Mirror-less Cameras and UAVs

UAV (Unmanned Aerial Vehicle) photography and photogrammetry has long been a balance between weight and the quality of the camera equipment carried.

Cameras

Low cost camera solutions such as the GoPro can be carried on almost all UAVs because they are small and lightweight, but these benefits are also drawbacks because limited size/fish eye lenses and small image sensors reduce the quality of the photographs they take, together with this the lack of control of many of the camera settings is a drawback.

High quality DSLR (Digital Single Lens Reflex) cameras have superior quality lenses and image sensors together with the fact that they have extensive control of the camera settings meaning that they take much better photographs. But they can only be carried by much higher power/cost octo and hexo-copter systems.

One solution is the lightweight point-and-shoot camera/compact camera used in some mapping solutions, such as those provided by 3DRobotics (Canon PowerShot S100). Although these cameras provide a better quality solution than the GoPro, and may be all that is required for mapping exercises; they are still limited in their optics and higher megapixel sensors which are much more important in the recording of complicated structures and photogrammetry work.

Changes in the camera industry due to competition from the phone industry has enhanced development of a different solution. This is the MILC (Mirrorless Interchangeable-lens camera) or DSLM (Digital Single Lens Mirrorless) Camera. These cameras don’t have the mirror reflex optical viewfinder of a DSLR camera, and the associated weight, replacing it with a LCD screen or with an app on a mobile device which controls the camera. As a result they have the capability to carry high quality interchangeable lenses without the weight associated with DSLR cameras. The system comes in two different forms; the first resembles a standard digital SLR camera, while the second resembles just a lens with all control being provided by an app on a mobile device.

Camera Comparison

Camera	Type	Megapixel	Weight	Cost
Canon EOS 5D Mark III	Digital SLR	22.3	Approx 950g	£2,544
Nikon D5300	Digital SLR	24.2	Approx 840g	£549.99
Sony A5000 DSLM	Digital SLM	20.1	Approx 388g	£250
Sony ILCE-QX1	Lens Style Camera	20.1	Approx 332g	£250
Canon PowerShot S100	Compact Camera	12.1	Approx 198g	£195
GoPro Hero3+ Black	Sports Camera	12	74/136g (with housing)	£349.99

Canon EOS 5D Mark III

Nikon D5300

α5000 E-mount Camera

ILCE-QX1 Lens-Style Camera

3DRobotics UAV Mapping Solutions, discussed in another blog entry, carry the Canon PowerShot S100 digital compact camera.

Canon PowerShot S100

GoPro Hero3+ Black

UAVs

UAVs come in a number of different configurations and increase in price with a higher level of complexity and ability to carry heavier loads.

UAV Comparison

UAV	Type	Payload Capacity	Price (Without Gimbal)
3D Robotics Iris+	Quadcopter	400g	£599
3D Robotics X8+	Octocopter	800g – 1Kg with reduced flight time	£880
Spreading Wings S900	Hexacopter	4.7 – 8.2Kg	£1,291-£1,540
DJI Spreading Wings S1000+	Octocopter	11Kg	£1,750-£2,057

3D Robotics Iris+ Quadcopter

3D Robotics X8+ Octocopter

Gimbals

Gimabls are an important element in stabilizing cameras during photography and video recording, as well as providing a motorized solution to move the camera to a desired angle during flight. They can add significantly to both the weight and price of any UAV solution depending on the camera equipment they are carrying.

Gimbal Price Comparison

Gimbal	Camera	Weight (Camera excluded)	Cost
DJI Zenmuse H4-3D	GoPro	168g	£249
DYS 3 axis brushless gimbal	Sony NEX size camera	388g	£231.95 – £299.94
DJI Zenmuse Z15-A7	Sony α7s and α7r	1.3Kg	£1,915
DJI Zenmuse Z15-5D III (HD)	Canon EOS 5D DSLR	1.53Kg	£2,831

Solutions

The 3DRobotics Iris+ Quadcopter has a payload capacity of 400g which would allow a rather small 15g for a mount to attach a Sony A5000 DSLM or 68g to attach a Sony QX1 Lens-Style Camera without weighing too much, although the system could be flown with excess weight reducing the flight time. A downward facing 3D Printed Sony A5000 Mapping Mount  is available for both the Iris+ Quadcopter and X8+ Octocopter, it weighs 36g.

