Power-limiting control method and system for a work vehicle

• US 6,745,117 B1
• Filed: 05/16/2003
• Issued: 06/01/2004
• Est. Priority Date: 05/16/2003
• Status: Active Grant

• Current Assignee: Deere & Company
• Original Assignee: Deere & Company
• Inventors: Thacher, Russell James, DeRoo, Chris Alan
• Primary Examiner(s): Camby, Richard M.
• Application Number:
  US10/439,517
• Time in Patent Office: 382 Days
• Field of Search: 180/65.2, 180/65.3, 180/65.8, 701/1, 701/29, 701/35, 701/36, 701/50, 701/70, 701/99, 477/7
• US Class Current: 701/50
• CPC Class Codes: A01B 63/00 Lifting or adjusting devices or arrangements for agricultural machines or implements lifting mechanisms for the cutter-bar of a mower A01D34/24; adjusting devices for the cutter-bar of a mower A01D34/28; constructional features of lifting devices per se B66F
• CPC Class Codes: A01B 67/00 Devices for controlling the tractor motor by resistance of tools preventing overstrain A01B61/00
• CPC Class Codes: B60K 6/26 characterised by the motors or the generators
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2200/40 Working vehicles
• CPC Class Codes: B60L 2220/12 Induction machines
• CPC Class Codes: B60L 2220/14 Synchronous machines
• CPC Class Codes: B60L 2220/16 DC brushless machines
• CPC Class Codes: B60L 2220/18 Reluctance machines
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/429 Current
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 2240/80 Time limits
• CPC Class Codes: B60L 50/62 charged by low-power generators primarily intended to support the batteries, e.g. range extenders
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/16 responding to battery ageing, e.g. to the number of charging cycles or the state of health [SoH]
• CPC Class Codes: B60L 58/40 for controlling a combination of batteries and fuel cells
• CPC Class Codes: B60W 10/24 including control of energy storage means
• CPC Class Codes: B60W 10/30 : including control of auxiliary equipment, e.g. air-conditioning compressors or oil pumps
• CPC Class Codes: B60W 20/00 : Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/13 : in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• CPC Class Codes: B60W 2300/156 : Ridable lawn mowers
• CPC Class Codes: B60W 2510/24 : Energy storage means
• CPC Class Codes: B60W 2510/244 : Charge state
• CPC Class Codes: B60W 2710/24 : Energy storage means
• CPC Class Codes: B60Y 2200/223 : Ridable lawn mowers
• CPC Class Codes: B60Y 2200/41 : Construction vehicles, e.g. graders, excavators
• CPC Class Codes: Y02P 90/60 : Electric or hybrid propulsion means for production processes
• CPC Class Codes: Y02T 10/40 : Engine management systems
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• 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
• CPC Class Codes: Y02T 90/40 : Application of hydrogen technology to transportation, e.g. using fuel cells
• CPC Class Codes: Y10S 903/906 : Motor or generator

Abstract

A capacity estimator determines a total maximum allowable power storage capacity for a work vehicle. A timer times the operating time of the work vehicle in an electrically propelled mode. A load manager, a driver or both decrease the available power to at least one of a drive motor of the work vehicle and an ancillary load over the operating time to conserve the available power stored for operating at least one critical work vehicle.

Claims

1. A method of controlling power consumption of a work vehicle, the method comprising:

determining a total maximum allowable power draw for a work vehicle;

classifying power loads of the work vehicle into critical power loads and non-critical power loads;

timing the operating time of the work vehicle in an electrically propelled mode; and

allocating the available power between the critical power loads and non-critical power loads according to the operating time.

2. The method according to claim 1 wherein allocating to the non-critical loads is decreased or eliminated such that the total maximum allowable power draw is decreased with an increase in the operating time in conformance with a generally linear mathematical function between maximum allowable power draw versus time in the electrically propelled mode.

3. The method according to claim 1 wherein the allocating to the non-critical loads is decreased or eliminated such that the total maximum power draw is decreased in accordance with a graphical map of maximum allowable power draw versus time in the electrically propelled mode.

4. The method according to claim 1 wherein the allocating comprises limiting the maximum velocity of a drive motor as a non-critical load and allowing power to be drawn by a motor for moving a motor blade as a critical load.

