Diagnosing malfunctions in materials handling vehicles

• US 6,212,449 B1
• Filed: 09/28/1998
• Issued: 04/03/2001
• Est. Priority Date: 09/30/1997
• Status: Expired due to Term

• Current Assignee: Crown Equipment Corporation
• Original Assignee: Crown Equipment Corporation
• Inventors: Wellman, Timothy A., Gaskell, James W., Meiring, Donald T.
• Primary Examiner(s): NGUYEN, TAN QUANG
• Application Number:
  US09/161,823
• Time in Patent Office: 918 Days
• Field of Search: 701/29, 701/30, 701/32, 701/33, 701/34, 701/35, 340/438, 340/439
• US Class Current: 701/29
• CPC Class Codes: B66F 9/24 Electrical devices or systems
• CPC Class Codes: G01R 31/007 using microprocessors or computers

Abstract

A diagnosis system for materials handling vehicles leads service personnel step-by-step through diagnosis and repair of faults within the vehicle. Faults are assigned corresponding event codes so that when a fault is detected, its corresponding event code is displayed. The event codes uniquely identify systems of the vehicle in which faults have occurred by having the event codes for a given vehicle system all start with the same number. Thus, the technician knows from the event code what system needs to be diagnosed/repaired and what tools and probable parts will be needed. The event code is used to access diagnosis information identifying the portion of the vehicle wherein the malfunction has occurred, the components which caused the malfunction and, preferably, provides a pictogram of that portion of the vehicle. The technician advances to the malfunctioning portion of the vehicle where another pictorial depiction of the components of that portion of the vehicle assists in locating the components. All components are marked within the vehicle by identifiers which are consistently used throughout the diagnostic information, pictorial representations and service manuals. The diagnostic information tells the technician what to do to diagnose the components with the diagnosis being preformed using the electronic control system of the vehicle to monitor inputs to and outputs from the electronic control system and to apply limited duration full power test signals to components to be tested. The diagnostic information is configured so that testing is done from the end of control paths back to the controller.

Claims

1. A method for diagnosing faults within a materials handling vehicle by providing information on time to a repair person, said method comprising the steps of:

providing diagnostic information for a plurality of possible faults within said vehicle, said plurality of possible faults being identified by a corresponding plurality of event codes with each of said plurality of event codes being within one of at least two series of event codes, each series of event codes identifying a system of said vehicle to enable a repair person to prepare for diagnosis of faults within an identified system corresponding to an event code'"'"'s series;

locating pictorial depictions of portions of said vehicle on corresponding portions of said vehicle to facilitate location and identification of components at said portions of said vehicle by reference to said pictorial depictions;

detecting a fault within a materials handling vehicle;

generating one event code of said plurality of event codes representative of said detected fault;

accessing said diagnostic information using said one event code, said diagnostic information identifying a portion of said vehicle within which said detected fault occurred and identifying one or more components at said portion of said vehicle capable of causing said detected fault thereby directing said repair person to said portion of said vehicle and said one or more components;

accessing a pictorial depiction of said portion of said vehicle within which said fault has been detected, said pictorial depiction being located at said portion of said vehicle for ready access by said repair person to facilitate location and identification of said one or more components; and

diagnosing said one or more components utilizing said diagnostic information.

2. A method for diagnosing faults within a materials handling vehicle as claimed in claim 1 wherein said step of providing diagnostic information for a plurality of possible faults within said vehicle comprises the step of providing said diagnostic information as a hard copy.

3. A method for diagnosing faults within a materials handling vehicle as claimed in claim 1 wherein said step of providing diagnostic information for a plurality of possible faults within said vehicle comprises the step of providing said diagnostic information on line.

4. A method for diagnosing faults within a materials handling vehicle as claimed in claim 1 wherein said portions of said vehicle are closed and said step of locating pictorial depictions of portions of said vehicle on corresponding portions of said vehicle comprises locating said pictorial depictions within said closed portions of said vehicle.

