May 12, 2015 - Micro-Sensor supplied curve detection systems for use on high speed trains on the Haramain High Speed Rail Project in Saudi Arabia. These high speed electric passenger trains travel at speeds of up to 186 mph across a 453km network between Medina and Mecca.
For high speed trains that travel at speeds in excess of 160km/h, European rail industry regulations stipulate that these trains must be fitted with suitable derailment safety protection systems. High vibrations resulting from the interactions between the train and the track can potentially cause a carriage to derail.
For the Haramain High Speed Rail Project, Micro-Sensor supplied bogie-mounted vibration sensors for improved derailment protection and curve detection systems to monitor carriage/wagon tilt in curves for better control of lubrication of the wheels during curves in the track.
Vibration sensors for bogies often need to be customised to suit different train types. The environment on a bogie is also harsh, with risk of damage to the sensors if they are not adequately protected from dirt, dust, rainwater and flying debris (e.g. stones and gravel) underneath the train. In order to survive in this type of environment, Micro-Sensor vibration sensors are housed in stainless steel or high thickness aluminium and certified to IP68 and EN50155.
Curve detection systems
In addition to vibration sensors fitted onto the bogies, each train is fitted with two curve detectors – one on the front carriage of the train and one on the very end of the rear carriage. The front sensor detects when the train moves into a curve; the rear sensor detects when the train moves out of the curve. The wheel lubrication system is activated on and off by these two sensors, providing lubricant to the wheels precisely when (and in the volume) it is needed.
Unlike other curve detection devices used on trains, which measure centrifugal forces, the Micro-Sensor curve detector operates using a gyroscope. This innovative technology is not influenced by inclination of the track in the curves. Made from silicon, the gyroscope measures the angular velocity of the train on a continuous basis. The curve detector provides a current and voltage output to the train’s central electronic control system or onboard telemetry system. This reduces wear of the wheels and lubricant costs.
In addition, the sensor can be used for collecting data for predictive maintenance of the wheels, which increases maintenance intervals and train availability. Furthermore, the measurement system can be retrofitted to existing trains.
Micro-Epsilon is a manufacturer of sensors, headquartered in Germany. The company’s range of displacement sensors measure everything from to distance, position, vibration, dimensions and thickness, using both contact and non-contact measurement techniques. These techniques include 1D, 2D and even 3D laser-optical sensors and systems, eddy-current, capacitive, LVDT & inductive, potentiometric and draw-wire principles. In addition, Micro Epsilon has developed its own range of non-contact infrared temperature sensors that can measure virtually any target temperature from -40 to +3,300°C. The company also manufactures a comprehensive range of colour recognition sensors.
