What is the working principle of ultrasonic sensors?
2 Answers
Ultrasonic sensors work by using sound waves to perform non-contact and wear-free detection of objects. Relevant details are as follows: Ultrasonic Sensors: An ultrasonic sensor is a device that converts ultrasonic signals into other forms of energy signals (typically electrical signals). Ultrasonic waves are mechanical waves with vibration frequencies higher than 20kHz: Ultrasonic sensors can detect transparent or colored objects, metallic or non-metallic materials, as well as solids, liquids, and powdered substances. Their detection performance is nearly unaffected by any environmental conditions, including smoky or rainy environments.
When I think about ultrasonic sensors, they remind me of a bat's navigation system. Simply put, these devices emit sound waves that are inaudible to the human ear, with frequencies exceeding 20,000 Hz. The sound waves bounce back when they hit an object, and the sensor has a receiver that captures this echo. The controller calculates the distance to the object by measuring the time difference between the emission and return of the sound wave. For example, a short time indicates the object is nearby, while a longer time means it's farther away. I've seen many applications in the automotive field, such as automatic parking or obstacle avoidance systems, which rely on this small component to prevent the car from hitting obstacles. The advantage of ultrasonic sensors is that they aren't affected by lighting conditions, working stably even on rainy nights. However, their drawback is weaker reflection on soft objects, which may lead to inaccurate readings. For maintenance, remember to keep the surface clean, as dirt can affect reception—a detail often overlooked in daily driving. Overall, the principle is easy to remember, and the applications are surprisingly widespread.
