Self-Contained Avionics Sensing And Flight Control System For Small Unmanned Aerial Vehicle

• US 20070069083A1
• Filed: 06/08/2006
• Published: 03/29/2007
• Est. Priority Date: 06/20/2005
• Status: Active Grant

• Current Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Original Assignee: The United States of America As Represented By The Secretary of Agriculture
• Inventors: Fox, Robert, Adams, James, Laughter, Sean, Ingham, John, Logan, Michael, Shams, Qamar, Babel, Walter, Fox, Melanie, Kuhn, Theodore
• Granted Patent: US 7,962,252 B2
• Time in Patent Office: Days
• US Class Current: 244/195
• CPC Class Codes: G05D 1/101 specially adapted for aircraft

Abstract

A self-contained avionics sensing and flight control system is provided for an unmanned aerial vehicle (UAV). The system includes sensors for sensing flight control parameters and surveillance parameters, and a Global Positioning System (GPS) receiver. Flight control parameters and location signals are processed to generate flight control signals. A Field Programmable Gate Array (FPGA) is configured to provide a look-up table storing sets of values with each set being associated with a servo mechanism mounted on the UAV and with each value in each set indicating a unique duty cycle for the servo mechanism associated therewith. Each value in each set is further indexed to a bit position indicative of a unique percentage of a maximum duty cycle for the servo mechanism associated therewith. The FPGA is further configured to provide a plurality of pulse width modulation (PWM) generators coupled to the look-up table. Each PWM generator is associated with and adapted to be coupled to one of the servo mechanisms.

Claims

1. An avionics sensing and flight control system, comprising:

a first circuit board adapted to be mounted on an unmanned aerial vehicle (UAV);

a first plurality of sensors mounted on said first circuit board for sensing a plurality of flight control parameters;

a second plurality of sensors mounted on said first circuit board for sensing a plurality of surveillance parameters;

a Global Positioning System (GPS) receiver mounted on said circuit board for providing signals indicative of location;

means, mounted on said first circuit board and coupled to said first and second plurality of sensors and said GPS receiver, for generating data packages with each of said data packages containing one of said flight control parameters, said surveillance parameters, and said signals indicative of location;

a second circuit board adapted to be mounted on the UAV;

a controller mounted on said second circuit board for processing ones of said data packages containing said flight control parameters and said signals indicative of location to generate flight control signals, and for storing ones of said data packages containing said surveillance parameters; and

a Field Programmable Gate Array (FPGA) coupled to said controller and configured to provide

(i) a look-up table storing sets of values with each of said sets being associated with a servo mechanism mounted on the UAV and with each of said values in each of said sets indicating a unique duty cycle for the servo mechanism associated therewith, each of said values in each of said sets being indexed to a bit position indicative of a unique percentage of a maximum duty cycle for the servo mechanism associated therewith, and

(ii) a plurality of pulse width modulation (PWM) generators coupled to said look-up table, each of said PWM generators being associated with and adapted to be coupled to one of the servo mechanisms, wherein each of said flight control signals specifies one of said bit positions in one of said sets and one of said PWM generators, and wherein said one of said PWM generators so-specified outputs a PWM signal having a duty cycle dictated by one of said values in said one of said sets stored at said one of said bit positions so-specified.

2. An avionics and flight control system as in claim 1 wherein said first plurality of sensors comprises accelerometers, gyros, pressure sensors, and ultrasonic sensors.

3. An avionics and flight control system as in claim 2 wherein said pressure sensors comprise absolute and differential pressure sensors.

4. An avionics and flight control system as in claim 2 wherein said pressure sensors comprise micro-electro-mechanical systems (MEMS) devices.

5. An avionics and flight control system as in claim 2 wherein said gyros comprise a first gyro configured to measure pitch rate, a second gyro configured to measure roll rate, and a third gyro configured to measure yaw rate.

6. An avionics and flight control system as in claim 2 wherein said gyros comprise micro-electro-mechanical systems (MEMS) devices.

7. An avionics and flight control system as in claim 2 wherein said accelerometers comprise micro-electro-mechanical systems (MEMS) devices.

