Deformation monitoring, the task of measuring an object's movement over time, plays a crucial role in assisting the construction process and understanding a structural asset's health. Owners, operators, and contractors rely on automated monitoring systems to measure and report on the movement of these objects to ensure public safety, protect the asset, and make informed decisions. Survey providers can easily take existing survey principles and equipment and apply them on an automated monitoring project. Total stations provided accurate, repeatable measurements to understand this key movement and accompany software platforms visualize and report the data in meaningful ways.
This article explains the differences between automated and manual monitoring, where and when an automated system is beneficial, and the steps to turn an existing robotic total station into an automated monitoring system using Trimble 4D Control (T4D).
Manual and Automated Monitoring Systems
Manual (also called periodic or campaign-based monitoring) monitoring schemes are not new in the industry. Typically, these are performed when a low frequency of measurement (e.g., once a week or month) and installation of instruments on site is not required (e.g., tripod, total station, and data collector). These operations are used to detect, slow, subtle movements such as natural land drift. Manual monitoring is also useful for monitoring an object during a specific operation such as moving a large load over a bridge where the project duration is less than a day when a crew can be on site at all times.
Image 1: An example system for performing manual monitoring using Trimble Access field software and S-series total station to measure the data and a reporting package such as Microsoft Excel to display the data.
Automated monitoring systems have become a norm in the construction and structural industries. When safety of life and high reaction times are required after movement has been detected, an automated monitoring system is required. They allow for the continuous measurement and analysis of geodetic (e.g., GNSS and total stations) and geotechnical (e.g., crack sensors, tiltmeter, and inclinometer) sensor data. Instruments are permanently or semi-permanently installed on site (e.g., concrete pillar in housing for total station mount connected to permanent infrastructure) to reduce returns to site and ability to collect data seamlessly. To ensure owners and contractors can react to sudden movements, data is collected at a high frequency (e.g., every minute or once per day).
|Factor||Manual (also called periodic or campaign-based monitoring)||Automated (also called real-time monitoring)|
|Types of movement||Slow, subtle||Sudden|
|Measurement frequency||Low (e.g., once a week or month)||High (e.g., every minute or once per day)|
|Installation||Sensors typically not installed on site (e.g., tripod, total station, and data collector)||Sensors installed in permanent or semi-permanent locations (e.g., concrete pillar in housing for total station mount)|
|Goals||Trends and settlement||Safety of life, critical infrastructure|
Automated monitoring systems are being used on a variety of man-made and natural objects. Transportation infrastructure construct requires an analysis of the surrounding infrastructure to ensure construction activities do not disturb them or threaten public safety. Buildings and historical features such as statues and monuments are monitored to detect the occurrence of defects or failure to inform occupants and owners so they can make decisions. Open and underground mines benefit from monitoring systems to ensure the safety of workers and stability of mine walls during the excavation and operations. Dams of all types, concrete, earthen, and tailings, can be catastrophic to the safety of downstream occupants when failure occurs. With automated monitoring systems, engineers and owners can detect movement and alert them before a failure occurs. For natural hazards, systems provide awareness of the changing earth’s landscape to provide insight into the geodynamics and risks they pose to the surrounding area.
Image 2: An automated monitoring system collecting data at the Frontier Mine in the Democratic Republic of Congo.
Image 3: A Trimble S-series total station keeps a constant eye on the Biel Railway track in Switzerland as freight is moved over top. The real-time monitoring system can alarm stakeholders and track operators of significant movement to ensure the safety of cargo and passengers.
Automated Monitoring System Components
An automated monitoring system is made of four components:
Infrastructure and installation of the system: This is the object you are monitoring such as a bridge pier, building facade, dam wall, etc.
Sensors with power and communication: The sensor/device that is measuring the state of the infrastructure such as a total station, GNSS, or geotechnical sensor.
Configuration, storage, and data management: Software locally deployed on a server (on-premise) that communicates with the sensor to receive and process data into a meaningful value as well as store it in a location.
Visualization, reporting, and alarming: Software used to create deliverables of collected data such as threshold alarms and reports on the infrastructure movement as measured by the sensor.
Image 4: System components that make up an automated monitoring solution.
Setup of an Automated Monitoring System
To setup your first automated monitoring system using a total station, you will need the following:
- Trimble S-series total station: S5, S7, S9, or S9HP instrument can be used. T4D also supports non-Trimble total station manufacturers.
- Settop M1 total station controller: This device powers, schedules, and controls the total station observations and sends data to the T4D database. Also has onboard storage for data communication gaps to prevent loss of data. USB cable to connect total station to Settop M1.
- Power cable for Settop M1: This cable powers the Settop M1 device from a local power source.
- Settop M1 communication to T4D: via cellular connection (SIM card) using IST Connect service, or Ethernet cable for Local Area Network (LAN) setup.
- License or subscription to Trimble 4D Control Advanced edition: Available in 3- and 12-month subscription terms, and perpetual license. This should be installed on the computer hosting the data.
Image 5: Hardware setup for a real-time monitoring system using the Settop M1 and Trimble S-series total station.
Configuring the Automated Monitoring System
Once the hardware has been set up and installed, the next step is to configure the data communication and storage. This starts with the Settop M1 web application to configure targets and scheduling of the data collection and finishes with T4D Control Server to receive, process, store, and visualize the data.
Image 6: An overview of the automated monitoring system using Trimble 4D Control software, S-series total station, and the Settop M1 controller.
For a detailed list of steps to setup a real-time monitoring system see this article.
We also have a variety of online resources to help you get up to speed:
- Visit our website
- Tips, Tricks, and Training videos on our YouTube channel
- Community forum to ask questions from Trimble and other users
- Watch the recording from the Monitoring Power Hour webinar covering this topic in detail.