In the modern sensor technology system, ultrasonic sensors, with their unique technical characteristics, have become a key support for the automation upgrade in fields such as industry, healthcare, and security. Its core advantages lie in non-contact measurement, high-precision feedback and wide applicability. The following is an analysis from four dimensions: principle, core functions, application scenarios and representative enterprises in the industry.

I. Core Working Principle of Ultrasonic Sensors

The operation logic of ultrasonic sensors is based on the reflection characteristics of ultrasonic waves. The overall process can be divided into four steps: "emission - reflection - reception - calculation", as detailed below:

Signal transmission: When the piezoelectric wafer (core transducer) inside the sensor is powered on, it generates mechanical vibration and emits ultrasonic waves with frequencies higher than 20kHz (imperceptible to the human ear). These sound waves have the characteristics of strong directionality and short wavelength, and can propagate along a specific path.

Signal reflection: When ultrasonic waves encounter the object being measured (whether solid, liquid or powdery), reflection occurs to form an "echo". The intensity of the echo is related to the material and surface flatness of the object.

Signal reception: The piezoelectric wafer of the sensor works again, converting the received reflected echo into an electrical signal.

Data calculation By analyzing the propagation time of electrical signals (the round-trip time of ultrasonic waves from emission to reception) and intensity, and combining the propagation speed of ultrasonic waves in the medium (such as about 340m/s in air), key parameters such as the distance, position, speed or thickness of the object can be calculated. This is similar to the working logic of a "micro-sonar system", but it is smaller in size and more flexible in adapting to various scenarios.

Ii. Four Core Functions of Ultrasonic Sensors

Non-contact measurement: It does not require direct contact with the object being measured, which can avoid the wear on the object's surface caused by traditional contact measurement (such as metal workpiece inspection), and also prevent contamination of the object during the measurement process (such as material inspection in the food and pharmaceutical industries).

High-precision data feedback: Relying on the precise calculation of the round-trip time of ultrasonic waves (accurate to the microsecond level), millimeter-level distance measurement can be achieved. In scenarios such as liquid level monitoring and workpiece thickness detection, the error can be controlled within an extremely small range.

Full-scene material compatibility: It is not restricted by the color, transparency or material of objects. Whether it is transparent glass, metal parts, liquid media or powdery materials (such as flour, cement), it can stably detect them, solving the problem that optical sensors fail to detect transparent/dark objects.

Real-time response: The delay from signal transmission to data output is extremely short (usually in the millisecond range), enabling rapid feedback of measurement results. This meets the demands of scenarios with high real-time requirements such as automated production lines and robot navigation, providing timely data support for dynamic control.

Iii. Diverse Application Scenarios of Ultrasonic Sensors

(1) Industrial sector: Empowering production automation and safety monitoring

Non-destructive testing: It is used for internal flaw detection of metal pipes, pressure vessels and other equipment. It detects cracks, pores and other defects inside materials through the penetrating power of ultrasonic waves, avoiding safety accidents caused by structural problems during equipment operation.

Liquid level monitoring: In chemical storage tanks and oil storage tanks, the height changes of the liquid are monitored in real time. When the liquid level exceeds the safe range, an automatic warning is issued to prevent leakage or overflow and ensure production safety.

Automation control: In automotive parts production lines and electronic component assembly lines, it is used for material positioning (such as confirming whether parts are in place), counting (counting the number of products on the conveyor belt), and sorting (screening out substandard products), thereby enhancing production efficiency and accuracy.

(2) Medical field: Facilitating diagnosis and treatment

Ultrasound diagnosis: It is one of the core technologies in medical imaging diagnosis. For instance, B-ultrasound scans internal organs of the human body (such as the liver, uterus, and heart) with ultrasound waves to generate real-time images, which help doctors determine whether there are any lesions in the organs (such as tumors and stones). Color Doppler ultrasound can further display blood flow conditions and assist in the diagnosis of cardiovascular diseases.

Therapeutic assistance: In the ultrasonic therapy device, the sensor generates ultrasonic energy of a specific frequency, which acts on the lesion area (such as joint inflammation, muscle strain). Through thermal and mechanical effects, it relieves pain and promotes tissue repair, providing technical support for physical therapy.

(3) Security and transportation fields: Strengthen security protection

Intrusion detection: In enclosed areas such as residential communities, factory fences, and substations, ultrasonic sensors form an "invisible monitoring network". When someone or an object illegally enters the monitoring range, the sensor triggers an alarm to promptly alert security personnel.

Vehicle anti-collision: In autonomous driving and assisted driving systems, it works in coordination with radar and cameras to detect obstacles around the vehicle (such as pedestrians, other vehicles, and roadside guardrails). When the distance is too close, it triggers an anti-collision warning and even assists in controlling braking to reduce the risk of traffic accidents.

(4) Other fields: Expand application boundaries

Environmental monitoring: In the field of environmental protection, it is used for water quality monitoring (judging the degree of water pollution through the speed of ultrasonic wave propagation) and air quality monitoring (detecting the concentration of particulate matter in the air), providing data references for environmental governance.

Robot navigation: In service robots (such as restaurant delivery robots) and industrial inspection robots, sensors detect obstacles ahead in real time, assisting the robots in planning their movement paths and avoiding obstacles, ensuring their stable operation in complex environments.