Fail Of The Week: Two Rotors Are Not Better Than Four

June 12, 2018 by Dan Maloney 20 Comments

Fair warning: [Paweł Spychalski]’s video is mostly him talking about how bad his “dualcopter” ended up. There are a few sequences of the ill-fated UAV undergoing flight tests, most of which seem to end with it doing a reasonable impression of a post-hole auger. We have to admit that it’s a pretty poor drone. But one can only truly fail if one fails to have some fun doing it, [Paweł] enjoyed considerable success, at least judging by the glee with which he repeatedly cratered the craft.

The overall idea seems to make sense, with coaxial props mounted in the middle of a circular 3D-printed frame. Mounted below the props are crossed vanes controlled by two servos. The vanes sit in the rotor wash and provide pitch and roll control, while yaw and thrust are controlled by varying the speeds of the counter-rotating props. [Paweł] knew going in that this was a sketchy aerodynamic design, and was surprised it performed as well as it did. But with ground effects limiting roll and pitch control close to the ground, the less-than-adequate thrust due to turbulence between the rotors, and the tendency for the center of mass and the center of gravity to get out whack with each other, all made for a joyously unstable and difficult to control aircraft.

Despite the poor performance, [Paweł] has plans for a Mark II dualrotor, a smaller craft with some changes based on what he learned. He’s no slouch at pushing the limits with multirotors, with 3D-printed racing quad frames and using LoRa for control beyond visual range. Still, we’re sure he’d appreciate constructive criticism in the comments, and we wish him luck with the next one.

Continue reading “Fail Of The Week: Two Rotors Are Not Better Than Four” →

Watching The Watchers: Are You The Star Of An Encrypted Drone Video Stream?

January 15, 2018 by Roger Cheng 40 Comments

Small aircraft with streaming video cameras are now widely available, for better or worse. Making eyes in the sky so accessible has resulted in interesting footage that would have been prohibitively expensive to capture a few years ago, but this new creative frontier also has a dark side when used to violate privacy. Those who are covering their tracks by encrypting their video transmission should know researchers at Ben-Gurion University of the Negev demonstrated such protection can be breached.

The BGU team proved that a side-channel analysis can be done against behavior common to video compression algorithms, as certain changes in video input would result in detectable bitrate changes to the output stream. By controlling a target’s visual appearance to trigger these changes, a correlating change in bandwidth consumption would reveal the target’s presence in an encrypted video stream.

Continue reading “Watching The Watchers: Are You The Star Of An Encrypted Drone Video Stream?” →

The Zombie Rises Again: Drone Registration Is Back

December 14, 2017 by Jenny List 69 Comments

It’s a trope of horror movies that demonic foes always return. No sooner has the bad guy been dissolved in a withering hail of holy water in the denoeument of the first movie, than some foolish child in a white dress at the start of the next is queuing up to re-animate it with a careless drop of blood or something. If parents in later installments of popular movie franchises would only keep an eye on their darn kids, it would save everybody a whole lot of time!

The relevant passage can be found in section 1092(d) of the National Defense Authorization Act, on page 329 of the mammoth PDF containing the full text, and reads as follows:

(d) RESTORATION OF RULES FOR REGISTRATION AND MARKING OF UNMANNED AIRCRAFT
.—The rules adopted by the Administrator
of the Federal Aviation Administration in the matter of registration
and marking requirements for small unmanned aircraft (FAA-2015-
7396; published on December 16, 2015) that were vacated by the
United States Court of Appeals for the District of Columbia Circuit
in Taylor v. Huerta (No. 15-1495; decided on May 19, 2017) shall
be restored to effect on the date of enactment of this Act.

This appears to reverse the earlier decision of the court, but does not specify whether there has been any modification to the requirements to prevent their being struck down once more by the same angle of attack. In particular, it doesn’t change any of the language in the FAA Modernization Act of 2012, which specifically prevents the Agency from regulating hobby model aircraft, and was the basis of Taylor v. Huerta. Maybe they are just hoping that hobby flyers get fatigued?

We took a look at the registration system before it was struck down, and found its rules to be unusually simple to understand when compared to other aviation rulings, even if it seemed to have little basis in empirical evidence. It bears a resemblance to similar measures in other parts of the world, with its 250 g weight limit for unregistered machines. It will be interesting both from a legal standpoint to see whether any fresh challenges to this zombie law emerge in the courts, and from a technical standpoint to see what advances emerge from Shenzhen as the manufacturers pour all their expertise into a 250 g class of aircraft.

Thanks [ArduinoEnigma] for the tip.

The British Drone Law Reaches Parliament

December 5, 2017 by Jenny List 52 Comments

We’ve brought you a variety of stories over the years covering the interface between multirotor fliers and the law, and looked at the credibility gap between some official incident reports and the capabilities of real drones. In the news this week is a proposed new law in front of the British House of Commons that would bring in a licensing scheme for machines weighing over 250 g, as well as new powers to seize drones. We’ve previously told you about the consultation that led up to it, and its original announcement.

