ELECTRIC DRIVE CONTROL FOR A MACHINE

• US 20130045072A1
• Filed: 08/17/2011
• Published: 02/21/2013
• Est. Priority Date: 08/17/2011
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Jensen, Jeffrey E.
• Granted Patent: US 8,589,037 B2
• Time in Patent Office: Days
• US Class Current: 414/699
• CPC Class Codes: E02F 9/2087 Control of vehicle steering for steering with hydraulic or pneumatic drives E02F9/225
• 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
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

A control system for a machine having a power source, one or more electric propulsion motors connected to the power source, and one or more lift and tilt cylinders. The control system includes an input unit, a processing unit and a control module. The input unit is configured to receive pressure values corresponding to the lift and tilt cylinders. The processing unit is configured to compare the pressure values to threshold pressure values for the lift and tilt cylinders to generate an operative signal. Further, the control module is configured to control electrical energy supplied to the one or more electric propulsion motors from the power source based on the operative signal.

Claims

1. A control system for a machine having a power source, one or more electric propulsion motors connected to the power source, and one or more lift and tilt cylinders, the control system comprising:

an input unit configured to receive pressure values corresponding to the lift and tilt cylinders;

a processing unit configured to compare the pressure values to threshold pressure values for the lift and tilt cylinders to generate an operative signal; and

a control module configured to control electrical energy supplied to the one or more electric propulsion motors from the power source based on the operative signal.

2. The control system of claim 1, wherein the input unit is configured to receive the pressure values from a sensor unit connected to the lift and tilt cylinders.

3. The control system of claim 1, wherein the threshold pressure values for the lift and tilt cylinders corresponds to a lift-off condition of the machine.

4. The control system of claim 3, wherein the processing unit is configured to store the threshold pressure values for the lift and tilt cylinders.

5. The control system of claim 4, wherein the processing unit generate the operative signal in case the pressure value is greater than the threshold pressure value.

6. The control system of claim 1, wherein the control module configured to stop electrical energy supply to the one or more electric propulsion motors.

7. A machine, the machine comprising:

a power source;

one or more electric propulsion motors connected to the power source;

one or more lift and tilt cylinders; and

a control system, the control system including;

an input unit configured to receive pressure values corresponding to the lift and tilt cylinders;

a processing unit configured to compare the pressure values to threshold pressure values for the lift and tilt cylinders to generate an operative signal; and

a control module configured to control electrical energy supplied to the one or more electric propulsion motors from the power source based on the operative signal.

8. The machine of claim 7, wherein the one or more electric propulsion motors are configured to provide torque output to front and rear wheels.

9. The machine of claim 7 further includes a sensor unit connected to the lift and tilt cylinders, the sensor unit configured to provide the pressure values to the input unit.

10. The machine of claim 7, wherein the threshold pressure values for the lift and tilt cylinders corresponds to a lift-off condition of the machine.

11. The machine of claim 10, wherein the processing unit is configured to store the threshold pressure values for the lift and tilt cylinders.

12. The machine of claim 11, wherein the processing unit generates the operative signal in case the pressure value is greater than the threshold pressure value.

13. The machine of claim 11, wherein the control module configured to stop electrical energy supply to the one or more electric propulsion motors.

15. The method of claim 13, wherein receiving the pressure values includes receiving the pressure values from a sensor unit connected to the lift and tilt cylinders.

16. The method of claim 13 further includes defining the threshold pressure value based on a lift-off condition of the machine.

17. The method of claim 15, wherein comparing the pressure values includes computing a difference between the pressure values and the threshold pressure values.

18. The method of claim 13 further includes supplying the electrical energy to the one or more electric propulsion motors from a power source.

19. The method of claim 16, wherein controlling electrical energy supplied includes stopping the electrical energy supplied to the one or more electric propulsion motors.

20. The method of claim 13 further includes providing torque to front and rear wheels of the machine by the one or more electric propulsion motors.

14. A method of operating a machine, the method comprising:

receiving pressure values corresponding to lift and tilt cylinders;

comparing the pressure values with threshold pressure values for the lift and tilt cylinders;

generating an operative signal when the pressure value is greater than the threshold pressure value; and

controlling electrical energy supplied to one or more electric propulsion motors based on the operative signal.