5. A method of controlling power consumption of a work vehicle, the method comprising:

determining a total maximum allowable power storage capacity for a work vehicle;

timing the operating time of the work vehicle in an electrically propelled mode; and

decreasing the available power to at least one drive motor of the work vehicle over the operating time to conserve the available power stored for operating at least one critical load of the work vehicle.

6. The method according to claim 5 wherein the decreasing comprises sending a signal to a motor driver for limiting a maximum rotational velocity of a motor.

7. The method according to claim 5 wherein the decreasing comprises sending a signal to a motor driver for changing a drive frequency to an alternating current motor to limit a maximum rotational velocity of a motor.

8. The method according to claim 5 wherein the decreasing comprises sending a signal to a motor driver for changing a digital signal to a direct current motor to limit a maximum rotational velocity of the motor.

9. The method according to claim 5 wherein the decreasing comprises sending a signal to a motor driver to limit at least one of the maximum current draw and the maximum voltage applied to the motor to limit the power consumption of the electric drive.

10. The method according to claim 5 further comprising maintaining a load history of loading placed on the work vehicle versus time from historical operations in the electrically propelled mode.

11. The method according to claim 10 wherein the available power to the drive motor is decreased pursuant to at least one of the maximum storage capacity, the operating time, and the load history.

12. The method according to claim 10 wherein the load history comprises a power draw over a time period immediately preceding operation in the electrically propelled mode.

13. A system of controlling power consumption of a work vehicle, the system comprising:

a capacity estimator for determining a total maximum allowable power draw for a work vehicle;

a classifier for classifying power loads of the work vehicle into critical power loads and non-critical power loads;

a timer for timing the operating time of the work vehicle in an electrically propelled mode; and

a controller for allocating the available power between at least one critical power load and at least one non-critical power load according to the operating time.

14. The system according to claim 13 wherein the controller decreases a total maximum allowable power draw of the at least one non-critical power load with an increase in the operating time in conformance with a generally linear mathematical function between the total maximum allowable power draw versus time of operation of the electrically propelled mode since a last recharge of an energy storage device.

15. The system according to claim 13 wherein the controller decreases the total maximum power draw of the at least one non-critical load in accordance with a graphical map of maximum allowable power draw versus operational time of the vehicle in the electrically propelled mode since a last recharge of an energy storage device.

16. The system according to claim 13 wherein the controller facilitates limiting a maximum velocity of a drive motor as the at least one non-critical load and allowing power to be drawn by an electrical motor as the at least one critical load;

the electrical motor arranged to move a cutting blade and the drive motor arranged to propel the vehicle.

17. A system of controlling power consumption of a work vehicle, the system comprising:

a capacity estimator for determining a total maximum allowable power storage capacity for a work vehicle;

a timer for timing the operating time of the work vehicle in an electrically propelled mode; and

a controller for decreasing the available power to at least one drive motor of the work vehicle over the operating time to conserve the available power stored for operating at least one critical load of the work vehicle.

18. The system according to claim 17 further comprising a driver coupled to the controller, the controller sending a signal to the driver for limiting a maximum rotational velocity of the drive motor to decrease the available power.

19. The system according to claim 17 further comprising a driver coupled to the controller, the controller sending a signal to the driver for changing a drive frequency of an input signal to an alternating current motor, as the drive motor, to limit a maximum rotational velocity of the driver motor.

20. The system according to claim 17 further comprising a driver coupled to the controller, the controller sending a signal to the driver for changing a digital signal to a direct current motor to limit a maximum rotational velocity of the drive motor.

21. The system according to claim 17 further comprising a driver coupled to the controller, the controller sending a signal to the driver to limit at least one of the maximum current draw and the maximum voltage applied to the driver motor to limit the power consumption of the drive motor.

22. The system according to claim 17 further comprising a data storage device associated with the controller;

the data storage device maintaining a historical power consumption of loading placed on the work vehicle versus time from historical operations in the electrically propelled mode.

23. The system according to claim 22 wherein the available power to the drive motor is decreased pursuant to at least one of the maximum allowable power storage capacity, the operating time, and the historical power consumption data.

24. The system according to claim 22 wherein the historical power consumption data comprises a power draw over a time period immediately preceding operation in the electrically propelled mode.