Active Ultrasonic Sensors

By means of a digital signal, the ultrasonic converters are set by the control module to either a combined sending and reception operation or to a pure reception operation:

• In the combined operation, the converter first sends out a packet of ultrasonic pulses and then receives the echoes which are reflected by an obstruction within its reception range. These echo signals are amplified and compared with a threshold that is programmed specifically to the vehicle.
• In the area of pure reception, the converter receives the pulses that have been emitted by the adjacent converters of the same system.

By the evaluation of these signals in the control module, the location resolution and the physical shape of the obstruction are better recorded.