Transportation Hacks

1499 Articles

An Android Phone Powers A Self Driving Car

June 27, 2023 by 31 Comments

As auto manufacturers have brought self-driving features to their products, we’re told about how impressive their technologies are and just how much computing power is on board to make it happen. Thus it surprised us (and it might also surprise you too) that some level of self-driving can be performed by an Android phone. [Mankaran Singh] has the full details.

It starts with the realization that a modern smartphone contains the necessary sensors to  perform basic self-driving, and then moves on to making a version of openpilot that can run on more than the few supported phones. It’s not the driver-less car of science fiction but one which performs what we think is SAE level 2 self driving, which is cruise control, lane centering, and collision warning. They take it out on the road in a little Suzuki on a busy Indian dual carriageway in the rain, and while we perhaps place more trust in meat-based driving, it does seem to perform fairly well

Self driving features are codified into a set of levels for an easy reference on what each is capable of doing. We’ve taken a look at it in the past, should you be interested.

Flying Submarine Documentary Is A Story Of Defied Assumptions

June 25, 2023 by 39 Comments

Donald Reid had a passion for applying himself to challenging problems, and in many ways his life’s work was that of developing a prototype submersible aircraft — or flying submarine — for which his son Bruce was a test pilot. [Jesse Moody] brought to our attention a fantastic documentary he created (with a short teaser trailer here) in which he interviews Bruce, and in the process teaches us all about a story that spanned decades and formed an important part of aviation history. Bruce experienced his share of hair-raising moments while testing the craft, but still has all of his fingers and limbs. Still, in his own words, “you wouldn’t be doing that kind of testing today!”

In many ways, the story revolves around defying assumptions. Without context, a “flying submarine” project might sound like a lone kook’s obsession, but Donald Reid was nothing of the sort. He was a brilliant engineer who was able solve problems by applying his skill and intellect with a laser-like focus. And it turns out that getting a submerged vehicle to successfully transition from waterbound craft to airborne is a source of numerous and novel problems that were not trivial to solve. In fact, these problems needed to be solved in order to develop the Tomahawk cruise missile, which is launched by submarine. And that brings us to the lawsuit that bookended it all.

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Will The Lilium Jet Work? A Deep-Dive Into The Physics Behind EVTOL Aircraft

June 22, 2023 by 26 Comments

The Lilium Jet is a proposed eVTOL (electric Vertical Take Off and Landing) aircraft that the German company Lilium GmbH has claimed it will bring to the market ‘soon’, which would made it the first eVTOL aircraft in the world to enter into commercial service. As anyone who has any experience with VTOL knows, it’s a tricky subject to engineer, let alone when you want to do it fully electric. In a deep-dive video on the Lilium Jet and eVTOL in general, [John Lou] goes through the physics behind VTOL take-off, landing and flight, as well as range and general performance.

It is clear that Lilium’s presented aircraft concept has many issues, some of which are due to new and unproven technologies, while others seem to be founded in over-promising and likely under-delivering. With Lilium having signed a number of contracts to deliver the first Pioneer Edition Lilium Jets and commercial service promised by 2025, it’s hard to ignore that the first full prototype of the 7-seater Lilium Jet is supposed to fly this year.

Although as [John] points out in the video, eVTOL is not an impossible concept, it is important to remain realistic about what is physically possible, and not seek to push the boundaries. When the UK introduced its first mass-produced VTOL jet in the form of the Harrier, it too faced an uncomfortable time as bugs got ironed out. As these eVTOL aircraft would be carrying real human passengers, it’s a good place to realize that although you can pick a fight with physics, you will never come out on the winning side.

Hopefully Lilium realizes this too, and these sleek, battery-powered aircraft will truly take to the skies in a few years.

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Is This The World’s Largest Dot Matrix Printer?

June 22, 2023 by 27 Comments

[RyderCalmDown] was watching a road painting vehicle lay down fresh stripes on the road one day and started thinking about the mechanism that lets it paint stripes in such a precise way. Effectively the system that paints the interspersed lines acts as a dot matrix printer that can only print at a single frequency. With enough of these systems on the same vehicle, and a little bit more fine control of when the solenoids activate and deactivate, [RyderCalmDown] decided to build this device on the back of his truck which can paint words on a roadway as he drives by. (Video, embedded below.)

