Autonomous method for detecting a pile

• US 9,702,115 B1
• Filed: 01/08/2016
• Issued: 07/11/2017
• Est. Priority Date: 01/08/2016
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Darukhanavala, Carl P.
• Primary Examiner(s): Jabr, Fadey
• Assistant Examiner(s): Mahne, Kevin P
• Application Number:
  US14/990,857
• Publication Number:
  US 20170198457A1
• Time in Patent Office: 550 Days
• Field of Search: None
• CPC Class Codes: B60T 8/174 characterised by using special control logic, e.g. fuzzy logic , neural computing
• CPC Class Codes: B60W 2050/0057 Frequency analysis, spectral techniques or transforms
• CPC Class Codes: E02F 3/431 for bucket-arms, front-end loaders, dumpers or the like
• 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 3/76 Graders, bulldozers, or the like with scraper plates or ploughshare-like elements soil-working A01B; Levelling scarifying devices street cleaning E01H; construction of roads E01C19/00, E01C23/00
• CPC Class Codes: E02F 3/7609 Scraper blade mounted forwardly of the tractor on a pair of pivoting arms which are linked to the sides of the tractor, e.g. bulldozers
• CPC Class Codes: E02F 3/84 Drives or control devices therefor , e.g. hydraulic drive systems
• CPC Class Codes: E02F 3/841 Devices for controlling and guiding the whole machine, e.g. by feeler elements and reference lines placed exteriorly of the machine construction of roads E01C19/008
• CPC Class Codes: E02F 3/844 for positioning the blade, e.g. hydraulically
• CPC Class Codes: E02F 9/2025 Particular purposes of control systems not otherwise provided for E02F3/16, E02F3/26, sub-groups of E02F3/43, E02F3/651, sub-groups of E02F3/84, E02F3/907, E02F5/145 take precedence
• 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
• CPC Class Codes: E02F 9/205 Remotely operated machines, e.g. unmanned vehicles E02F3/8866 takes precedence
• CPC Class Codes: E02F 9/26 Indicating devices E02F5/145 takes precedence
• CPC Class Codes: E02F 9/264 Sensors and their calibration for indicating the position of the work tool
• CPC Class Codes: E02F 9/265 with follow-up actions (e.g. control signals sent to actuate the work tool)

Abstract

An autonomous method for detecting when an earthmoving machine has moved a pile of dirt into contact with another pile of dirt may include receiving at a controller a plurality of signals indicative of one or more parameters including a ground speed of the machine, a target ground speed of the machine, a load on a work implement of the machine, an output speed of a torque converter of the machine, a machine pitch, a machine steering command, a machine heading, and a heading of a slot the machine is in. The controller may standardize and normalize each signal from the plurality of signals in order to create values for each of the one or more parameters that all fall within a common range, wherein the common range is representative of a range from minimum to maximum values for each of the one or more parameters. The controller may also determine a variation of each of the values for the one or more parameters over each of a plurality of time periods to calculate relative rates of change for the one or more parameters, weight each of the values for each of the one or more parameters as a function of the relative rates of change, add up the weighted values of the parameters, and apply a sigmoid function to the weighted values of the parameters in order to limit the effect any one of the parameters has on an output indicative of behavior characteristic of the machine having pushed a pile of dirt into contact with another pile of dirt.

Claims

1. An autonomous method for detecting when an earthmoving machine has moved a pile of dirt into contact with another pile of dirt, the method comprising:

receiving at a controller a plurality of signals indicative of one or more parameters including a ground speed of the machine, a target ground speed of the machine, a load on a work implement of the machine, an output speed of a torque converter of the machine, a machine pitch, a machine steering command, a machine heading, and a heading of a slot the machine is in;

standardizing and normalizing each signal from the plurality of signals using the controller in order to create values for each of the one or more parameters that all fall within a common range, wherein the common range is representative of a range from minimum to maximum values for each of the one or more parameters;

determining, using the controller, a variation of each of the values for the one or more parameters over each of a plurality of time periods to calculate relative rates of change for the one or more parameters;

weighting each of the values for each of the one or more parameters as a function of the relative rates of change for the one or more parameters;

adding up the weighted values of the parameters;

applying a sigmoid function to the weighted values of the parameters using the controller in order to limit the effect any one of the parameters has on an output indicative of behavior characteristic of the machine having pushed a pile of dirt into contact with another pile of dirt; and

transitioning a work implement of the machine from a carry configuration to a spread configuration.

2. The autonomous method of claim 1, further including weighting the weighted values of each of the one or more parameters in relationship to each of the other weighted values of other parameters based on which of the parameters predominates in exhibiting behavior of the machine characteristic of the machine having pushed a pile of dirt into contact with another pile of dirt.

3. The autonomous method of claim 1, wherein transitioning the work implement to a carry configuration includes racking the work implement backwards in order to retain more material in the work implement, and transitioning the work implement to a spread configuration includes pitching the work implement forward in order to shed more material from the work implement.

4. The autonomous method of claim 1, further including determining a configurable reverse time that is allowed to elapse between detection that the machine has pushed a pile of dirt into contact with another pile of dirt and when the machine is reversed.

