Implement control based on noise values

Patent metadata

Field	Value
Publication number	US-10011974-B2
Application number	US-201715426624-A
Country	US
Kind code	B2
Filing date	Feb 7, 2017
Priority date	Dec 22, 2015
Publication date	Jul 3, 2018
Grant date	Jul 3, 2018

Abstract

An earthmoving machine comprises a sensor, an implement, and control architecture comprising a controller and configured to facilitate movement in response to a signal indicative of a measured implement position and an implement control value comprising a gain value associated with implement speed. The controller is programmed to execute machine readable instructions to generate a noise value that is based on an error between the signal and a target signal, determine whether the noise value is acceptable to lock the gain value, adjust the gain value to control the implement speed when the noise value is unacceptable until the noise value is acceptable, and operate the machine based on the locked gain value.

First claim

What is claimed is:

1. An earthmoving machine comprising a machine chassis, a linkage mechanism, an earthmoving implement, an adaptive environmental sensor, and control architecture, wherein:
the earthmoving implement is coupled to the machine chassis via the linkage mechanism;
the control architecture is configured to facilitate movement of the earthmoving implement, the machine chassis, and the linkage mechanism in one or more degrees of freedom at least partially in response to an implement control value and an adaptive signal;
the implement control value represents control of the movement of the earthmoving implement and comprises a gain value as a parameter thereof;
the implement control gain value is associated with a speed of movement of the earthmoving implement;
the adaptive signal is generated by the adaptive environmental sensor and is indicative of a measured position of the earthmoving implement relative to a given operational terrain; and
the control architecture comprises a machine controller that is programmed to execute machine readable instructions to
generate a noise value that is based on an error between the adaptive signal and a target position signal indicative of a target position of the earthmoving implement,
determine whether the noise value is at an acceptable noise level or an unacceptable noise level,
lock the implement control gain value when the noise value is at the acceptable noise level,
adjust the implement control gain value to control the implement speed when the noise value is at the unacceptable noise level until the noise value is at the acceptable noise level, and the implement control gain value is locked, and
operate the earthmoving machine based on the locked implement control gain value.

2. An earthmoving machine as claimed in claim 1 wherein the machine controller is further programmed to execute machine readable instructions to:
generate a RMS error value of the measured position of the earthmoving implement relative to the given operational terrain when the noise value is at the unacceptable noise level, the RMS error value being based on a comparison of the adaptive signal to the target position signal;
determine whether the RMS error value is at an acceptable RMS level or an unacceptable RMS level;
lock the implement control gain value when the RMS error value is at the acceptable RMS level; and
set the RMS error value as the noise value when the RMS error value is at the unacceptable RMS level.

3. An earthmoving machine as claimed in claim 2 wherein the machine controller is programmed to execute machine readable instructions to decrease the implement speed when the noise value is greater than a noise threshold and increase the implement speed when the noise value is less than a noise threshold.

4. An earthmoving machine as claimed in claim 1 wherein the machine controller is further programmed to execute machine readable instructions to:
generate a RMS error value of the measured position of the earthmoving implement relative to the given operational terrain when the noise value is at the unacceptable noise level, the RMS error value being based on a comparison of the adaptive signal to the target position signal;
determine whether the RMS error value is at an acceptable RMS level or an unacceptable RMS level;
lock the implement control gain value when the RMS error value is at the acceptable RMS level; and
generate the noise value when the RMS error value is at the unacceptable RMS level.

5. An earthmoving machine as claimed in claim 4 wherein:
the determination of whether the RMS error value is at the acceptable RMS level or the unacceptable RMS level is based on a comparison of the RMS error value to a RMS error value threshold;
the RMS error value is based on an average of a plurality of error ranges;
each of the plurality of error ranges depicts a difference between a pair of data points setting forth respective expected and actual position measurements of the earthmoving implement related to the given operational terrain and measured over a distance window; and
the distance window is greater than a length of the earthmoving machine.

6. An earthmoving machine as claimed in claim 1 wherein:
the determination of whether the noise value is at the acceptable noise level or the unacceptable noise level is based on a comparison of the noise value to a noise threshold; and
the noise threshold is measured in units representing a distance within a time domain.

7. An earthmoving machine as claimed in claim 6 wherein the machine controller is programmed to execute machine readable instructions to increase the implement speed when the noise value is greater than the noise threshold and decrease the implement speed when the noise value is less than the noise threshold.

8. An earthmoving machine as claimed in claim 1 wherein:
a Fast Fourier Transform (FFT) operation is applied to the noise value to convert the noise value from a time domain into a frequency domain to generate a frequency-based noise value; and
the frequency-based noise value is compared to a frequency-based noise threshold to determine whether the noise value is at the acceptable noise level or the unacceptable noise level.

9. An earthmoving machine as claimed in claim 8 wherein the machine controller is programmed to execute machine readable instructions to decrease the implement speed when the noise value is greater than a noise threshold and increase the implement speed when the noise value is less than a noise threshold.

10. An earthmoving machine as claimed in claim 8 wherein the earthmoving machine comprises a filtration device that applies a low pass filter, a high pass filter, a band pass filter, or a combination thereof, to the frequency-based noise value, the frequency-based noise threshold, or both, to replace the frequency-based noise value with a minimized associated noise.

11. An earthmoving machine as claimed in claim 1 wherein:
the noise value is generated, at least in part, by dividing a machine travel speed value by a terrain bump count frequency value; and
the machine controller is programmed to execute machine readable instructions to generate the machine travel speed value based on a distance the machine travels across a distance window in a time domain and the terrain bump count frequency value based on a virtual noise generated from the adaptive signal measured over the given operational terrain over a time domain.

12. An earthmoving machine as claimed in claim 11 wherein:
the terrain bump count frequency value is based on a measurement of cycles of virtual noise per unit time;
the virtual noise is representative of counts of virtually detected bumps in the given operational terrain; and
the counts of virtually detected bumps are generated from the adaptive signal measured over the given operational terrain and divided by a measured time.

13. An earthmoving machine as claimed in claim 1 wherein the machine controller comprises a single controller or a plurality of independent controllers.

14. An earthmoving machine as claimed in claim 1 wherein:
the machine controller comprises a proportional-integral (PI) controller;
the gain value reflects a tuning parameter of the PI controller; and
the machine controller is programmed to execute machine readable instructions to adjust a proportional term coefficient (K p ) associated with the PI controller to adjust the tuning parameter.

15. An earthmoving machine as claimed in claim 1 wherein:
the machine controller comprises a proportional-integral-derivative (PID) controller;
the

Assignees

• Caterpillar Trimble Control Tech Llc

Inventors

• Zhang Yanchai
• Green Francisco R
• Wray Albert A
• Chang Insu

Classifications

• E02F3/435

  for dipper-arms, backhoes or the like · CPC title

• E02F3/32

  working downwardly and towards the machine, e.g. with backhoes · CPC title

• E02F9/2041 Primary

  Automatic repositioning of implements, i.e. memorising determined positions of the implement (for dipper-arms or bucket-arms E02F3/434, E02F3/437, E02F3/438, E02F3/439 take precedence) · CPC title

• E02F3/844

  for positioning the blade, e.g. hydraulically · CPC title

• E02F3/7609

  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 title