TOKYO -- Flying cars have long been the stuff of science fiction, but the day may be approaching when anyone can take to the skies in their own vehicle. An engineering group backed by major automakers has taken on the challenge of creating an affordable flying car, with the goal of making a grand entrance at the opening ceremony of the Tokyo Olympic Games in 2020.

When Los Angeles hosted the games back in 1984, the opening ceremony saw a "rocket man" descend into the stadium from the sky, powered by a small jet-propulsion pack strapped to his back. Cost and safety concerns meant the personal jet system never caught on, but at the time the venue bubbled with excitement and spectators briefly embraced the dream.

Researchers now have a different dream in mind for the 2020 games, said Tsubasa Nakamura, an engineer at a major automaker. Cartivator, an automobile engineering group led by Nakamura, is moving forward with development of the SkyDrive, a flying car for personal use. The group aims to take the concept to market by the Tokyo Olympics and is targeting the opening ceremony as the ideal setting to showcase the product.

The car is still very much a work in progress, but in June of this year, a scaled-down remote-controlled prototype took to the air in public for the first time at the Infinity Ventures Summit, a high-profile gathering of entrepreneurs and venture capitalists. There, it garnered considerable attention, winning the IVS prize for new businesses.

There have been numerous attempts at making flying cars a reality in the past, particularly in Europe and the U.S. Few make it past the initial development phase, with size and maneuverability proving major stumbling blocks.

Previous attempts have mainly featured design modifications to small airplanes or helicopters. Consequently, the vehicles have been hindered by the need for a large wingspan or propeller, making them unable to take off or land on public roads. In addition, operation was complicated and they required a special license, making them difficult to market to regular consumers.

Cost has been another factor in limiting the viability of flying cars. To build one of the few models that have made it past the drawing board took between 20 million yen and 30 million yen ($167,800 and $251,700).

Unconventional drone

In contrast, Cartivator's SkyDrive will be a single-person vehicle that does not require special licensing. With a price tag envisioned at around 5 million yen, the goal is to create a far more affordable vehicle. If it can be commercialized, Nakamura said it will "be the world's first flying car that can run on public roads and be technologically capable of takeoff and landing."

The SkyDrive is a three-wheeled vehicle with propellers mounted on its four corners. The image it presents is that of a rectangular multicopter or drone that is also equipped with wheels and a cockpit.

The vehicle runs on a single lithium ion battery, and each of the four propellers is powered by an individual motor. The plan is for the vehicle to fly at an altitude of 10-20 meters. Unlike conventional drones, it will not only be able to take off and land vertically, but will reportedly also be capable of a running takeoff, just like an airplane.

The planned speed of the car is around 100-150kph. The planned range is approximately 50km on the ground or around 5km when in flight.

One key feature that researchers are also looking into is a chassis that is controlled by the operator simply shifting their body weight, without the need for a steering wheel. For example, when the person leans forward, the revolution speed of the front two propellers would drop so that the vehicle tilts and moves forward.

According to Nakamura's vision, the SkyDrive could start out as an emergency vehicle. "Even if the roads are congested, it could fly and swiftly arrive at the patient's location," he says. Moreover, it could also be used over terrain where driving a regular car is impossible. If so, it could even be used to travel in places where traffic infrastructure is incomplete, leading Nakamura to speculate that the vehicle may completely "change the layout of cities" by reshaping the need for infrastructure.

Nakamura, 31, admits to being a big car aficionado. After completing his studies at Keio University's Graduate School of Science and Technology, he began working as an engineer at a major automaker. However, what he saw there was a serious movement away from automobiles, particularly among young people. One reason he set out to develop the SkyDrive was "to create a dream vehicle that would attract young people."

Three existing technologies provided inspiration -- single-person compact electric automobiles, drones and the Segway, a two-wheeled electric vehicle that is controlled by the driver shifting their body weight.

Young engineers and designers at the automaker where Nakamura worked endorsed the idea, as did people in the sales, procurement and legal departments. The circle widened to include engineers at major autoparts manufacturers and even data management specialists at software companies, eventually leading to the launch of Cartivator in 2012. At present, development is underway with technological assistance from Tokushima University and Nagoya University, among others. "To this point, there has never been the notion of creating a drone that people could ride, but it is sufficiently possible in technical terms," said Masafumi Miwa, an associate professor in Tokushima University's engineering department who has cooperated in chassis design and control technology. "I want to be at the front of the line when manned flight becomes possible."

Lightweight carbon fiber body

A number of hurdles remain before the SkyDrive can be commercialized, with performance in windy conditions and greater control being Nakamura's biggest concerns.

To stop the vehicle losing its balance, more precise control technology is a research priority. The design includes multiple sensors that detect tilt and movement in order for the vehicle to instantly read its position in the air. If an unstable posture is detected, the rotation speed of the propellers is adjusted within thousandths of a second, returning it to stable position.

Safety mechanisms are also vital. It must be able to remain airborne even if a small collision damages one of the propellers, so the team is considering attaching emergency reserve propellers. Another idea is mounting an airbag under the chassis to absorb the impact in the event of a crash.

However, the more components the vehicle is equipped with, the heavier it becomes, making control that much harder in addition to shortening the traveling range. "The SkyDrive's weight must be at most one-tenth that of a normal automobile," Nakamura said. Hence, the plan is to make the body from carbon-fiber reinforced plastic, a much lighter material than steel.

Funds are another issue. Capital needed to develop a manned craft will run into the hundreds of millions of yen. At present, Cartivator is a volunteer organization outside the corporate structure, so procuring large amounts of capital is difficult, leading the team to turn to crowdfunding. In the future, it will be necessary to secure more development money, possibly by accepting support from automakers or procuring capital from investment funds.

Despite the plethora of issues, development moves forward. Last December, flight tests on an actual-size unmanned version were launched in cooperation with Tokushima University. But with the Tokyo Games just five years away, Nakamura faces a battle to get his product off the ground in time.