Slope-limited retarding control for a propelled machine

• US 7,460,941 B2
• Filed: 02/28/2005
• Issued: 12/02/2008
• Est. Priority Date: 09/29/2004
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Sychra, Robert Roy, Garnett, Stephen Carl
• Primary Examiner(s): To; Tuan C
• Application Number:
  US11/067,623
• Publication Number:
  US 20060069488A1
• Time in Patent Office: 1,373 Days
• Field of Search: 701 50- 99, 477/7, 374/14, 373/48, 374/12, 373/82, 172/2
• US Class Current: 701/50
• CPC Class Codes: B60K 6/46 Series type
• CPC Class Codes: B60L 2220/18 Reluctance machines
• CPC Class Codes: B60L 2240/642 Slope of road
• CPC Class Codes: B60L 50/13 using AC generators and AC motors
• CPC Class Codes: B60L 7/06 for vehicles propelled by ac motors
• CPC Class Codes: B60L 7/26 Controlling the braking effect
• CPC Class Codes: B60T 1/10 by utilising wheel movement for accumulating energy, e.g. driving air compressors
• CPC Class Codes: B60T 13/586 the retarders being of the electric type
• CPC Class Codes: B60T 2201/04 Hill descent control
• CPC Class Codes: B60T 2230/03 Overturn, rollover
• CPC Class Codes: B60T 2270/604 Merging friction therewith; Adjusting their repartition
• CPC Class Codes: B60T 7/12 for automatic initiation; for initiation not subject to will of driver or passenger limiting speed of vehicles other than rail vehicles B60K31/00
• CPC Class Codes: B60T 8/245 Longitudinal vehicle inclination
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/18 including control of braking systems
• CPC Class Codes: B60W 10/184 with wheel brakes
• CPC Class Codes: B60W 10/196 acting within the driveline, e.g. retarders
• 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 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2552/15 : Road slope, i.e. the inclination of a road segment in the longitudinal direction
• CPC Class Codes: B60W 30/02 : Control of vehicle driving stability
• CPC Class Codes: B60W 30/18127 : Regenerative braking
• CPC Class Codes: B60Y 2200/25 : Track vehicles
• CPC Class Codes: B60Y 2200/411 : Bulldozers, Graders
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• 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 90/16 : Information or communication technologies improving the operation of electric vehicles

Abstract

A method is provided for dissipating power in a propelled machine having an electric drive system and a mechanical brake system. An inclination of the machine is determined. A speed of the machine is determined. A retarding requirement is determined based on the determined inclination and speed. A first portion of the retarding requirement is allocated to be met by the electric drive system, the first portion being less than or equal to a retarding capacity of the electric drive system. A second portion of the retarding requirement is allocated to be met by the mechanical brake system if the retarding requirement is greater than the retarding capacity of the electric drive system.

Claims

1. A system for dissipating power in a propelled machine having an electric drive system and a mechanical brake system, comprising:

an inclination indicator configured to output a signal corresponding to an inclination of the machine;

a speed indicator configured to output a signal corresponding to a speed of the machine;

a retarding requirement calculator configured to determine a retarding requirement based on the indicated inclination and speed; and

a controller configured to;

allocate the retarding requirement to be met by the electric drive system, if the retarding requirement is less than or equal to a retarding capacity of the electric drive system; and

allocate the retarding requirement between the electric drive system and the mechanical brake system if the retarding requirement is greater than the retarding capacity of the electric drive system.

2. The system of claim 1, wherein the inclination indicator is configured to indicate inclination around a pitch axis of the machine.

3. The system of claim 2, wherein the inclination indicator is further configured to indicate inclination around a roll axis of the machine.

4. The system of claim 1, wherein the inclination indicator is configured to indicate inclination around a roll axis of the machine.

5. The system of claim 1, further including a travel direction indicator configured to indicate a travel direction of the machine;

and

wherein the retarding requirement calculator is further configured to determine a retarding requirement of the electric drive system based on the travel direction.

6. The system of claim 1, wherein the controller is further configured to control the electric drive system to dissipate the retarding requirement allocated to the electric drive system and to control the mechanical brake system to dissipate the retarding requirement allocated to the mechanical brake system.

7. The system of claim 1, wherein the controller is further configured to control at least one of an engine of the electric drive system and a resistive grid of the electric drive system to dissipate the retarding requirement allocated to the electric drive system.

8. The system of claim 1, wherein the controller is further configured to control at least one brake of the mechanical brake system to dissipate the retarding requirement allocated to the mechanical brake system.

9. A propelled machine, comprising:

an electric drive system;

a mechanical brake system;

an inclination indicator configured to output a signal corresponding to an inclination of the machine;

a speed indicator configured to output a signal corresponding to a speed of the machine;

a retarding requirement calculator configured to determine a retarding requirement based on the indicated inclination and speed; and

a controller configured to;

allocate the retarding requirement to be met by the electric drive system, if the retarding requirement is less than or equal to a retarding capacity of the electric drive system; and

allocate the retarding requirement between the electric drive system and the mechanical brake system if the retarding requirement is greater than the retarding capacity of the electric drive system.

10. The machine of claim 9, wherein the inclination indicator is configured to indicate inclination around a pitch axis of the machine.

11. The machine of claim 10, wherein the inclination indicator is further configured to indicate inclination around a roll axis of the machine.

12. The machine of claim 9, wherein the inclination indicator is configured to indicate inclination around a roll axis of the machine.

13. The machine of claim 9, further including a travel direction indicator configured to indicate a travel direction of the machine;

and

wherein the retarding requirement calculator is further configured to determine a retarding requirement of the electric drive system based on the travel direction.

14. The machine of claim 9, wherein the controller is further configured to control the electric drive system to dissipate the retarding requirement allocated to the electric drive system and to control the mechanical brake system to dissipate the retarding requirement allocated to the mechanical brake system.

15. The machine of claim 9, wherein the controller is further configured to control at least one of an engine of the electric drive system and a resistive grid of the electric drive system to dissipate the retarding requirement allocated to the electric drive system.

16. The machine of claim 9, wherein the controller is further configured to control at least one brake of the mechanical brake system to dissipate the retarding requirement allocated to the mechanical brake system.