DJI FPV obstacle avoidance [full guide and warnings]

Modern drones often come with sophisticated obstacle avoidance systems. These systems are very important for keeping your drones safe and being an extra set of eyes in the sky. Most modern consumer drones in the higher price bracket have nearly 360° obstacle avoidance systems. However, the DJI FPV obstacle avoidance system is not as sophisticated.

The DJI FPV obstacle avoidance sensing system has a forward and downward Sensor capable of detecting to 18 m away. The forward sensor is only available in normal mode, and a single LED bottom auxiliary light supports the downward sensor.

DJI have chosen to avoid using too many sensors due to the high-speed flying this drone can achieve.

Sensors are fantastic for camera drones when the pilot is more focused on framing the shot and capturing the most impressive aerial photo or video possible.

When flying a stunt drone in FPV, you need to have full control over the drone without it getting in the way of flying close to obstacles.

That said, the DJI FPV obstacle avoidance system has forward sensing capabilities to be beginner-friendly and give new FPV pilots the chance to try out stunt flying at high speeds with a little safety net.

What type of obstacle avoidance does DJI FPV have?

The DJI FPV drone does not have a sophisticated obstacle avoidance system like some camera drones manufactured by the same company.

The drone features a forward and downward obstacle avoidance sensing system and cannot sense obstacles to the side, rear, or above.

DJI FPV obstacle avoidance

The drone can only sense obstacles when it is in normal flight mode.

Normal mode

The DJI FPV drone has three flight modes and a fourth automatic mode that the aircraft changes to in certain scenarios. The flight modes can be switched via the flight mode switch on the remote controller.

In normal mode, the aircraft utilises its internal sensors and hardware. The aircraft utilises GPS, the forward and downward vision systems, and the infrared sensing system to locate itself in the environment and provide stabilisation.

In this mode, the maximum flight angle is 25°, and the maximum flight speed is 15 m/s.

To travel faster, you will need to enter sport or manual mode. A warning to beginners: do not enter full manual mode as automatic stabilisation and all the sensing systems are turned off.

Sensing system:

If you want a full rundown on the sensing system of the DJI FPV drone, the table below will tell you everything you need to know about the relatively limited sensing system you get when you purchase this drone.

ForwardPrecision Measurement Range: 0.5-18 m Obstacle Sensing: Only available in Normal mode FOV: 56° (horizontal), 71° (vertical)
DownwardInfrared Sensor Measurement Range: 10 m Hovering Range: 0.5-15 m Vision Sensor Hovering Range: 0.5-30 m
Auxiliary Bottom LightSingle LED
Operating EnvironmentNon-reflective, discernible surfaces with diffuse reflectivity of >20%; Adequate lighting of lux >15

You will notice that the forward obstacle sensing is only available in normal mode and is a Precision measurement between 0.5 and 18 m. The downward sensing system is accurate up to 10 m and has a vision Sensor which can detect hovering up to 30 m.

Even though these are the technical components of the DJI FPV obstacle sensing system, in reality, you will get an on-screen warning once this system is activated.

On screen display obstacle detection system

Because this drone relies on goggle displays for streaming the first-person view video stream and providing all of the on-screen data, you have to become familiar with all the information available when viewing through the goggles.

Here is what you will see when you are close to an obstacle, and the system wants to warn you that you are too close to an object or obstruction.

The bar at the top of the screen indicates the distance between the aircraft and obstacles and the general direction the obstacles are in. Red, orange, and grey bars show the distance to the object ranging from near (red) to far (grey). Red bars are displayed when you get too close to an obstacle, and an orange bar will show you that an obstacle is within detection range.

The sensing system works best when:

The DJI FPV obstacle avoidance system works best under a few simple conditions. If you are flying outside of these conditions, I recommend that you pay extra attention to your surroundings and stay further away from any potential obstacles.

Clear texture

The vision systems and infrared systems only work in certain scenarios. The downward vision system may not function properly when the aircraft is flying over water and when the aircraft is flying too fast.

You mustn’t fly over surfaces that are:

  • one colour – pure black, white, or any other colour
  • highly reflective surfaces
  • transparent surfaces such as water
  • flying over moving surfaces or objects
  • flying over obstacles with a small surface area, such as tree branches and wires
  • flying over surfaces with repetitive textures such as tiles
  • and flying over surfaces that strongly reflect or absorb infrared radiation, such as mirrors.

Extra care should be taken if flying over any of these types of surfaces.