As a British voter with some interest in the matter, I decided to write to my Member of Parliament about it, and since my letter says what I would have written to cover the story anyway it stands below in lieu of the normal Hackaday article format. If you are a British multirotor flier this is an issue you need to be aware of, and if you have any concerns you should consider raising them with your MP as well. Continue reading “The British Drone Law Reaches Parliament” →

Where Can You Fly? Worldwide Drone Laws Mapped

September 26, 2017 by Jenny List 10 Comments

If you are a flier of a multirotor, or drone, you should be painfully aware of the regulations surrounding them wherever you live, as well as the misinformation and sometime bizarre levels of hysteria from uninformed people over their use.

Should you travel with your drone, you will also probably be resigned to being interrogated by airport staff high on The War On Terror security theatre, and you’ll probably not find it surprising that they have little idea of the laws and regulations over which they have pulled you aside. It’s a confusing situation, and it’s one that [Anil Polat] has addressed by collating information about drone laws worldwide, and presenting his results on a Google map.

To do this must have been a huge undertaking, particularly since he got in touch with the appropriate authorities to access the information from the horse’s mouth. Looking at the map, we can almost view the green, yellow, and red pins showing different levels of restriction on flight as a fascinating indication of differing levels of security paranoia worldwide. If your territory has an orange or red pin, our commiseration.

This is a useful resource for anyone with an interest in multirotor flying, and he has also made it available as an app. However, it is always safest to check with the authorities concerned before flying in another territory, in case any laws have changed.

Here at Hackaday we’ve held an interest in the interface between multirotor fliers, governments, and the general public for a while now. In 2015 we took a look at FAA regulations for example, and last year we examined the inaccuracies in British air incident reports.

Via Adafruit.

UK To Register Multirotor Fliers

July 22, 2017 by Jenny List 34 Comments

The British government has shown a surprisingly light touch towards drone fliers in the face of the strident media demands for them to be banned following a series of reports of near-misses with other aircraft. That is about to change with reports of the announcement of a registration scheme for craft weighing over 250 g (about 9 oz). Details are still a bit sketchy, but it is reported that there will be a written test and an element of geofencing around sensitive locations.

Our friendly professional multirotor flier’s reaction is that the existing laws are clear enough, and that this is likely to be no deterrent to any people who already use their drones illegally. It seems that the UK government is following the lead set by the USA in this matter, with the 250 g limit on that side of the Atlantic having already spawned an industry of smaller craft. Time will tell on whether the measures will be effective, we suspect that their success will depend on their not being overly stringent.

[Editor’s note: Following a lawsuit, the US FAA registration requirement was struck down for hobbyists because model aircraft are explicitly excluded from the FAA’s purview. The Brits are not likely to be so lucky.]

If there is a positive side to this announcement, it might be that the 250 g class of multirotor will inevitably become the focus of a lot of attention as manufacturers and engineers work to pack the most performance into the small platform. This small silver lining to the drone registration cloud might not be much, but we’ll take it.

We’ve covered the UK drone story as reported in the media in detail in the past.

Palace of Westminster image: Diliff [CC BY-SA 2.5].

London Gatwick Airport Closes Runway In Alleged Drone Strike

July 4, 2017 by Jenny List 118 Comments

London is one of those cities with an identity problem when it comes to airports. There is no one London airport, instead a group of airports serve the city at various distances from it. London Gatwick is the second largest of these, and sits with its single runway in the Sussex countryside about 30 miles south of the city.

If you follow British news sources, you may have heard a little about Gatwick in the last couple of days. Its runway was closed for two short periods and a selection of flights were diverted, because of what is being reported as a drone sighting. This is an extremely serious matter, responsible multirotor owners will be painfully aware of the distance and altitude regulations surrounding flights near airports.

An oft-shared drone identification guide for airline pilots, of uncertain provenance. — An oft-shared drone identification guide for airline pilots, of uncertain provenance (phantompilots.com).

If you are familiar with the way that drone stories are reported by the mass media, you will probably not need to click on the link above to the BBC reporting to find out its tone. There is significant concern within the multirotor community that it presents a very one-sided view, and takes at face value the assertion that the sighting was a drone, when in fact there is no proof at all of that being the case. For those of us who have seen many such stories come and go it is difficult not to agree with the drone pilots, there is at best some lazy reporting in the air, and at worst some outright journalistic irresponsibility.

As Hackaday readers, you are used to writers with an in-depth knowledge of the subjects upon which they write. We don’t know all possible facets of technology and we occasionally get things wrong, but we all have very strong backgrounds in the tech, hacker, and maker industries and communities we write about. We have engineering education, we’ve worked in a wide variety of technology industries, we build our own stuff for fun, and we’ve founded and run hackspaces.

By comparison the journalists whose work you will read in the mainstream media are generalists. They will have a specific educational background and a particular set of interests, but in their work they cover whatever stories tumble off the endless conveyor belt of events. Thus when a drone story appears, they find themselves out of their normal comfort zone of politics or local news, and can not rely on their experience to inform their coverage of it. The responsible journalistic approach is to do a little research and ask the pertinent questions asking for concrete proof of drone involvement. We’re still waiting for that to happen in these allege drone encounters.

Multirotor building and flying is a significant feature of our community, and anything that brings the attention of law enforcement to the kind of work we do should be a worry to us all. Multirotors are not the only things covered by Hackaday that could be misrepresented in the same way. We’ve visited this topic before, take a look at our analysis of a series of air proximity reports blamed on drones. Some of them, you couldn’t make up.

Gatwick airport image: Andre Wadman [GFDL 1.2].