Of course, he’s not using actual paint for this one; that might be prohibitively expensive and likely violate a few laws. Instead he’s using a water-based system which only leaves temporary lettering on the pavement. To accomplish this he’s rigged up a series of solenoids attached to a hitch-mounted cargo rack. A pump delivers water to each of the solenoids, and a series of relays wired to a Raspberry Pi controls the precise timing needed to make sure the device can print readable letters in much the same way a dot matrix printer works. There’s an algorithm running that converts the inputted text to the pattern needed for the dot matrix, and after a little bit of troubleshooting it’s ready for print.

Even though the printer works fairly well, [RyderCalmDown] had a problem thinking of things to write out on the roadways using this system, but it’s an impressive build based around a unique idea nonetheless. Dot matrix printers, despite being mostly obsolete, have a somewhat vintage aesthetic that plenty of people still find desirable and recreate them in plenty of other ways as well, like this 3D printer that was modified to produce dot matrix artwork.

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How To Land A Model Rocket Vertically

June 21, 2023 by 20 Comments

Perhaps most readers will remember when they saw the first SpaceX demonstration of a rocket stage landing vertically on the pad under control. It’s something of a shock to be reminded that their first suborbital demonstration “hops” were around a decade ago, and how quickly what was once so special has become commonplace. We’re now in the era of the more complex model rockets having the same capability, with [BPS.space] managing it last year, and now [TTS Aerospace] sharing a video showing how they achieved the same feat.

The basics of the system revolve around a directed rocket nozzle, but to make it work is a lot more complex than simply hooking up a flight controller and calling it good. The steps in arriving at a landable rocket are examined, with plenty of failures shown along the way. Even the legs are more complex than they might appear, having to combine lightness, ease of unfurling under the power of elastic, and enough strength and give to survive a rough landing.

Those of us from countries where model rocketry is a highly licensed activity can only look on in envy at these projects, and we look forward to seeing where this avenue leads next. We covered the [BPS.space] rocket last year, should you be interested.

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A Ride-On Picnic Table For Those Idylic Summer Evenings

June 12, 2023 by 12 Comments

For most outsiders the Netherlands is a country of picturesque cities, windmills, tulips, and maybe those famous coffee shops. Head away from the coast though and you enter the country’s rural hinterland, farming country with lush green fields, dairy cattle, and farm lads doing what they do best, which is hacking old machinery to do crazy things under those wide skies. [Plodno] are based on a farm somewhere in the eastern Netherlands, and the latest of these lads’ creations is a motorised picnic table (Dutch language, you’ll need YouTube translated subtitles).

This is farm hacking at its best, with a scrap FIAT hatchback donating its running gear to a welded tubular frame, with a chain drive to a small single-cylinder engine. There’s no suspension save for the air in the tyres, the steering column is vertical, and the brake is a single inboard disk on the rear axle. Perhaps it’s fortunate that the intended beating heart, a Kawasaki motorycle engine, was misfiring, as it would have been truly lethal with that much power. We’re not too convinced at the legality of taking such a contraption on the public road in the Netherlands, but they seem to get away with it. Take a look at the build in the video below the break.

Here at Hackaday we like a good hacky farm build, even though sometimes they’re not so well-assembled.

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High Voltage Ion Engines Take Trip On The High Seas

June 12, 2023 by 21 Comments

Over the last several months, we’ve been enjoying a front-row seat as [Jay Bowles] of Plasma Channel has been developing and perfecting his design for a high voltage multi-stage ionic thruster. With each installment, the unit has become smaller, lighter, and more powerful. Which is important, as the ultimate goal is to power an RC aircraft with them.

There’s still plenty of work to be done before [Jay] will be able to take his creation skyward, but he’s making all the right moves. As a step towards his goal, he recently teamed up with [RcTestFlight] to attach a pair of his thrusters — which have again been further tweaked and refined since we last saw them — to a custom catamaran hull. The result is a futuristic craft that skims across the water with no moving parts and no noise…if you don’t count the occasional stray arc from the 40,000 volts screaming through its experimental thrusters, anyway. Continue reading “High Voltage Ion Engines Take Trip On The High Seas” →