Contact scanning or measurement acquisition <br> <br> this embodiment is mainly used as a coordinate measuring scan. The acquisition method mainly uses the stylus installed on the instrument to collect the data on the surface of the object point by point. When the probe is running along the surface of the object, the reaction force on the surface of the object displaces the probe. The displacement is reflected by the spring inside the probe. A spring-connected transducer measures the magnitude, direction, etc. of the displacement. Then, the three-dimensional coordinates of each collection point are displayed by calculation. Previous page next page
Due to the mechanical structure and design of the coordinate measuring machine itself, the accuracy of the collected data is high, and there is no special requirement for the color and reflection characteristics of the surface of the object to be scanned. When the data is collected, the probe is pressed against the object, so some soft foamed rubber and the like cannot be accurately scanned because the scanned object is deformed by the probe pressing. Probes are often prone to wear when running on tough surfaces, so it is necessary to constantly correct the diameter of the probe to maintain a certain degree of accuracy. Because it collects data point by point, the scanning speed is relatively slow, mainly used to measure objects that are less complex and have a small number of feature surfaces.
There is a dedicated contact scanner on the market today. The Cyclone scanner from Renishaw, UK, collects complex object surface curve data at a speed of four hundred points per second and three meters per minute for easy operation. The collected data is converted into a tool path in computer processing through the software originally equipped with the scanner, and the mold is directly manufactured.
Non-contact scanning method
The principle of structured light method is to project a certain mode of light source onto the surface of the object to be scanned, and project the reference surface light source, which will be blocked by the scanned object placed at the position and deformed. The angle image, and then the deformed light source, can calculate the three-dimensional coordinates of the entire image of the surface of the object being measured. The light source used in structured light method is more common with grating shadows. At present, the methods for analyzing the deformation of the grating shadow line mainly include the half-leaf and phase-shifting methods. The phase shift method is relatively accurate. The advantage of this method is that the measurement speed is fast, the scanning area is large, the equipment is relatively light, and there is no special requirement for the measurement site. In the automotive industry, it is commonly used to scan large areas of objects such as the body of a car. The Steinblicher COMET IV scanner from Germany can scan from 100 x 75 mm2 to 1200 x 1200 mm2. Its camera can be mounted on a tripod, free to move to any position for high-speed scanning, the camera can be mounted on the robot, scanning complex objects, the resolution can reach 4 million pixels. Good data can be collected for some fine parts.
Laser triangulation
The laser triangulation method is to scan a surface of a scanned object with a laser beam having a regular geometric shape, such as a point source or a line source, and the scanned surface forms a diffuse reflection spot, a light band, and then an image sensor mounted on the optical path. The light spot and the light band are received, and then the spatial coordinates of the collected point are calculated by using the trigonometric principle. The technology of the laser trigonometry is mature and widely used, and the scanning speed is high and the precision is high. Its image sensor is small and light in size and easy to install. It can even be mounted on three coordinates, easy to install and disassemble, which is another feature of it. It can also scan objects with softer materials, such as rubber. Japan's Konica Minolta's non-contact Vivid 9i scans up to 0.05mm and takes just 2.5 seconds to get accurate data.
Application of 3D reverse technology
The application of 3D reverse technology is very extensive. Some high-tech aviation, aerospace industries and automotive industries have adopted this technology for product development and manufacturing. In the manufacturing industry, data collected is used in mold making, product design, development, such as consumer electronics.
In addition, the reverse technology combined with rapid prototyping technology can take advantage of rapid prototyping technology and expand its application range. With reverse technology and related software, designers can quickly manufacture physical objects, and at the same time quickly modify, optimize and innovate the physical design, which can shorten the cycle of product design, accelerate the emergence of new products and enhance the company's competitiveness. The application of 3D reverse technology is as follows: