Sterblue Blog


DJI M300 RTK: How we added a new drone to Sterblue Ecosystem!

Last May, DJI announced the Matrice 300 RTK, a drone designed notably for industrial inspections. As the central platform for infrastructure inspections, Sterblue couldn’t miss the opportunity to add this powerful machine to our family of compatible drones. Here’s why and how we’ve made our software ready to fly with the brand new M300!

Drone inspection programs bring visibility and traceability to asset managers

When it comes to infrastructure inspections, Sterblue’s strategy has always been clear: separately perform the data capture and data analysis phases. This means that our platform can process multiple sources and formats of imagery, no matter which inspection method our customers have in place. However, we’ve also consistently shared on the importance of capturing data in a clean, precise and standardized manner. 

Sterblue developed an iPad application (Sterblue Mobile) which is able to control off-the-shelf drones and their cameras during the flight. The app guides the drone along predefined automatic trajectories, giving instructions to capture hundreds or even thousands of images as close as within a 4m (13 feet) distance from the inspected asset.

Sterblue Mobile app during cooling tower inspection

Thanks to that, we can cover 100% of the asset, allowing drone pilots on field to collect a high quality set of pictures. Then, back in the office, industry experts are able to have a detailed look at everything, ensuring no defect or problem is missed. This allows energy and utility companies to closely monitor asset health evolution, by comparing inspection data over the years and avoiding dangerous and costly consequences.

Battery, camera, action! Industrial inspections starring the M300

It’s 2020 and we are still waiting for a multi gigapixel drone camera that would allow us to take only a few pictures in a couple of minutes and later massively zoom in to spot even the smallest defects. Therefore, we have to accept the fact that industrial inspections performed with a classical camera sensor require taking many, many, (many) images.

The DJI M300 is equipped with a H20T sensor and a thermal +RGB camera with a 20MP sensor and a powerful 20x zoom capability. Not exactly the gigapixel sensor we were hoping for, but it has other advantages: the most recent DJI drone is now able to fly for some serious 45 minutes, while precisely assessing the distance to the asset thanks to an incorporated rangefinder.

Recently, DJI also announced 2 new sensors to be released early 2021:

  • A full frame 45MP sensor which is a great improvement for industrial inspections
  • A camera with an embedded lidar perfect for power grid digitalization

This is especially appealing for inspections of larger assets, like cooling towers, since it demands less battery changes during the field operation. The choice of payload makes the M300 a more versatile machine when compared to previous series, with further improved flight autonomy. But the real question is: how does the Matrice 300 RTK compare with its closest brother in the DJI drone family, the Matrice 210 RTK?

Different drones, different applications, different levels of compatibility

Camera quality and flight time are far from being the only criterias for a drone to become part of the Sterblue family. There are two initial levels of compatibility that must be taken into account:

Below you can find the list of hardware compatible with Sterblue’s solution, varying in models, applications and compatibility levels:

The M300 is the latest drone to be compatible with both Sterblue Cloud platform and Sterblue Mobile app. Now, let’s have a closer look at the process to make this integration possible.

Behind the scenes: how did Sterblue integrate with the M300?

We wouldn’t be telling you this story without the support of Abot, who lended us one M300 DJI drone and allowed us to test it and integrate it with our software. Abot specializes in professional drones and is part of the STN2 Group, along with other companies like studioSPORT, the French leader in drones and on-board video systems.

“As the leader Professional Drone Retailer in France, we worked with Sterblue to have their software working with DJI latest industrial drone. Utility companies can now inspect their assets automatically with the M300!” Maxence Trogneux, Expert in Professional Applications for Drones at Abot
Vincent (left) and Nacho (right) from Sterblue team with the new DJI M300 lended by Abot

As soon as the M300 arrived at Sterblue headquarters in Nantes, France, our Operations and Engineering teams couldn’t keep their hands off it. As a matter of fact, Nacho, Lead Mobile Engineer at Sterblue, travelled all the way from our office in Lisbon, Portugal, only to meet the brand new DJI drone and make it ready to fly with Sterblue’s software. The initial plan was clear:

  • 3 days of software development to integrate the drone with Sterblue Mobile app.
  • Flight time on field to test the efficiency of this powerful machine when combined with Sterblue solution.

