Ultrasonic Sensors in Self-Driving Cars

The ultrasonic sensors send out short ultrasonic impulses which are reflected by obstacles. The echo signals are then received and processed. Within the plastic case of an ultrasonic sensor is themain components, the ultrasonic transducer. It consists of an aluminum pot with diaphragm containing a piezoceramic element). The sensor receives a digital transmit signal from the ECU. This causes the aluminum diaphragm to oscillate with square waves for about 300µsec with resonant frequency of about 48 kHz which results in emission of ultrasonic pulses. The diaphragm then relaxes for about 900µsec (during which no reception is possible) receives the reflected sound from an obstacle and vibrates. These vibrations are outputted by the piezoceramic element as analog signals, it’s then amplified and converted to a digital signal. <a href="https://medium.com/@BabakShah/ultrasonic-sensors-in-self-driving-cars-d28b63be676f">Learn More</a>