Sony α5000 Mount

Although the X8+ is a octocopter by definition, it gets over the intrinsic problems of size, weight and cost caused by eight separate arms by having two rotors on each arm, one pointing up and the other downwards. With a maximum payload of 1KG it can carry a Sony A5000 DSLM camera (388g) together with a gimbal such as the DYS 3 Axis Brushless Gimbal for Sony NEX size cameras (609g) to support and move it, the gimbal is designed for the NEX range of cameras, but they are almost identical to the A5000 in design. Although a lighter mount could be used.

3 Axis Brushless Gimbal for Sony Nex size cameras

Conclusions

The mirror-less camera would seem to provide a solution to the problem of how to carry a high specification camera capable of capturing high quality images on a fairly low-cost UAV solution.

Sources

http://en.wikipedia.org/wiki/Mirrorless_interchangeable-lens_camera

http://www.dummies.com/how-to/content/gopro-cameras-understand-the-cameras-limitations.html

http://www.japantimes.co.jp/news/2013/12/30/business/mirrorless-cameras-offer-glimmer-of-hope-to-makers/

http://dronebly.com/quadcopter-vs-hexacopter-vs-octocopter-the-pros-and-cons

3DRobotics Dronekit

3DRobotics have announced the release of DroneKit which offers an Open Source Software Development Kit (SDK) and web Application Program Interface (API) for developing drone apps. It works on systems powered by the APM flight code such as the ArduPilot, APM and Pixhawk autopilot systems, all supplied by 3DRobotics.

It allows the creation of custom purpose built UAV (Unmanned Aerial Vehicle) control apps without having to redesign the control system software.

The apps can be developed on three different platforms:

1. Mobile apps with DroneKit Android.
2. Web-based apps with DroneKit Cloud.
3. Computer apps with DroneKit Python.

It enables the user to:

• Control the flight path with waypoints.
• Control a spline flight path with fine control over the vehicle velocity and position.
• Set the UAV to follow a GPS target (Follow Me).
• Control the camera and gimbal by setting Regions Of Interest (ROI) points which the camera locks on to.
• Access full telemetry from the UAV using 3DR Radio, Bluetooth, Wi-Fi, or over the internet.
• Playback and analyse the log of any mission.

The advantages of DroneKit are:

• It is truly open unlike the similar DJI SDK, without levels of access.
• Once an app has been created the interface is always the same across different computing platforms.
• It can be used with planes, copters and rovers.
• It works on laptop computers as well, mobile devices and vehicle data can even be accessed via the web.

DroneKit already powers a number of flight control programs:

• The Tower (formerly Droidplanner) flight planning mobile app for Android was built on DroneKit for Android.

• Droneshare is a global social network for drone pilots that allows them to view and share missions, it is built on DroneKit web services.
• Googles Project Tango Indoor Navigation is built on the Pixhawk and APM sutopilot systems and the Tower flight planning app.
• The IMSI/Design TurboSite aerial reporting app for construction allows the setting up of flight waypoints to GPS locations and the capturing of photographs, videos, dictations, text notes and “punch list” action items. Photographs can be annotated while the UAV is still in flight using markup and measurements tools.

Aero-M

The Aero-M is one of two aerial mapping platforms introduced by 3D Robotics, it is a fixed wing aircraft . It is designed to have everything that you need for mapping straight out of the box and as well as having standard elements includes:

• Pixhawk autopilot system.
• Canon SX260 with custom 3DR EAI software and fixed mount.
• Pix4Dmapper LT 3DR Edition, which is only capable of creating two-dimensional maps.
• It also includes a custom-designed hard-top travel case.

Additional elements that can be purchased include:

• An upgrade to Pix4Dmapper Pro 3DR Edition, this allows the creation and export of DSM (Digital surface models) and terrain models as well as orthomosaic editing. This costs an extra $5000.
• An OSD (On screen display)/FPV (First person view) system which uses a Sony HAD 520 line camera to stream video to a viewing device while a MinimOSD on-screen-display module superimposes live telemetry data onto the video feed. This costs an additional $249.99. A monitor needs to be purchased to view the data.

