3D scanners

Lecture



A 3D scanner is a device that analyzes a physical object and, on the basis of the data obtained, creates a 3D model.

3D scanners are divided into two types according to the scanning method:

  • Contact, this method is based on the direct contact of the scanner with the object under study.
  • Contactless

Non-contact devices, in turn, can be divided into two separate categories:

  • Active scanners
  • Passive scanners

Active scanners emit some directional waves (most often light, a laser beam) onto an object and detect its reflection for analysis. The possible types of radiation used include light, ultrasound or x-rays.

Passive scanners do not emit anything on an object, but instead rely on the detection of reflected ambient radiation. Most scanners of this type detect visible light — readily accessible ambient radiation.

The 3D models obtained by scanning can be further processed by CAD tools and, in the future, can be used to develop manufacturing technology (CAM) and engineering calculations (CAE). To display 3D models, tools such as a 3D monitor, a 3D printer or a milling machine with G-code support can be used.

3D scanner (also known as 3D scanner or 3D scanner - “three de”) is an innovative device that allows you to create accurate three-dimensional models of real objects with a high degree of detail and receive information about the surface, shape and color of an object in a computer / mathematical / digital form. It converts an object into its digital image, just as a simple 2D scanner converts an image on a piece of paper into an image on a computer.

What are 3D scanners for?

3D scanners can be used for a wide range of tasks in many areas of industry, science, medicine and art. In particular, they successfully solve the tasks of reverse engineering, control of the shape of objects, preservation of cultural heritage, are used in museum business, in medicine and design. Thus, they are necessary in all cases when it is necessary to register the shape of an object with high accuracy and in a short time. Three-dimensional scanners can simplify and improve manual labor, and sometimes even complete tasks that seemed impossible.

As a rule, a 3D scanner is a small electronic device, manual ( weighing up to 2 kg ) or stationary, which uses a laser or a lamp as a backlight. There are 3D scanner models designed to scan objects of various types and sizes, be it jewelry, museum artifacts, or people's faces. The accuracy of the obtained models of objects varies from tens to hundreds of micrometers . Possible to scan with the transfer of color or only the shape of the surface. These devices not only simplify the process of creating three-dimensional models, but also solve this problem with maximum accuracy in relation to the original original.

How to choose a 3D scanner by application.

3D scanners are used in various fields and are used to obtain models of objects with a complex profile, increase the speed of development, reduce production time.

In the field of reverse engineering, 3D scanners allow you to take measurements of objects and create their 3D models. At the output of the 3D scanner, the user receives a highly accurate digital model of a real physical object.

These devices will be useful in the industry for contactless control of surfaces of complex geometric shape of parts, system design. They are also useful for assessing tool wear and creating packaging that exactly matches the shape of the product.

In medicine, with the help of a 3D scanner, you can monitor the progress of patient treatment, carry out preoperative planning, and create anatomical shoes. They are widely used in the field of orthodontics, where accurate, high-quality scanning of small objects is necessary.

Designers use 3D scanners to get the shape of an object, and refine it. In museums and archeology, they are useful for detailed scanning, accurate restoration and reconstruction of sculptures and architectural monuments.

Scanning people (obtaining a color 3D model of a person) can be used for the film industry and animation.

Buy a 3D scanner can afford as a factory, design office, and a small company. Today, 3D scanners are an affordable tool. The price of 3D scanners depends on the technology used for scanning.

Optical 3D scanning technology

The company Artec Group is an innovator in the field of three-dimensional scanning. Its special technology provides unique speed and accuracy when scanning information about an object's surface ( depth ), it is based on the principle of structured backlighting.

Information is determined by projecting at a parallax angle onto an object of a special grid. The calculation of the exact position of the points in 3D space is made due to the distortions of the lattice projection, which is created by the geometry of the objects.

Due to the triangulation of the obtained points, a polygonal surface is formed - its representation is possible in all common 3D formats .

Thanks to these systems, it is possible to obtain high-quality three-dimensional surfaces during video filming. Artec scanning technology provides the ability to integrate devices into spatial systems to scan various objects.

The difference between the optical and laser 3D scanner

Various technologies can be used to create 3D scanners, each of which has its own limitations, advantages and disadvantages. Today the main are optical and laser technologies .

In the first case, a laser class II is safe for vision . In order for the 3D scanner with laser illumination to be tied to the scanned object, special reflective marks are often used, which are fixed near the scanned object or directly on it at certain points.

In the second case, the scan is performed using the backlight object flash lamp. Lines are projected onto the object, forming a unique pattern. Information about the shape of the surface of an object is contained in the distortion of the shape of the projected image.

Restrictions in the scanned objects are present in each of these technologies. For the most part, laser scanners are not applicable for scanning moving objects , since the scan takes quite a long time. Therefore, their use is difficult if the object is a person. In addition, there is a need for special reflective labels. The advantage of using this technology is the high accuracy of the resulting 3D model.

Optical 3D scanners face difficulties when scanning shiny, specular or transparent surfaces. The advantages of such devices is a high scanning speed, which eliminates the problem of distortion of the resulting model when the object is moving , and there is no need to apply reflective marks. This makes it possible to scan human faces.

The principle of the 3D-scanner

The principle of operation of the 3D scanner is quite simple, and consists in obtaining and comparing images from two cameras. Just as a person is able to determine the distance to objects with two eyes, an optical 3D scanner calculates the distance to an object using 2 cameras. Usually, in addition to cameras, a backlight ( laser or flash lamp ) is used, which helps to achieve high accuracy and reliability in measurements.

All measurement data, as well as images, are transferred to a laptop computer, the data and the surface of the scanned part are memorized, analyzed and displayed on the screen as a three-dimensional image. Using a computer, you can control the scanning process, select the resolution and the necessary areas to refine the detail, save and modify the results obtained using a three-dimensional laser.

created: 2014-09-30
updated: 2021-04-09
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Electromechanical devices of electronic devices

Terms: Electromechanical devices of electronic devices