In modern industrial and scientific research fields, precise measurement of the displacement of objects is an important link for achieving high-precision control and detection. Laser technology, due to its non-contact, high precision, and high response speed, is widely used in various displacement measurement systems. This article will introduce the working principle, common methods, and applications of laser in displacement testing.
1. Basic principle of laser displacement
measurement
Laser displacement measurement technology is mainly based on the principle of triangulation or interference. Among them, the laser triangulation method is the most common way. Its basic structure includes a laser emitter, the measured object, and a photoelectric detector (such as CCD or PSD). When the laser beam is照射 to the surface of the measured object, the reflected light will project onto the detector to form a light spot. When the object moves, the position of the reflected light spot will also change on the detector. By calculating the relationship between the displacement of the light spot and the actual displacement, the amount of movement of the object can be measured.
Laser interferometry is suitable for higher precision applications, utilizing the coherence of laser light to measure tiny displacements through the interference pattern changes of reference light and measurement light. This method can achieve precision up to the nanometer level and is widely used in precision processing, semiconductor manufacturing, and other fields.
2. Classification of laser displacement sensors
According to the measurement principle and structure, laser displacement sensors can be divided into the following categories:
1. Single-point laser displacement sensor: Suitable for rapid measurement of displacement at a single location, commonly used in industrial automation production lines.
2. Laser line scanner sensor: Can perform linear scanning on the surface of the measured object to obtain two-dimensional or three-dimensional shape information, which is often used in
3D modeling and surface detection.
3. Multi-axis laser measurement system: Through the collaborative work of multiple laser heads, it can achieve real-time monitoring of complex motion trajectories and is widely used in robot navigation and precision assembly.
3. Application fields
Laser displacement measurement technology has been widely used in many fields:
- Manufacturing industry: Used for part size detection, surface flatness measurement, assembly gap control, and other applications.
- Civil engineering: Can be used to monitor the settlement and deformation of bridges and buildings.
- Medical equipment: Used for high-precision positioning of surgical instruments and monitoring of biological tissue deformation.
- Aerospace: Used for real-time monitoring of structural deformation of aircraft and vibration analysis.
4. Advantages and Development Trends
Compared with traditional contact measurement methods, laser displacement measurement has the advantages of non-contact, fast speed, high accuracy,
and strong adaptability. With the development of optical, electronic, and image processing technology, the future of laser displacement measurement will move towards higher resolution, smaller volume, stronger environmental adaptability, and intelligence.
In summary, as one of the core tools of modern measurement technology, laser plays an increasingly important role in displacement testing. With the advancement of intelligent manufacturing and Industry 4.0, the application prospects of laser displacement sensing technology will be even broader.