It has a 40 minutes flight time and can record up to 250 acres in one flight.

http://store.3drobotics.com/products/aero-m/

The basic price of the Aero-M is $5400, with all of the additions it costs $10724.99. According to 3D Robotics this is providing “advanced mapping capabilities at a price five times less than that of our nearest technological competitor”..

The 3DRobitics Aero-M fixed-wing drone

Example
An example of an photo-mosaic map creating using the Pix4Dmapper software from an aerial platform.

Potential
The flight time of the Aero-M is significantly longer than the other mapping system, X8-M, which demonstrates the benefits of using a fixed wing platform over a multi-rotor platform which needs to power all of the rotors to stay in the air.

The multiple overlapping photographs taken by the camera can be used to create digital elevation models (DEM) these are an important element is archaeological prospection, although they can be created with LIDAR data a much higher level of detail can be generated from those created by photogrammetry using UAV (Unmanned Aerial Vehicle) photographs. The overalapping photographs can also be stitched together to create a high quality mosaic. They can also be used to create a 3D model of the site.

3d Robotics is part of the open-source hardware and software community based at DIY Drones which can help with all aspects of drone construction and use.

The Pixhawk autopilot system allows the easy creation of a flight path by selecting points on a map displayed in the mission planning software. By selecting a polygon around the area the software can create a grid flight pattern to fly; the altitude, camera type and overlap of images can also be set which alters the amount of times the aerial vehicle flies across the area under study.

Limitations
The problems with using a fixed wing platform for mapping are, takeoffs and landings, and tree cover around the area under study; the X8-M multi-rotor platform has the ability to turn on the spot.

Although the Aero-M is an expensive purchase it appears to still be a bargain.

The extra $5000 for software is also a lot, there are other cheaper options such as Agisoft Photoscan Professional which costs $3499.

It comes with a Canon SX260 camera which is a cheap, compact, lightweight, digital camera that fits well into the system; but it has neither the optics nor the image size (12.1 megapixels vs. 24.2 megapixels) of a higher quality digital SLR camera, so information will be lost from photographs that could be taken by a higher quality camera. The Aero-M platform can carry 500g so it will be able to carry higher specification digital SLR cameras than the Canon, allowing higher definiti0on pictures to be taken.

It is designed solely for mapping so the camera is in a fixed position and can only record downwards.

Although accuracy may have its limitations, by placing targets on the ground in a grid pattern and recording their position with GPS (Global Positioning System) the accuracy can be improved, and as the DEM is accurately georeferenced it can be imported accurately into GIS software.

X8-M

The X8-M is one of two aerial mapping platforms introduced by 3D Robotics, it is a multi-rotor UAV (Unmanned Aerial Vehicle) with a fully redundant propulsion system thanks to the fact that four of the propellers face up while the other four face down on the same struts, so if one fails there is still propulsion from the other. It has the ability to conduct mapping at a low altitude, at a low speed and at a high level of accuracy which is impossible to capture by manned flights or using satellite imaginary.

It is designed to have everything that you need for mapping straight out of the box and as well as having standard elements includes:

• Pixhawk autopilot system.
• Canon SX260 with custom 3DR EAI software and fixed mount.
• Pix4Dmapper LT 3DR Edition, which is only capable of creating two-dimensional maps.
• It also includes a custom-designed hard-top travel case.

Additional elements that can be purchased include:

• An upgrade to Pix4Dmapper Pro 3DR Edition, this allows the creation and export of DSM (Digital surface models) and terrain models as well as orthomosaic editing. This costs an extra $5000.
• An OSD (On screen display)/FPV (First person view) system which uses a Sony HAD 520 line camera to stream video to a viewing device while a MinimOSD on-screen-display module superimposes live telemetry data onto the video feed. This costs an additional $249.99. A monitor needs to be purchased to view the data.

The basic price of the x8-M is $5400, with all of the additions it costs $10729.98. According to 3D Robotics this is providing “advanced mapping capabilities at a price five times less than that of our nearest technological competitor”.

