WO2019222798A1

WO2019222798A1 - Drone flight programming method and system

Info

Publication number: WO2019222798A1
Application number: PCT/AU2019/050489
Authority: WO
Inventors: Jason Ian Nathaniel Beath
Original assignee: Acid Ip Pty Ltd
Priority date: 2018-05-22
Filing date: 2019-05-21
Publication date: 2019-11-28

Abstract

This invention relates in general to a method of controlling a drone to fly an autonomous grid pattern while capturing images or data of a target area. The method reduces ground sampling distance and provides greatly improved survey accuracy by tilting the flight grid, folding the flight grid and wrapping the flight grid. The method also reduces the number of flights required to achieve improved survey accuracy and improves flight and drone safety.

Description

DRONE FLIGHT PROGRAMMING METHOD AND SYSTEM

FIELD OF THE INVENTION

This invention relates to a method and system for controlling the flight of an unmanned aerial vehicle (UAV), otherwise known as a drone, and in particular relates to a programming method and system for improved survey accuracy.

BACKGROUND OF THE INVENTION

It should be noted that reference to the prior art herein is not to be taken as an acknowledgement that such prior art constitutes common general knowledge in the art.

The type of drone to which this invention relates is a rotary-wing type generally described in US 2018/0109731 A1 , US 9,387,927 B2, WO

2010/061099 and WO 2008/056051 A2, although this invention would equally apply to any suitable UAV or drone.

In recent years civilian drones have been used for many different purposes. Beyond photography and videography for recreational purposes and for making motion pictures and television programs, including documentaries, drones are used in land surveying, in agriculture, and in the mining, real estate and other industries, as well as for surveillance, disaster management, search and rescue, safety inspections, wildlife monitoring and poaching enforcement, and storm tracking.

The flight of drones is generally controlled from the ground, usually by some form of radio communication. Some are able to be preprogrammed with flight commands and fly autonomously. Many drones are controlled by smart phones such as iPhones, or tablets such as iPads.

Photogrammetry is the science of making measurements from photographs, especially for recovering the exact positions of surface points. Photogrammetry is used in fields such as topographic mapping, architecture, engineering manufacturing, quality control, police investigation, and geology. Recently, drones are more commonly being used for 3D photogrammetry surveys. The drone collects a series of images which are then processed by a photogrammetry program which uses the GPS (Global Positioning System) data imbedded within each image to triangulate a point cloud and 3D model in which measurements can then be made.

The drone with its GPS positioning inserts EXIF (Exchangeable Image File Format) data into each image which provides precise camera location, camera direction both heading and vertical angle as well as camera megapixels and lens angle.

The method of controlling the drone to take these images is usually either a program built into the drone controller, a flight software application (App) which is downloaded into a smart phone or iPad (iOS, Android or other) and connected to the drone’s transmitter to design and upload waypoints to the drone to control flight, or by using a laptop or computer program to design and upload waypoints to the drone to direct its flight and image taking. These flight paths could also be set on the actual drone itself and not through a transmitter. Presently, an image taking flight path is designed and the waypoints are uploaded to the drone but real time flight control from the controller could also be used.

The present method of designing an image taking flight path on the controller, phone, iPad or computer is to view a satellite or other image or map and to draw or select a square, rectangle, polygon or other shape to bound the borders of the flight paths. The flight path may be defined such that it covers the desired area of interest, wherein the acquisition of image data is set for providing a lateral overlap of the captured images regarding the respectively covered regions. The grid pattern flight path spacing is usually calculated by the program which uses the drone’s camera lens angle, image overlap selected and flight height to provide the parallel flight paths for image taking.

Some programs can also calculate the flight grid spacing based on any other combination of user programmed or selected parameters such as camera lens angle, camera overlap plus GSD (Ground Sampling Distance). GSD is the area in which each pixel covers on the ground from a particular altitude. This is particularly important in aerial survey as the smaller the GSD, the more accurate the survey can be. The photogrammetry program has sharper, more detailed marks on the ground to work with rather than large blurry blobs of colour. Likewise, the more distance there is between the drone and the surface being surveyed, the larger the ground sampling distance, and the less precise the position data obtained. A drone camera lens has a predetermined angle and the image sensor has a predetermined number of pixels. So the higher in altitude that the drone flies and takes images from, the larger the area that the image covers and the larger the coverage area on the ground each pixel covers.

It is generally recommended that a GSD of between 0.75cm and 2.5cm is optimum for survey accuracy. That is to say, each pixel should cover no more than around 2.5cm

The flight grid can be both in single grid and double grid - meaning the second grid flies 90 degrees to the first grid to provide better triangulation for mapping. However, both the single and double grids only form a horizontal flight path area at the specified altitude.

The program also calculates the image taking interval within its calculations but can calculate image taking by distance or time or these parameters can be manually selected.

Either nadir or angled images can be selected and each has their own benefits depending on what is being surveyed and the type of photogrammetry program being used. The nadir images are taken in the direction pointing directly below the drone location.

Presently all drone flight grid planning programs or controllers only provide the capability to conduct flat, single plane or horizontal flight grids. Many sites which require drone survey are either sloping, undulating or cut into a mountain side. Taking images of a quarry cut into a hill side takes several flight grids at differing altitudes to achieve even a reasonably constant GSD. This means more time, more batteries, decreased drone safety and usually less accuracy.

Clearly it would be advantageous if a method and system for controlling the flight of an unmanned aerial vehicle (UAV) could be devised that helped to at least ameliorate some of the shortcomings described above. In particular, it would be beneficial to provide a method and system for controlling the flight of an unmanned aerial vehicle (UAV) which reduced the number of flights required and to achieve greatly improved survey accuracy and also improve flight and drone safety.

SUMMARY OF THE INVENTION

In accordance with a first aspect, the present invention provides a method of controlling a drone to fly an autonomous flight area pattern for capturing images or data from a target area, the method comprising the steps of: i) loading a flight program and selecting the target area, wherein the target area contains a flight path and a plurality of points selectable within the target area, each point defining a specific location in physical space with a vertical height; ii) adjusting the vertical height of one or more of the plurality of points to suit a changing terrain height or a three dimensional shape of the target area; iii) determining a set of waypoints for controlling the drone within the target area; iv) uploading or loading the waypoints to the drone; and wherein the flight path is tilted, folded or wrapped to suit the changing terrain height or the three dimensional shape of the target area.

Preferably, the method may further comprise using the captured images or data to develop a survey of the target area.