5. A method for diagnosing faults within a materials handling vehicle as claimed in claim 1 wherein said portion of said vehicle within which said detected fault occurred is under the control of a single module of an electronic control system of said vehicle and said step of diagnosing said one or more components utilizing said diagnostic information comprises the steps of:

monitoring inputs to said single module; and

monitoring outputs from said single module.

6. A method for diagnosing faults within a materials handling vehicle as claimed in claim 5 further comprising the step of displaying monitored inputs and outputs.

7. A method for diagnosing faults within a materials handling vehicle as claimed in claim 6 further comprising the step of saving a history of operation of at least some of said monitored inputs and wherein said step of displaying monitored inputs and outputs comprises the step of displaying said history.

8. A method for diagnosing faults within a materials handling vehicle as claimed in claim 7 wherein said step of saving a history of at least some of said inputs comprises the step of saving inputs generated by switches within said vehicle.

9. A method for diagnosing faults within a materials handling vehicle as claimed in claim 8 wherein said step of saving inputs generated by switches within said vehicle comprises saving at least the last three inputs generated by said switches.

10. A method for diagnosing faults within a materials handling vehicle as claimed in claim 5 wherein said step of diagnosing said one or more components utilizing said diagnostic information further comprises the steps of generating outputs from said single module.

11. A method for diagnosing faults within a materials handling vehicle as claimed in claim 10 wherein said step of generating outputs from said single module comprises the step of generating full power outputs from said single module.

12. A method for diagnosing faults within a materials handling vehicle as claimed in claim 11 wherein said step of generating outputs from said module comprises the step of limiting the time duration of said full power outputs from said single module.

13. A method for diagnosing faults within a materials handling vehicle as claimed in claim 12 wherein said step of limiting the time duration of said full power outputs from said single module comprises the step of limiting said full power outputs to 2 seconds or as long as a test is requested, whichever is shorter.

14. A method for diagnosing faults within a materials handling vehicle as claimed in claim 1 further comprising the step of displaying said one event code of said plurality of event codes representative of said detected fault.

15. A method for diagnosing faults within a materials handling vehicle as claimed in claim 14 wherein said step of displaying said one event code of said plurality of event codes representative of said detected fault comprises the step of displaying said one event code on an alphanumeric display.

16. A method for diagnosing faults within a materials handling vehicle as claimed in claim 14 wherein said step of displaying said one event code of said plurality of event codes representative of said detected fault comprises the step of displaying said one event code with a blinking light source.

17. A method for diagnosing faults within a materials handling vehicle as claimed in claim 16 wherein said one event code is a numeric having at least two digits and said step of displaying said one event code with a blinking light source comprises the steps of:

providing an initialization signal; and

blinking each digit of said event code in seriatim, each digit of said one event code being separated from another digit of said event code by a first dark period of said light source.

18. A method for diagnosing faults within a materials handling vehicle as claimed in claim 17 wherein said initialization signal comprises a second dark period of said light source.

19. A method for diagnosing faults within a materials handling vehicle as claimed in claim 16 wherein one event code is a numeric having at least two digits and said step of displaying said one event code with a blinking light source comprises the steps of:

providing an initialization signal;

blinking a run time event signal; and

blinking each digit of said event code in seriatim, each digit of said event code being separated from another digit of said event code and from said run time event signal by a dark period of said light source.

20. A method for diagnosing faults within a materials handling vehicle as claimed in claim 1 wherein said portion of said vehicle within which said detected fault occurred is under the control of a single module of an electronic control system of said vehicle and said step of diagnosing said one or more components utilizing said diagnostic information comprises the step of first testing said one or more components and circuitry external to said single module.

21. A method for diagnosing faults within a materials handling vehicle as claimed in claim 1 wherein said portion of said vehicle within which said detected fault occurred is under the control of a single module of a multiple module electronic control system of said vehicle and said step of diagnosing said one or more components utilizing said diagnostic information comprises the step of generating outputs from said single module.

22. A method for diagnosing faults within a materials handling vehicle as claimed in claim 21 wherein said multiple module control system comprises at least a primary control module and said single module, and said step of generating outputs from said single module comprises the step of driving said single module from said primary control module.