Large-field displacement measurement system using sampling moiré camera | |
| Author | Nutchapat Theetawatwong |
| Call Number | AIT Thesis no.ST-21-05 |
| Subject(s) | Structural health monitoring Moiré method |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Structural Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. ST-21-05 |
| Abstract | Monitoring the civil infrastructure is one of the important tasks in civil engineering works in order to be able to ensure the safety and the performance of the structures. To study the behaviors and properties of the structure, the network of the sensors needs to be constructed and installed to the structure. Recently, the digital image-based processing for displacement measurement called “Sampling Moiré Method” was established and studied. The technique is able to perform high accuracy displacement measurement of both vertical and horizontal direction in real-time. The system can detect the displacement of the target structure from the distant location by using an ordinary camera connected to a decent quality laptop for the process without complicate setup or calibration. However, the technique is normally applied for a single node monitoring system. This study aims to develop the network monitoring system by utilizing the real-time sampling moiré camera. The developed network is wireless based system that the monitoring stations (real-time sampling moiré cameras) and the developed monitoring office can communicate to each other through cloud broker/server which can be accessed by the internet. The MQTT (Message Queueing Telemetry Transport), low bandwidth protocol, was used as a main protocol in exchanging the data between the cloud broker/server and the monitoring station or monitoring office. The engineers with the developed monitoring office application can control, get status update, and visualize/log displacement data from monitoring stations in real-time. In terms of the data synchronization, the timestamps of the displacement data are made according to the laptop’s internal clock which is being synchronized to the certified and trusted source (Royal Thai Navy Server) by NTP (Network Time Protocol) scheme. The quality of the proposed time and data synchronization method was evaluated in the laboratory and field experiment, and found that the method is satisfied and good enough for the developed monitoring system. Finally, the developed monitoring system was employed to monitor the displacement response of the real structures, and shows the great potential that the developed system can overcome the limitations which the engineers normally encounter in the traditional monitoring civil infrastructures. |
| Year | 2021 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. ST-21-05 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Structural Engineering (STE) /Former Name = Structural Engineering and Construction (ST) |
| Chairperson(s) | Pennung Warnitchai;Punchet Thammarak (Co-Chairperson); |
| Examination Committee(s) | Thanakorn Pheeraphan;Methee Chiewanichakorn; |
| Scholarship Donor(s) | His Majesty the King’s Scholarships Thailand,; |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2021 |