Japanese engineers have unveiled a robot that transforms into a car that can actually carry people on board, in what they said was the first such accomplishment in the history of robots.

The 3.7-metre-tall two-seater robot "J-deite RIDE" can transform into a sportscar in a process that takes about a minute.

It can technically walk at a speed of 100 metres per hour or drive on its four wheels.

But developers said they have never really tested it outside the factory cargo bay area.

'J-deite RIDE' is a prototype that developers hope will inspire others. ( Reuters: Toru Hanai )

Brave Robotics chief executive officer Kenji Ishida, who initiated the co-project with Asratec —an affiliate of the Japanese mobile phone giant SoftBank— said he was motivated by his childhood transformer heroes in anime movies.

"The robots I've seen in animation movies since childhood all had this kind of look and they transform into or combined with each other to become something else with people on board," Mr Ishida said.

"So I grew up believing that robots had to be capable of such things, which became my motivation to develop this robot."

While admitting that it may seem like an expensive toy, Mr Ishida said the robot is an attempt to inspire others and broaden the human imagination.

Developers said they will begin with utilising the technology in the entertainment industry, such as amusement parks and street parades.

Reuters