1.   As your car enters the garage, an ultrasonic sensor activates a green light.

2.   In its base is a crescent-shaped array of ultrasonic sensors that scan the area ahead.

3.   The robot uses ultrasonic sensors to avoid any stationary or moving objects that might be in its way.

4.   The self-righting mines will detect the distance to their neighbors using ultrasonic sensors and communicate with each other by radio.

5.   This little robot grabs the outsides of storage tank walls with its four suction-cup feet and uses cameras and ultrasonic sensors to inspect welds and detect cracks.

6.   Ultrasonic sensors, which emit high-frequency sound waves, are one technology under consideration.

7.   At the base of the unit, an array of ultrasonic sensors and a small onboard computer are mounted on a two-wheeled steering axle.