Diagnostic supervisor to determine if a traction system is in a fault condition

• US 9,868,445 B2
• Filed: 08/11/2016
• Issued: 01/16/2018
• Est. Priority Date: 08/14/2015
• Status: Active Grant

• Current Assignee: Crown Equipment Corporation
• Original Assignee: Crown Equipment Corporation
• Inventors: Mangette, Stephen T., Hammer, Joe K., Barnhart, Brent A.
• Primary Examiner(s): Bendidi, Rachid
• Application Number:
  US15/234,152
• Publication Number:
  US 20170043787A1
• Time in Patent Office: 523 Days
• CPC Class Codes: B60W 2050/0037 Mathematical models of vehicle sub-units
• CPC Class Codes: B60W 2050/021 Means for detecting failure or malfunction
• CPC Class Codes: B60W 2300/121 Fork lift trucks, Clarks
• CPC Class Codes: B60W 2510/20 Steering systems
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2520/26 Wheel slip
• CPC Class Codes: B60W 2520/28 Wheel speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/18 Steering angle
• CPC Class Codes: B60W 2710/20 Steering systems
• CPC Class Codes: B60W 2710/207 Steering angle of wheels
• CPC Class Codes: B60W 2720/24 Direction of travel
• CPC Class Codes: B60W 2720/26 Wheel slip
• CPC Class Codes: B60W 30/02 Control of vehicle driving stability
• CPC Class Codes: B60W 40/10 related to vehicle motion
• CPC Class Codes: B60W 50/0098 Details of control systems ensuring comfort, safety or stability not otherwise provided for
• CPC Class Codes: B60W 50/0205 Diagnosing or detecting failures; Failure detection models
• CPC Class Codes: B60W 50/045 Monitoring control system parameters
• 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: B60W 50/087 where the control system corrects or modifies a request from the driver
• CPC Class Codes: B66F 9/06 : movable, with their loads, on wheels or the like, e.g. fork-lift trucks vehicle aspects B60 - B62; vehicles predominantly for transporting loads and modified to facilitate loading or unloading B60P1/00; low-lift hand trucks for transporting goods B62B3/06
• CPC Class Codes: B66F 9/07568 : Steering arrangements
• CPC Class Codes: G05D 1/0223 : involving speed control of the vehicle vehicle fittings for automatically controlling, i.e. preventing speed from exceeding an arbitrarily established velocity or maintaining speed at a particular velocity, as selected by the vehicle operator B60K31/00
• CPC Class Codes: G07C 5/0808 : Diagnosing performance data testing of vehicles G01M17/00; testing of electrical installation on vehicles G01R31/005

Abstract

A steering application executing on a vehicle control module receives a steering control input to control a steered wheel of a vehicle. Based on the steering control input, the steering application determines a traction threshold value associated with a traction control attribute related to a traction wheel of the vehicle. A first diagnostic supervisor executing on the vehicle control module receives a measured value of the traction control attribute and the traction threshold value. When the measured value of the traction control attribute exceeds the traction threshold value, the first diagnostic supervisor repeatedly calculates a respective difference between the traction threshold value and the measured value of the traction control attribute to generate a set comprising a plurality of the respective differences. Based on the plurality of respective differences, the first diagnostic supervisor determines a first operating condition of a traction system of the vehicle.

Claims

1. A method comprising:

receiving, by a steering application executing on a vehicle control module;

a steering control input to control a steered wheel of a vehicle;

based on the steering control input, determining, by the steering application;

a traction threshold value associated with a traction control attribute related to a traction wheel of the vehicle;

receiving by a first diagnostic supervisor executing on the vehicle control module;

a measured value of the traction control attribute, and

the traction threshold value;

when the measured value of the traction control attribute exceeds the traction threshold value, repeatedly calculating, by the first diagnostic supervisor, a respective difference between the traction threshold value and the measured value of the traction control attribute, to generate a set comprising a plurality of the respective differences; and

based on the plurality of respective differences, determining, by the first diagnostic supervisor, a first operating condition of a traction system of the vehicle.

2. The method of claim 1, comprising:

for each respective difference;

determining if the difference is greater than a difference threshold;

when the difference is greater than the difference threshold, incrementing a first counter value; and

when the difference is less than or equal to the difference threshold, resetting the first counter to a first initial value.

3. The method of claim 2, comprising:

determining a fault condition of the traction system has occurred when the first counter value is greater than a first counter threshold.

4. The method of claim 2, wherein the first counter threshold and the difference threshold are based on response characteristics of the traction system to at least one operational input received by the vehicle.

5. The method of claim 1, wherein the traction threshold value comprises a traction speed limit.

6. The method of claim 1, comprising:

for each respective difference;

determining if the difference is greater than a difference threshold;

when the difference is greater than the difference threshold, incrementing a first counter value;

when the difference is less than or equal to the difference threshold, resetting the first counter to a first initial value;

determining if the difference is greater than an immediately preceding difference in the set of respective differences;

when the difference is greater than the immediately preceding difference, incrementing a second counter value; and

when the difference is less than or equal to the immediately preceding difference, resetting the second counter value to a second initial value.

