Collision avoidance systems used to be reserved for expensive commercial and military drones. However, as the sensors become more affordable, we are starting to see the technology on more accessible light domestic drones. The first light consumer drone with sonar obstacle detection came on the market about three years ago. They offered a single plane sensor which was capable of detecting obstacles in the direct line of flight.
But today, companies such as DJI are starting to deploy more advanced sensors such as ultrasonic, infrared and monocular vision. This gives them the capability to detect obstacles, above, below and to the side of the direction of flight. This makes them much more capable machines. They can operate at much greater distances out of the line of sight from the pilot.
Benefits of collision avoidance
Drones are expensive so the fewer collisions you have the better. With drones that operate within line of sight, collision avoidance isn’t an issue. This is because the pilot can see obstacles from the ground. But as drone operating distances increase and pilots start operating out of the line of sight, a level of collision avoidance is necessary to ensure safe operation of the drone. Even pressing the return to home button does not guarantee a safe return for the drone. This however is if it doesn’t have collision avoidance built-in.
Collision avoidance systems can also help you reduce costs by lowering insurance premiums. The cost of insuring a drone can run to several thousand pounds. Especially if it is intended to be used at public events which require public liability insurance. In fact, most insurance companies today will insist that you use a drone fitted with some sort of collision avoidance before providing cover for a public event.
So which drone is the best one for you? To help you make a decision, we’ve taken a closer look at 5 of the latest obstacle detection and collision avoidance drones from DJI. As you will see, some of these drones are aimed at specific professions, such as the inspection engineers. Users are advised to choose a drone that meets their specific requirements rather than make do with a cheaper drone which may not provide satisfactory results.
NOTE: If you purchase one of these drones it is important that you read the manual before taking flight. The obstacle detection sensors may not work properly if light conditions are not suitable for the type of sensor fitted and in some cases, the system may be turned off if certain modes are selected. So keep safe and make sure you are familiar with the type of sensor your drone uses and the light conditions when in operation.
The new Mavic Air from DJI uses the most advanced collision avoidance and obstacle detection system currently available in a light consumer-centric drone. With forward, backward and downward vision the Mavic Air can scan for objects which may obstruct the flight path.
It also has the ability to recalculate its flight path to fly around the obstacle, only resorting to hovering if a remap cannot be achieved. This level of automation is achieved thanks to DJI’s updated FlightAutonomy 2.0 system which uses an integrated system of IMU, gyroscope and accelerometer sensors along with Visual Inertial Odometry (VIO) technology. This detects its surroundings and alter flight paths accordingly, all without having to rely on external satellite navigation systems. This enables the drone to be used in all environments both outside and inside where a satellite signal can’t be received.
The Mavic Pro is a compact drone that packs a powerful punch thanks to its two sensor obstacle detection system. Simple to operate, the Mavic Pro uses DJI’s original FlightAutonomy system which is connected to both downward facing ultrasonic and forward facing vision sensors. These create a 3D map of the terrain, helping to identify obstacles which pose a threat. This system is extraordinarily simple but effective, with the ability to see up to 15m ahead in good conditions.
However, unlike the Mavic Air, the Mavic Pro is not able to navigate around objects and will hold its position until further inputs are applied by the pilot. But the system is very effective at identifying obstacles both large and small. It is also able to follow terrain using height information gathered from the downward facing ultrasonic sensors. These sensors can also be used without connection to a GPS network so are useful for indoor flights where a satellite connection cannot be established.
Phantom 4 Pro
As its name suggests, the Phantom 4 Pro is a powerful drone aimed at commercial users. It comes with a range of obstacle avoidance features making it useful for interior or exterior filming in confined spaces.
The drone comes with three sets of dual vision sensors. These are combined with infrared sensors to create a 5 direction obstacle sensing system. Using this system of forward, down and rear-facing sensors. The Phantom 4 Pro can precisely hold its position without the need for external GPS.
The DJI FlightAutonomy system can also take data from these sensors to follow and track objects in autonomous flight mode. This makes the Phantom 4 drone particularly useful for 3D imaging, professional filmmakers, and photographers who need an easy to fly, reliable drone capable of carrying out high-quality photography in all environments.
Designed for commercial use the DJI Matrice 200 can be fitted with a range of imaging equipment. It’s particularly suitable for the inspection of power lines, cellphone towers, railway tunnels, bridges and more.
For collision avoidance and obstacle detection, the Matrice 200 comes with dual forward-facing stereo vision sensors. It also has one down facing vision sensor, ultrasonic sensors on the top and bottom and two time of flight infrared laser sensors on top. This comprehensive 360° system allows the Matrice 200 to constantly scan for obstacles and fly around them without any input from the pilot.
As a commercial drone, reliability and uptime are of paramount importance. So the Matrice 200 comes with a level of system redundancy built-in. There are dual batteries, and backup GPS positioning, reducing the risk of losing your drone or running out of power at a critical moment.
The M200 is also built to comply with IP43 water ingress protection standards. The IMU (gyroscope and accelerometer) comes with vibration isolation and shock protection to ensure accuracy in the most demanding conditions.
The Inspire 2 is designed for professional filmmakers and cinematographers and supports a number of professional features such as pro-grade video compression and dual-operator control. As you would expect, such a capable machine also comes with an advanced collision avoidance system.
Obstacle detection and collision avoidance are handled by a comprehensive collection of sensors, including; 2 forward facing stereo vision sensors, 2 downward facing ultrasonic sensors and 2 upward facing infrared sensors. Together these sensors can detect obstacles up to 30 metres ahead at speeds up to 34 mph.
These sensors can also be combined with the flight control system to create a range of intelligent flight modes, including; Active Track, Spotlight Pro, Tripod Mode, QuickSpin, TapFly and Profile Mode. When combined with the advanced CineCore 2.0 image processing system built into the nose, the Inspire 2 can record spectacular 5.2K professional grade videos fit for any movie with very little input from the pilot.
Which one should you choose?
As you can see, you are not short of choice when it comes to drones with collision avoidance. The best choice will depend on your available budget and specific requirements.
If you are a consumer and your drone flying is more of a hobby, then you won’t go far wrong with the DJI Mavic Air. It’s compact, lightweight, easy to fly and cost-effective.
However, users who want to create professional style images suitable for commercial projects should opt for the Inspire 2.
The Matrice 200 optimised for inspection professionals and the Phantom 4 Pro targeted at photographers and filmmakers.
So long as you choose a drone which has the right features for your desired application, you won’t go far wrong with any of the drones mentioned here. Good luck and happy flying.
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