Hey man, where’s my drone? (a tale of a runaway UAV) [w/ Japanese vocabulary list]

By | June 17, 2019

Blogs can generally be broken in to two categories: those of a personal nature that talk about someone’s day-to-day life, and those that focus on a specific topic. While surely some blogs are a hybrid of these two groups, I’d guess that readers generally prefer one or the other.

I’m pretty strict about keeping Self Taught Japanese about things related to Japan or Japanese, but once in a blue moon something comes up that I feel is important to deserve an exception. This is one such post. However, to keep those of you happy who come to this blog for information on studying Japanese, I’ve put a vocabulary list at the end.

So, now with the preface out of the way I can focus on today’s special topic: drones, or more formally UAV (Unmanned Aerial Vehicles). I’ve been interested in drones for several years now, and have experimented with a few inexpensive, palm-sized ones. While a lot of fun to fly, they tended to break in a few weeks, so it was hard to stay interested without putting in a lot of money.

Eventually I bought a slightly more expensive drone (around the $200 range) which had a camera on it. But that had problems of it’s own: the camera quality was really bad (very shaky) and that broke twice in the span of a few weeks. To make things worse, the place I bought it went out of business. So I gave up the drone hobby for over a year, hoping to save up and eventually buy a more expensive, and hopefully more robust drone.

A few weeks ago, I finally decided on purchasing what they call a “prosumer” drone, basically something halfway between the entry-level consumer items and those used by pros. It was the DJI “Spark”, which I got for around $500 in a kit with a remote control and an extra battery.

After opening the box, it took over an hour to charge the batteries, and then roughly another hour to figure out how to set up the mobile app and controller, and eventually get the Spark off the ground.

The first surprising thing about this drone was the raw power it emanated, from not only the loud sound of the propellers but the terrific wind force they generated. The carpet in my living room literally started moving in a series of ripples from the resultant wind current, almost like a magic carpet.

The first cool thing I experienced about this drone was that it had auto-takeoff, such that when you do a certain sequence on the app the drone would takeoff and hover at a pre-defined height, awaiting further orders. But this was just the beginning.

After flying it around the house for a little while, I brought it outside and experimented with it in a park, playing with the controls and taking some pictures and videos. A single battery charge lasted only around 10-15 minutes; this is quite short but I had known about this before purchasing the drone, so I wasn’t disappointed by it. I ended up getting the hang of many of the basic controls: how to move the camera, take videos, and return home. The drone features a RTH (return to home) mode that automatically navigates back to the “home point” using GPS, which it marks around take off time. This gave me a certain level of comfort since the drone had a pretty large range (around a mile).

Looking through the initial videos I took, I was impressed by quality, especially how stable things were. This is achieved through what is called a gimble, a device that helps with stabilizing.

A few days later, I decided on taking the drone up for another flight. This time I pointed the camera straight down, turned on recording mode, and gradually took the drone up, hoping to make a cool “zoom-out” style video. As I brought it up, I watched the altitude (listed on the app) and counted out loud, being extra dramatic like I was someone at NASA launching a rocket.

10 feet, 20 feet, 30 feet…50 feet…

Since there was something obstructing my view of the drone part of the time, it was extra tense––though I could still see the live video streamed to the app.

Once I made up to about 100 feet I decided to stop, point the camera to the horizon, and then rotate so I could take a 360 degree video of the surroundings. I pointed the camera back down and was about ready to lower the drone, but then it happened.

Some error message popped up on the app, but before I had a chance to understand what it meant I saw the camera view (now pointing down) start to gradually pan. In other words, my drone was now drifting off in some direction, despite the fact I wasn’t directing it to move horizontally. The horizontal speed gradually increased, and in the midst of mounting panic I tried to engage the “RTH” mode to make it return to my location, but it didn’t respond. Because I couldn’t see the drone the entire time, and because of various obstacles, it was difficult to follow on foot.

About a minute later the video stream cut, and after that the drone got disconnected completely. I was now in a total state of panic, shocked by this unexpected turn of events.

Fortunately, the app gave me access to the full video I just shot, so by watching that several times and carefully observing my surroundings, I was able to find the last location shown on the video, which was in a residential area. I asked a few people (one kind guy even let me walk into his back yard) but no drone in sight. In retrospect, it should have been obvious the drone was not there because, judging from the video image, it was still at a pretty high altitude.

Eventually I discovered a “find my drone” feature in the application, and spent around an hour trying to search around the location that I indicated. But this just led me on a wild goose chase to a place where the drone could not be. Besides the video, I had the statement of a person who actually witnessed the drone fly away, so I had high confidence about what direction it had went.

I searched the surrounding area, focusing on the projected trajectory of the drone assuming it kept going on a straight line. This lead me to a large residental community where another old gentleman was nice enough to let me climb on his house and look around the area. Searching was tough––not only were the houses pretty close together, but there were a lot of garden areas where the drone would be nearly impossible to spot.

Several hours later I returned home, legs tired, exhausted, and sweaty (it just happened to be an extra hot day). I was empty handed; my search mission had ended in failure.

It just so happened that I had an extremely busy the schedule the next week, and very little time to go searching again for the drone. Besides, the more time that passes the higher the odds someone would find it, and with no easy way to identify the drone’s owner that person would likely keep it for themselves. Finally, I really wasn’t comfortable with searching in people’s gardens, or stopping and each door and asking for their permission to do so.