7. The method of claim 6, comprising:

determining a fault condition of the traction system has occurred when either the first counter value is greater than a first counter threshold or the second counter value is greater than a second counter threshold.

8. The method of claim 7, wherein the first counter threshold, the second counter threshold and the difference threshold are based on response characteristics of the traction system to at least one operational input received by the vehicle.

9. The method of claim 1, comprising:

for each respective difference;

determining if the difference is greater than a first difference threshold;

when the difference is greater than the first difference threshold, incrementing a first counter value,

when the difference is less than or equal to the first difference threshold, resetting the first counter to a first initial value;

determining if the difference is greater than a second difference threshold;

when the difference is greater than the second difference threshold, incrementing a second counter value; and

when the difference is less than or equal to the second difference threshold, resetting the second counter to a second initial value.

10. The method of claim 9, comprising:

determining a fault condition of the traction system has occurred when either the first counter value is greater than a first counter threshold or the second counter value is greater than a second counter threshold.

11. The method of claim 10, wherein the first counter threshold, the second counter threshold, the first difference threshold, and the second difference threshold are based on response characteristics of the traction system to at least one operational input received by the vehicle.

12. A vehicle control system comprising:

a controller comprising;

a first input configured to receive a steering control input to control a steered wheel of a vehicle,

a second input configured to receive a measured value of a traction control attribute related to a traction wheel of the vehicle, and

a third input configured to receive a traction speed control input to control the traction wheel of the vehicle;

a memory coupled with the controller and storing code executable by the controller;

the executable code comprising a steering application configured to;

receive the steering control input to control the steered wheel of the vehicle, and

determine, based on the steering control input, a traction threshold value associated with the traction control attribute related to the traction wheel of the vehicle; and

the executable code comprising a diagnostic supervisor configured to;

a) receive;

a measured value of the traction control attribute, and

the traction threshold value;

b) repeatedly calculate, when the measured value of the traction control attribute exceeds the traction threshold value, and a respective difference between the traction threshold value and the measured value of the traction control attribute, to generate a set comprising a plurality of the respective differences; and

c) determine, based on the plurality of respective differences, a first operating condition of a traction system of the vehicle.

13. The system of claim 12, wherein the diagnostic supervisor is configured to:

for each respective difference;

determine if the difference is greater than a difference threshold;

when the difference is greater than the difference threshold, increment a first counter value; and

when the difference is less than or equal to the difference threshold, reset the first counter to a first initial value.

14. The system of claim 13, wherein the diagnostic supervisor is configured to:

determine a fault condition of the traction system has occurred when the first counter value is greater than a first counter threshold.

15. The system of claim 14, wherein the first counter threshold and the difference threshold are based on response characteristics of the traction system to at least one operational input received by the vehicle.

16. The system of claim 12, wherein the traction threshold value comprises a traction speed limit.

17. The system of claim 12, wherein the diagnostic supervisor is configured to:

for each respective difference;

determine if the difference is greater than a difference threshold;

when the difference is greater than the difference threshold, increment a first counter value;

when the difference is less than or equal to the difference threshold, reset the first counter to a first initial value;

determine if the difference is greater than an immediately preceding difference in the set of respective differences;

when the difference is greater than the immediately preceding difference, increment a second counter value; and

when the difference is less than or equal to the immediately preceding difference, reset the second counter value to a second initial value.

18. The system of claim 17, wherein the diagnostic supervisor is configured to:

determine a fault condition of the traction system has occurred when either the first counter value is greater than a first counter threshold or the second counter value is greater than a second counter threshold.

19. The system of claim 18, wherein the first counter threshold, the second counter threshold and the difference threshold are based on response characteristics of the traction system to at least one operational input received by the vehicle.

20. The system of claim 12, wherein the diagnostic supervisor is configured to:

for each respective difference;

determine if the difference is greater than a first difference threshold;

when the difference is greater than the first difference threshold, increment a first counter value; and

when the difference is less than or equal to the first difference threshold, reset the first counter to a first initial value;

determine if the difference is greater than a second difference threshold;

when the difference is greater than the second difference threshold, increment a second counter value; and

when the difference is less than or equal to the second difference threshold, reset the second counter to a second initial value.

21. The system of claim 20, wherein the diagnostic supervisor is configured to:

determine a fault condition of the traction system has occurred when either the first counter value is greater than a first counter threshold or the second counter value is greater than a second counter threshold.

22. The system of claim 21, wherein the first counter threshold, the second counter threshold, the first difference threshold, and the second difference threshold are based on response characteristics of the traction system to at least one operation.