Train doors are a subsystem of trains which are relatively vulnerable to failure. When train doors cease to function correctly, it can result in discomfort to passengers and impact negatively on operations leading to increased costs. Therefore, determining the root cause of failures, and reliably analysing train door systems, has an important significance and is necessary for maintenance and design optimisation.
The vibration signals of the mechanism are separated into two cases, namely: door opening and closing. For each of them, a signature of N openings, or closings, respectively is defined. All subsequent acquisitions would be then stored and compared to the original signature.
The VANDA system is a train door health inspection and monitoring system that utilises vibration analysis to assess the condition of train doors.
The methodology is based on capturing a vibration profile or signature, emitted by any piece of mechanical equipment in motion. The signature reflects its operating, or specific health, condition at a certain point in time. It is considered that the mechanism would either continue its operation in the same health condition, or have noticeable degradation when compared to its signature.
The main features of the VANDA system include:
User friendly controls and touch screen
Compatibility with different sensors, i.e., 325, 326, 354, 1001, 1002
Sampling rate of 4000 data points per second
Parameter setting interface
Manually set measuring duration
Recorded vibration data display
Signal processing capabilities, i.e., relevant features of the vibration signal, allowing time-domain and frequency-domain analysis
Recorded data and results streamed to computer for post analysis
An experimental rotating rig was setup in TWI’s laboratory and used to test the sensitivity of VANDA to changes in the vibration of the mechanism. During the algorithm validation process, the DEWESoft commercial system was used, proving that different levels of vibration can be distinguished.