Our customer requested a custom real-time monitoring, measurement, and data-logging system to measure the vibration levels from a track rail without causing disruptions to its existing systems and operations. The system needed to withstand harsh operating environments and provide continuous recording capabilities. We chose the CompactRIO platform and industrial-grade touch panel computer (TPC) to meet the required conditions and combined them with precision accelerometers to continuously acquire accurate vibration measurement data.
The project began with the customer’s request for a versatile and cost-effective vibration monitoring, measurement, and data-logging system to mount on its vehicle units that run on the track rail. The customer wanted to use precision accelerometers to gather the measurements, and approached us to build the system around these requirements of versatility and portability. The customer also wanted us to mount the accelerometers in a variety of locations. The system needed to provide data from all three axes of the sensors, record them, and read the data from the file.
First, we built the versatile and portable system hardware. The customer accepted the proposal to use the rugged CompactRIO platform and modules along with an NI TPC mounted onto an industrial-grade mild-steel enclosure to ensure sturdiness under harsh operating conditions (see figures 1, 2, and 3). The additional precautionary measure of adding an uninterruptible power supply unit to the system’s enclosure prevents the system from going down due to an accidental loss of power during the course of system operation.
We divided the system software into two parts: the real-time software code and the TPC human-machine interface (HMI) software code.
The real-time software code is embedded on the NI cRIO-9025 controller that handles communication with the TPC HMI and other interfacing hardware. It also handles data acquisition from the NI 9234 modules connected to the accelerometers. The real-time software offers vibration monitoring and measurement capabilities with the user-defined vibration detection threshold. When it meets the threshold, the real-time program code sends the data set to the TPC HMI. It also continuously records vibration measurements from all accelerometer channels in the background and stores them on the cRIO-9025 controller (see figures 4 and 5).
We embedded the TPC HMI software code on the NI TPC that the operator uses to stop and start the measurement and data-logging operation, as well as set the vibration threshold levels and data file name. The program offers a user interface to view the vibration data that triggers based on the threshold settings defined by the user and readings from the externally connected devices (see figures 6 and 7).
The track rail vibration monitoring, measurement, and data-logging system we created is portable so that the user can deploy it in the train carriage, where the accelerometers are mounted.
After the system establishes all hardware connections, the user boots the system, launches the TPC HMI program interface, and starts the measurements. The system operates completely independently from the train, so it can operate while the user collects measurement data on the desired portions of the track rail.
During the measurement process, the user enters the “start station” using the onscreen keyboard and sets the desired vibration threshold levels for measurement and acquisition. After clicking “start logging,” the system automatically monitors, measures, and logs the vibration levels from the accelerometers. It also displays and logs the train’s distance traveled and current speed. The user can conduct multiple “start/stop” vibration measurements or collect one large data file.
After completing the data collection, the user can transfer all collected data for analysis using the USB port. With the data analysis program, the user can load and view the collected data files for analysis. This program shows the vibrations recorded throughout the journey with respect to the distance traveled. The user can identify the respective locations of the high vibration values from the “start station” and perform maintenance procedures to tackle the vibration issues (see Figure 8).
CompactRIO combined with LabVIEW gave us versatile operation in a portable design. With a built-in uninterruptable power supply, the system is completely independent from the train’s operation system and does not affect normal train operation. The rugged hardware is ideal for the harsh environment, and precision measurement sensors offer accurate readings, on-the-fly vibration-level readings display, and data logging. The post-analysis software offers in-depth analysis of recorded vibration data.
Ken Engineering and Consulting Pte Ltd
10 Ubi Crescent, Lobby E, #01-88, Ubi Techpark