Acceleration based automated slip control system

• US 20080179124A1
• Filed: 01/31/2007
• Published: 07/31/2008
• Est. Priority Date: 01/31/2007
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Stratton, Kenneth L.
• Granted Patent: US 7,779,947 B2
• Time in Patent Office: Days
• US Class Current: 180/197
• CPC Class Codes: B60T 8/175 Brake regulation specially adapted to prevent excessive wheel spin during vehicle acceleration, e.g. for traction control safety devices for propulsion unit control responsive to, or preventing, skidding of wheels B60K28/16
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/184 with wheel brakes
• CPC Class Codes: B60W 2300/125 Heavy duty trucks
• CPC Class Codes: B60W 2300/17 Construction vehicles, e.g. graders, excavators
• CPC Class Codes: B60W 2720/20 Sideslip angle
• CPC Class Codes: B60W 2720/26 Wheel slip
• CPC Class Codes: B60W 30/18172 Preventing, or responsive to skidding of wheels
• CPC Class Codes: B60W 40/10 related to vehicle motion
• CPC Class Codes: B60Y 2200/411 Bulldozers, Graders
• CPC Class Codes: E02F 9/2246 Control of prime movers, e.g. depending on the hydraulic load of work tools
• CPC Class Codes: E02F 9/2253 Controlling the travelling speed of vehicles, e.g. adjusting travelling speed according to implement loads, control of hydrostatic transmission

Abstract

A system for controlling slip of a machine is disclosed. The system has a power source configured to produce a power output, at least one driven traction device, and a transmission operably connected to transmit the power output from the power source to the at least one driven traction device. The system further has at least one sensor configured to detect an acceleration of the machine and to generate a corresponding signal, and a controller configured to receive the signal and to reduce a magnitude of power or torque transmitted to the at least one driven traction device when the detected acceleration indicates slip of the at least one driven traction device.

Claims

1. A system for controlling slip of a machine, the system comprising:

a power source configured to produce a power output;

at least one driven traction device;

a transmission operably connected to transmit the power output from the power source to the at least one driven traction device;

at least one sensor configured to detect an acceleration of the machine and to generate a corresponding signal; and

a controller configured to receive the signal and to reduce a magnitude of power transmitted to the at least one driven traction device when the detected acceleration indicates slip of the at least one driven traction device.

2. The system of claim 1, wherein the detected acceleration is in a direction substantially normal to a work surface on which the machine is operating.

3. The system of claim 1, wherein;

the controller compares the signal to a predetermined threshold associated with slip; and

the predetermined threshold varies in response to at least one of a machine operational parameter, a physical machine characteristic, and a ground condition.

4. The system of claim 1, wherein the magnitude of power transmitted to the at least one driven traction device is reduced by decreasing an output of the power source.

5. The system of claim 1, further including a braking mechanism associated with the at least one driven traction device, wherein the magnitude of power transmitted to the at least one driven traction device is reduced by actuating the braking mechanism.

6. The system of claim 1, wherein the magnitude of power transmitted to the at least one driven traction device is reduced by changing operation of the transmission.

7. The system of claim 6, wherein the transmission is a mechanical transmission and a torque transmitted to the at least one driven traction device is reduced by switching to a higher output gear ratio.

8. The system of claim 6, wherein the transmission is a hydraulic transmission and a torque transmitted to the at least one driven traction device is reduced by adjusting the displacement of at least one of a hydraulic motor and a hydraulic pump.

9. The system of claim 6, wherein the transmission is an electric transmission and a torque transmitted to the at least one driven traction device is reduced by limiting current to an electric motor.

10. A method of controlling slip of a machine including:

imparting force to propel the machine;

detecting an acceleration of the machine corresponding to tractive slip of the machine; and

reducing a magnitude of the imparted force in response to the detection.

11. The method of claim 10, further including comparing the acceleration to a predetermined threshold, wherein, the predetermined threshold varies in response to at least one of a machine operational parameter, a physical machine characteristic, and a ground condition.

12. The method of claim 10, wherein, the predetermined threshold is a magnitude of acceleration in a direction substantially normal to a work surface on which the machine is operating.

13. A machine, comprising:

a power source configured to produce a power output;

a work implement driven by the power source;

at least one driven traction device;

a transmission operably connected to transmit power from the power source to the at least one driven traction device;

at least one sensor configured to detect an acceleration of the machine and to generate a corresponding signal; and

a controller configured to receive the signal and to reduce a magnitude of power transmitted to the at least one driven traction device when the detected acceleration indicates slip of the at least one driven traction device.

14. The machine of claim 13, wherein the detected acceleration is in a direction substantially normal to a work surface on which the machine is operating.

15. The machine of claim 13, wherein the magnitude of power transmitted to the at least one driven traction device is reduced by decreasing an output of the power source.

16. The machine of claim 13, further including a braking mechanism associated with the at least one driven traction device, wherein the magnitude of power transmitted to the at least one driven traction device is reduced by actuating the braking mechanism.

17. The machine of claim 13, wherein the magnitude of power transmitted to the at least one driven traction device is reduced by changing operation of the transmission.

18. The machine of claim 17, wherein the transmission is a mechanical transmission and a torque transmitted to the at least one driven traction device is reduced by switching to a higher output gear ratio.

19. The machine of claim 17, wherein the transmission is a hydraulic transmission and a torque transmitted to the at least one driven traction device is reduced by adjusting the displacement of at least one of a hydraulic motor and a hydraulic pump.

20. The machine of claim 17, wherein the transmission is an electric transmission and a torque transmitted to the at least one driven traction device is reduced by limiting current to an electric motor.