Having basically given up, I decided to at least open a support case with DJI. I thought that maybe they would explain to me what happened, and possibly even offer a small coupon towards a replacement.

As part of the support process I was asked to extract and provide my drone’s “Flight Records”, which is a log with a wealth of information about the drone’s location, height, status, and other valuable data. This site allowed me to visualize the entire GPS track, and I confirmed that the drone had likely ended up somewhere in the large community I had searched through. Looking through the flight record of my drone’s final flight, I could see there was a bunch of “compass error” and “Yaw error” messages, and something about “ATTI” mode.

After hours of research, including feedback from the support team, I determined that due to a compass or GPS problem the drone had switched into “ATTI” mode, which means there is no longer horizontal auto-stabilization. This explains the drones erratic movement in one direction––it was simply being blown by the wind. While I did not notice too much wind during that time, it seems that wind currents can be stronger higher up. The other thing I learned is that when in ATTI mode, the return to home command does not work because accurate location cannot be determined.

DJI’s customer service procedures were pretty efficient, involving an exchange of a few emails over about a week. The support agents were generally polite and responded within a day or two.

DJI explained that because they did not determine any fault of mine (had I done something strange I guess it would have shown up in the flight records), they offered to send me a replacement drone at no cost. Thank you DJI!

This was a wonderful surprise, since I was never expecting full compensation. I consider myself very lucky, since my internet research showed several cases where DJI only offered to compensate a small portion of the drone’s total cost, if that. So please don’t assume DJI will always send you a new drone if you lose one.

While this ordeal was quite stressful, it ended in a positive way and I learned a great deal about drones in the process. Drones of this caliber are designed with an array of advanced technologies, but despite the apparent ease-of-use there is a great deal of understanding required to properly pilot them, especially in emergency situations where automatic features don’t work. If you get a drone, I highly recommend reading the entire manual before you take your first flight.

Despite all of the technology used in drones, it still seems that these so-called “flyaways” are not uncommon, caused by a combination of user error and (potentially) design or hardware issues with the drones themselves. This page has a great set of suggestions (over 70) to help prevent flyaways. While I can’t say for certain, had I known all these tips I might have been able to prevent my flyaway, or maybe at least recover the drone. At minimum, had I kept the drone in sight at all times (which is apparently a law in the US anyway) I might have been able to better control the drone during those last few critical moments.

As a result of this experience, I’ve learned that drones can seem like expensive toys, but are actually carefully designed pieces of equipment that deserve the respect and time investment to learn how to properly pilot them.

When I decide to fly my replacement drone, I’ll be doing so armed with the knowledge of how the drone and it’s various systems work, and will put utmost care into avoiding a similar accident. While there is still a chance the same thing will happen, the very fact that I could lose the drone makes me value it even more. And understanding the details of how drones work should help me to appreciate and enjoy flying one of them even more.

Finally, as promised, I’ll give a vocabulary list of drone-related words for those of you studying Japanese.

(Update: after writing this article, I took the replacement drone for a few rides. Things have went pretty well so far, with only a few minor issues.)

Japanese vocabulary list: drone-related words

  • ドロン (doron): drone
  • 機体 (kitai): body or main part (of an airplane)
  • 空撮 (kuusatsu): aerial photography
  • 動画 (douga): video
  • カメラ (kamera): camera
  • 撮影する (satsuei suru): to film or photograph something
  • ジンバル (jinbaru): Gimbal
  • 帰還する (kikan suru): to return home
  • ホバリング (hobaringu suru): hover
  • 障害物 (shougaibutsu): obstacle
  • 飛行する(hikou suru): to fly (a drone, etc.)
  • 飛ばす (tobasu): to fly (a drone, etc.) [less formal than 飛行する]
  • 飛行時間 (hikou jikan): flight time
  • プロペラ (puropera): propeller
  • 充電器 (juudenki): charger
  • 起動する (kidou suru): start up (a drone, etc.)
  • 接続する (setsuzoku suru): connect
  • 高度 (koudo): altitude
  • 速度 (sokudo): speed
  • 距離 (kyori): distance
  • 視野 (shiya): field of view
  • 着陸 (chakuriku): landing (can use as a verb with “suru”)
  • 離陸 (ririku): takeoff (can use as a verb with “suru”)
  • 残量 (zanryou): remaining amount (battery power, etc.)
  • 水平 (suihei): horizontal
  • 垂直 (suichoku): vertical
  • 範囲 (han’i): range
  • 送信機 (soushinki): transmitter (controller, etc.)
  • 地面 (jimen): surface of the ground
  • 自動的 (jidouteki): automatically
  • 検知する (kenchi suru): to detect (a problem, etc.)
  • 回転する (kaiten suru): to spin
  • 位置 (ichi): position
  • 点滅する(tenmetsu suru): to flash off and on (a light, etc.)
  • 制限 (seigen): limit (for speed, altitude, etc.)
  • 墜落 (tsuiraku): crash (can use as a verb with “suru”)
  • 操作する (sousa suru): to operate (a controller, etc.)
  • 飛んでいく (tonde iku): to fly away
  • 静止する (seishi suru): to stop moving

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