The X8-M has a flight time of 14 minutes covering 25 acres.

https://store.3drobotics.com/products/x8-m

Potential
The multiple overlapping photographs taken by the camera can be used to create digital elevation models (DEM) these are an important element is archaeological prospection, although they can be created with LIDAR data a much higher level of detail can be generated from those created by photogrammetry using UAV (Unmanned Aerial Vehicle) photographs. The overalapping photographs can also be stitched together to create a high quality mosaic. They can also be used to create a 3D model of the site.

3d Robotics is part of the open-source hardware and software community based at DIY Drones which can help with all aspects of drone construction and use.

The Pixhawk autopilot system allows the easy creation of a flight path by selecting points on a map displayed in the mission planning software. By selecting a polygon around the area the software can create a grid flight pattern to fly; the altitude, camera type and overlap of images can also be set which alters the amount of times the aerial vehicle flies across the area under study.

Example
An example of an photo-mosaic map creating using the Pix4Dmapper software from an aerial platform.

An example of this type of work with a multi-rotor UAV can be seen here.

While a 3D model created from images captured from a hexacapoter can be seen here on the p3d.in 3D model sharing website.

Limitations
Although the Aero-M is an expensive purchase it appears to still be a bargain.

The flight time of 14 minutes is quite small for a large area survey, but multiple batteries could be carried and mapping done in stages.

The extra $5000 for software is also a lot, there are other cheaper options such as Agisoft Photoscan Professional which costs $3499.

It comes with a Canon SX260 camera which is a cheap, compact, lightweight, digital camera that fits well into the system; but it has neither the optics nor the image size (12.1 megapixels vs. 24.2 megapixels) of a higher quality digital SLR camera, so information will be lost from photographs that could be taken by a higher quality camera. But the X8-M platform can only carry 200g so it is not capable of carrying these heavier cameras which weigh 530g (in the case of the Nikon D5300) so the quality is probably at the highest level possible.

It is deigned solely for mapping so the camera is in a fixed position and can only record downwards, a camera gimbal could be easily attached to the UAV frame allowing the camera to view a multiple angles and so record much more than just what is below it.

Although the accuracy of any DEM or photogrammetry model may have its limitations, by placing targets on the ground in a grid pattern and recording their position with GPS (Global Positioning System) the accuracy can be improved, and as the DEM is accurately georeferenced it can be imported accurately into GIS software.

News – Dronecode Project

The Open Source Dronecode Project has been announced under the auspices of the Linux Foundation, it will bring together existing projects including the APM/ArduPilot and PX4 open source autopilot systems as well as advancing new technologies. It will provide a common platform for Drone and robotics opens source projects aiming to unite the open source industry.

The maker community has already dramatically increased the development of drones and the Dronecode Project is hoping to advance the technologies required and both improve them and make them more affordable.

The Linux Foundation can provide an existing organisation and collaborative framework allowing the the Dronecolde Project to concentrate on the innovation of new technology.

http://www.linuxfoundation.org/news-media/announcements/2014/10/linux-foundation-and-leading-technology-companies-launch-open
https://www.dronecode.org/

News – 3D Robotics announces partnership with Intel

3D Robotics has announced a partnership with Intel in which they will be using the new Intel Edison for development of their autopilot systems. The Intel Edison is a microcomputer the size of a postage stamp which provides the power of a personal computer.

The extra processing power of the Edison will allow a person or object to be tracked with the follow me technology of the Pixhawk autopilot. So a person can be filmed automatically with the camera on the UAV (unmanned aerial vehicle) by tracking the person without the need for them to carry a mobile device, with its reliance on a less accurate GPS signal, as the UAV will be able to visually recognise a person.

It will also allow developments in image processing, sense and avoidance with new classes of sensors allowing further developments of autonomous UAV flight and object avoidance.

IRIS+

The IRIS+ is the latest in a range of open source UAVs (Unmanned Aerial Vehicles) from 3D Robotics, an open source hardware and software company. It is designed to carry the GoPro cameras, comes with an autopilot system and provides 16 minutes of flight time fully loaded with camera and gimbal.

It improves on the previous version of the quadcopter.

