SYSTEMS AND PROCESSES FOR CALIBRATING UNMANNED AERIAL VEHICLES

• US 20180024571A1
• Filed: 02/19/2016
• Published: 01/25/2018
• Est. Priority Date: 02/19/2015
• Status: Active Grant

• Current Assignee: Flir Unmanned Aerial Systems ULC (Teledyne Technologies Incorporated)
• Original Assignee: Aeryon Labs, Inc. (Teledyne Technologies Incorporated)
• Inventors: PEASGOOD, Michael
• Granted Patent: US 10,747,236 B2
• Time in Patent Office: Days
• CPC Class Codes: B64C 19/00 Aircraft control not otherwise provided for
• CPC Class Codes: B64C 29/0033 the propellers being tiltable relative to the fuselage
• CPC Class Codes: B64U 10/13 Flying platforms
• CPC Class Codes: B64U 2201/10 autonomous, i.e. by navigating independently from ground or air stations, e.g. by using inertial navigation systems [INS]
• CPC Class Codes: G01C 25/00 Manufacturing, calibrating, cleaning, or repairing instruments or devices referred to in the other groups of this subclass testing, calibrating or compensating compasses G01C17/38
• CPC Class Codes: G01C 25/005 initial alignment, calibration or starting-up of inertial devices
• CPC Class Codes: G05D 1/102 specially adapted for vertical take-off of aircraft

Abstract

An unmanned aerial vehicle and process for automatically calibrating the unmanned aerial vehicle having at least one magnetic sensor is described. The calibration process involves receiving an internal or external control command to initiate a take-off process by the unmanned aerial vehicle. A hover mode maintains the unmanned aerial vehicle at hover position, and a calibration rotation sequence rotates the unmanned aerial vehicle. The calibration process further involves receiving measurement data from sensors of the unmanned aerial vehicle during the calibration rotation sequence and calculating calibration parameters using the measurement data. The calibration process may implement corrections using the calibration parameters.

Claims

1. An unmanned aerial vehicle comprising:

a frame;

an operations control to control operation of the unmanned aerial vehicle;

a calibration control to initiate automatic calibration of the unmanned aerial vehicle by a hover mode for maintaining the unmanned aerial vehicle at hover position, and a calibration rotation sequence for rotating the unmanned aerial vehicle around at least one axis of the frame;

flight control and navigation control for controlling motion of the unmanned aerial vehicle to implement the hover mode and the calibration rotation sequence;

sensors to obtain measurement data during the calibration rotation sequence, wherein the sensors include at least one magnetic sensor for calibration;

a calibration calculator to calculate calibration parameters using the measurement data obtained during the calibration rotation sequence.

2. The unmanned aerial vehicle of claim 1 wherein the calibration control updates or corrects measurement or compensation values of the magnetic sensor or other instrument using the calibration parameters.

3. The unmanned aerial vehicle of claim 1 wherein the calibration parameters comprise a bias factor and a scale factor.

4. The unmanned aerial vehicle of claim 1 further comprising a communication device to transmit the measurement data obtained during the calibration rotation sequence or calibration parameters or other calibration data to a control station or a ground station.

5. The unmanned aerial vehicle of claim 2 wherein the communication device receives a verification notification indicating a successful calibration from an internal component or from the control station or the ground station.

6. The unmanned aerial vehicle of claim 2 wherein the communication device receives a calibration error notification indicating an unsuccessful calibration from an internal component or the control station or the ground station.

7. The unmanned aerial vehicle of claim 1 further comprising a data store device to store the measurement data obtained during the calibration rotation sequence, the calibration parameters, and other calibration data.

8. The unmanned aerial vehicle of claim 1 further comprising a communication device to transmit location data, the location data identifying the location of the unmanned aerial vehicle during the calibration rotation sequence to a control station or a ground station.

9. The unmanned aerial vehicle of claim 1 further comprising a communication device to transmit a calibration error notification computed by a processor using the measurement data obtained during the calibration rotation sequence, the bias factor, and the scale factor.

10. The unmanned aerial vehicle of claim 1 further comprising a transceiver to receive calibration trigger signals to trigger the calibration control to initiate the automatic calibration.

11. The unmanned aerial vehicle of claim 1 wherein the calibration control initiates the automatic calibration without human intervention.

12. The unmanned aerial vehicle of claim 1 wherein the calibration control automatically checks stored calibration data for expiry or errors to trigger initiation of the automatic calibration.

13. The unmanned aerial vehicle of claim 1 wherein the calibration control detects environmental factors to adjust the calibration rotation sequence dynamically with a tilt movement for calculation of the calibration measurements to address the environmental factors.

14. The unmanned aerial vehicle of claim 1 wherein the calibration parameters are based on requirements of the at least one magnetic sensor.

15. A process for calibrating an unmanned aerial vehicle having at least one magnetic instrument, the process comprising:

receiving an internal or external control command or detecting a calibration event to calibrate the at least one magnetic sensor of the unmanned aerial vehicle automatically;

automatically initiating a hover mode for maintaining the unmanned aerial vehicle at hover position, the hover position being an in-air position;

automatically initiating a calibration rotation sequence to rotate the unmanned aerial vehicle;

receiving measurement data from one or more sensors of the unmanned aerial vehicle during the calibration rotation sequence;

calculating calibration parameters using the measurement data obtained during the calibration rotation sequence; and

updating measurement or compensation values obtained from the at least one magnetic sensor using the calibration parameters.

16. The process of claim 15 further comprising receiving an internal or external control command to initiate a take-off process by the unmanned aerial vehicle to move the unmanned vehicle from a ground position to an in-air position.

17. The process of claim 15 further comprising receiving an internal or external control command or detecting a calibration event without human intervention.

18. The process of claim 15 further comprising automatically checking stored calibration data for expiry or errors to trigger initiation of the automatic calibration.

19. The process of claim 15 further comprising automatically detecting environmental factors to adjust the calibration rotation sequence dynamically with a tilt movement for calculation of the calibration measurements to address the environmental factors.

20. The process of claim 15 further comprising automatically calculating the calibration rotation sequence using onboard measurement data.

21. A system for calibrating an unmanned aerial vehicle comprising:

an unmanned aerial vehicle having;

a frame;

an operations control to control operation of the unmanned aerial vehicle;

a calibration control to initiate automatic calibration of the unmanned aerial vehicle by a hover mode for maintaining the unmanned aerial vehicle at hover position, and a calibration rotation sequence for rotating the unmanned aerial vehicle around at least one axis of the frame;

flight control and navigation control for controlling motion of the unmanned aerial vehicle to implement the hover mode and the calibration rotation sequence;

sensors to obtain measurement data during the calibration rotation sequence, wherein the sensors include at least one magnetic sensor for calibration;

a calibration calculator to calculate calibration parameters using the measurement data obtained during the calibration rotation sequence;

a remote control station to send control commands to trigger the automatic calibration and receive the calibration parameters and location data for the vehicle; and

an interface for displaying the location data for the vehicle and a visual representation of the calibration parameters.

22. The system of claim 21 wherein the calibration control detects environmental factors to adjust the calibration rotation sequence dynamically with a tilt movement for calculation of the calibration measurements to address the environmental factors.