Method for controlling a functional system of a materials handling vehicle

• US 9,981,836 B2
• Filed: 01/28/2016
• Issued: 05/29/2018
• Est. Priority Date: 03/31/2015
• Status: Active Grant

• Current Assignee: Crown Equipment Corporation
• Original Assignee: Crown Equipment Corporation
• Inventors: Castaneda, Anthony T., Clapp, James E., Thobe, Nicholas D., Schnipke, Eric L.
• Primary Examiner(s): Sample, Jonathan L
• Application Number:
  US15/009,174
• Publication Number:
  US 20160289056A1
• Time in Patent Office: 852 Days
• Field of Search: 701 50
• CPC Class Codes: B60R 16/033 characterised by the use of electrical cells or batteries for propulsion puposes B60K1/04; supplying batteries to, or removing batteries from, vehicles B60S5/06; testing of charge state G01R31/36
• CPC Class Codes: B66F 9/07572 Propulsion arrangements
• CPC Class Codes: B66F 9/20 Means for actuating or controlling masts, platforms, or forks power take-off from vehicle transmissions, combined with vehicle propulsion systems B60K
• CPC Class Codes: B66F 9/24 Electrical devices or systems

Abstract

Controlling a functional system of a materials handling vehicle includes monitoring a current delivered by an energy storage system for powering the functional system, wherein the energy storage system may include at least one of a battery and a fuel cell. When the current delivered by the energy storage system exceeds a first predetermined amount, performance of the functional system is reduced from a first operating level to a second operating level for at least one task of the functional system to attempt to reduce the current delivered by the energy storage system.

Claims

1. A method of estimating a period of time comprising:

periodically sensing a respective temperature of each of a plurality of components of an industrial vehicle while the vehicle is powered on;

from among the most recently sensed respective temperatures, storing the maximum respective temperature;

from among the most recently sensed respective temperatures, storing the minimum respective temperature;

detecting that the industrial vehicle is powered on from a powered off condition;

sensing a new respective temperature of each of the plurality of components;

from among the new respective temperatures, determining a maximum new respective temperature;

estimating, by a computer of the industrial vehicle, a period of time the industrial vehicle was in the powered off condition based on the stored maximum respective temperature and the maximum new respective temperature;

storing, by the computer of the industrial vehicle, an array of stored current values for a functional system of the industrial vehicle;

adjusting, by the computer of the industrial vehicle, respective current values based on the estimated period of time; and

calculating, by the computer of the industrial vehicle, a monitored current value for the functional system of the industrial vehicle based on the adjusted current values.

2. The method of claim 1, wherein estimating the period of time is based on a difference between the stored maximum respective temperature and the maximum new respective temperature.

3. The method of claim 2, wherein estimating the period of time is based on the stored minimum respective temperature.

4. The method of claim 2, wherein estimating the period of time is based on scaling the difference by a temperature decay rate.

5. The method of claim 4, wherein the temperature decay rate is selected from among a respective, corresponding temperature decay rate for each of the plurality of components.

6. The method of claim 5, wherein the selected temperature decay rate is the slowest of the respective corresponding temperature decay rates.

7. The method of claim 1, wherein the period of time is estimated according to:

8. The method of claim 7, wherein the estimated period of time is at least partly based on a stored ambient temperature value.

9. The method of claim 8, wherein the temperature decay rate is calculated according to:

10. The method of claim 9, wherein the thermal time constant value is selected from among a respective, corresponding thermal time constant value for each of the plurality of components.

11. The method of claim 5, wherein the selected thermal time constant value is the slowest of the respective corresponding thermal time constant values.

12. A method of estimating a period of time comprising:

periodically sensing a temperature of at least one component of an industrial vehicle while the industrial vehicle is powered on;

storing the most recently sensed temperature;

detecting that the industrial vehicle is powered on from a powered off condition;

sensing a new temperature of the at least one component;

estimating, by a computer of the industrial vehicle, a period of time the industrial vehicle was in the powered off condition based on the stored temperature and the new temperature;

storing, by the computer of the industrial vehicle, an array of stored current values for a functional system of the industrial vehicle;

adjusting, by the computer of the industrial vehicle, respective current values based on the estimated period of time; and

calculating, by the computer of the industrial vehicle, a monitored current value for the functional system of the industrial vehicle based on the adjusted current values.

13. The method of claim 12, wherein estimating the period of time is based on a difference between the stored temperature and the new temperature.

14. The method of claim 13, wherein estimating the period of time is based on scaling the difference by a temperature decay rate.

15. The method of claim 14, wherein the temperature decay rate is based on the at least one component.

16. The method of claim 12, wherein the period of time is estimated according to:

17. The method of claim 16, wherein the estimated period of time is at least partly based on a stored ambient temperature value.

18. The method of claim 17, wherein the temperature decay rate is calculated according to:

19. The method of claim 18, wherein the thermal time constant value is based on the at least one component.