Preferably, capturing images or data to develop the survey of the target area may further comprise developing the survey to produce a three dimensional survey of the target area.

Preferably, capturing images or data may further comprise capturing thermal images of the target area using a thermal camera.

Preferably, capturing data may comprises: capturing global positioning data from a GPS receiver on the drone; or capturing image data from a camera on the drone; or capturing distance data from a light detection and ranging device on the drone.

Preferably, the flight path may maintain an approximately constant ground sampling distance or height above the terrain to suit the changing terrain height or the three dimensional shape of the target area.

Preferably, the ground sampling distance or height above the terrain may be dependent upon the required accuracy of the survey of the target area. The ground sampling distance may be in the range of 0.4 cm to 5.0 cm.

Preferably, step ii) further comprises: obtaining the target area changing terrain height or the three dimensional shape using a previously processed geometric data of the target area from two-dimensional images; and using the data and adjusted vertical heights to create the flight grid. The previously processed geometric data is any one or more of: a photogrammetry software application which extracts geometric information from two-dimensional images of the target area; a 3D CAD file of the target area; a web-based service that provides detailed information about the target area; or any other type of shape information.

Preferably, the tilting, folding or wrapping the flight path may allow a data capture of the target area of any shape and any varying terrain.

Preferably, the data capture of the target area may comprise any one or more of: i) a sloping target area wherein the drone flight path is tilted to maintain the approximately constant ground sampling distance or height above the terrain to match the slope of the target area; ii) a target area with a ridge or valley and the flight path is folded on each side of the ridge or valley to maintain the approximately constant ground sampling distance or height above the terrain to match the slope on each side of the ridge or valley of the target area; iii) a target area with a convex or a concave shape and the flight path is wrapped to maintain the approximately constant ground sampling distance or height above the terrain to match the convex or concave shape of the target area; and iv) a target area with a different height at more than one of the plurality of points within the target area wherein the drone flight path grid is warped to maintain the approximately constant ground sampling distance or height above the terrain to match the different heights of the target area.

Preferably, the target area ii) may have more than one ridge or valley.

Preferably, the flight path of the drone over the target area is any one or more of: i) a single flight path; ii) a double flight path; or iii) a multiple flight path.

Preferably, the flight area pattern of the drone over the target area may have any one or more of the following shapes: i) a square shape; ii) a rectangular shape; iii) a circular shape; iv) a triangular shape; v) an oval shape; or vi) any regular or irregular polygon shape.

Preferably, step ii) may further comprise: obtaining the target area changing terrain height or the three dimensional shape of the target area by: i) flying the drone to a first position on the target area; ii) saving the first position coordinates and vertical height; iii) flying the drone to a another position on the target area; iv) saving the another position coordinates and vertical height; v) repeating steps iii) and iv) until at least three positions have been saved to obtain the changing terrain height or the three dimensional shape of the target area; and vi) using the saved positions and vertical heights to create the flight grid. Preferably, adjusting the vertical height of one or more of the plurality of points may provide images or data captured by the drone flying the flight path at a similar height above the changing terrain height or the three dimensional shape of the target area.

Preferably, adjusting the vertical height of one or more of the plurality of points in the target area, may tilt, fold, or wrap the flight path over the changing terrain height or the three dimensional shape of the target area to provide improved image and data collection accuracy.

In accordance with a further aspect, the present invention provides a method of controlling a drone to fly an autonomous flight path for collecting data or images about a target area, the method comprising the steps of: i) selecting target area boundaries and vertical heights of the target area by: a) flying the drone to a first position on the target area; b) saving the first position coordinates and vertical height; c) flying the drone to another position on the target area; d) saving the another position coordinates and vertical height; and e) repeating steps c) and d) until at least three positions have been saved; ii) determining a set of waypoints for controlling the drone within the target area using the saved positions and vertical heights; iii) uploading the waypoints to the drone; and wherein the flight path is tilted, folded or wrapped to suit the vertical heights of the target area.

Preferably, the method may further comprise using the collected data and images to develop a survey of the target area.

Preferably, the flight path may maintain an approximately constant ground sampling distance or height above the terrain to suit the changing vertical height within the target area. The ground sampling distance may be dependent upon the required image or data accuracy of the survey of the target area. The ground sampling distance may be in the range of 0.4 cm to 5.0 cm.

Preferably, the tilting, folding or wrapping the flight path may allow a data capture of the target area of any shape and any varying terrain. The data capture of the target area may comprise any one or more of: i) a sloping target area wherein the drone flight path is tilted to maintain the approximately constant ground sampling distance or height above the terrain to match the slope of the target area; ii) a target area with a ridge or valley and the flight path is folded on each side of the ridge or valley to maintain the approximately constant ground sampling distance or height above the terrain to match the slope on each side of the ridge or valley of the target area; iii) a target area with a convex or a concave shape and the flight path is wrapped to maintain the approximately constant ground sampling distance or height above the terrain to match the convex or concave shape of the target area; and iv) a target area with a different height at more than one of the plurality of points within the target area wherein the drone flight path grid is warped to maintain the approximately constant ground sampling distance or height above the terrain to match the different heights of the target area.

Preferably, the target area ii) may have more than one ridge or valley.

Preferably, the flight path of the drone over the target area may be any one or more of: i) a single flight path; ii) a double flight path; or iii) a multiple flight path.

Preferably, the target area boundaries of the flight path may be formed in the shape of any one or more of the following: i) a square shape; ii) a rectangular shape; iii) a circular shape; iv) a triangular shape; v) an oval shape; or vi) any regular or irregular polygon shape.

In accordance with a still further aspect, the present invention provides a method for developing a three-dimensional (3D) survey of a target area using a drone to obtain images, the method comprising: providing at least one camera on the drone; preparing the drone for flight and programming using a flight controlling application to produce an autonomous flight path about the target area, the flight controlling application comprising: i) selecting the target area, wherein the target area contains the flight path and a plurality of points selectable within the target area, each point defining a specific location in physical space with a vertical height; ii) adjusting the vertical height of one or more of the plurality of points to suit a changing terrain height or a three dimensional shape of the target area; iii) determining a set of waypoints for controlling the drone within the target area; and iv) uploading the waypoints to the drone; flying the drone around the target area; obtaining images from the at least one camera of the target area during the flight; using the images and a software program which extracts geometric data from two-dimensional images to develop the three- dimensional (3D) survey of the target area; and wherein the autonomous flight path maintains an approximately constant ground sampling distance to suit the changing terrain height or the three dimensional shape of the target area by tilting, folding or wrapping the flight path.

