Method and apparatus for determining a material condition

• US 6,205,687 B1
• Filed: 06/24/1999
• Issued: 03/27/2001
• Est. Priority Date: 06/24/1999
• Status: Expired due to Term

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Rocke, David J.
• Primary Examiner(s): BATSON, VICTOR D
• Application Number:
  US09/339,457
• Time in Patent Office: 642 Days
• Field of Search: 373/48, 373/82, 172/2, 172/3, 172/4, 172/4.5, 172/7, 172/8, 172/9, 701/50, 414/699, 414/694
• US Class Current: 37/348
• CPC Class Codes: E02F 3/431 for bucket-arms, front-end loaders, dumpers or the like
• CPC Class Codes: E02F 3/432 for keeping the bucket in a predetermined position or attitude
• CPC Class Codes: E02F 3/434 providing automatic sequences of movements, e.g. automatic dumping or loading, automatic return-to-dig
• CPC Class Codes: E02F 3/844 for positioning the blade, e.g. hydraulically
• CPC Class Codes: E02F 9/2029 Controlling the position of implements in function of its load, e.g. modifying the attitude of implements in accordance to vehicle speed control for hydraulic or pneumatic drives E02F9/2203, E02F9/2221 and E02F9/2253 take precedence

Abstract

An apparatus for determining a condition indicative of a level of difficulty of excavation of a material engaged by a work machine having a work implement. A controller receives a first signal during a dig pass of the work machine, and determines a material condition indicative of a level of difficulty of excavation during the dig pass as a function of the first signal, and transmits an output signal during the dig pass as a function of the material condition.

Claims

1. An apparatus for determining a material condition indicative of a level of difficulty of excavation for use with a work machine having a work implement, the apparatus comprising a controller operable to receive a first signal during a dig pass of the work machine, and to determine the material condition indicative of a level of difficulty of excavation during the dig pass as a function of the first signal, and to transmit an output signal during the dig pass as a function of the material condition.

2. The apparatus of claim 1 wherein the first signal comprises one of:

a total angle error signal;

an x-direction force average signal;

an accumulated x-direction energy signal;

an accumulated torque signal;

a speed drop signal;

a lift force/torque ratio signal;

a tilt cylinder velocity/command ratio signal;

a machine speed signal;

a gear signal; and

a combination signal.

3. The apparatus of claim 1 wherein the controller is operable to receive at least one other signal during the dig pass, and is operable to transmit the output signal as a function of the first signal and the at least one other signal.

4. The apparatus of claim 3 wherein the at least one other signal respectively comprises at least one of:

a total angle error signal;

a x-direction force average signal;

a accumulated x-direction energy signal;

a accumulated torque signal;

a speed drop signal;

a lift force/torque ratio signal;

a tilt cylinder velocity/command ratio signal;

a machine speed signal;

a gear signal; and

a combination signal;

the at least one other signal being a different signal than the first signal.

5. The apparatus of claim 3 wherein the controller includes a timer operable to receive the first signal and the at least one other signal, the first signal being a signal indicative of contact by the work implement with the material, and the at least one other signal being indicative of a distance traveled since contact with the material, the controller operable to transmit the material condition signal as a function of a time taken after contact to travel a predetermined distance.

6. The apparatus of claim 1 further comprising a signal processor, the signal processor operable to receive a plurality of signals and to generate the first signal as a function of the plurality of signals.

7. The apparatus of claim 6 wherein the first signal comprises one of a total angle error signal, an x-direction force average signal, and an accumulated x-direction energy signal, and the plurality of signals comprise:

a lift cylinder position signal;

a first lift cylinder pressure signal;

a tilt cylinder position signal; and

a first tilt cylinder pressure signal.

8. The apparatus of claim 7 wherein the plurality of signals further comprise:

a second lift cylinder pressure signal; and

a second tilt cylinder pressure signal.

9. The apparatus of claim 6 wherein the first signal comprises an accumulated torque signal, and the plurality of signals comprise:

an engine speed signal; and

a torque converter output speed signal.

