Figure 1: DJI Mavic Air (Mavic, n.d.)
The Mavic Air employs a host of technology for capturing or aiding in the capturing of high quality video and photography. The Mavic Air is designed about a small but capable 12-megapixel CMOS camera system. The camera is capable of capturing video from 720p at 120 frames per second all the way up to 4K video at 30 frames per second and still pictures in multiple modes including panorama, sphere, interval and high dynamic range (Mavic Air, n.d.). This camera, while highly capable, is only able to capture the high-quality images if given a smooth, stable platform. This is partly accomplished using a 3-axis gimbal system and partly accomplished through automation. One of the hallmark technologies of the DJI systems is their Flight Autonomy 2.0, a system that can do exactly what is needed, keep the camera as stable as possible. This system uses a suite of sensors to enable both precision autonomous flight and reliable obstacle avoidance, allowing the operator to focus on getting the perfect shot. This system consists of the primary camera described above, dual-vision cameras mounted on the front, rear and bottom of the vehicle, and a downward pointing infrared sensor (Figure 2). The information from these sensors is then combined with dual inertial measurement unit data and sent to a set of processors that interpret the data and generate precise control commands for vehicle control (Mavic, n.d.).
Figure 2: Mavic Air Dual-Vision Sensors for Flight
Autonomy 2.0 (Mavic Air, n.d.)
To power the system the Mavic Air utilized DJIs Intelligent Flight Battery System. The battery is a densely packed, 3-cell lithium polymer design with a capacity of 2375 milliamp-hours, operating at 11.55 volts (Figure 3). This allows for flight times reaching 21-minutes in ideal (no wind) conditions while flying at a speed of 25 kilometers per hour. Not only does this battery operate the 4 electric motors, but it also operates all the sensors and cameras installed on the vehicle. Power consumption data for each of the sensors and onboard computers was not available, just the overall system (Atkinson, 2018).
Figure 3: Mavic Air Intelligent Flight Battery (Mavic Air, n.d.)
The data storage and processing for the Mavic Air is all done internally, and the video sent back to the smart controller is only used for control purposes for both the vehicle and camera system and is not saved on the receiving end. The Mavic Air contains eight-gigabytes of internal data storage utilizing the FAT32 file system. Video files are captured and stored using either the MP4 or MOV file formats and still imagery is saved utilizing either the JPEG or DNG (RAW) formats. The size of captured videos varies drastically based upon settings utilized for the camera system and the duration of the flights the operate is conducting. Since 4K video files (the worst case scenario for storage) can quickly become rather large, eight-gigabytes is often not enough storage. For this reason, the Mavic Air has expandable storage through the use of an external SD card slot. It can utilize SD cards ranging is size up to 128-gigabytes. Files stored on the SD card are processed and stored using the same file system and file formats. In general, data from the sensing suite utilized by the Flight Autonomy 2.0 system is not stored by the Mavic Air. The only exception to this would be the 3-dimensional map that the system generates during its flights. However, no information was readily available on how large these files would be or what file format is utilized (Mavic Air, n.d.).
There are few ways that the Mavic Air could be improved upon when it comes to file storage and processing. One thing the system can never have enough of is storage. Currently, the vehicle only has one SD card slot, but because of the small size and light-weight of these SD cards it would be very easy to add additional slots to the vehicle to increase the amount of storage it has. Another data treatment enhancement could include the ability for the primary camera data to be stored external to the vehicle via a transmission system. Not only could this allow the storage to easily be increased because weight would be a much smaller factor, but it would also reduce the power consumption and weight of the vehicle which could help to increase flight time and performance characteristics. One limitation of this style of data management would be bandwidth. The current transmission system only has a limited amount of bandwidth which means that adjustments to bandwidth allocations would be required. Additionally, with high-resolution video transmission time would be longer meaning that delays in video feed could be seen. This would result in real-time, manual control, being impossible for the operator. However, despite these shortfalls, the advantage of increased flight times and storage capacities could greatly enhance the Mavic Air.
References
Atkinson, D.
(2018, February 23). Heliguy Insider. Retrieved July 26, 2018, from
https://www.heliguy.com/blog/2018/02/23/dji-mavic-air-in-depth-series-part-1-intelligent-flight-battery/
Mavic Air:
Adventure Unfolds. (n.d.). Retrieved July 26, 2018, from https://www.dji.com/mavic-air?site=brandsite&from=nav
Mavic Air– Specs,
FAQ, Tutorials and Downloads. (n.d.). Retrieved July 26, 2018, from
https://www.dji.com/mavic-air/info#specs
Douglas,
ReplyDeleteThe DJI Mavik Air boasts some excellent specifications. Your suggestion that one can never have enough storage is absolutely correct. While a micro SD card with 128 GB of storage is large having a second memory card slots would be beneficial. One of the reasons why DJI may have shied away from doing just that is the short flight time that the Mavik Air is gathering data. The designer’s intentions may be that when the aircraft lands after a flight that the pilot swaps in a new battery and a new memory card. This is one of the reasons why DJI has partnered up with Seagate to use an external transfer and backup hard drive. Please take a look at my blog post regarding the Seagate DJI fly Drive.
References
Seagate. (2018). Seagate DJI Fly Drive. Retrieved 29 July 2018, from https://www.seagate.com/consumer/backup/dji-fly-drive/