Preferably, the method may further comprise any one of the features of the first aspect.

In accordance with a still further aspect, the present invention provides a method for controlling or programming the flight path of a drone for surveying an area of land, comprising the steps of: using a 3D shape or terrain data file from a previously conducted flight over the area of land or any other data file source of the area of land; selecting a vertical height parameter to set a flight height of the drone above the area of land; determining a set of waypoints using the 3D shape file and the vertical height parameter for the flight path; uploading to a flight controller the set of waypoints for controlling the drone within the flight path; flying the drone using the waypoints to produce images or data of the area of land; and wherein the flight path is tilted, folded or wrapped to suit a changing terrain height or a three dimensional shape of the area of land.

Preferably, selecting the vertical height parameter above the area of land to improve survey accuracy may comprise selecting a vertical height to maintain an approximately constant ground sampling distance or height above the terrain to suit the changing terrain height or the three dimensional shape of the area of land.

In accordance with a still further aspect, the present invention provide a method for flying a drone for survey purposes in respect of an area, the method comprising the steps of: providing a drone in communication with a controller, the drone constantly transmitting its location and vertical height along with real time camera footage back to the controller; selecting area boundaries and vertical heights of the area by: a) flying the drone to a first position on the area; b) saving the first position coordinates and vertical height to the controller; c) flying the drone to a further position on the area; d) saving the further position coordinates and vertical height to the controller; and e) repeating steps c) and d) until at least three positions on the area have been saved to the controller; determining a set of waypoints from the at least three saved positions; uploading the waypoints to the drone and flying the drone autonomously around the area; obtaining images from at least one camera of the area during the flight; using the images to develop a survey of the area; and wherein a flight path of the drone maintains an approximately constant ground sampling distance or height above the terrain to suit a changing height or a three dimensional shape of the target site by tilting, folding or wrapping the flight path.

In accordance with as still further aspect, the present invention provide a software program that can be downloaded or reside on a controller for controlling a drone for capturing images and data, the software program comprising instructions capable of using a method according to any one of the features of the first aspect for the remote control of the drone.

In accordance with a still further aspect, the present invention provides a system for collecting photographic images or data of a target area for input to a survey, the system comprising: a drone having a microprocessor for managing control of the drone and transmitting and receiving data; an image or data capturing device; a controller with wireless data-transmission means capable of transmitting commands to the drone; a flight program on the controller, the flight program being programmed to fly the drone in an autonomous flight path around the target area, wherein the flight program comprises instructions capable of using a method according to any one of the features of the first aspect for autonomous control of the drone.

In accordance with a still further aspect, the present invention provides a drone for developing a three-dimensional (3D) model of a target area, the drone comprising: one or more rotors disposed to a body; a camera or data collection device associated with the body; at least one wireless interface and a processor coupled to the at least one wireless interface, the data collection device and the camera; a controller in wireless communications with the drone and a flight program residing on or downloaded to the controller for controlling the flight of the drone; and memory storing instructions that, when executed, cause the processor to: process commands to prepare the drone for flight and receive program instructions for an autonomous flight path about the target area from the controller, wherein the autonomous flight path comprises a changing terrain height or a three dimensional shape of the target area; process commands to cause the drone to fly around the target area; process commands to obtain images or data of the target area during the flight; and provide the images to develop the three-dimensional (3D) model of the target area; process commands for communicating with the controller; and wherein the flight program to develop the autonomous flight path around the target area comprises instructions capable of using a method according to any one of claims 1 to 18 for autonomous control of the drone.

Any one or more of the above embodiments or preferred features can be combined with any one or more of the above aspects.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood more fully from the detailed description given hereinafter and from the accompanying drawings of the preferred embodiment of the present invention, which, however, should not be taken to be limitative to the invention, but are for explanation and understanding only.

Fig. 1 shows a multiple axis tilt grid or wrapped flight grid for a drone in accordance with an embodiment of the present invention;

Fig. 2 illustrates a single axis tilt grid in accordance with an embodiment of the present invention;

Fig. 3 illustrates a multiple axis folded tilt grid in accordance with an embodiment of the present invention;

Fig. 4 shows a 3D shape file which could be utilised to provide the terrain and 3D shape of a target area;

Fig. 5 illustrates a tilted oval or racetrack shaped flight path in accordance with an embodiment of the present invention;

Fig. 6 shows a modified tilted oval or dog-leg shaped flight path;

Fig. 7 illustrates another wrapped flight grid in which the flight path is designed to follow the convex curve of a mountain;

Fig. 8 illustrates another 3D shape file which illustrates a concave curve similar to a valley;

Fig. 9 shows some of the exemplary shapes of the target areas of the present invention;

Fig. 10 illustrates a flowchart of the method in accordance with an embodiment of the present invention;

Fig. 1 1 shows a flowchart of the initial set-up of the drone;

Fig. 12 shows a flowchart of the steps in uploading a previous 3D shape file of the target area; and Fig. 13 shows the steps involved in producing a flight path by flying a drone around the target area.

DETAILED DESCRIPTION OF THE INVENTION

The following description, given by way of example only, is described in order to provide a more precise understanding of the subject matter of a preferred embodiment or embodiments.

The present invention provides in a broad aspect, a method of controlling a drone to fly a flight path around or over a target area to capture images or data which are at a similar height above the ground, including the step of tilting the flight grid, using a split tilted flight grid, or wrapping the grid over the terrain or over the three dimensional shape of the terrain by being able to tilt, fold or wrap the flight grid to provide a much reduced ground sampling distance and therefore greatly improved survey accuracy.

The method of controlling the drone 10 to fly an autonomous flight area pattern or flight path which has been tilted, folded or wrapped to suit the changing terrain height or the three dimensional shape of the target area. The present invention has been designed for capturing images or data from the target area. The method has a number of steps which define the creation of the autonomous flight pattern. The first step is to load or open a flight program and selecting the target area, wherein the target area contains a flight path and a plurality of points selectable within the target area, each point defining a specific location in physical space with a vertical height. The next step is to adjust the vertical height of one or more of the plurality of points to suit a changing terrain height or a three dimensional shape of the target area. This is followed by determining a set of waypoints for controlling the drone within the target area and uploading the waypoints to the drone 10.

