Hitachi unveiled the "Emiew", its first humanoid robot, on Tuesday, saying it was the world's quickest-moving robot yet.

"We aimed to create a robot that could live and coexist with people," Toshihiko Horiuchi, project leader at Hitachi's Mechanical Engineering Research Laboratory Robotics Technology Project, told a news conference.

"We want to make the robots useful for people ... If the robots moved slower than people, users would be frustrated," he said, explaining why Hitachi bucked the industry trend and went for wheels instead of feet for its 130 cm-tall (4.22 ft) robot.

Hitachi built the two Emiews -- Pal and Chum -- for the World Expo, which will take place beginning later this month in Aichi prefecture, about 330 km (205 miles) west of Tokyo.

Emiew, which stands for "excellent mobility and interactive existence as workmate,"can run as fast as 6 km/h (3.7 mph), compared with Honda Motor Co.'s celebrated Asimo, whose top speed is a pokey 3 km/h.

At their debut on Tuesday, Pal moved forward on Chum's command and avoided obstacles using sensors on his head, around his waist, and near his wheels.

"I want to be able to walk about in places like Shinjuku and Shibuya in the future without bumping into people and cars," Pal told amused reporters, citing two of Tokyo's most crowded shopping areas.