Autor: Redaktion

An Introduction to Drones

Drones are unmanned aerial vehicles (UAVs), autonomous or controlled aircraft.

Drones - An Introduction

What’s the definition of a drone?
Drones are unmanned aerial vehicles (UAVs), autonomous or controlled aircraft. The term "unmanned" is important for the definition.
Drones are used both privately (e.g., as hobby aircraft or for making home movies) as well as for commercial (e.g., television or advertising) and military use (e.g., reconnaissance).

This article will explore the civilian use in the following areas:

•    Aerial photography (e.g., film footage)
•    Technical control (e.g., windmills, wind parks, high voltage masts, buildings)
•    Surveying
•    Forestry and agriculture
•    Exploration / research
•    Animal protection / nature conservation
•    Police / fire brigade
•    Leisure and hobbies

The following diagram shows the typical configuration and design of drones. In practice the quadcopter, hexacopter and octocopter are the most common.  All copters with more than 2 rotors in the same plane are also grouped under the term "multicopter".

Based on the positioning and number of the rotors, the following structural shapes can therefore be distinguished

•    Y3 Copter (Y-shape with 3 rotors)
•    Y6 Copter (Y-shape with 6 rotors)
•    + 4 Copter (+ form with 4 rotors) partly also designated as I4
•    X4 Copter (X-shape with 4 rotors)
•    I6 Copter (I-mold with 6 rotors)
•    X6 Copter (X-shape with 6 rotors) partly also referred to as V6
•    I8 Copter (I-shape with 8 rotors)
•    X8 Copter (X-shape with 8 rotors) partly also referred to as V8

The DJI drones universe

One of the most popular producers of hobby and professional drones is the Chinese technology company DJI. It has specialised in new recording technologies (for example DJI Osmo, DJI Ronin) and the production of drones.

DJI Phantom Series

This quadcopter series is designed for private pilots and beginners. It is easy to use and can be controlled by inexperienced persons. The flight system consists of the quadcopter (propeller, motors, controller, GPS receiver, compass, gyroscope and the battery) and the remote control for the pilot.

1st Generation

In 2012 DJI released the Phantom 1. It did not have an integrated camera system, but could have an action camera fitted. This camera lacked any form of suspension or damping of the camera built in, although operators could purchase a separate damped 2/3-axis gimbal.

2nd Generation

In 2013 the Phantom 2 was introduced. It came with an uprated battery, which almost doubled the flight time compared to the predecessor. The Phantom 2 was sold as a basic version without a camera.

The Phantom 2 Vision was equipped with a vertically pivoting camera and the pilot could fly by FPV (First Person View) via video signal transmission.

The Phantom 2 Vision + appeared in 2014 and offered a gimbal mechanism, which enabled a horizontally balanced camera, independent of the flight situation. For the first time a full HD camera was used.

3rd Generation

DJI Phantom 3 with accessories, batteries and remote control

Based on the experience of the Vision +, DJI launch several new Phantom-3 variants in April 2015:

•    Phantom 3 Standard: The entry-level model had a gimbal-mounted 2.7k camera with simple video transmission
•    Phantom 3 Advanced: integrates Lightbridge HD video transmission (higher datarate at a higher resolution)
•    Phantom 3 Professional: Included a 4K camera combined with Lightbridge technology
•    Phantom 3 4K: In 2016 DJI introduced a new entry-level model with a 4K camera. It is technically based on the Phantom 3 Standard, but was supplemented by the Vision Positioning System and the new remote control system.

In March 2016 DJI announced the current generation, the Phantom 4. The series has all the features of the Phantom 3 Professional. It is distinguished by its simpler design and shiny housing. The Gimbal unit was partially integrated into the case and is made of lighter magnesium

• Phantom 4: Two cameras on the front allow them to detect airports and avoid collisions automatically. The 4K camera is almost identical to the Phantom 3 Professional and was only supplemented by a 120 fps mode for 1080p video. The battery capacity was increased to 5350 mAh and the flight time is now about 28 minutes.

• Phantom 4 Pro: On November 15, 2016 the improved Phantom 4 Pro was introduced. The battery capacity was increased again to 5870 mAh which achieves a flight time of 30 minutes. The anti-collision system now also works sideways and backwards with additional sensors.