Fig. 1 illustrates a multiple axis tilt grid or wrapped flight grid for a drone 10. As shown in this embodiment, the flight path 40 is drawn and the desired flight height which the drone 10 is programmed to fly over the flight path 40 is selected. The flight path consists of a first tilted grid 41 which is folded at point 42, the path between points 42 and the next point 43 could represent a valley between two mountains, wherein the tilted grid 41 and the tilted grid 44 forming two sides of the mountain. In order to control the drone 10 a flight program is loaded on a controller, in this case the controller is represented as the computer 30. The positioning of both the drone 10 and the controller 30 is determined through the use of the global positioning satellite 20.

Fig. 2 is another representation of the type of flight path which can be achieved through the use of a drone 10 in accordance with the present invention. The flight path 53 represents a standard tilt grid or single axis tilt 53. In this embodiment, one would draw the flight grid 50 and pick one end, side or corner 51 and select a first height. One then selects the other end, side or corner 52 and selects the second height. This represents a flight path 53 which is flat (or in one plane) but tilted. The drone 10 is programmed to fly a height above the terrain or 3D shape of the area of the flight path 53. The flight path 53 is designed to maintain a similar height above the terrain and therefore maintain a similar ground sampling distance to provide an improved survey accuracy.

By providing this flight path we are able to maintain an approximately constant ground sampling distance or height above the terrain to suit the changing terrain height or the three dimensional shape of the target area. Put another way, this embodiment provides a sloping target area wherein the drone flight path is tilted to maintain the approximately constant ground sampling distance or height above the terrain to match the slope of the target area. In providing surveys the ground sampling distance or height above the terrain is dependent upon the required accuracy of the survey of the target area. By way of example, the ground sampling distance may be in the range of 0.4 cm to 5.0 cm.

Fig. 3 illustrates a multiple axis folded tilt grid 60 which relates to a double or multiple split tilt. This grid 60 is representative of a mine cut into a mountain on a 45 degree slope cutting 64, 68 or a crop farmed on a flat 62, 66 as well as a slope 64, 68. As shown, multiple fold lines 63, 65, 67 are drawn or selected across the flight grid area. The height of each fold line 63, 65, 67 or alternatively different heights of each end of the fold lines 63, 65, 67 and either ends or corners 61 , 69 of the flight grid area are selected, or different heights for each end or corners 61 , 69 of the flight grid are selected. This is like folding a piece of paper a few degrees and then tilting it to best fit the terrain. Once the flight path 70 has been determined, the drone 10 will fly based on the waypoints 71 located throughout the flight grid area 60. The waypoints 71 can also represent positions within the flight path 70 which a camera or data collecting device is programmed to be activated. In a folded tilt grid with multiple axis tilt, for example, a target area with a ridge or valley the flight path is folded on each side of the ridge or valley to maintain the approximately constant ground sampling distance or height above the terrain to match the slope on each side of the ridge or valley of the target area. While Fig. 3 shows two ridge lines and one valley line, any number of both ridge and valley lines are possible with the present invention.

The position of a single fold line or multiple fold lines is drawn or selected across the flight grid area. Select end heights, select middle or percentage along flight grid’s height, and select other end height. The fold line position could be manually selected as desired. One end of the flight grid could be flat to fly a level area and then tilt up to fly the slope, or down to fly the edge of a ridge line or fly a ridge line and fold the sides lower than the centre.

The captured images or data can then be used to develop a survey of the target area 60. By way of example only, the survey may be a three dimensional survey of the target area or some three dimensional shape. Alternatively, the camera of the drone 10 may be a thermal camera used for producing a thermal imaging survey. This technique uses the heat given off by an object located within the target area and the thermal camera produces an image which can be used to locate the object within the area.

The process of capturing data can include retrieving the global positioning data from the GPS receiver on the drone 10, capturing image data from the camera on the drone or using a light detection and ranging device to capture distance data from the drone 10. The camera data can include the GPS data embedded within each image to triangulate a point cloud and 3D model in which measurements can then be made. Typically, the drone 10 with its GPS positioning inserts exchangeable image file format data (EXIF) into each image which provides precise camera location, camera direction both heading and vertical angle as well as camera megapixels and lens angle.

The light detection and ranging device may be any surveying method that measures distance to a target by illuminating the target with pulsed laser light and measuring the reflected pulses with a sensor. Differences in laser return times and wave lengths can then be used to make digital 3D representations of the target. One method of obtaining the target area changing terrain height or the three dimensional shape is to utilise a previously processed geometric 3D shape file containing data of the target area obtained from a two-dimensional image. This data and by adjusting the vertical heights within the target area enables the method to create the flight grid. The previously processed geometric data can be obtained from a photogrammetry software application which extracts geometric information from two-dimensional images of the target area. Alternatively, the previously processed geometric data can be obtained from a 3D CAD file of the target area or through a web-based service that provides detailed information about the target area, such as Google maps or any other type of shape information available for the target area.

Fig. 4 shows an example of a 3D shape file obtained from a photogrammetry software application. The grid 80 shows a undulating terrain which starts at a point 81 on the left hand side which descends to a valley 82 which then rises again to point 83 which extends across a flat plane to point 84 and then slopes away to the point 85 located on the right hand side of the 3D shape file. By way of example only, the drone 10 could be programmed to follow the flight paths 86, 87, 88 to maintain a similar height above the terrain and therefore maintain a similar ground sampling distance to provide for improved survey accuracy. The method of the present invention allows the tilting, folding or wrapping of the flight path to allow data capture of the target area of any shape and any varying terrain.

Figs. 5 and 6 are examples of a tilted oval flight in accordance with another embodiment of the present invention. In figure 5, the oval flight path 90 is designed to allow a user to select two points 91 , 92 to make a line which the drone 10 orbits around. The height at each end 91 , 92 can be selected along with the radius 93, speed and direction of flight to achieve a tilted flight path 95. As shown, the oval flight path 90 can be used for small or large area survey imaging. The user would select a spacing 94 and the flight program would calculate the distance to continue orbit flights 96, 97, 98 with a greater radius and/or height with each orbit. This would achieve image and data collection of a larger area on a sloping site.

The tilted oval flight path may use two or more locations along with altitude to plan an oval flight. Each point or location on the map would be selected along with the altitude or height required. As described above an indicating line may be drawn by the program between each of these selected points. The radius or distance would also be selected in which the drone 10 would remain from the selected point and line between each point. The program would then calculate the latitude, longitude and flight height or altitude to maintain the tilted flight height around this "race track" flight path.

