Adaptive control system for cyclic excavation machine

Patent metadata

Field	Value
Publication number	US-2016003171-A1
Application number	US-201414324602-A
Country	US
Kind code	A1
Filing date	Jul 7, 2014
Priority date	Jul 7, 2014
Publication date	Jan 7, 2016
Grant date	—

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.

First claim

What is claimed is:

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.

Assignees

• Caterpillar Inc

Inventors

• Ge Xinyu Gary

Classifications

• F16H59/14

  Inputs being a function of torque or torque demand · CPC title

• E02F9/265

  with follow-up actions (e.g. control signals sent to actuate the work tool) · CPC title

• F02D2200/501

  Vehicle speed · CPC title

• E02F9/267

  Diagnosing or detecting failure of vehicles · CPC title

• E02F9/2246 Primary

  Control of prime movers, e.g. depending on the hydraulic load of work tools · CPC title