Adaptive control system for cyclic excavation machine

• US 9,469,972 B2
• Filed: 07/07/2014
• Issued: 10/18/2016
• Est. Priority Date: 07/07/2014
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Ge, Xinyu
• Primary Examiner(s): Holmes, Justin
• Application Number:
  US14/324,602
• Publication Number:
  US 20160003171A1
• Time in Patent Office: 834 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: E02F 9/2246 Control of prime movers, e.g. depending on the hydraulic load of work tools
• CPC Class Codes: E02F 9/265 with follow-up actions (e.g. control signals sent to actuate the work tool)
• CPC Class Codes: E02F 9/267 Diagnosing or detecting failure of vehicles
• CPC Class Codes: F02D 2200/501 Vehicle speed
• CPC Class Codes: F16H 2059/142 of driving resistance calculated from weight, slope, or the like
• CPC Class Codes: F16H 59/14 Inputs being a function of torque or torque demand

Abstract

A control system is disclosed for use with a powertrain of a machine. The control system may have a first sensor configured to generate a first signal indicative of an actual speed, a second sensor configured to generate second signal indicative of at least one of a force bearing on the machine and a position of an implement, and an interface device configured to generate a third signal indicative of a desired speed. The control system may also have a controller configured to determine a closed-loop gain value based on a difference between the actual and desired speeds, to classify a current operation of the machine based on the second signal, and to determine an open-loop gain value based on classification of the current operation. The controller may also be configured to control fueling of the machine based on a superposition of the closed-loop gain value and the open-loop gain value.

Claims

1. A control system for a powertrain of a machine, comprising:

a first sensor configured to generate a first signal indicative of an actual speed of the powertrain;

a second sensor configured to venerate a second signal indicative of at least one of a force bearing on the machine and a position of an implement of the machine;

an interface device configured to generate a third signal indicative of a desired speed of the powertrain; and

a controller in communication with the first sensor, the second sensor, and the interface device, the controller being configured to;

determine a closed-loop gain value based on a difference between the actual speed and the desired speed;

classify a current operation of the machine as one of a plurality of predetermined operations of a duty cycle based on the second signal;

determine an open-loop gain value based on classification of the current operation of the machine; and

control fueling of the machine based on a superposition of the closed-loop gain value and the open-loop gain value.

2. The control system of claim 1, wherein the controller is further configured to:

record a history of machine operations; and

classify the current operation by comparing the current operation to the history.

3. The control system of claim 2, wherein the machine operations include at least one of a tool movement, a machine movement, a movement of an operator interface device, and a change in a load bearing on the machine.

4. The control system of claim 1, wherein:

the machine includes a work tool;

the controller is configured to determine a load bearing on the machine as a function of the second signal and a known weight of the machine; and

the closed-loop gain value is determined based also on the load.

5. The control system of claim 4, further including at least one grade sensor configured to generate a fourth signal indicative of a work surface grade on which the machine is operating, wherein the controller is further configured to determine the load based also on the work surface grade and a travel direction relative to the work surface grade.

6. The control system of claim 5, further including at transmission sensor configured to generate a signal indicative of a gear ratio of the powertrain, wherein the controller is further configured to determine the load based also on the gear ratio.

7. The control system of claim 1, wherein:

the controller is configured to determine a weighting factor based on a probability that the classification is correct; and

the open-loop gain value is determined as a function of the weighting factor.

8. The control system of claim 7, wherein when the probability is less than a threshold amount, the open-loop gain value is zero.

9. The control system of claim 8, wherein when the probability is higher than the threshold amount, the open-loop gain value is determined based on at least one machine state predicted for a future time in the duty cycle.

10. The control system of claim 9, wherein the controller is further configured to:

determine a vector of adjustment values for a plurality of anticipated future times in the duty cycle; and

selectively use the vector of adjustment values to determine the open-loop gain value.

11. The control system of claim 10, wherein the controller is further configured to:

determine a weighting for each of the plurality of anticipated future times; and

apply the weighting to each adjustment value in the vector to determine the open-loop gain value.

12. The control system of claim 11, wherein the weighting decreases for anticipated future times of the duty cycle that are more distant from a current instant in time.

13. The control system of claim 9, wherein the closed-loop gain value is greater when the probability is less than the threshold amount.

14. The control system of claim 1, wherein the controller is further configured to:

determine a change in fueling as a function of the superposition;

compare the change in fueling to a value in a limit map; and

selectively implement a lower of the change in fueling and the value in the limit map.

15. A method for controlling a powertrain of a machine, the method comprising:

sensing an actual speed of the powertrain;

sensing at least one of a force bearing on the machine and a position of an implement of the machine;

receiving a desired speed of the powertrain;

determining a closed-loop gain value based on a difference between the actual speed and the desired speed;

classifying a current operation of the machine as one of a plurality of predetermined operations of a duty cycle based on the at least one of the force bearing on the machine and the position of the implement of the machine;

determining an open-loop gain value based on the current operation of the machine; and

controlling fueling of the machine based on a superposition of the closed-loop gain value and the open-loop gain value.

16. The method of claim 15, further including recording a history of machine operations, wherein classifying the current operation includes comparing the current operation to the history of machine operations.

17. The method of claim 15, further including sensing a work surface grade over which the machine is operating, wherein:

the machine includes a work tool; and

the sensing at least one of a force bearing on the machine and a position of the implement includes determining a load moved by the machine as a function of a load in the work tool, a known weight of the machine, and the work surface grade.

18. The method of claim 15, further including determining a weighting factor based on a probability that the current operation of the machine was correctly classified, wherein the determining the open-loop gain value includes determining the open-loop gain value as a function of the weighting factor.

19. The method of claim 18, wherein:

when the probability is less than a threshold amount, determining the open-loop gain value includes setting the open-loop gain value to zero; and

when the probability is higher than the threshold amount, the determining the open-loop gain value includes determining the open-loop gain value based on an anticipated future time in the duty cycle.

20. A computer readable medium having executable instructions stored thereon for performing a method for controlling a powertrain of a machine, the method comprising:

sensing an actual speed of the powertrain;

sensing at least one of a force bearing on the machine and a position of an implement of the machine;

receiving a desired speed of the powertrain;

determining a closed-loop gain value based on a difference between the actual speed and the desired speed;

classifying a current operation of the machine as one of a plurality of predetermined operations of a duty cycle based on the at least one of the force bearing on the machine and the position of the implement of the machine;

determining an open-loop gain value based on the current operation of the machine; and

controlling fueling of the machine based on a superposition of the closed-loop gain value and the open-loop gain value.