Fig. 6 is another example of a tilted oval flight 100 with a dog leg. In this example the oval flight path is designed to allow a user to select three or more points 101 , 102, 103 to make a line which the drone 10 orbits around. The heights at each point 101 , 102, 103 can vary and is dependent upon the slope of the target area. Like the tilted oval flight of Fig. 5, the radius 104, speed and direction of the flight to achieve a tilted flight path 106 can be selected. The user would select a spacing 105 and the flight program would calculate the distance to continue orbit flights 107, 108, 109 with a greater radius and/or height with each orbit.

Both Figs. 5 and 6 provide a target area with a different height at more than one of the plurality of points within the target area, where the drone flight path grid is warped to maintain the approximately constant ground sampling distance or height above the terrain to match the different heights of the target area.

Two other parameters settings could also be used with the oval flight paths illustrated in Figs 5 and 6. The first parameter is used if the drone 10 was to conduct several orbits around this possibly tilted "race track", the distance between further out (or greater radius from the centre points and lines between) could be selected. Meaning, the first race track flight path may have a radius of 40 metres from the marked points and lines between, and each consecutive race track flight path may be selected to fly further increments of 15 metres further out. Also selectable is the number of orbits to be conducted by the drone 10. The increasing radius or distance further out from the first radius selected flight could also be automatically calculated and selected by the program by using the camera front and side overlap settings.

The second of the parameters is if the points, heights and radius were first selected and then the drone 10 would continue to conduct the selected amount of further flights vertically above the initial flight with a parameter being selected for the height above each consecutive flight path. The camera angle and direction may also be programmable to point and capture images perpendicular to the flight path and decrease its angle to continue to look at the altitude or height of the initial points and lines between those points, or maintain the angle with each consecutive flight orbit. The camera angle may also be programmed to look in the flight direction or at any other angle or direction if selected.

Alternatively, camera angle and direction may also be selected in which the camera may be angled at say 50 degrees below horizontal and always pointing perpendicular to the flight path (or directly at the line between each selected point) as the drone swivels its camera or flies sideways. The camera could also point in the direction of flight travel or any other selected angle relative to flight path, selected points or lines between the selected points.

For drones 10 such as fixed wing drones with only forward looking cameras or to provide improved image collection, the oval or tilted oval flight path may be conducted in both clockwise and counter clockwise directions around the originally marked points to obtain a kind of "double grid" type flight. Even though it would not be a grid and not perpendicular to the first flight taken, it would allow images taken from opposite directions which would improve survey accuracy.

Fig. 7 illustrates another embodiment of the present invention in which a concave flight path is shown. By way of example, a mountain 1 10 with an upward slope 11 1 , a first peak 112, a second peak 1 13 and a downward slope 1 14 can be modeled to allow a drone 10 to capture both data and images of the mountain 110. A drone 10 would initially be positioned on a take-off and landing platform 1 1. Once the 3D shape file has been uploaded to the controller software application (as will be described in more detail below) the drone initially takes off and hovers at a first point 12 for a few seconds then climbs to the selected flight height 115 and proceeds to fly to the starting waypoint 1 16 at a first height located from the slope 11 1 of the mountain 1 10. The drone 10 then flies to the points 1 17, 1 18 and 1 19 while maintaining a relatively similar height above most of the terrain.

Fig. 8 illustrates a similar embodiment of that of Fig. 7, however illustrates a 3D shape file 120 of a convex curved elevation having a first point 121 at a first height, a second point 122 at the bottom and a third point 123 at a further height. The drone 10 is programmed to maintain a relatively similar height above most of the terrain as it traverses the flight path 125.

For both the concave and convex flight paths, the flight program calculates and wraps the flight grid into the shapes/heights which are selected and therefore allows the operator to design the flight grid area to maintain a similar height above the terrain or subject and therefore maintain a similar or approximately constant ground sampling distance. Put another way, the target area with a convex or a concave shape, the flight path is wrapped to maintain the approximately constant ground sampling distance or height above the terrain to match the convex or concave shape of the target area. A smoothing setting may be used in the program settings to remove or smooth sharp or erratic changes in the flight grid height.

In this embodiment, the flight grid area is drawn and the desired flight height is selected of any or all parts of the boundary of the flight grid. Then the flight height of a single location or multiple locations within the flight grid is/are selected. This wrapped flight grid could have multiple high and low spots and be able to reasonably accurately hug the terrain. The flight program of this embodiment calculates and wraps the flight grid into the shape/heights one selects and therefore allows the operator to design the flight grid to maintain a similar height above the terrain or subject and therefore maintain a similar GSD and improve survey accuracy.

For all embodiments of the present invention, the flight path over the target area can be a single flight path, double flight path, or a multiple flight path. For a double grid flight path means the second grid flies 90 degrees to the first grid to provide better triangulation for data and image capture. Likewise, a multiple flight path can include more than one flight path at different angles to the first flight path and consecutive flight paths. Also, both clockwise and counter-clockwise flight paths can be selected. Likewise, the flight area pattern of the drone over the target area can have a square, rectangular, circular, triangular, oval or any regular or irregular polygonal shape. For example, Fig. 9 illustrates a circular 200, a rectangular 201 , a square 202 and a irregular polygon 203 shaped flight areas.

Figs. 10 to 13 show flow charts of the process for controlling a drone 10 to fly an autonomous grid pattern for capturing images or data of a target area. The process starts at 210 to provide the steps to complete a flight. The first step 21 1 is to setup the drone and is explained further below with reference to item A and Fig. 1 1. Any number of steps can be done in the initial setup of the drone 10, however to illustrate some exemplary steps are shown at reference 212a. For example, the battery is inserted, the propellers are fitted and checked and an overall safety check is completed of the drone 10. The next step in the setup of the drone is to setup the controller. This can include, but is not only limited to inserting the control device (tablet etc.) into the controller if required, switching on the transmitter, switching on the control device and then switching on the drone 10.

The next step 213 is to load or open the flight program or flight controlling program. With some controllers and drones, the control program will need to be uploaded to the controller or alternatively may be a software application or software program running on a computer or other device. With the drone, controller and flight controlling program connected, you are now able to check and set various parameters for the drone 10. For example, the battery charge, the return to home flight settings and camera settings such as the SD card, focus, white balance and shutter speed. Once you have checked and set the above drone parameters you are then ready to program the grid pattern and flight path for a target area.

