Patent Office: 761 Days
• Field of Search: 123/361, 123/339.18, 123/339.19, 123/339.23, 123/339.21, 123/339.16, 123/339.17
• US Class Current: 123/339.17
• CPC Class Codes: F02D 41/083 taking into account engine load variation, e.g. air-conditionning

Abstract

A computer-implemented apparatus and method for inferring power steering load and for controlling airflow to an engine of a vehicle having an engine speed. A sensor which is connected to the engine senses the engine speed of the engine. An engine speed reference data table stores at least one engine reference speed, and a reference comparator module which is connected to the sensor and to the reference data table performs a comparison between the sensed engine speed and the engine reference speed. The airflow to the engine is controlled based upon the comparison.

Claims

1. A computer-implemented apparatus for controlling airflow to an engine of a vehicle having an engine speed comprising:

a sensor connected to the engine for sensing the engine speed of the engine;

an engine speed reference data table for storing first and second engine reference speeds; and

a reference comparator module for selecting between the first and second engine reference speeds based upon operational state of the vehicle, said reference comparator module performing a comparison between said sensed engine speed and said selected engine reference speed

wherein the comparator module does not perform the comparison using vehicle load sensed data nor using temperature sensed data;

whereby the airflow to the engine is controlled based upon said comparison.

2. The apparatus of claim 1 wherein said reference comparator module determines the difference between said sensed engine speed and said engine reference speed, said apparatus further comprising:

an engine speed threshold data table for storing at least one engine speed difference threshold;

a flag setting determinator module connected to said engine speed threshold data table and to said reference comparator module for performing a comparison between said determined difference with said stored engine speed difference threshold,

whereby the airflow to the engine is controlled based upon said comparison by said flag setting determinator module.

3. The apparatus of claim 1 further comprising:

historical data storage for storing historical data related to the engine speed; and

a valve opening determinator module connected to said flag setting determinator module for determining the amount of airflow to be provided to the engine.

4. The apparatus of claim 3 further comprising:

an air flow valve connected to said valve opening determinator module for controlling the amount of airflow to the engine, said valve opening determinator module providing control signals indicative of the degree of opening for said valve, said control signals being based upon the determined amount of airflow.

5. The apparatus of claim 1 further comprising:

a reference adjustment module for adjusting the reference speed based upon detection of a predetermined condition.

6. The apparatus of claim 5 wherein said predetermined condition is selected from the group consisting of air conditioning system being activated, a change in transmission state of the vehicle, activation of an engine fan, and combinations thereof.

7. The apparatus of claim 1 further comprising:

a reference adjustment module for delaying for a predetermined time said comparison by said reference comparator module between said sensed engine speed and said engine reference speed, said reference adjustment module delaying said comparison based upon detection of a predetermined condition.

8. The apparatus of claim 7 wherein said predetermined condition is a change in transmission state of the vehicle.

9. The apparatus of claim 1 wherein the value of said engine reference speed is established based upon fuel economy factors and upon steering sensitivity.

10. The apparatus of claim 1 wherein said engine reference speed is decreased in order to substantially follow said sensed engine speed.

11. The apparatus of claim 1 wherein said engine reference speed is decreased at a predetermined time unit in order to substantially follow said sensed engine speed.

12. The apparatus of claim 1 wherein said engine reference speed is increased based upon said sensed engine speed satisfying a predetermined lower limit.

13. A computer-implemented method for controlling airflow to an engine of a vehicle having an engine speed, comprising the steps of:

sensing the engine speed of the engine;

storing at least one engine reference speed;

performing a comparison between said sensed engine speed and said engine reference speed,

said performing of the comparing not being based upon vehicle load sensed data nor upon temperature sensed data;

controlling the airflow to the engine based upon said comparison.

14. The method of claim 13 further comprising the steps of:

determining the difference between said sensed engine speed and said engine reference speed;

storing at least one engine speed difference threshold;

performing a comparison between said determined difference with said stored engine speed difference threshold; and

controlling the airflow to the engine based upon said comparison by said flag setting determinator module.

15. The method of claim 13 further comprising the steps of:

storing historical data related to the engine speed;

and determining the amount of airflow to be provided to the engine.

16. The method of claim 13 further comprising the step of:

adjusting the reference speed based upon detection of a predetermined condition.

17. The method of claim 13 further comprising the steps of:

delaying for a predetermined time said comparison by said reference comparator module between said sensed engine speed and said engine reference speed; and

delaying said comparison based upon detection of a predetermined condition.

18. The method of claim 13 further comprising the step of:

decreasing said engine reference speed in order to substantially follow said sensed engine speed.

19. The method of claim 13 further comprising the step of:

increasing said engine reference speed based upon said sensed engine speed satisfying a predetermined lower limit.