A reliable gas detection solution developed by a consortium of German companies and research institutes uses a FLIR GF320 optical gas imaging camera.
Detection of gas leaks in industrial facilities is not only dangerous and time-consuming but also susceptible to human error and interpretation. That’s why rigorous inspection specifications apply to the chemical industry, biogas facilities and gas suppliers. Operators of industrial plants give top priority to the safety of their staff and their production facilities. During these regular inspections, staff members check the system for proper functionality and usually rely on perceptions and experience without making use of measuring technology.
A consortium of nine companies and research institutes worked together on the German technology program AUTONOMIK to provide a safer, more efficient and more reliable detection solution called RoboGasInspector. This innovative robot system for remote detection and localisation of gas leaks uses a FLIR GF320 optical gas imaging camera.
The consortium came up with a prototype of a system that can perform inspection tasks in industrial facilities without having to access hazardous areas directly, and without requiring any human presence. The robot can be used for routine inspections of facilities or for targeted inspections of specific system parts. Various navigation sensors have been used for independent mobility of the system with the option of manual intervention via remote control at any time. The system is also equipped with video and optical gas telemetry to inspect system parts that were previously difficult to inspect due to restricted accessibility.
The collaborative research project was headed by Dr Andreas Kroll and Dr Ludger Schmidt at the Mechanical Engineering Department of the University of Kassel and subsidised with € 2.4 million from the Federal Ministry of Economics and Technology.
Dr Andreas Kroll of the Department of Measuring and Control Technology at the University of Kassel explained that the objective of the project was the development and testing of an innovative human-machine system with mobile inspection robots equipped with remote gas measuring technology and local intelligence. During this process, the mobile robots should also analyse the measured data and document the inspections.
For professors Andreas Kroll and Ludger Schmitt, a top requirement for the new system was that it should allow for automated, hazard-free inspection and monitoring, and that it should be able to respond independently to problems. During routine procedures such as repeat inspections, there is always a risk of inadvertently overlooking possible sources of danger.
Therefore, the development of innovative inspection technologies and focusing the flexibility and performance of human operators on managing the technological systems made sense not only for economic reasons, but also with regard to relieving humans from repetitive routine tasks and improving coverage of the wide range of inspection tasks.
The RoboGasInspector was demoed for the first time in a hall at the University of Kassel, with the robot independently completing an inspection route, successfully overcoming obstacles and a ramp in the process.
At specified inspection sites it inspected various pipelines and found a methane leak. In the following months, this success was expanded to several square kilometres of large industrial facilities under laboratory conditions, in which environmental factors such as wind and sun as well as confounding factors resulting from system operation were included.
The RoboGasInspector consists of three modules: a chain-driven mobile platform, a navigation module and an inspection module, which incorporates the FLIR GF320 optical gas imaging camera. The chain-driven platform is equipped with an electric drive and conventional batteries.
The navigation module consists of 2D laser scanners (front and back, particularly important for navigation inside buildings) as well as a GPS for outdoor orientation. Continuous comparison of the area to be inspected with a digital map enables the chain-driven RoboGasInspector to determine its position at any time, with obstacles and blocked areas noted on this map. According to Professor Kroll, thanks to its 2D laser scanners, the RoboGasInspector also avoids unexpected objects such as parked cars, pallets, barrels or persons, moving around the obstacles or stopping until the path is clear again.
The inspection module combines various metrological instruments on a pan-tilt unit, including a Remote Methane Leak Detector (RMLD), which is based on an active Turnable Diode Absorption Spectroscopy (TDLAS) instrument. It works by means of an infrared laser: when the laser beam hits a surface, it is reflected and its residual intensity is measured. In addition, a FLIR GF320 thermal imaging camera is mounted on the inspection module to visualise the gases.
The RoboGasInspector is also equipped with a built-in gas sensor that shuts down the entire system from 10% of the lower explosion limit (LEL) onwards in order to prevent possible danger to a flammable atmosphere.
The robot also processes the measured data and pattern recognition independently in addition to the inspection of the specified routes while continuously being in contact with the control room. A video camera is also incorporated in the pan-and-tilt measuring module for remote controlled operation of the robot. However, in normal operating mode, the RoboGasInspector works independently and merely transmits all measured data to the control room via WLAN.
The system prototype of the RoboGasInspector has impressively demonstrated its use and capability in extensive testing with the drive unit, navigation system and complementary sensor systems performing extremely well.
While facilitating independent gas detection and leak localisation in sites that are otherwise difficult to access and also helping to avoid the use of human inspectors in potentially dangerous environments, the RoboGasInspector will need to be further developed before deployment in industrial settings.