Emotion-detecting robot cars will face off against eavesdropping flying saucers in the English countryside when scientists, academics and schoolchildren compete later this year to design the next generation of military equipment. The British Ministry of Defense's first ever "Grand Challenge" intends to encourage participants to turn their ideas into prototypes for machines the army can use in urban environments. The six finalists, who each received $600,000 to build such contraptions as a disc-shaped remote-controlled flying robots fitted with heat and motion sensors, were in London last week to display their models.

From Swarm Systems Ltd. comes a set of tiny helicopters that fly in formation into a village and record images and audio tracks to beam back to headquarters. And British aeronautical company BAE Systems teamed up with the University of Manchester to build a self-propelled, remote-controlled camera.

The Silicon Valley Group PLC, a small research company in southeast Britain, teamed with the Bruton School for Girls in Somerset to build an unmanned buggy that can analyze gunmen's movements to determine whether they are angry or nervous.

"This project has really allowed us to broaden out our vision and look at what other work is being done out there in our field," said Norman Gregory, the company's business manager. "We are a small company and would not have been able to put together a consortium to develop such a sophisticated system without this competition."

The government wanted participants to get schools involved, Gregory said, so the company consulted the Bruton School, which already sponsored robot design competitions.

Finalists will take part in a mock battle in August in Copehill Down, a village built near Stonehenge for military training during the Cold War. The contestants will have their machines search for pretend gunmen and mock bombs, earning points for each find and losing points for hitting civilians or transmitting data too slowly.

The contest's winner gets a trophy made from the recycled metal recovered from a WWII fighter jet. The best designs also will get further financial backing from Britain's defense ministry.