10. The apparatus of claim 6 wherein the first signal comprises one of a speed drop signal and a machine speed signal, and the plurality of signals comprise:

a torque converter output speed signal;

a transmission speed signal; and

a gear signal.

11. The apparatus of claim 6 wherein the first signal comprises a lift force/torque ratio signal and the plurality of signals comprise:

a lift force signal; and

a torque converter output speed signal.

12. The apparatus of claim 6 wherein the first signal comprises a tilt cylinder velocity/command ratio signal and the plurality of signals comprise:

a tilt cylinder command signal; and

a tilt cylinder position signal.

13. The apparatus of claim 6 wherein the first signal comprises a combination signal, and the plurality of signals comprise:

a total angle error signal;

a lift force/torque ratio signal;

a tilt cylinder velocity/command ratio signal; and

a machine speed signal.

14. The apparatus of claim 13 wherein the combination signal comprises an average of the total angle error signal, the lift force/torque ratio signal, the tilt cylinder velocity/command ratio signal, and the machine speed signal.

15. The apparatus of claim 6 wherein the first signal comprises a combination signal, and the plurality of signals comprise:

a x-direction force average signal;

an accumulated x-energy signal;

an accumulated torque signal; and

a speed drop signal.

16. The apparatus of claim 15 wherein the combination signal comprises an average of the x-direction force average signal, the accumulated x-energy signal, the accumulated torque signal, and the speed drop signal.

17. The apparatus of claim 11, further comprising a second signal processor, the second signal processor operable to receive a second plurality of signals and to transmit the lift force signal as a function of the second plurality of signals.

18. The apparatus of claim 17 wherein the second plurality of signals comprise:

a lift cylinder position signal; and

a first lift cylinder pressure signal.

19. The apparatus of claim 18 wherein the second plurality of signals further comprise a second lift cylinder pressure signal.

20. The apparatus of claim 6 wherein the signal processor receives the plurality of signals between a first predetermined time and a second predetermined time.

21. The apparatus of claim 20 wherein the first predetermined time comprises approximately 0 seconds after the work machine engages a pile of material and the second predetermined time comprises approximately 1 second after the work machine engages the pile of material.

22. The apparatus of claim 20 wherein the first predetermined time comprises approximately 0 seconds after the work machine engages a pile of material and the second predetermined time comprises a point in time at which initial penetration of the pile is substantially complete.

23. The apparatus of claim 20 wherein the first predetermined time comprises approximately 1 second after the work machine engages a pile of material and the second predetermined time comprises approximately 3 seconds after the work machine engages the pile of material.

24. The apparatus of claim 20 wherein the first predetermined time comprises one of an approximate point in time wherein the bucket begins to tilt back after engaging the pile and an approximate point in time when the lift cylinder makes a first pause after contact with the pile.

25. The apparatus of claim 17 wherein the signal processor receives the second plurality of signals between a third predetermined time and a fourth predetermined time.

26. The apparatus of claim 25 wherein the third predetermined time comprises approximately 1 second after the work machine engages a pile of material and the fourth predetermined time comprises approximately 3 seconds after the work machine engages the pile of material.

27. The apparatus of claim 1 wherein the material condition comprises a hardness.

28. An apparatus for determining a material condition indicative of a level of difficulty of excavation for use with a work machine having a torque converter, comprising:

a controller operable to receive a gear signal, a torque converter output speed signal, a tilt cylinder position signal, a tilt cylinder command signal, and

at least one of an engine speed signal and a transmission speed signal, each signal being received during a dig pass, the controller operable to determine an accumulated torque as a function of the engine speed signal and the torque converter output speed signal, to determine a speed drop as a function of the transmission output signal, to determine a tilt cylinder velocity/command ratio as a function of the tilt cylinder position signal and the tilt cylinder command signal, and to determine a machine speed as a function of the gear signal and at least one of the engine speed signal and the transmission speed signal, the controller further operable to determine a material condition indicative of a level of difficulty of excavation during the dig pass as a function of the accumulated torque, the speed drop, the tilt cylinder/command ratio, and the machine speed, and to transmit a material condition signal as a function of the material condition.

