3D laser scanning in construction is a technology that uses laser beams to capture precise, detailed measurements of a space, creating accurate 3D models that aid in planning, design, and documentation throughout the construction process. It involves using LiDAR (Light Detection and Ranging) technology to map spaces and objects by emitting laser beams and measuring the time it takes for them to return. This data is then processed to generate Point Clouds, which can be used to create detailed 2D drawings and 3D models.
How it works:
- LiDAR technology:
3D laser scanners utilize LiDAR to send out laser beams that reflect off surfaces and return to the scanner.
- Distance measurement:
By precisely measuring the time it takes for the laser beams to return, the scanner calculates the distance to each point, creating a dense cloud of 3D coordinates.
- Point cloud generation:
These coordinates are processed to form a point cloud, a digital representation of the scanned space.
- Model creation:
The point cloud data can be used to create accurate 2D drawings and 3D models, including BIM (Building Information Modeling) models.
Applications in construction:
- As-built documentation:
3D laser scanning captures the existing conditions of a structure, providing accurate as-built documentation for renovations, expansions, and improvements.
- BIM integration:
Scanned data can be integrated into BIM models, allowing for better coordination, clash detection, and efficient planning.
- Progress monitoring:
Regular scans can track construction progress, identify deviations from the plan, and ensure quality control.
- Remote access:
3D models can be used for remote site visits, allowing stakeholders to view and analyze the site from anywhere.
- Design and planning:
Accurate 3D models enable better design visualization, precise measurements for fabrication, and improved planning for MEP (Mechanical, Electrical, and Plumbing) systems.
- Reduced errors and rework:
By providing accurate data and facilitating early clash detection, 3D laser scanning helps minimize errors and rework, saving time and costs.
Data from 3D laser scans can be used to create highly realistic visualizations, aiding in the design, analysis, and communication of complex structures and spaces.
In contrast, Laser Scanners are non-contact devices that capture millions of discrete data points to measure an object or space using laser infrared technology that produces detailed 3D images in minutes.
The 3D scanner collects and processes millions of X-Y-Z data points into a “point cloud,” creating a detailed digital twin of the object. Since the distance between the sensor, cameras, and angles is all known, the principle of triangulation is applied, producing accurate, reliable measurement results.
Understanding Laser Scanners
When complex or large environments need to be documented, Laser Scanners provide a practical and economical solution.
Capturing large environments traditionally involved tools like tape measures and total stations, which only provided single-point measurements. This method was extremely time-consuming, often taking weeks or months depending on the size of the area. Additionally, these traditional tools were prone to user error, leading to inconsistent measurements and data gaps that could cause a chain of inaccuracies.
In contrast, laser scanners are non-contact devices that capture millions of data points in minutes using infrared laser technology. This process quickly generates a detailed 3D image, known as a point cloud.
So, how do they accomplish all of that so quickly? The Laser Scanner emits a beam of infrared laser light onto a rotating mirror that effectively paints the surrounding environment with light. The scanner head rotates, sweeping the laser across the object or area. Objects in the path of the laser reflect the beam back to the scanner, providing the geometry that is interpreted into 3D data. In addition to the distance measurement, Laser Scanners also capture measurements on the horizontal and vertical planes, providing a full scope of measurement data.
A Laser Scanner typically captures data through two kinds of systems:
- Time-of-flight systems: Also known as a pulse measurement system, this works by emitting a single pulse of laser light and determining the distance to the end point by measuring the time it takes for the light to be reflected back to a sensor on the scanner.
- Phase-shift systems: Similarly, this system also uses an emitted laser light, but in this system, the intensity of the light is modulated with specific wave forms. The reflection of the intensity patterns is displaced by the impact on the surface of the object. Measuring the displacement between the sent out and the received laser signal provides a precise distance calculation. Generally, Laser Scanners that use phase-shift systems are accurate, fast and provide high-resolution data.
Applications and Industries:
Laser Scanners are versatile, easy to use and move, and accurate, making them an ideal tool for many applications and industries:
Law enforcement & fire safety: Laser Scanners are effective tools for crime scene documentation, crash and accident scene reconstruction, fire scene analysis, forensic investigations and more. Laser scanning saves hours of documentation time and preserves a digital replica of scenes that may be environmentally vulnerable.
Safety & security: Laser Scanners capture highly detailed, valuable data used by security personnel to save lives when responding to potential threats.
Insurance: Laser Scanners are used to document the actual state of a piece of property at a point in time, helpful for setting a baseline for value and obligation, as well as documenting losses with vehicles, damaged properties or products.