Lots of light

There must be sufficient light for the obstacle avoidance system to work properly. If the lighting changes frequently or dramatically, there may be an issue in determining the distance of an object. Avoid flying over extremely dark or bright surfaces.

The altitude of 0.5 – 15 m

Once you fly over 15 m, the downward-facing sensing system can no longer detect the ground. If the forward obstacle is more than 15 m away, the bar will be grey, and you can proceed with caution.

You must look after the sensing system very diligently as they will be your last lifeline should you lose concentration and fly towards obstacles.

Caring for the DJI FPV obstacle avoidance system

Keep the sensors clean or time and do not tamper or try to adjust the sensors. If you are flying in environments with high levels of dust or humidity, you must clean the windows of the sensors as quickly as possible. Avoid areas with a significant amount of dust or very high humidity.

If you are in an accident, you must calibrate the cameras if prompted to do so with the goggles. Alternatively, regular calibration of the obstacle avoidance system will mean that your drone stays as safe as possible.

Before every flight, you should ensure no stickers or other obstructions over the infrared sensing system or other vision systems.

Clean the systems with a soft cloth and make sure that you do not use any cleanser that contains alcohol – this can cause the sensors’ surface to become foggy.

If there are any issues or you have sustained damage to the glass of the infrared sensing system or vision detection system, contact DJI support.

Obstacle avoidance during return to home

The return to home function will bring back your drone to the last recorded home point and GPS location. When the GPS signal is strong, you can achieve a smart return to home that will take your drone in a straight line back to the takeoff location.

There are three types of return to home: smart return to home, low battery return to home, and failsafe return to home.

Obstacle avoidance is activated during return to home, and the drone will break when it senses an obstacle in front. After stopping, the drone will ascend 5 m and try to continue flying forward.

If the drone senses an object below, it will ascend into the obstacles that are no longer detected before flying forward.

It is important to note that the aircraft cannot avoid obstacles from the side, rear or above because it does not have any sensors pointing in those directions.

If you manually turn off the forward and downward vision systems, you will not be able to avoid obstacles while returning home, and you must fly with much more caution.

When is the obstacle avoidance system turned off?

The obstacle avoidance system is a fantastic failsafe for the drone and ensures that even beginners can fly the DJI FPV drone with safety and security as a priority.

Some people like to turn off the obstacle avoidance system, which you can do manually.

Manual avoidance system off

If you have turned off the the avoidance system manually fly with extra care. If you are used to flying your drone with the avoidance system turned on the drone may act differently during flying.

My recommendation is to fly in normal flight mode with all of the sensors activated until you are comfortable with everything the DJI FPV drone can do.

There is a lot of power and speed behind this drone and you should utilise it with respect.

Not in normal mode

You can change the mode of the FPV drone by toppling the switch at the back of the remote. You will also be able to see the mode that you are currently in on the heads up display.

This drone has a variety of flying settings for novices to try out:

  • S mode is a hybrid flight mode that combines the freedom of manual flight with the simplified controls found on older DJI drone models.
  • N mode – provides an immersive flight experience with traditional drone flight controls, including object detection and obstacle avoidance.
  • M mode — allows you complete manual control over the system, including the ability to alter the parameters. It takes only 2.0 seconds to accelerate from 0 to 100 km/h.

If your drone loses control, it features an emergency brake that allows it to stop and hover with a single button press.

If you switch out of normal mode, none of the obstacle avoidance systems will be working.

Summary

This article has covered everything you need to know about DJI FPV obstacle avoidance systems and the best way to utilise the advanced software to keep your drone safe.

The DJI FPV drone is a very fast and powerful drone that can be flown by beginners thanks to its forward and downwards obstacle avoidance system.

However, a variety of situations will turn the sensing systems off, and you need to ensure that you are aware of the situations that could happen.

Turning off the obstacle avoidance systems means putting your drone at a greater risk of coming into contact with obstacles. It is much better suited for advanced pilots and those who have perfected the art of flying a drone manually without GPS or vision positioning systems.

Make sure your DJI FPV drone always has a clean glass sensing window by dusting with a microfibre cloth and removing any stickers that may be obscuring the sensing system.

The Author

Dr Andrew Stapleton is a writer and YouTuber with a PhD in science. His drone footage has been featured on TV and he has written and/or produced videos for Science Alert, COSMOS magazine, and Australia's Science Channel among others. He has been a drone pilot for many years and has flown many types of drones. His favourite is still the DJI Mavic Air for the portability and functionality packed into a small and portable drone!