Steps 214, 216 and 217 show three exemplary processes for selecting the grid pattern and flight path for the required target area. At step 214, the 3D shape file for the flight grid and pattern can be extracted from geometric information from images. As shown in Fig. 12 and with reference to item B and reference number 215, the first step 230 is to upload the previous 3D shape file. By way of example, this can be achieved using photogrammetry software 231 , 3D CAD files 232 or a web-based service 233 that provides detailed information about the target area. Once the 3D file has been uploaded at step 234 the flight path is set to follow a height above the terrain, and finally at step 235 the waypoints for the flight grid and flight path are determined.

At step 216, another way of selecting the flight grid and flight path is for a user to manually select points and heights on a map of the area and location which the flight is to be carried out on the flight controller program. On the selected flight grid a plurality of points can be selected and the required height provided. Manually adjusting the vertical height of one or more of the plurality of points will provide a flight path at a similar height above the changing terrain height or the three dimensional shape of the target area. Likewise, by manually adjusting the vertical height of one or more of the plurality of points in the target area, tilts, folds, or wraps the flight path over the changing terrain height or the three dimensional shape of the target area.

At step 217, another exemplary way of selecting the flight grid is through the use of a manual flight over the target area by the drone 10. As illustrated in Fig. 13 and with reference to item C at figure reference 218 and starting at step 240 a user can select a target area boundaries and vertical heights of the target area by flying the drone to a first position on the target area and saving the first position coordinates and vertical height to the controller program at step 241. Next, the user flies the drone to a second position 242 on the target area and saves the second position coordinates and vertical height at step 243. In order to adequately define the flight grid, at least three position coordinates are required to be saved. However, the drone 10 can be flown to any number of further positions 244 and those further positions and heights saved 245 to the controller program. This is largely dependent upon the size, shape and the terrain of the target area. The next step 246 is to determine a set of waypoints for controlling the drone within the target area using the saved positions 241 , 243, 245 and vertical heights.

Returning to Fig. 10, the next step 219 is to upload the waypoints from any one of the exemplary processes for selecting the grid pattern to the drone 10. Once the drone 10 has been programmed with the flight path which is tilted, folded or wrapped to suit the vertical heights of the target area at step 220 the drone will start the flight by flying to the first waypoint on the flight grid and continue through the consecutive waypoints until the drone 10 reaches the end of flight 221 and returns to the programmed return to home position.

The flight control program also determines the points in which the camera or the device for data capture will be activated. By way of example, the camera could be set to point in the direction of travel or any other selected angle relative to the flight path selected points or lines between the selected grid pattern. The flight program will also select the path spacing which is typically calculated by the program which uses the drones camera lens angles, image overlap selected and flight height to provide the parallel paths for image taking.

As noted above the flight path can be for both single, double and multiple grid square, rectangle, circular, oval or polygon with tilt, fold or wrap capability with camera angle select and camera overlap both front and side and with height adjustment settings.

The drone 10 includes any unmanned aerial vehicle (UAV) such as single or multi-rotor vehicles and also fixed-wing aircraft.

As previously described selecting the flight grid can be through the use of a manual flight over the target area by the drone 10. A quick flight using the drone’s laser, sonic, optical or other vertical distance sensor could be used to collect terrain height data to plan a flight survey grid without the need to manually save position and height locations setting for grid design. The drone could adjust its height in real time to climb and descend to maintain a relatively constant GSD using its height sensor while remaining within the flight grid programmed.

This can be particularly beneficial for wrapped flight grids. This method of planning a drone flight grid allows the operator to fly the drone to each area of the survey area to mark and save the location and height required at that position to allow the program to calculate the wrapped flight grid. This method can be used when the operator is unsure of the correct altitudes to fly or are unsure of the grid boundary areas. It can also be used when there are no maps or satellite images to work from. The drone is positioned at the correct or desired height and location and input to the program marks that location and height. Then the drone is flown to mark the next position. When three or multiple locations and heights have been marked, the program calculates the shape of the flight grid. The drone camera can be used in real time to position the drone over the desired boundary location or over a desired position where a height and location marker is required. This method of grid design provides much improved grid boundary and flight safety as well as greatly improved survey accuracy.

The present invention can be implemented in the form of a software program that can be downloaded or reside on the controller for controlling a drone 10 for capturing images and data. The software program provides instructions capable of using a method according to the steps illustrated and described above. The flight programming software provides the ability to tilt, warp, fold or wrap a flight grid path or tilt an oval flight path with respect to altitude or differing flight heights.

The present invention also extends to a system for collecting photographic images or data of a target area for input to a survey. The system consist of the of a number of components but is not only limited to these components. For example, the system may consist of a drone having a microprocessor for managing control of the drone and transmitting and receiving data, an image or data capturing device and a controller with wireless data-transmission means capable of transmitting commands to the drone. A flight program is located on or is downloaded to the controller. The flight program is programmed to fly the drone in an autonomous flight path around the target area, wherein the flight program comprises instructions capable of using the method described and illustrated above for autonomous control of the drone.

In a further embodiment, the present invention also provides a drone for developing a three-dimensional (3D) model of a target area. The drone consists of one or more rotors disposed to a body and a camera or data collection device associated with or on the body. The drone 10 also has at least one wireless interface and a processor coupled to the at least one wireless interface, the data collection device and the camera. A controller is also in wireless communication with the drone and a flight program residing on or downloaded to the controller controls the flight of the drone 10. The drone also has at least one memory device for storing instructions that, when executed, cause the processor to perform a number of steps. Firstly, the memory device can process commands to prepare the drone for flight and receive program instructions for an autonomous flight path about the target area from the controller. The autonomous flight path has a changing terrain height or a three dimensional shape of the target area. The memory device can also process commands to cause the drone to fly around the target area and obtain images or data of the target area during the flight.

The images can be stored on an SD card and then used to develop the three-dimensional (3D) model of the target area. Typically this also requires some form of photogrammetry software to produce the 3D shape file.

Likewise, and as noted above the flight program when the waypoints are produced for the autonomous flight could save the required flight grid and flight path waypoints to an SD card which could be inserted into the drone 10 and be accessed by the drone processor for the autonomous flight. Alternatively the SD card could be installed in the control device of the controller for access by the controller.

The known presently existing flight programming settings and capabilities may be used with the improved method of incorporating height or altitude changes into the flight path. For example, the flight programming software of the present invention could be modified to work with the existing flight programming software.

Within the context of the present invention a survey or aerial survey is taken to mean a collection of any data or information over a prescribed flight area or object. By way of example only, a survey could include surveys of land, property objects, buildings, mines, mountains, rivers, animals, people or the like.