8. A self-contained avionics sensing and flight control system adapted to be mounted on one or more circuit boards that are adapted to be mounted on an unmanned aerial vehicle (UAV), comprising:

a first plurality of sensors for sensing flight control parameters;

a second plurality of sensors for sensing surveillance parameters;

a Global Positioning System (GPS) receiver for providing signals indicative of location;

flash memory for storing at least said surveillance parameters;

means for processing said flight control parameters and said signals indicative of location to generate flight control signals; and

a Field Programmable Gate Array (FPGA) coupled to said means for processing and configured to provide

(i) a look-up table storing sets of values with each of said sets being associated with a servo mechanism mounted on the UAV and with each of said values in each of said sets indicating a unique duty cycle for the servo mechanism associated therewith, each of said values in each of said sets being indexed to a bit position indicative of a unique percentage of a maximum duty cycle for the servo mechanism associated therewith, and

(ii) a plurality of pulse width modulation (PWM) generators coupled to said look-up table, each of said PWM generators being associated with and adapted to be coupled to one of the servo mechanisms, wherein each of said flight control signals specifies one of said bit positions in one of said sets and one of said PWM generators, and wherein said one of said PWM generators so-specified outputs a PWM signal having a duty cycle dictated by one of said values in said one of said sets stored at said one of said bit positions so-specified.

9. An avionics and flight control system as in claim 8 wherein said first plurality of sensors comprises accelerometers, gyros, pressure sensors, and ultrasonic sensors.

10. An avionics and flight control system as in claim 9 wherein said pressure sensors comprise absolute and differential pressure sensors.

11. An avionics and flight control system as in claim 9 wherein said pressure sensors comprise micro-electro-mechanical systems (MEMS) devices.

12. An avionics and flight control system as in claim 9 wherein said gyros comprise a first gyro configured to measure pitch rate, a second gyro configured to measure roll rate, and a third gyro configured to measure yaw rate.

13. An avionics and flight control system as in claim 9 wherein said gyros comprise micro-electro-mechanical systems (MEMS) devices.

14. An avionics and flight control system as in claim 9 wherein said accelerometers comprise micro-electro-mechanical systems (MEMS) devices.

15. A self-contained avionics sensing and flight control system adapted to be mounted on one or more circuit boards that are adapted to be mounted on an unmanned aerial vehicle (UAV), comprising:

a first plurality of sensors for sensing flight control parameters;

a second plurality of sensors for sensing surveillance parameters;

a Global Positioning System (GPS) receiver for providing signals indicative of location;

flash memory for storing at least said surveillance parameters;

means for processing said flight control parameters and said signals indicative of location to generate flight control signals; and

a Field Programmable Gate Array (FPGA) coupled to said means for processing and configured to provide

(i) a look-up table storing sets of values with each of said sets being associated with a servo mechanism mounted on the UAV and with each of said values in each of said sets indicating a unique duty cycle for the servo mechanism associated therewith, each of said values in each of said sets being indexed to a bit position indicative of a unique percentage of a maximum duty cycle for the servo mechanism associated therewith,

(ii) a plurality of addressable input/output (I/O) ports coupled to said means for processing and coupled to said look-up table, and

(ii) a plurality of pulse width modulation (PWM) generators, each of said PWM generators being coupled to a corresponding one of said I/O/ ports and adapted to be coupled to one servo mechanism, wherein each of said flight control signals specifies one of said bit positions in one of said sets and one of said I/O ports, and wherein said PWM generator coupled to said one of said I/O ports so-specified outputs a PWM signal having a duty cycle dictated by one of said values in said one of said sets stored at said one of said bit positions so-specified.

16. An avionics and flight control system as in claim 15 wherein said first plurality of sensors comprises accelerometers, gyros, pressure sensors, and ultrasonic sensors.

17. An avionics and flight control system as in claim 16 wherein said pressure sensors comprise absolute and differential pressure sensors.

18. An avionics and flight control system as in claim 16 wherein said pressure sensors comprise micro-electro-mechanical systems (MEMS) devices.

19. An avionics and flight control system as in claim 16 wherein said gyros comprise a first gyro configured to measure pitch rate, a second gyro configured to measure roll rate, and a third gyro configured to measure yaw rate.

20. An avionics and flight control system as in claim 16 wherein said gyros comprise micro-electro-mechanical systems (MEMS) devices.

21. An avionics and flight control system as in claim 16 wherein said accelerometers comprise micro-electro-mechanical systems (MEMS) devices.