Robotic security guards have been patrolling the Stanford Shopping Centre in Palo Alto, California, and a number of other locations across Silicon Valley.
The Knightscope robots, which can be leased from the company for $7 per hour, can navigate autonomously using technology similar to that of self-driving cars, and are equipped with a wide array of sensors including HD infra-red cameras, microphones that can listen for warning sounds such as breaking glass, and softwarethat can read up to 300 car licence plates per minute.