TOKYO — Hitachi’s robot on wheels avoids obstacles, responds to simple voice commands and reads the weather forecast.

But it is very much a work in progress: Reporters invited to a demonstration were warned not to touch the two prototypes for safety’s sake. They also were asked not to use a camera flash at certain angles or to cross a white line on the floor.

The 150-pound, 51-inch-tall robots, nicknamed Pal and Chum, are equipped with digital cameras and radar sensors, allowing them to avoid obstacles with a reaction time of one-tenth of a second.

They don’t have legs but zip around on two wheels at the speed of a slow jog. They appear a bit wobbly but manage to balance themselves and won’t fall, even if nudged gently.

One showed it can raise its arm upon command. It also swiveled in a circle, gave directions to the bathroom and read the weather forecast.

“My name is Pal, which means ‘friend,’ ” the mouthless robot said in Japanese in a soft electronic voice.

The machine, with its thick barrel-like abdomen and bubbly head, was developed for display at the World Exposition, which opens this month in the central Japanese city of Aichi. Hitachi officials hope to rent or sell such robots within six years.

-Yuri Kageyama, AP Business Writer.