ADVANTAGES

A number of advantages are apparent in the present invention. The present invention provides the ability to tilt, warp, fold or wrap a flight grid path or tilt an oval flight path with respect to altitude or differing flight heights.

The present invention, once the folded or wrapped flight grids are designed as described in the various options above, or the photogrammetry terrain height data is uploaded to the drone or controller, drones can be programmed to conduct survey flights to collect images or data with a much improved survey and or data accuracy.

The present invention also reduces the number of flights required to achieve the improved survey accuracy and also improves flight and drone safety. In particular, improve drone safety by crash or obstacle avoidance by tilting, folding or wrapping the flight path to suit the changing terrain height or the three dimensional shape of the target area.

VARIATIONS

It will be realized that the foregoing has been given by way of illustrative example only and that all other modifications and variations as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of the invention as herein set forth. As used herein the term“and/or” means“and” or“or”, or both.

As used herein“(s)” following a noun means the plural and/or singular forms of the noun.

In this specification, adjectives such as first and second, left and right, top and bottom, and the like may be used solely to distinguish one element or action from another element or action without necessarily requiring or implying any actual such relationship or order. Where the context permits, reference to an integer or a component or step (or the like) is not to be interpreted as being limited to only one of that integer, component, or step, but rather could be one or more of that integer, component, or step etc.

The above description of various embodiments of the present invention is provided for purposes of description to one of ordinary skill in the related art. It is not intended to be exhaustive or to limit the invention to a single disclosed embodiment. As mentioned above, numerous alternatives and variations to the present invention will be apparent to those skilled in the art of the above teaching. Accordingly, while some alternative embodiments have been discussed specifically, other embodiments will be apparent or relatively easily developed by those of ordinary skill in the art. The invention is intended to embrace all alternatives, modifications, and variations of the present invention that have been discussed herein, and other embodiments that fall within the scope of the above described invention.

In the specification the term“comprising” shall be understood to have a broad meaning similar to the term“including” and will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. This definition also applies to variations on the term“comprising” such as“comprise” and“comprises”.

Claims

CLAIMS:

1. A method of controlling a drone to fly an autonomous flight area pattern for capturing images or data from a target area, the method comprising the steps of: i) loading a flight program and selecting the target area, wherein the target area contains a flight path and a plurality of points selectable within the target area, each point defining a specific location in physical space with a vertical height;

ii) adjusting the vertical height of one or more of the plurality of points to suit a changing terrain height or a three dimensional shape of the target area; iii) determining a set of waypoints for controlling the drone within the target area;

iv) uploading or loading the waypoints to the drone; and

wherein the flight path is tilted, folded or wrapped to suit the changing terrain height or the three dimensional shape of the target area.

2. A method as claimed in claim 1 , further comprising using the captured images or data to develop a survey of the target area.

3. A method as claimed in claim 1 or claim 2, wherein capturing images or data to develop the survey of the target area further comprises developing the survey to produce a three dimensional survey of the target area.

4. A method as claimed in any one of the preceding claims, wherein capturing images or data further comprises capturing thermal images of the target area using a thermal camera.

5. A method as claimed in claim 1 , wherein capturing data comprises:

capturing global positioning data from a GPS receiver on the drone; or capturing image data from a camera on the drone; or

capturing distance data from a light detection and ranging device on the drone.

6. A method as claimed in any one of the preceding claims, wherein the flight path maintains an approximately constant ground sampling distance or height above the terrain to suit the changing terrain height or the three dimensional shape of the target area.

7. A method as claimed in claim 6, wherein the ground sampling distance or height above the terrain is dependent upon the required accuracy of the survey of the target area.

8. A method as claimed in claim 7, wherein the ground sampling distance is in the range of 0.4 cm to 5.0 cm.

9. A method as claimed in claim 1 , wherein step ii) further comprises:

obtaining the target area changing terrain height or the three dimensional shape using a previously processed geometric data of the target area from two- dimensional images; and

using the data and adjusted vertical heights to create the flight grid.

10. A method as claimed in claim 9, wherein the previously processed geometric data is any one or more of:

a photogrammetry software application which extracts geometric information from two-dimensional images of the target area;

a 3D CAD file of the target area;

a web-based service that provides detailed information about the target area; or

any other type of shape information.

1 1. A method as claimed in any one of the preceding claims, wherein the tilting, folding or wrapping the flight path allows a data capture of the target area of any shape and any varying terrain.

12. A method as claimed in claim 1 1 , wherein the data capture of the target area comprises any one or more of:

i) a sloping target area wherein the drone flight path is tilted to maintain the approximately constant ground sampling distance or height above the terrain to match the slope of the target area;

ii) a target area with a ridge or valley and the flight path is folded on each side of the ridge or valley to maintain the approximately constant ground sampling distance or height above the terrain to match the slope on each side of the ridge or valley of the target area;

iii) a target area with a convex or a concave shape and the flight path is wrapped to maintain the approximately constant ground sampling distance or height above the terrain to match the convex or concave shape of the target area; and

iv) a target area with a different height at more than one of the plurality of points within the target area wherein the drone flight path grid is warped to maintain the approximately constant ground sampling distance or height above the terrain to match the different heights of the target area.

13. A method as claimed in claim 12, wherein the target area ii) has more than one ridge or valley.

14. A method as claimed in any one of the preceding claims, wherein the flight path of the drone over the target area is any one or more of:

i) a single flight path;

ii) a double flight path; or

iii) a multiple flight path.

15. A method as claimed in any one of the preceding claims, wherein the flight area pattern of the drone over the target area has any one or more of the following shapes:

i) a square shape;

ii) a rectangular shape;

iii) a circular shape;

iv) a triangular shape;

v) an oval shape; or

vi) any regular or irregular polygon shape.

16. A method as claimed in claim 1 , wherein step ii) further comprises:

obtaining the target area changing terrain height or the three dimensional shape of the target area by:

i) flying the drone to a first position on the target area;

ii) saving the first position coordinates and vertical height;

iii) flying the drone to a another position on the target area;

iv) saving the another position coordinates and vertical height;

v) repeating steps iii) and iv) until at least three positions have been saved to obtain the changing terrain height or the three dimensional shape of the target area; and

vi) using the saved positions and vertical heights to create the flight grid.

17. A method as claimed in any one of the preceding claims, wherein adjusting the vertical height of one or more of the plurality of points provides images or data captured by the drone flying the flight path at a similar height above the changing terrain height or the three dimensional shape of the target area.

