Let's go deep into history: where do the legs of quadrocopters grow

Drones, remotely controlled helicopters, spyware and military multicopters - all these flying devices have long been a part of everyday life. Today, you can’t surprise anyone with an electric wingless flying machine. Here it is, hanging in the sky on its little fans, without any wings and only due to electricity!

However, until recently, cars with vertical take-off and electric traction were just an unattainable dream. How did this become possible and why no one has done them before? Who was the first to lift the electric helicopter into the air? Let's see the story of the appearance in our sky of multi-propeller hummers.

Prerequisites for the emergence of electric vertical take-off

Fifteen years ago, in the sky among compact flying devices, only planes and helicopters with internal combustion engines could be observed.

And all over the world, and in the USSR, aircraft were invariably the basis of aircraft modeling. These were cordless, uncontrolled and radio-controlled models. There were only rumors about helicopter models, someone boasted that he had watched such a flight, but they did not believe them, and no one really saw the radio-controlled helicopters in their eyes.

Competition of radio-controlled helicopters of 1982 in the USSR


For aircraft models with aircraft engines operating not on fuel, but on electricity, the situation was better, but for helicopter construction, electric motors for more than one hundred and fifty years, from the very moment of their appearance, were absolutely unsuitable. The helicopters in the 1982 video also have internal combustion engines, and they were all completely home-made.

The helicopter model industry simply did not exist, so everything from which the helicopters were made on video was selected with great difficulty from other models and electrical appliances, it was sawn, machined and glued together manually.

However, time does not stand still, and two things necessary for lifting electric traction gradually appeared. Firstly, small-sized, as well as brushless, or valve, electric motors appeared ( https://ru.wikipedia.org/wiki/Ventilny_engine)

The fact is that before their appearance, no electric motors gave such power that would be sufficient to lift the desired weight with an acceptable dead weight. Therefore, electric motors could be used in cars, trams and the subway, with their help it was possible to shave, grind food and pump water. You could even contrive and add wings to them by placing them on a plane. However, the first electric motors in airplanes certainly lost in the internal combustion engine in all respects. The advent of modern small-sized electric motors was promoted by the invention of heavy-duty magnets. True, not all electric motors of the new generation were originally intended for aviation, now we will talk about it.

Helicopter Fisherman, 2010 ICE Model


And secondly, compact and capacious batteries appeared, which, most likely, significantly contributed to the development of mobile electronics. For example, lithium-polymer and lithium-ion batteries began to be produced, which replaced nickel-cadmium and nickel-metal hydride.

The very first batteries were not light and compact, and it was practically not possible to lift such into the air. At first, they tried to use them in cars, but an internal combustion engine appeared and at that time quickly put an end to the development of electric vehicles. Modern lithium-polymer batteries have allowed to obtain a higher specific capacity.

First pancakes

The first attempts to create commercial electric models were Kalt Whisper and Kyosho EP Concept. The designers of some of the manufacturers of hobby device devices managed to select the weight and other characteristics of the components so that these first helicopters, still on old collector motors, could take off the ground. Kalt Whisper and Kyosho EP Concept started production around 1991. A little later, products of the German company Icarus with the names ECO 8 and ECO 16 (1995) took off. The most advanced was the GWS Dragonfly model, but it also appeared later, in about 1998.

However, the first electric helicopter models had a bunch of insoluble problems. Low-power electric motors did not allow to gain high speed of lifting and moving in the horizontal plane. From old heavy nickel-cadmium batteries with 7-8 "banks" and a low specific capacity it was possible to achieve from 4 to 12 minutes of flight.

Kalt Whisper, 1991 Promotional Video


The main problem was the high cost in stores and the exorbitant price of repairs. Piloting these models at least somehow became possible only after several weeks of hard training.

Since at that time effective stabilization systems were absent in nature, and not all owners were masters of aerobatics, the models crashed every second flight. Hundreds of dollars went into the purchase of repair parts. The Kalt Whisper pilot with the video above is clearly a professional in his field, for that she’s an advertisement. In reality, almost everyone who mentions on the Internet that he owned an electric helicopter at that time writes that he stood there all the time on a shelf or in a garage.

