System and method for estimating position of machine

Patent metadata

Field	Value
Publication number	US-9254822-B1
Application number	US-201414519822-A
Country	US
Kind code	B1
Filing date	Oct 21, 2014
Priority date	Oct 21, 2014
Publication date	Feb 9, 2016
Grant date	Feb 9, 2016

Abstract

A system having a primary inertial measurement unit and a secondary inertial measurement unit configured to generate a primary position signal and a secondary position signal respectively is provided. The system also includes an error detection module communicably coupled to the primary inertial measurement unit and the secondary inertial measurement unit. The error detection module is configured to receive the primary position signal and the secondary position signal and detect if an out-range error is present in at least one of the primary position signal and the secondary position signal. The error detection module is also configured to detect if an in-range error is present in at least one of the primary position signal and the secondary position signal and determine an action to be performed based on the presence of at least one of the out-range error and the in-range error.

First claim

What is claimed is:

1. A system comprising:
a primary inertial measurement unit configured to generate a primary position signal, the primary position signal indicative of an estimated position of a machine on a worksite;
a secondary inertial measurement unit configured to generate a secondary position signal, the secondary position signal indicative of the estimated position of the machine; and
an error detection module communicably coupled to the primary inertial measurement unit and the secondary inertial measurement unit, the error detection module configured to:
receive the primary position signal from the primary inertial measurement unit;
receive the secondary position signal from the secondary inertial measurement unit;
detect if an out-range error is present in at least one of the primary position signal and the secondary position signal, wherein the presence of the out-range error is based on the respective primary position signal or the secondary position signal exceeding a first predetermined threshold;
detect if an in-range error is present in at least one of the primary position signal and the secondary position signal based, at least in part, on the presence of the out-range error in the respective primary position signal or the secondary position signal, wherein the presence of the in-range error is based on the respective primary position signal or the secondary position signal exceeding a second predetermined threshold; and
determine an action to be performed based, at least in part, on the presence of at least one of the out-range error and the in-range error in the respective primary position signal or the secondary position signal.

2. The system of claim 1 , wherein the first predetermined threshold is at least one of:
a threshold gyroscopic value; and
a threshold acceleration value.

3. The system of claim 1 , wherein the second predetermined threshold is based on a correlation between the primary position signal and the secondary position signal.

4. The system of claim 1 , wherein the error detection module is communicably coupled to a transmission module associated with the machine.

5. The system of claim 4 , wherein if the presence of the out-range error is detected in the primary position signal, the action includes any one of:
stopping the machine within at least one of a first predetermined distance and a first predetermined time duration; and
stopping the machine within at least one of a second predetermined distance and a second predetermined time duration, such that the first predetermined distance is greater than the second predetermined distance and the first predetermined time duration is greater than the second predetermined time duration.

6. The system of claim 5 , wherein the machine is stopped within at least one of the first predetermined distance and the first predetermined time duration if the presence of the out-range error is not detected in the secondary position signal.

7. The system of claim 5 , wherein the machine is stopped within at least one of the second predetermined distance and the second predetermined time duration if the presence of the out-range error is detected in the secondary position signal.

8. The system of claim 1 , wherein the error detection module is communicably coupled to a position detection system associated with the machine, the position detection system configured to generate a signal indicative of a current position of the machine on the worksite.

9. The system of claim 8 , wherein if the presence of the out-range error is not detected in the primary position signal and if the presence of any of the out-range error and the in-range error is detected in the secondary position signal, the action includes:
adding a predetermined noise to the primary position signal; and
forwarding the primary position signal with the added predetermined noise to the position detection system.

10. The system of claim 8 , wherein if the presence of the in-range error is not detected in the primary position signal and the secondary position signal, the action includes:
forwarding the primary position signal to the position detection system.

11. A method comprising:
receiving a primary position signal from a primary inertial measurement unit, wherein the primary position signal is indicative of an estimated position of a machine on a worksite;
receiving a secondary position signal from a secondary inertial measurement unit, wherein the secondary position signal is indicative of the estimated position of the machine;
detecting if an out-range error is present in at least one of the primary position signal and the secondary position signal, wherein the presence of the out-range error is based on the respective primary position signal or the secondary position signal exceeding a first predetermined threshold;
detecting if an in-range error is present in at least one of the primary position signal and the secondary position signal based, at least in part, on the presence of the out-range error in the respective primary position signal or the secondary position signal, wherein the presence of the in-range error is based on the respective primary position signal or the secondary position signal exceeding a second predetermined threshold; and
determining an action to be performed based, at least in part, on the presence of at least one of the out-range error and the in-range error in the respective primary position signal or the secondary position signal.

12. The method of claim 11 , wherein the first predetermined threshold is at least one of:
a threshold gyroscopic value; and
a threshold acceleration value.

13. The method of claim 11 , wherein the second predetermined threshold is based on a correlation between the primary position signal and the secondary position signal.

14. The method of claim 11 , wherein if the presence of the out-range error is detected in the primary position signal, the action includes any one of:
stopping the machine within at least one of a first predetermined distance and a first predetermined time duration; and
stopping the machine within at least one of a second predetermined distance and a second predetermined time duration, such that the first predetermined distance is greater than the second predetermined distance and the first predetermined time duration is greater than the second predetermined time duration.

15. The method of claim 14 , wherein the machine is stopped within at least one of the first predetermined distance and the first predetermined time duration if the presence of the out-range error is not detected in the secondary position signal.

16. The method of claim 14 , wherein the machine is stopped within at least one of the second predetermined distance and the second predetermined time duration if the presence of the out-range error is detected in the secondary position signal.

17. The method of claim 11 , wherein if the presence of the out-range error is not detected in the primary position signal and if the presence of any of the out-range error and the in-range error is detected in the secondary position signal, the action includes:
adding a predetermined noise to the primary position signal; and
forwarding the primary position signal with the added predetermined noise to a position detection system.

18. The method of claim 11 , wherein if the presence of the in-range error is not detected in the primary position signal and the secondary position signal, the action includes:
forwarding the primary position signal to a position det

Assignees

• Caterpillar Inc

Inventors

• Friend Paul R
• Evans Timothy
• Chen Qi
• Whitten Andrew T
• Vogel Nicholas R
• Chang Hong
• Chikni Salman
• Willis Frank A

Classifications

• G01C21/188 Primary

  for accumulated errors, e.g. by coupling inertial systems with absolute positioning systems · CPC title

• B60T7/12 Primary

  for automatic initiation; for initiation not subject to will of driver or passenger {(limiting speed of vehicles other than rail vehicles B60K31/00)} · CPC title

• G01C21/16

  by integrating acceleration or speed, i.e. inertial navigation · CPC title

• B60T7/16

  operated by remote control, i.e. initiating means not mounted on vehicle · CPC title