Development of Low Cost Stationary Laser Scanning System for Generation of Building Information Models

This project presents a method to develop 3D point cloud map of any indoor and outdoor vicinities using indigenously developed stationary scanning system comprising of a single low cost 2D laser scanner. The data logging of scanner and required inertial measurement units (IMU) have been carried

Project Title

Development of Low Cost Stationary Laser Scanning System for Generation of Building Information Models

Project Area of Specialization

Robotics

Project Summary

This project presents a method to develop 3D point cloud map of any indoor and outdoor vicinities using indigenously developed stationary scanning system comprising of a single low cost 2D laser scanner. The data logging of scanner and required inertial measurement units (IMU) have been carried out using Robot Operating System (ROS). Multiple divergent environments have been scanned and 3D point clouds have been developed which have been found accurate when compared to the ground truth. In addition, the Building Information Model (BIM) of the surveyed vicinities have been developed using generated point clouds. In comparison to available surveying solutions present in the local market, the developed system has been found accurate, faster, economical and user friendly to generate structural results of the surveyed vicinities in detail.

Project Objectives

This project aims to design a 3D Scanner whose base principle is Non-Contact and is a combination of both Active and Passive Technology and aims at developing an effective and efficient 3D Scanner i.e. a generalized 3D Scanner which can be implemented in any domain.Specific needs of this domain are: medium-high accuracy, ease of use, affordable cost of the scanning device, self-registered acquisition of shape and color data, and operational safety.

Project Implementation Method

Mechanical Design

To develop mechanical structure of the motorized hardware for indoor and outdoor stationary surveying applications, a CAD model of the platform has been designed in the SolidWorks software as shown in Fig 1. Main base platform comprising of a rectangular box is used for installation of a vertically mounted motor coupled with rotating plate. Two pillars have installed on the plate to integrate top square box platform connected with a horizontally coupled second motor. Both platforms have designed to rotate ±90° degree in order to provide required views to the scanning system. A potentiometric encoder along with IMU have been associated with the each rotating plate. On top platform, 2D Hokuyo laser scanner has been mounted along with three HD cameras. The main base rectangular box platform is further used to place required electronic components and batteries for the system. After finishing the CAD model, manufacturing of the motorized stationary scanning system has been initiated. The complete structure is manufactured with acrylic sheet of 0.5cm thickness for providing good strength at lightweight as shown. In order to get precision in the system, the acrylic sheet has been cut using laser cutting machine in order to keep minimal tolerance in the actual system. For rotating applications, hybrid stepper motors have been installed in the system. These motors provide good precision at high torque and generally in use in CNC machines. Two IMUs have been installed in the system along with encoders to perceive the rotational changes. Finally Hokuyo UTM-30LX laser scanner and cameras have been installed as shown in Fig 2.

Instrumentation Design

The instrumentation scheme of the stationary scanning system has shown in Fig. 3. Each stepper motor has been controlled by Arduino UNO controller board and the rotational rate feedback of the motor has been provided by encoder to Arduino board. The angular displacement feedbacks have been provided by both IMUs to respective controller boards which deliver control commands to the motor drivers. Both controllers have connected through USB ports to the laptop having Robot Operating System (ROS). The controllers have implemented the commands and sent back the continuous rotational feedbacks to the laptop in order to generate the 3D point cloud of the vicinity. All the online data has been viewed in RVIZ package of ROS and stored in a ROS bag file for offline processing using Matlab scripting. Later the segmentation of geometrical planes have been performed on developed point cloud in order to view the structural details of the vicinity. Finally the BIM of the surveyed region with 2D floor plan has been made.

Benefits of the Project

The main objective of this project is to create accurate 3D point clouds. A point cloud is a collection of an enormous number of measurements: a set of data points or coordinates in three dimensions. The measurements are usually made by 3D laser scanners and Light Detection and Ranging (LIDAR) technology. A laser measures where light hits surfaces within its line of sight. A point cloud needs to be processed to create a 3D model of the reality. In reality capture terminology, you need to register and mesh the final data. Point cloud registration is where you align overlapping point clouds – if you moved your laser scanner to different positions on site to capture a larger or more complete scene – to form one accurate model of the area. Meshing is where software converts point cloud data into triangles or polygons to represent the surface of scanned objects; the mesh stores the data of the original points, but is smaller and faster to work with.

What can you do with a point cloud?

Once point cloud data becomes a 3D model its benefits are unlocked. These differ by industry and application but are mainly based on increased accuracy and safety. Let’s look at examples in a few industries where point clouds are commonly used.

Engineers and architects can use Leica CloudWorx for Revit software to efficiently and accurately create a Building Information Model (BIM) of an existing structure or update original design models with real-world conditions post-construction. When they are working on retrofit design projects, they can experience a virtual site presence and check for conflicts with the existing conditions. This helps stop critical errors in their tracks before they slow or halt a project.

Fields that can get benefit: 

Industrial design & engineering

Innovative 3D scanners are widely used in industrial design, engineering, and manufacturing, due to their ability to quickly and precisely capture the data. Without advanced 3D devices, measurements would have to be collected by manual methods, which can be too costly and time-consuming.

Forensics

Advanced 3D scanning technologies are becoming popular in forensics as well, due to their portability, flexibility, and accuracy. And professional 3D scanning solutions are now being used around the world by police, insurance companies, and even during court hearings for presenting evidence.

Technical Details of Final Deliverable

The generation scheme of 3D point cloud and its building information modelling have been presented in Fig.4. The left side is showing the conceptual working of the scanner which can rotate horizontally and vertically through motors as per commands as shown by the green and cyan colour arrows. Right side of the is indicating the scan line falling on multiple planes in front of the scanner. The up and down movement of scan line can be controlled as per given rotational commands to motors which may ultimately use to completely scan the environment. an industrial manipulator of two joints and two links as shown in Fig. 5. In order to establish transformation representation for this system, a popular Denavit-Hartenburg (DH) parameterisation scheme has been used.

The system has been tested at various locations. The results are attched

• Point Cloud and 3D Model of Lab

• Point Cloud and 3D Model of a ground

 

Final Deliverable of the Project

Hardware System

Core Industry

Others

Other Industries

Core Technology

Robotics

Other Technologies

Sustainable Development Goals

Industry, Innovation and Infrastructure

Required Resources

If you need this project, please contact me on contact@adikhanofficial.com