The camera now features a 20-megapixel CMOS sensor and a lens with adjustable aperture, mechanical centering and autofocus. The Phantom 4 Pro is available in two versions. The more expensive Plus version has a 5.5 "-1080p display, which is integrated into the remote control.

The Phantom 4 Advanced was introduced in April 2017, the Phantom 4 Advanced is the combination of the flight chassis of the previous Phantom 4 with the camera of the Phantom 4 Pro. The Phantom 4 Pro 5870 mAh battery is included as standard.

DJI Mavic Pro

In September 2016, DJI introduced a new Quadcopter, the Mavic Pro. It is significantly more portable and smaller than the Phantom series and features folding propeller arms. Despite its more compact design, it is technically similar in performance to the Phantom 4. The camera of the Mavic has a slightly reduced angle of view (compared to that of the Phantom 4) and features a new approach to autofocus – much more like the prosumer cameras that operators are used to.

The Mavic has a 3-axis, 12 megapixel 4K camera and can achieve a flight time of about 27 minutes, with a flight range of up to 7 km. The remote control has been reduced in size and now offers support for smartphones as well as a monochrome display. The Mavic Pro can also be controlled via smartphone over a WLAN connection, however this can only operate over a very short range.

For the first time, the OcuSynch technology was used for data transfer between the quadcopter and the remote control. This allows a further  range, while monitored compared to the previous LightBridge method and an improved transmission quality when in close range.. In September 2017, a newer variant was introduced: the Mavic Pro Platinum. This flies for 3 minutes longer and is 4 db quieter.

DJI Spark

Spark is currently (September 2017) the smallest, lightest and most affordable quadcopter from DJI. A 12MP camera is integrated on a 2-axis gimbal, videos are recorded at up to 1080p @ 30fps. The weight of the copter is 300g. The control is either via a controller or a smartphone.

DJI Mavic Air

The Mavic Air drone was released by DJI in early 2018. It combines the compact design of the DJI Spark with the camera and flight safety features of the DJI Mavic Pro.

Perhaps most striking is the Mavic Air’s compact design and low weight of 430g. Maximum flight time is  21 minutes, which is shorter than the Mavic Pro. The Mavic Air has a maximum flying range of 10km or a duration of 21 minutes of flight per charge. The range is limited to 2000 metres which is mainly due to the WLAN-based communication system between the controller and the drone.

The Mavic Air works with 6 sensors, including sensors at the rear of the drone, in addition to the Advanced Pilot Assisting System (APAS), this ensures high flight safety. APAS generates a 3D model of the environment and keeps the drone away from obstacles and flies around them on its own.

The camera on the “Mavic Air” captures up to 30fps in UHD-1 and up to 120fps in full HD, both at 100Mbit/s. It also boasts 3-axis stabilization.

The new Sphere mode allows panorama photos, which are composed of 25 individual images each up to a resolution of 32 megapixels.

The Mavic Air also features object tracking via Active Track, improved gesture control and a sports mode. The Mavic Air  can record, in Sports Mode,  while flying at up to 68km/h (42mph). However, in this mode the obstacle detection is disabled.

DJI Inspire- Series

The Inspire series offers quadrocopters designed primarily for professional use. Compared to the Phantom series, they offer 360 ° pivoting cameras and the option to control the camera separately with an additional remote control.

DJI Inspire 1

At the end of 2014, the company launched the Inspire 1, an aerodynamic quadcopter for professional aerial photography. The built-in camera captures images in 4K and 12 megapixels.

The Inspire 1 Pro camera system is equipped with very small digital camera housings to support Micro Four Thirds system cameras, developed specifically for aerial photography, on the Zenmuse X5 and X5R models.

DJI Inspire 2

The second generation of the Inspire was introduced in November 2016. The Quadcopter achieves a top speed of 94 km / h. The new camera Zenmuse X4s and X5s takes pictures in resolutions up to 5.2k with a 20.8 megapixels sensor.

The Inspire 2 is equipped with downward, upward and forward sensors for automatic obstacle detection and has a bayonet connector for the Micro Four Thirds standard.

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