AI builds virtual homes where robots learn from their mistakes

Ask a robot to put a coffee mug in the cabinet, and you quickly see how complicated an ordinary chore can become. You know where the mug belongs. You can step around a chair, avoid the clutter on the counter and open the right cabinet without giving it much thought. A robot has to work through every part of that process.

That helps explain why today's robots can look impressive during a demonstration but still struggle with basic jobs around a home or factory. They need experience in many...