Figure 2. Pulsed time-of-flight (TOF) measurement principle
We can regulate an autonomous vehicle’s braking system with ultrasonic sensors to avoid accidents. Ultrasonic sensors can help autonomous vehicles brake when they encounter obstacles. It goes like this: Ultrasonic sensors face outward on the car’s front and back. Sensors emit high-frequency sound waves and listen for echoes from nearby objects. Sound waves’ travel time and return time define a sensor’s distance from an object. The car’s autonomous driving system can brake to slow or stop if an obstruction is within a certain range. We try to prevent tragic accidents with supersonic. Our major goal is to compute car-obstacle distances. See figure 3. Used HC-SR04 modules have a 50-cm range. The sensor has an ultrasonic transmitter, receiver, and management circuit. It has four pins: 5v VCC, input trigger pulse, output feedback pulse, and ground. Ultrasonic sensor electrical parameters: It operates at 5 V DC and 40 kHz. It requests the 10us TTL pulse indication. Simply said, ultrasonic sensors use piezoelectricity. After a 10 us rapid pulse, the module sends an audio beam of eight ultrasonic cycles at 40 kHz. The receiver and microcontroller will analyse the reflected wave (echo) after an impediment is detected. The microcontroller will warn the driver if the distance exceeds the limit. The period is the next trigger pulse transmitted once the received echo is minimised. No less than 50 milliseconds for HC-SR04 cycle time. [11].