Oil & gas: Laser scanning is well-equipped to assist in engineering, maintenance and planning on oil platforms and in refineries. They are also highly useful in documenting complex piping structures to avoid installation issues or errors.
Heritage & historical preservation: Laser scanning can document the complex geometries of existing buildings in order to study, preserve or restore them.
Site surveying: Laser Scanners can be used to make volume calculations as well as topographic and as-built surveys.
Construction: Laser scanning can provide continuous in-field verification at every stage of a construction project lifecycle, helping predict and prevent errors and enabling significant cost, scrap and time savings.
Architectural & civil engineering: Laser Scanners are useful for capturing as-built documentation of existing buildings and in developing 3D models as part of project planning.
Facilities management & asset documentation: Laser scanning offers precise data of complex factory and plant installations, useful in maintaining and documenting assets and facilities.
Methods of 3D Construction
The most common approach involves extrusion, where the material is pushed through a nozzle to create layers that form the structure. This method can use a variety of materials, including concrete, which is favored for its strength and durability.
How accurate is 3D laser scanning?
Handheld structured-light 3D scanners typically capture surfaces with 0.01-1.0 mm accuracy, but it’s possible to get even closer-to-reality scans. Desktop solutions like Artec Micro II, for instance, are capable of 3D scanning with a deviation of just 0.005 mm (or 5 microns).
What is the difference between LiDAR and 3D laser scanning?
Unlike laser scanning, which is more focused on close-range detail, LiDAR can be positioned on aerial, terrestrial, and mobile systems, to gather spatial data over large areas. It is highly valuable in fields such as topographic mapping, environmental management, and infrastructure planning.
What is the process of laser scanning?
Laser 3D scanning works by projecting laser light onto an object and measuring reflected light to determine the object’s shape and dimensions. Collected data forms a detailed point cloud, which is then processed into 3D models for analysis and further use in various applications.
What are the advantages of 3D scanners?
Enhanced Accuracy and Precision
3D scanners are renowned for their ability to capture the intricacies of an object with remarkable precision. This is particularly beneficial in industries where minute details are critical, such as aerospace and automotive manufacturing.
Laser triangulation scanners derive three-dimensional data using the principles of triangulation, with the laser being the illumination source. Laser triangulation scanning is an active sensing technology because it has an energy-emitting component.
BIM
BIM stands for Building Information Modeling, a process that uses a shared digital representation of a physical and functional characteristics of a facility. Essentially, BIM is a digital twin of a building, encompassing everything from the initial design to eventual demolition.
- Digital Representation:
BIM creates a 3D model of the building, incorporating not just the visual aspects but also information about the building’s geometry, spatial relationships, quantities of materials, and other relevant data.
- Collaborative Process:
It facilitates collaboration among architects, engineers, contractors, and other stakeholders by providing a shared platform for information storage, exchange, and management.
- Lifecycle Management:
BIM is used throughout the entire lifecycle of a building, from planning and design to construction, operation, and even demolition.
- Benefits:
BIM offers numerous advantages, including improved communication, reduced errors, better cost control, and enhanced project efficiency.
- Beyond Software:
While BIM utilizes software like Revit, it’s more than just software; it’s a process, a workflow, and a collaborative methodology.
BIM stands for Building Information Modeling and is a workflow process. It’s based around models used for the planning, design, construction, and management of building and infrastructure projects. BIM software is used to model and optimize projects by planning, designing, building, and operating BIM models.
How many types of BIM are there?
Exploring the Seven Types of BIM Dimensions. 2D, 3D, 4D, 5D, 6D, and 7D, each of these BIM dimensions have their unique purpose and benefits. These are useful in finding out the project cost, timeline, and sustainability graph for future purposes.
3D Laser Scanning Technology in land surveying have become to be an indispensable tool for surveyors. 3D Laser scanning technology provides highly detailed and accurate 3D models of landscapes, structures, and infrastructure especially indoors. 3D laser scanning is a technology that captures the shape and appearance of real-world objects and environments to create digital 3D models. It uses laser beams to measure distances and create a detailed point cloud, which is then processed into a 3D model. This technology is versatile and used in various industries for applications like reverse engineering, quality control, and as-built documentation. The types of 3D laser scanners include Short Range 3D Scanners, Laser based 3D Scanners, Projected or Structured Light 3D Scanners, Laser pulse-based 3D scanners, Laser Phase-shift 3D Scanners, Coordinate Measuring Machine Scanners.
Briefings described by:
Benson A. , with 25+ years’ experience in the industry