Prototypes of modern models

Proxflyer

The first to combine the achievements of new technologies was the guess of the Norwegian engineer Peter Muren. He created a site describing his first invention in 2003 if Archive.org is not lying. The site was called Proxflyer.com (with such a spelling, through “Y”) and contained photos and videos of flights of an incredible device for that time: a helicopter the size of just a pack of cigarettes, while being controlled remotely.



Archive.org shows the first versions of the site as created in 2003 ( http://web.archive.org/web/20031001000000*/proxflyer.com ).

To make the model fly into the air, Peter used the most stable helicopter flight scheme - coaxial (like the Black Shark KA-50). In his design, he did not use non-existent mini-swash plates and, moreover, gyroscopes, thereby facilitating the model.

Peter Muren Demonstrates World's First Electric Helicopter Model 2004


Drives from electric motors were made on pulleys, and thin belts of the type used in belts for cassette recorders were used as belts. There were no gears in this scheme. One motor twisted both screws, the other turned its tail.

Transmission about Proxflyer, 2004


Do not forget that YouTube was opened only in 2005, so the video was uploaded later.

Peter was able to achieve the desired mass of the device by using new lithium-polymer batteries in his helicopter. To reduce the weight of the blades and parts of the helicopter body were made of balsa wood. As motors, he used those that had just appeared and were initially used in vibrating calls of pagers (who does not know what a pager is, ask your parents) and mobile phones. Such electric motors were called: Pager motor (motor from a pager):



Therefore, the first micromotors were not made at all for vertical take-off.

Later, Peter built other models, where the change in the position of the helicopter in space was carried out by changing the rotation speed of one of the two coaxial screws, and they were driven by separate motors. In total, two were responsible for the rise.



The forward movement was carried out due to the third electric motor, mounted not vertically, as in classical helicopters or as in the first model, but horizontally and lifting the model's tail up.



The engineer managed to find such a combination of miniature and light motors with other weight-reducing parts, which, finally, allowed the model to soar above the table.

After receiving a patent for his invention, Peter began to improve his models, and a little later, Interactive Toy Concepts began to produce toy helicopters according to his scheme.

Newer Proxflyer model, circa 2004.

Pixelito

The second scheme, which is being developed in parallel, was a scheme with a vertical entry of a modeller from Belgium named Alexander. He named his helicopter Pixelito. Alexander used a scheme different from Proxflyer, which had only one main rotor.



The stability of its flight was facilitated by a special device on the screw: for lack of electronic flight stabilizers acceptable in weight, a massive top was placed on the screw, which played the role of a gyroscope controlling the angle of attack of the blades.

On top is a balancer (flybar, Bell / Hiller bar):



No matter how later the designers tried, without this thing helicopters with one screw refused to fly (until electronic stabilizers appeared that controlled the angle of attack of the blades - flybarless helicopter circuits). The first helicopter scheme did not need a balancer, or maybe its function was partially fulfilled by the restrictive ring on the balsa wood blades.

There were also two motors in this model: for the main propeller, which allowed flying up and down, and for the stabilizing propeller, with which it was possible to turn. The model turned out to be incredibly small in size, which can be judged by the photo with the hamster, it is 2003, so sorry for the quality. The model weighed only 6.9 grams.

In 2003, Alexander was almost ready to create a workable model, and found Peter, the creator of Proxflyer. They decided to join forces, and thus brought their models to working prototypes.



A record dated December 15, 2003 states:

“Today, Peter and I are pleased to present the result of our latest joint developments. I created a Pixelito helicopter, and Peter created a Proxflyer Micron (at that time it was already not the first Norwegian model - my note). The Pixelito is a helicopter with my own rotor control system, and Peter's design is already pretty well known. We call them robots, because such a name describes them best. About 2 weeks ago, Peter and I spent a wonderful weekend at my place and after that decided that it would be nice to conduct joint research, each at home, but moving towards a common goal. This resulted in the creation of a model weighing only 6.9 grams together with the battery, and we both know that this is not the limit.

