What Is a 3D Laser Scanner?
A 3D Laser Scanner is a device designed to accurately measure the shape and position of objects or environments in three dimensions with high precision.
When laser light is emitted towards the target object, the laser light reaches the object, reflects, and returns. By measuring the time and angle until it returns, the distance and position can be determined. The 3D Laser Scanner uses this laser-based measurement to rapidly and voluminously acquire distance and position data, generating digital data (point cloud data) that reproduces the three-dimensional shape by combining this data.
Due to its capability to measure distance and position data with extremely high accuracy, it is advantageous in applications where precise three-dimensional models or measurements are required.
Furthermore, it can operate quickly and non-contactly, allowing the acquisition of a large amount of data without damaging the surface of the object. Hence, it is considered a high-performance device used in various applications such as architectural, civil, and topographic surveys, contributing to tasks involving urban space investigation.
Uses of 3D Laser Scanner
3D Laser Scanners find applications in various industries, and the primary uses are as follows:
1. Architecture
3D Laser Scanners are used to capture complex shapes and details accurately and non-invasively at high speed. They are employed in current-condition surveys of existing buildings and structures, as well as in the planning of renovations and expansions for buildings without drawings. The rapid and non-contact measurement, along with the ability to visualize point cloud data and 3D models digitally, improves the accuracy of architectural design, leading to cost savings in terms of work hours and labor.
2. Civil Engineering
In civil engineering, 3D Laser Scanners are utilized for the maintenance, design, and construction of civil infrastructure such as roads, bridges, tunnels, and dams. They are used for tasks such as detecting unevenness and cracks on road surfaces, evaluating the safety of structures like bridges and tunnels, and conducting condition surveys during disasters.
Moreover, on construction sites, they are used for real-time progress and quality assessment, as well as detecting differences between design plans and the actual construction site. In the field of civil engineering, they serve as effective tools to enhance infrastructure quality, prolong lifespan, and improve management and quality on construction sites.
3. Factory, Facility, and Equipment Management
Due to its ability to accurately understand complex situations, 3D Laser Scanners are applied in the management of factories, facilities, and equipment. Factories and facilities often undergo frequent equipment replacement and expansion, making it difficult to understand the layout through drawings. 3D Laser Scanners digitize the current situation, facilitating the optimization of layouts and equipment configurations, planning facility renovations, and managing periodic equipment replacements, contributing to the efficient management of factories, facilities, and equipment.
4. Cultural Heritage
3D Laser Scanners are employed in the research, preservation, and utilization of cultural heritage. They are used to record ruins and excavated items at excavation sites, as well as to digitally capture detailed information on a wide range of cultural heritage, including historical buildings and sculptures. The digitization of cultural heritage enables tasks such as restoration, replica creation, monitoring of damage progression, and virtual public display and educational use of cultural heritage in remote or restricted locations.
5. Digital Content
3D Laser Scanners are utilized to reproduce real locations and objects as high-precision digital data, creating digital twin spaces that closely resemble reality. Additionally, by editing and processing the data from 3D Laser Scanners, it is more efficient to produce new digital content with a realistic feel compared to creating it from scratch. This makes 3D Laser Scanners essential tools for creating a wide range of digital content, including 3DCG, game characters, background designs, video production, tourism content, and metaverse applications.
Principles of 3D Laser Scanner
The 3D Laser Scanner directs very fine laser beams toward the surface of the target object. These laser beams, characterized by their linearity, reflect partly upon hitting the object’s surface, and the 3D Laser Scanner detects the reflected light.
There are multiple methods for measuring distance, with the two main ones being the “Time of Flight (TOF)” method and the “Phase Shift” method. The TOF method calculates distance by measuring the time it takes for the laser beam to be emitted and returned. On the other hand, the Phase Shift method modulates the phase of the laser light while irradiating it and detects the phase difference in the reflected light to calculate the distance to the object.
The 3D Laser Scanner covers the entire scanning area by rotating the laser light source, enabling the acquisition of many distance data points at once. The collected distance data is integrated with the irradiation angle information, resulting in the calculation of XYZ spatial position coordinates. This data constitutes the three-dimensional point cloud data, a set of data that reproduces the position and shape of the object in the digital domain.
How to Choose a 3D Laser Scanner
There are factors to consider when selecting a 3D Laser Scanner. As the applications of 3D Laser Scanners are diverse, selection based on the intended use is necessary. Below are some examples of selection criteria for 3D Laser Scanners commonly used indoors and outdoors:
1. Measurement Accuracy
Measurement accuracy indicates how accurately a 3D Laser Scanner can reproduce the actual shape of an object. It is usually expressed in millimeters. The choice of a 3D scanner should be based on the required accuracy.
2. Maximum Measurement Distance
The maximum measurement distance indicates how far a 3D Laser Scanner can measure the distance to an object. Particularly in outdoor environments or large areas, products with longer maximum measurement distances are required.
3. Resolution
Resolution indicates the detail of the 3D data generated by the 3D scanner. Higher resolution allows for a detailed capture of the object’s surface and small features.
4. Water and Dust Resistance
Depending on the usage environment, water resistance and dust resistance may be essential. These are generally indicated by an IP rating, with two digits representing the level of protection. A higher first digit indicates higher water resistance, while a higher second digit indicates higher dust resistance.