Seizing the moment: Sterblue new Sensor API makes any integration possible

From a software integration point of view, DJI brought some tricky changes with this new hardware release. Luckily, Sterblue knows how to take advantage of a good challenge!

The M300 camera has now a 4 video feed - Thermal, Wide FOV, Inspection camera and FPV camera. This added some complexity to the integration, demanding that our software was capable of handling all these sources. To do so, we rushed the development and launch of an important feature: Sterblue Sensor API.

Testing the M300 video feed in Sterblue Mobile app at the office

The new Sensor API brings a layer of abstraction between user actions such as "take a picture" and the command sent to the sensor, enabling Sterblue Mobile app to integrate more easily with different kinds of sensors and drones. As an example, since we developed the API, we have already added the iPad built-in camera as a compatible sensor. This is especially helpful for ground based inspections or emergency situations.

“The changes DJI had included in its SDK, especially for handling M300 payloads, represented a great opportunity to work on our so called Sensor API. Thanks to this, Sterblue is now more ready than ever to include new drones and payloads in its list of compatible devices!” Nacho Carnicero, Lead Mobile Engineer at Sterblue

The M300 also challenged Sterblue to reconsider some of our previous assumptions concerning waypoints. For example, before if you sent a drone to a waypoint with 10m height, you would expect it to fly 10m above the ground, right? Well the new M300 will fly 10m above the ellipsoid used to model the earth.

As you can imagine, this brought some “nice” surprises to the first flight tests, as the drone kept going down, trying to dig underground. Since we did not find any information concerning changes in the height reference, we’ve already reached out to the DJI Developer Support looking for some answers.

Testing the DJI M300 on wind turbines and transmission towers

Software solutions like Sterblue allow industrial inspections to be performed with minimum risk and maximum efficiency. Despite the current pandemic situation and restrictions varying geographically, all it takes to go on the field is a trained drone pilot and the necessary equipment.

That being said, Sterblue Operations team could safely test the new DJI Matrice 300 RTK with a beautiful French landscape as background. Here is our feedback:

  • Wind Turbines: The autonomy of the drone is great. It allows drone pilots to inspect large wind turbines (with more than 120m diameter) without needing to land and change batteries. Plus, the rangefinder gives the exact distance between the drone and the blades, which will mean more precise defect measurements for the end user. 
  • Transmission Grid: The M300 allows the drone pilot to create a high resolution panorama. This is great to zoom in and capture more detailed pictures of a specific area of the tower. And the best part is that these sets of images will be automatically stitched together. Finally, long distance flights are made easy with the new DJI hardware. The extended range allows pilots to operate Beyond Visual Line of Sight (where legally authorized) and thus improving the drone’s productivity.
Examples of zoomed pictures captured by Sterblue on a wind turbine (left) and transmission tower (right)

Sterblue’s ultimate feedback on the DJI M300 RTK

After two weeks with the DJI drone, a new version of Sterblue Mobile app was  finally pushed into production. Despite a couple of extra challenges either in software development and flight tests, the M300 is certainly a good addition to the Sterblue drone fleet which will help boost the efficiency and precision of our customers’ asset inspections.

There is no doubt DJI stepped up the game in terms of flight time and obstacle avoidance with this release, although the camera could be slightly more tailored for the purpose of industrial inspections. Sure the High Resolution Grid Photo feature is great, as well as the zoom capabilities, but the autofocus remains slow and the resolution could be higher. Luckily, DJU is already announcing some new payloads… Let's wait and see!

And as for Sterblue? This new drone integration pushed our Engineering team to develop a sensor API which will make future drone integrations much easier. If you are a drone manufacturer and are interested in having your hardware used by large utility companies thanks to our solution, this is the time to reach out!

Sterblue testing the DJI M300 on a transmission tower