18. A method as claimed in claim 17, wherein adjusting the vertical height of one or more of the plurality of points in the target area, tilts, folds, or wraps the flight path over the changing terrain height or the three dimensional shape of the target area to provide improved image and data collection accuracy.

19. A method of controlling a drone to fly an autonomous flight path for collecting data or images about a target area, the method comprising the steps of:

i) selecting target area boundaries and vertical heights of the target area by:

a) flying the drone to a first position on the target area; b) saving the first position coordinates and vertical height;

c) flying the drone to another position on the target area; d) saving the another position coordinates and vertical height; and e) repeating steps c) and d) until at least three positions have been saved;

ii) determining a set of waypoints for controlling the drone within the target area using the saved positions and vertical heights;

iii) uploading the waypoints to the drone; and

wherein the flight path is tilted, folded or wrapped to suit the vertical heights of the target area.

20. A method as claimed in claim 19, further comprising using the collected data and images to develop a survey of the target area.

21. A method as claimed in claim 19 or claim 20, wherein the flight path maintains an approximately constant ground sampling distance or height above the terrain to suit the changing vertical height within the target area.

22. A method as claimed in claim 21 , wherein the ground sampling distance is dependent upon the required image or data accuracy of the survey of the target area.

23. A method as claimed in claim 22, wherein the ground sampling distance is in the range of 0.4 cm to 5.0 cm.

24. A method as claimed in any one of claims 19 to 23, wherein the tilting, folding or wrapping the flight path allows a data capture of the target area of any shape and any varying terrain.

25. A method as claimed in claim 24, wherein the data capture of the target area comprises any one or more of:

26. A method as claimed in claim 25, wherein the target area ii) has more than one ridge or valley.

27 A method as claimed in any one of claims 19 to 26, wherein the flight path of the drone over the target area is any one or more of:

i) a single flight path;

ii) a double flight path; or

iii) a multiple flight path.

28. A method as claimed in any one of claims 19 to 27, wherein the target area boundaries of the flight path are formed in the shape of any one or more of the following:

i) a square shape;

ii) a rectangular shape;

iii) a circular shape;

iv) a triangular shape;

v) an oval shape; or

vi) any regular or irregular polygon shape.

29. A method for developing a three-dimensional (3D) survey of a target area using a drone to obtain images, the method comprising:

providing at least one camera on the drone;

preparing the drone for flight and programming using a flight controlling application to produce an autonomous flight path about the target area, the flight controlling application comprising:

i) selecting the target area, wherein the target area contains the flight path and a plurality of points selectable within the target area, each point defining a specific location in physical space with a vertical height; ii) adjusting the vertical height of one or more of the plurality of points to suit a changing terrain height or a three dimensional shape of the target area;

iii) determining a set of waypoints for controlling the drone within the target area; and

iv) uploading the waypoints to the drone;

flying the drone around the target area;

obtaining images from the at least one camera of the target area during the flight;

using the images and a software program which extracts geometric data from two-dimensional images to develop the three-dimensional (3D) survey of the target area; and

wherein the autonomous flight path maintains an approximately constant ground sampling distance to suit the changing terrain height or the three dimensional shape of the target area by tilting, folding or wrapping the flight path.

30. A method as claimed in claim 29, further comprising any one of the features of claims 1 to 18.

31. A method for controlling or programming the flight path of a drone for surveying an area of land, comprising the steps of:

using a 3D shape or terrain data file from a previously conducted flight over the area of land or any other data file source of the area of land;

selecting a vertical height parameter to set a flight height of the drone above the area of land;

determining a set of waypoints using the 3D shape file and the vertical height parameter for the flight path; uploading to a flight controller the set of waypoints for controlling the drone within the flight path;

flying the drone using the waypoints to produce images or data of the area of land; and

wherein the flight path is tilted, folded or wrapped to suit a changing terrain height or a three dimensional shape of the area of land.

32. A method as claimed in claim 31 , wherein selecting the vertical height parameter above the area of land to improve survey accuracy comprises selecting a vertical height to maintain an approximately constant ground sampling distance or height above the terrain to suit the changing terrain height or the three dimensional shape of the area of land.

33. A method for flying a drone for survey purposes in respect of an area, the method comprising the steps of:

providing a drone in communication with a controller, the drone constantly transmitting its location and vertical height along with real time camera footage back to the controller;

selecting area boundaries and vertical heights of the area by:

a) flying the drone to a first position on the area;

b) saving the first position coordinates and vertical height to the controller; c) flying the drone to a further position on the area;

d) saving the further position coordinates and vertical height to the controller; and

e) repeating steps c) and d) until at least three positions on the area have been saved to the controller;

determining a set of waypoints from the at least three saved positions; uploading the waypoints to the drone and flying the drone autonomously around the area;

obtaining images from at least one camera of the area during the flight; using the images to develop a survey of the area; and

wherein a flight path of the drone maintains an approximately constant ground sampling distance or height above the terrain to suit a changing height or a three dimensional shape of the target site by tilting, folding or wrapping the flight path.

34. A software program that can be downloaded or reside on a controller for controlling a drone for capturing images and data, the software program comprising instructions capable of using a method according to any one of claims 1 to 18 for the remote control of the drone.

35. A system for collecting photographic images or data of a target area for input to a survey, the system comprising:

a drone having a microprocessor for managing control of the drone and transmitting and receiving data;

an image or data capturing device;

a controller with wireless data-transmission means capable of transmitting commands to the drone;

a flight program on the controller, the flight program being programmed to fly the drone in an autonomous flight path around the target area, wherein the flight program comprises instructions capable of using a method according to any one of claims 1 to 18 for autonomous control of the drone.

36. A drone for developing a three-dimensional (3D) model of a target area, the drone comprising:

one or more rotors disposed to a body;

a camera or data collection device associated with the body;

at least one wireless interface and a processor coupled to the at least one wireless interface, the data collection device and the camera;

a controller in wireless communications with the drone and a flight program residing on or downloaded to the controller for controlling the flight of the drone; and

memory storing instructions that, when executed, cause the processor to: process commands to prepare the drone for flight and receive program instructions for an autonomous flight path about the target area from the controller, wherein the autonomous flight path comprises a changing terrain height or a three dimensional shape of the target area;

process commands to cause the drone to fly around the target area;

process commands to obtain images or data of the target area during the flight; and

provide the images to develop the three-dimensional (3D) model of the target area; process commands for communicating with the controller; and

wherein the flight program to develop the autonomous flight path around the target area comprises instructions capable of using a method according to any one of claims 1 to 18 for autonomous control of the drone.