Flight Planning for Unmanned Aerial Tower Inspection with Long Baseline Positioning

• US 20180095478A1
• Filed: 03/17/2016
• Published: 04/05/2018
• Est. Priority Date: 03/18/2015
• Status: Active Grant

• Current Assignee: Izak Van Cruyningen
• Original Assignee: Izak Van Cruyningen
• Inventors: van Cruyningen, Izak Jan
• Granted Patent: US 10,509,417 B2
• Time in Patent Office: Days
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 19/14 specially adapted for specific applications
• CPC Class Codes: G01S 19/43 using carrier phase measurements, e.g. kinematic positioning; using long or short baseline interferometry
• CPC Class Codes: G05D 1/0094 involving pointing a payload, e.g. camera, weapon, sensor, towards a fixed or moving target

Abstract

FIG. 1 is a perspective view of transmission tower 10, phase conductors 12, insulators 14, and shield wires 15. They are to be inspected by unmanned aerial vehicle UAV 20 with embedded processor and memory 22, radio 24, location rover 26, and camera 28. Continuously operating reference station 16 has GNSS antenna 17, GNSS receiver 19, and radio 18. The relative location between UAV 20 and reference station 16 can be accurately calculated using location corrections sent by radio 18 to radio 24. Camera 28 on UAV 20 is first used to capture two or more orientation images 38 and 39 of tower 10; lines 12 and 15; and insulators 14 from different vantage points. Terrestrial or close-range photogrammetry techniques are used create a three dimensional model of tower 10; lines 12 and 15; and insulators 14. Based on inspection resolution and safety objectives, a standoff distance 50 is determined. Then a flight path with segments for ascent 40, one or more loops 42, 44, 46, and a descent 48 is designed to ensure full inspection coverage via inspection images like 52 and 54.

Claims

1. A method to plan a flight to inspect a tower with an unmanned aerial vehicle comprising

defining a reference base station,

receiving location correction messages from a plurality of continuously operating reference stations more than two tower heights away from said tower,

incorporating said correction messages in a location rover mounted on said unmanned aerial vehicle,

scanning said tower in three dimensions to create a three dimensional model of said tower relative to said reference base station,

determining a standoff distance for said flight,

generating a plurality of flight segments from said model maintaining said standoff distance, positioned relative to said reference base station to inspect said tower.

2. The method of claim 1 wherein said scanning comprises

acquiring more than one orientation image of said tower,

creating said three dimensional model of said tower from said orientation images.

3. The method of claim 1 wherein the closest of said continuously operating reference stations to said tower is defined as said reference base station.

4. The method of claim 1 wherein said reference base station is a virtual base station location defined by a network real time kinematic server.

5. A flight planning system for the inspection of a tower using an unmanned aerial vehicle comprising

a location rover mounted on said unmanned aerial vehicle to receive correction messages from a reference base station,

a non-contact three-dimensional scanner to create a three dimensional model of said tower relative to said reference base station,

standoff means to determine a standoff distance for said inspection,

flight segment generation means to generate a plurality of flight segments for said unmanned aerial vehicle relative to said reference base station, each flight segment maintaining said standoff distance.

6. The apparatus of claim 5 further comprising

a camera to acquire orientation images,

a processor and memory to create said three dimensional model from said orientation images.

7. The apparatus of claim 5 wherein said reference base station is the closest continuously operating reference station to said tower.

8. The apparatus of claim 5 wherein said reference base station is a virtual base station location defined by a network real-time kinematic server.

9. A method to inspect a tower with an unmanned aerial vehicle comprising

defining a reference base station,

receiving location correction messages from a plurality of continuously operating reference stations more than two tower heights away from said tower,

incorporating said correction messages in a location rover mounted on said unmanned aerial vehicle,

scanning said tower in three dimensions to create a three dimensional model of said tower relative to said reference base station,

determining a standoff distance for said flight,

generating a plurality of flight segments from said model maintaining said standoff distance, positioned relative to said reference base station to inspect said tower,

communicating said flight segments to said unmanned aerial vehicle,

providing a plurality of inspection sensors on said unmanned aerial vehicle,

locating said unmanned aerial vehicle relative to said reference base station in near real-time,

flying said flight segments with said unmanned aerial vehicle while gathering inspection data with said inspection sensors.

10. The method of claim 9 wherein said scanning comprises

acquiring more than one orientation image of said tower,

creating said three dimensional model of said tower from said orientation images.

11. The method of claim 9 wherein the closest of said continuously operating reference stations to said tower is defined as said reference base station.

12. The method of claim 9 wherein said reference base station is a virtual base station location defined by a network real time kinematic server.

13. A tower inspection system comprising

an unmanned aerial vehicle,

a location rover mounted on said unmanned aerial vehicle to receive correction messages from a reference base station,

a non-contact three-dimensional scanner to create a three dimensional model of said tower relative to said reference base station,

standoff means to determine a standoff distance for said inspection,

flight segment generation means to generate a plurality of flight segments for said unmanned aerial vehicle relative to said reference base station, each flight segment maintaining said standoff distance,

inspection sensors mounted on said unmanned aerial vehicle,

locating means to determine location during flight of said unmanned aerial vehicle relative to said reference base station in near real time.

14. The apparatus of claim 13 further comprising

a camera to acquire orientation images,

a processor and memory to create said three dimensional model from said orientation images.

15. The apparatus of claim 13 wherein said reference base station is the closest continuously operating reference station to said tower.

16. The apparatus of claim 13 wherein said reference base station is a virtual base station location defined by a network real-time kinematic server.