• 16-22 minutes flight time
• Payload capacity 400 g (.8 lbs)
• Follow me technology

https://store.3drobotics.com/products/IRIS

It comes with an open source autopilot system developed by Pixhawk which allows mission planning involving flight between waypoints and automated grid pattern flight which takes into account the type of camera used.

A number of different free software solutions can be used on different platforms to program the UAV: Droidplanner 2 software on the Android , Mission Planner on Windows and APM Planner on OSX operating system.

The Pixhawk autopilot system means that the UAV can run automated missions recording topographical features to create a digital elevation model. This software also enables the quadcopter to use Follow ME technology which follows the operator, altering the camera angle with the gimbal when necessary.

What adds additionally to the usefulness of this autopilot system, is the fact that it is not tied to the UAV, it can also be used on other types of copters, planes, ground rovers, cars and boats – https://pixhawk.org/modules/pixhawk.

The IRIS+ costs $960 with a 2-axis gimbal.

Potential
The IRIS+ is a high quality budget quadcopter with many useful abilities out of the box, such as an autopilot, which other systems do not. The similar DJI Phantom 2 series requires additional hardware and software which attaches to the UAV system – DJI iOS Ground Station inc 2.4Ghz Data link and Bluetooth Module – and costs an additional £124.

3D Robotics is a company which is part of a large amateur Unmanned Aerial Vehicles community providing expertise in all aspects of the hardware, software and flying and photography skills. In fact the co-founder of the company, Chris Anderson, also founded the website DIYDrones.com.

The release of this may have been the reason the market leader in camera drones/quadcopters, DJI, reduced the prices of their quadcopters, some by as much as $200 – http://www.dji.com/info/news/phantom-2-series-price-drop

Limitations
As it is a quadcopter it is limited to lifting cameras the size of a GoPro.

Pixhawk Autopilot

The Pixhawk is an high-performance autopilot system designed by the PX4 open-hardware project and manufactured by 3D Robotics that can be used with fixed wing aircraft, multi-rotor aircraft, cars, boats and any other autonomous vehicle. It is designed for everything from research, amateurs and industry.

It is a combination of the PX4FMU Autopilot / Flight Management Unit and the PX4IO Airplane/Rover Servo and I/O Module previously created by PX4.

The Pixhawk includes the following sensors:

• ST Micro L3GD20H 16 bit gyroscope.
• ST Micro LSM303D 14 bit accelerometer / magnetometer.
• MEAS MS5611 barometer.

It also allows the connection of a number of other useful external devices such as:

• SF02/F Range Finder.
• PX4FLOW Smart Camera. This can replace the position stabilisation usually provided by GPS where GPS is unavailable in both outdoor and indoor environments providing a static position close to the ground with very little drift.
• PX4 Airspeed Sensor.
• https://store.3drobotics.com/products/lidar-lite

Pixhawk Autopilot

It is controlled by an app available on a number of different hardware platform; either Mission Planner (Windows) or APM Planner for (Windows, OS X, and Linux) and Droiplanner2 on Android.

Aerial flight paths can easily be set in the software by clicking way points on a map of the area.

By selecting a polygon around the area the software can create a grid flight pattern to fly; the altitude, camera type and overlap of images can also be set which alters the amount of times the aerial vehicle flies across the area under study. This allows either an image mosaic to be created or a photogrammetry model.

The 3DR Radio Set allows wireless communication between the Pixhawk and an Android device using the DroidPlanner or Andropilot ground station app, while the inclusion of a bluetooth data link also allows an Android device with ground station apps and Bluetooth to connect to the Pixhawk. Both of these options also allow the use of the Follow Me mode in the software which allows the autopilot to follow the system that is running the app.

As it is an open hardware project the schematics can be downloaded.

The Pixhawk costs $199.99 in its basic form, $474.97 with all of the standard available options.

Potential
The Pixhawk has great potential for the control of any type of autonomous vehicle, whether flying mapping missions, flying a per-determined course to record things, or in “follow-me” mode recording site tours. The fact that it is part of an open-source community means that it is continually in development with input from the people who are using the technology.

It has become so popular in the industry that it is the technology used in a number of Kickstarter UAV projects including the AirDog and HEXO+ as well as 3D Robotics’s IRIS+ quadcopter.

The community provides extensive instructions for the system and its uses.