5. The autonomous method of claim 4, wherein a longer configurable reverse time corresponds to the machine compacting the material from the pile of dirt being pushed by the machine into another pile of dirt by a greater amount than when a shorter configurable reverse time is allowed to elapse.

6. The autonomous method of claim 5, wherein a longer configurable reverse time corresponds to a smaller material load being carried by the machine and a shorter configurable reverse time corresponds to a larger material load being carried by the machine.

7. The autonomous method of claim 1, wherein the common range is set from approximately −

1000 to +1000, and wherein an upper threshold of the range corresponds to the machine pushing a pile of dirt into another pile of dirt, and a lower threshold of the range corresponds to the machine shedding material from a work implement of the machine.

8. The autonomous method of claim 1, wherein the method steps only commence when the machine is within a predetermined distance from a last pile of dirt.

9. A system for autonomously controlling an earthmoving machine, wherein the earthmoving machine includes:

a frame;

a plurality of driving members connected to the frame and configured to support the frame;

a powertrain mounted to the frame and configured to drive the plurality of driving members;

a work implement operatively connected to the frame and having a surface configured to engage a material to be moved by the machine; and

at least a first sensor configured to generate a first signal indicative of at least one of a plurality of operational parameters of the machine;

the system further including

a controller in communication with the at least a first sensor, controls for the powertrain, and controls for the work implement, the controller being configured to implement a method for operating the machine comprising;

receiving a plurality of signals indicative of one or more parameters including a ground speed of the machine, a target ground speed of the machine, a load on the work implement of the machine, an output speed of a torque converter of the machine, a machine pitch, a machine steering command, a machine heading, and a heading of a slot the machine is in;

standardizing and normalizing each signal from the plurality of signals in order to create values for each of the one or more parameters that all fall within a common range, wherein the common range is representative of a range from minimum to maximum values for each of the one or more parameters;

determining a variation of each of the values for the one or more parameters over each of a plurality of time periods to calculate relative rates of change for the one or more parameters;

weighting each of the values for each of the one or more parameters as a function of the relative rates of change for the one or more parameters;

adding up the weighted values of the parameters; and

applying a sigmoid function to the weighted values of the parameters in order to limit the effect any one of the parameters has on an output indicative of behavior characteristic of the machine having pushed a pile of dirt into contact with another pile of dirt.

10. The system of claim 9, wherein the controller is further configured to weight the weighted values of each of the one or more parameters in relationship to each of the other weighted values of other parameters based on which of the parameters has the greatest effect on a determination that the machine has pushed a pile of dirt into another pile of dirt.

11. The system of claim 9, wherein the controller is further configured to transition the work implement of the machine from a carry configuration to a spread configuration.

12. The system of claim 11, wherein the controller is configured to transition the work implement to a carry configuration by racking the work implement backwards in order to retain more material in the work implement, and transition the work implement to a spread configuration by pitching the work implement forward in order to shed more material from the work implement.

13. The system of claim 9, wherein the controller is further configured to determine a configurable reverse time that is allowed to elapse between detection that the machine has pushed a pile of dirt into contact with another pile of dirt and when the machine is reversed in a direction away from the pile of dirt.

14. The system of claim 13, wherein a longer configurable reverse time corresponds to the machine compacting the material from the pile of dirt being pushed by the machine into another pile of dirt by a greater amount than when a shorter configurable reverse time is allowed to elapse.

15. The system of claim 14, wherein a longer configurable reverse time corresponds to a smaller blade load being carried by the machine and a shorter configurable reverse time corresponds to a larger blade load being carried by the machine.

16. The system of claim 9, wherein the common range is set from −

1000 to +1000, and wherein one threshold of the range corresponds to the machine pushing a pile of dirt into another pile of dirt, and an opposite threshold of the range corresponds to the machine shedding material from a blade of the machine.

17. The system of claim 9, wherein the method steps implemented by the controller only commence when the machine is within a predetermined distance from a last pile of dirt.

18. A non-transitory computer-readable media comprising computer-executable instructions that, when executed on one or more processors, perform a method for detecting when an earthmoving machine has moved a pile of dirt into contact with another pile of dirt, the method comprising:

receiving a plurality of signals indicative of one or more parameters including a ground speed of the machine, a target ground speed of the machine, a load on a work implement of the machine, an output speed of a torque converter of the machine, a machine pitch, a machine steering command, a machine heading, and a heading of a slot the machine is in;

standardizing and normalizing each signal from the plurality of signals in order to create values for each of the one or more parameters that all fall within a common range, wherein the common range is representative of a range from minimum to maximum values for each of the one or more parameters;

determining a variation of each of the values for the one or more parameters over each of a plurality of time periods;

weighting each of the values for each of the one or more parameters as a function of how quickly each value is changing over each of the plurality of time periods;

adding up the weighted values of the parameters;

applying a sigmoid function to the weighted values of the parameters in order to limit the effect any one of the values of the parameters has on an output indicative of a determination that the machine has pushed a pile of dirt into another pile of dirt; and

transitioning a work implement of the machine from a carry configuration to a spread configuration.

19. The non-transitory computer-readable media of claim 18, wherein the method further includes weighting the weighted values of each of the one or more parameters in relationship to each of the other weighted values of other parameters based on which of the parameters has the greatest effect on a determination that the machine has pushed a pile of dirt into another pile of dirt.