29. An operating machine, comprising:

a chassis;

an engine coupled with the chassis, the engine operable to generate a propelling force;

a propulsion system coupled with the engine to receive the propelling force and operable to propel the operating machine as a function of receiving the propelling force;

a work implement coupled with the chassis;

a hydraulic system including a hydraulic cylinder, the hydraulic system coupled with the work implement and the chassis, the hydraulic system operable to move the work implement;

a first plurality of sensors operable to determine respective first parameters during a dig pass, and to transmit respective condition signals during the dig pass as a function of the respective parameters;

at least one signal processor, each signal processor coupled with a respective second plurality of sensors to receive respective condition signals, each signal processor operable to generate a respective processed signal as a function of the respective condition signals;

a first controller coupled with the at least one signal processor to receive the respective processed signal, the controller operable to determine a material condition indicative of a level of difficulty of excavation during the dig pass as a function of the respective processed signal, and to transmit an output signal during the dig pass as a function of the material condition; and

a second controller coupled with the first controller to receive the output signal, the first controller operable to adjust an operating characteristic of the work machine during the dig pass as a function of receiving the output signal.

30. The apparatus of claim 29 wherein the respective condition signals comprise a respective one of:

a total angle error signal;

a x-direction force average signal;

an accumulated x-direction energy signal;

an accumulated torque signal;

a speed drop signal;

a lift force/torque ratio signal;

a tilt cylinder velocity/command ratio signal;

a machine speed signal;

a gear signal; and

a combination signal.

31. A method for determining a material condition indicative of a level of difficulty of excavation in real time, comprising:

determining at least one parameter during a dig pass;

determining the material condition during the dig pass as a function of the at least one parameter; and

transmitting a material condition signal during the dig pass as a function of the material condition.

32. The method of claim 31 wherein the at least one parameter comprises at least one of:

a total angle error;

a x-direction force average;

an accumulated x-direction energy;

an accumulated torque;

a speed drop;

a lift force/torque ratio;

a tilt cylinder velocity/command ratio;

a machine speed;

a combination of the total angle error, the lift force/torque ratio, the tilt cylinder velocity/command ratio, and the machine speed; and

a combination of the x-direction force average, the accumulated x-direction energy, the accumulated torque, and the speed drop.

33. The method of claim 31, further comprising adjusting an operating characteristic of a work machine as a function of the material condition signal.

34. The method of claim 31 wherein determining the at least one parameter during the dig pass comprises:

sensing a plurality of conditions of the work machine; and

calculating the at least one parameter as a function of at least some of the plurality of conditions.

35. The method of claim 34 wherein at least one parameter is determined at a time between approximately 0-1 seconds after a dig pass begins.

36. The method of claim 34 wherein at least one parameter is determined at a time between approximately 1-3 seconds after a dig pass begins.

37. The method of claim 32 wherein the combination of the total angle error, the lift force/torque ratio, the tilt cylinder velocity/command and the machine speed comprises an average of the total angle error, the lift force/torque ratio, the tilt cylinder velocity/command ratio, and the machine speed.

38. The method of claim 31 wherein determining the at least one parameter comprises:

sensing a first operating characteristic of a work machine;

sensing a second operating characteristic of the work machine; and

calculating the at least one parameter as a function of the first and second operating characteristics.

39. The method of claim 38 wherein one of the first and second operating characteristics comprises one of:

a lift cylinder position;

a first lift cylinder pressure;

a tilt cylinder position; and

a first tilt cylinder pressure;

a second lift cylinder pressure;

a second tilt cylinder pressure;

an engine speed;

a torque converter output speed;

a transmission speed;

a gear; and

a tilt cylinder command.

40. The method of claim 39 wherein the other of the first and second operating characteristics comprises another of:

the lift cylinder position;

the first lift cylinder pressure;

the tilt cylinder position; and

the first tilt cylinder pressure;

the second lift cylinder pressure;

the second tilt cylinder pressure;

the engine speed;

the torque converter output speed;

the transmission speed;

the gear;

the tilt cylinder command; and

the second operating characteristic being a different operating characteristic than the first operating characteristic.