Alexander and Peter »

Video of the newly created Pixelito mini-helicopter, but in the video it is controlled by a friend of its creator, author Proxflyer Peter Muren. You can guess that Alexander is holding a camera.

Pixelito 2003


The third prototype could be the sensational at the same time development of the Japanese company Seiko Epson. The model could only fly up and down.



Unfortunately, after the very first news about this coaxial flying miracle device, information about it disappeared, only an article with a description remained: https://www.ixbt.com/news/hard/index.shtml?02/35/48 .

Apparently, the development failed and did not receive further development, in addition, there were no videos demonstrating his work. The photo shows that a circuit was used in it, in which the coaxial screws were combined with the balancer.

Electric Helicopter Development

With the advent of flying prototypes, other toy manufacturers also picked up the idea, and using new engines, batteries and choosing a more modern and lightweight plastic, they began to produce helicopter models one after the other, first according to the Norwegian scheme, and then, similar to Pixelito, in my opinion , the first production models were called Pixelito.

A helicopter is one of the first models according to a scheme similar to Proxflyer, Syma, 2007


Also one of the first models of the English company Fastek Computers, 2007


At first, the helicopters were mostly coaxial. One of the most prolific manufacturers of toy radio-controlled helicopters at that time was the Chinese company Syma. Aircraft modelers from all countries have also tried with all their might different versions of building models with vertical take-off, and some of their achievements were quite outstanding, but what most quickly reached the final consumer was the products of toy manufacturers.

One of the first Pixelito models, 2-channel, only with a balancer, 2008


As a result, both Norwegian and Belgian modelers made good money by selling the rights to manufacture remote-controlled helicopters made according to their schemes.

Subsequently, DARPA and the Norwegian Ministry of Defense became interested in the development of Peter, the engineer created his own company Prox Dynamics and began to develop a spy helicopter for military purposes.



What is happening there and at what stage is production is unknown.

Improvements and improved flight stabilization

While the first toy helicopters had only 2 control channels (forward-up and turn only one way), amateurs made models for themselves on multi-channel radio control. To control the very first models of remotely controlled helicopters, a rather long training was required, since it was quite difficult to keep it in the air, and a lot depended on the pilot's skill.

For the simplest toy helicopters, instead of radio control, infrared radiation control was used. In more advanced models - over the air. In cheap models, it was two-channel, the more expensive, the more control channels there were.

In the cheapest models, a third channel was added to replace the two-channel control, and the control became more like a full-fledged flight. Just keep in the air, despite the many channels, it was still not easy.

Please note how difficult it is for the pilot to cope with holding the model in place:

One of the first helicopter models, a scheme like Pixelito, 2007.


The advent of miniature gyroscopes has greatly improved this situation. After adding this device to the model, the flight became directly unusually stable, it was not necessary to constantly keep your fingers on the control keys. However, such models cost much more than helicopters without a gyroscope. Gyroscopes have also been used in helicopter models with internal combustion engines.

Video about helicopter models with gyroscopes, 2011


The most popular of the models with a gyroscope for the mass buyer was the Syma S107 model, but the most reliable helicopter helicopters, probably withstanding direct collisions with walls, cat teeth and endless furniture rams.

After its appearance, new stabilization devices began to be put on the very first models of electric helicopters. Kalt Whisper, Kyosho EP Concept, Icarus ECO 8 and 16 and GWS Dragonfly upgrade kits appeared in stores. On the very same helicopters, after installing a gyroscope, lithium-polymer batteries and light and powerful brushless motors, it became possible not only to fly normally, but even to do aerobatics. However, again, their value was exorbitant. Somewhere before 2006, they were also not available to everyone, and almost no one bought them.

Demonstration of the capabilities of an electric helicopter with a gyroscope, 2014. Can your quadrocopter do that?


In the military field, the first test of shots from a radio-controlled helicopter began to be carried out by a certain company Neural Robotics (again, mind you, attributing flying models controlled remotely to robots) in 2006. They hung a shotgun on a helicopter model and began to study its behavior during shots, as well as how the shooting affects control.

