The principle of 3D scanner

A 3D scanner is a scientific instrument used to detect and analyze the shape (geometric structure) and appearance data (such as color, surface reflectivity, etc.) of objects or environments in the real world. Its working principle is mainly based on the following technologies:

Principle of structured light scanning

The principle of structured light scanning is an important method in 3D scanning technology, which combines structured light technology, phase measurement technology, 3D vision technology, and composite 3D non-contact measurement technology. Specifically, this method projects specific light patterns (such as stripes, dots, or grids) onto the surface of an object, and then uses a camera to capture the deformations of these light patterns on the surface of the object. By analyzing the deformation light mode, the three-dimensional information of the object surface can be calculated. This method usually has high accuracy and speed, and is suitable for scanning various complex surfaces.

Laser scanning principle

The principle of laser scanning is another common 3D scanning technology. It uses a laser beam as a measuring tool to measure the distance from a point on the surface of an object to a scanner by emitting the laser beam onto the object surface and receiving the reflected laser. According to different measurement principles, laser scanning technology can be divided into various types, such as pulse laser scanning and phase laser scanning. Pulse laser scanning calculates distance by measuring the flight time of laser pulses, while phase laser scanning determines distance by measuring the phase change of reflected light. Laser scanning technology has the advantages of high precision, long-distance measurement, and applicability to various material surfaces.

Three coordinate measurement principle

The principle of three coordinate measurement is a measurement method based on the Cartesian coordinate system. It uses three mutually perpendicular axes of motion X, Y, Z to establish a Cartesian coordinate system, and the probe (usually a probe with a small ball) moves in the coordinate system and contacts the surface of the object. The detection system records the precise position of the center point of the measuring ball in the coordinate system. By moving the measuring head and measuring multiple points, the geometric dimensions, shape, and positional tolerances of the object can be calculated. This method is commonly used in the fields of precision measurement and quality control, and has the advantages of high accuracy and reliability.

Principles of Stereoscopic Vision

The principle of stereoscopic vision is similar to the working principle of the human eye, which uses two cameras to simultaneously capture objects from slightly different angles. By analyzing the difference (i.e. disparity) between the images captured by two cameras, the three-dimensional coordinates of surface points of an object can be calculated. This method is commonly used in the fields of rapid measurement and 3D reconstruction, and has the advantages of low cost, easy implementation, and applicability to various scenarios.

Other principles

In addition to the common principles mentioned above, there are also other principles used in 3D scanning technology. For example, projecting sine wave shaped light onto the surface of an object and detecting the phase change of the reflected light to determine the three-dimensional shape of the object surface; Alternatively, methods such as grating projection and phase calculation can be used to achieve three-dimensional measurements.

In summary, the working principles of 3D scanners are diverse, and each principle has its own advantages, disadvantages, and scope of application. When choosing a 3D scanner, it is necessary to comprehensively consider factors such as specific application requirements, measurement accuracy, speed, object characteristics (such as material, color, shape, etc.), and cost.