Shotgun Shot, 2006


Their helicopter possessed ICE, and this experience became significant - it pushed the development of the direction of shock drones. Now military multicopters are dropping bombs in full, spying and directing missiles at targets.

If in doubt - put more propellers!

Almost immediately after the appearance of helicopter models, attempts began to create multi-propeller, so to speak, machines.



The more propellers were in the model, the more difficult it was to coordinate their work. The same Chinook helicopter from the picture above, without a gyroscope, was sausage during the flight so that it became doubtful to use two pairs of screws. For the flight of models with three or more engines, electronics was required, an order of magnitude more complicated than a helicopter.

At first they began to experiment with the number of electric motors. This is now almost always put an equal sign between the drone and the quadrocopter, but at the dawn of their appearance it was not at all like that.

Initially, multi-engine models were assembled exclusively by enthusiasts. Almost immediately, the idea came up to put compact cameras on the model, which were not numerous at that time, and GoPro appeared later, and successfully fit into the trend. The cameras were assembled from soldered controllers to cameras from mobile phones and so on. Multicopter designers selected materials for their frames, experimented with different electric motors, began to solder various modules for coordinated control of propellers, write software for this and exchange successful finds with each other. It turned out with varying success.

While there was no reliable electronics for matching motors and miniature gyroscopes did not appear, it was scary to look at the flights of such devices. There were broken frames, and lost video cameras, and expensive electronic modules drowned in ponds. However, from year to year, stability, flight range, ease of management and the quality of the videos shot were constantly increasing.

Copters appeared with two, three, four, five, six, eight and more propellers - bicopters, tricopters, quadro-, penta-, hexa- and octacopters, respectively.

One of the first tricopter, 2010


And now, after long experiments, the models began to fly stably. You could not be afraid that she would fall sideways in the air or that vibration during flight would interfere with control.

Bikopter



At first, everyone set themselves as many propellers as they wanted, but later, each scheme, nevertheless, found its application.

Span of a quadrocopter with a GoPro Hero 3 camera on board through fireworks, better viewed in HD, 2014


Machines with three and four engines have become more often used for recreational flights, for shooting videos, and the increased number of propellers was useful in copters for transporting goods, as well as in those cases where reliability is required from a multicopter. After all, if one of the engines in the helicopter model fails, its crash inevitably occurs, then in the case of models with several engines, the load of the failed motor can be distributed to others and the machine can be kept in the air. For a long time, disputes between adherents of tricopters and quadrocopters over the balance between simplicity and stability of flight have not subsided.

Oktakopter, specially designed for the transport of goods, 2012

Further development and prospects

Thanks to the improvement of on-board electronics and the use of GPS modules, the models have learned to maintain their position in space and a constant height. The multicopter began to set telecontrol, which in English is called FPV - First Person View, a first-person view. With it, you can control the drone, stroking the world through a camera mounted on it. On the Web, almost all videos are now removed from such drones.

Multicopter races are being held, which is facilitated by a first-person control system.

FPV-controlled drones, 2015


Later, one company at some technological institute began to develop a system of automatic control of not just one, but many multicopter and achieved impressive results: they not only were able to make a swarm of electrical devices fly along predetermined paths without colliding. Adding illumination to them and using a separate multicopter as a pixel, they were able to compose volumetric images and inscriptions from them. They first applied their invention in an advertisement by Intel.

Hologram from Drones, 2015


Already in 2011, a prototype multicopter was built, capable of lifting a person above the ground. Now this direction is actively developing. After all, for transporting people there are advantages over helicopters. This is the convenience of management, and more compact sizes, and electricity as a fuel, and safety due to the presence of several propellers instead of one or two.

The first multicopter with a man on board, 2011


The device of drones continues to improve, for them there are more and more areas of application. Multicopters are improved by many aircraft manufacturers, including Boeing. Why is there Boeing - the Russian Post itself is already experimenting with delivery of goods by air.

Flying in a quadrocopter with a first-person view from which is breathtaking, 2017.


Perhaps soon we will be waiting for air taxi, huge spatial three-dimensional sculptures from drones at any big celebration, delivery of parcels and correspondence, regardless of where you are, and pizza in just three minutes!