Robust rail sensors improve rolling stock

This new sensor series is helping railway operators improve their rolling stock with tailor-made solutions meeting critical EN standards.

High-precision measurement of the smallest vibrations in vehicles and infrastructure is a basic requirement for safe, comfortable rail transport, with inertial sensors playing a key role.

The RAIL series by ASC Sensors provides high-precision, robust and flexible inertial sensor technology to support railway operators in improving the safety, capacity and productivity of their rolling stock.

“The rigorous testing and documentation of our RAIL sensor series’ performance makes it significantly easier for operators to implement customised inertial sensor solutions on their rolling stock,” says Renate Bay, CEO of ASC Sensors. “They can rely on a proven set of stable precision sensors ready for installation, which meet the required norms and significantly reduce individual documentation requirements on the part of the operator.”

All components of the ASC RAIL series have been rigorously tested according to EN 50155 to confirm climatic resistance and dynamic-mechanical robustness, as well as EN 50121 to confirm electromagnetic compatibility. They meet the latest fire protection standards, including EN 45545 for electronic equipment on rolling stock. This includes a robust, non-flammable, laser-welded stainless-steel housing with protection class IP68, and rail-certified cables and cable glands. The housing is capable of withstanding the hardest shocks, vibrations and temperatures encountered in rail applications. As a result, this protection ensures the sensors maintain optimal performance and stable long-term operation even under extremely harsh conditions.

ASC’s standard accelerometers ASC RAIL-x152LN are available in uniaxial, biaxial and triaxial configuration. A new more compact housing option can be applied to fit the accelerometers into narrower spaces than before.

Both models are based on proven MEMS technology and capacitive operating principle. This technology enables the measurement of static (DC) and constant accelerations, which can be used to calculate the velocity and displacement of moving objects. Depending on the design of the spring-mass-damping system, however, it is also capable of detecting dynamic (AC) accelerations of amplitudes from ±2g up to ±400g and within a maximum frequency response range of up to 1kHz (±5%). The integrated electronic circuits enable differential analogue voltage output (±4 V FSO) and outstanding noise performance from 7 to 400μg/√Hz.

The ASC RAIL-27x1 gyroscopes are based on established MEMS vibrating ring sensor elements. The micro-mechanical silicon structures make these gyroscopes extremely insensitive to external impacts and vibrations. Their integrated electronic circuitry enables a single-ended, analogue voltage output (0.66 to 2.64 V FSO). These uniaxial, biaxial or triaxial gyroscopes are available in four measurement ranges (75°/s to 900°/s), featuring a bias stability of 12°/hr and an angular random walk of 0.2°/√hr.

“In essence, rail operators can now mix and match from ASC’s ready RAIL series components in building customised sensor solutions to meet their unique needs,” adds Bay. “Choosing from a proven set of inertial sensors meeting applicable national and international standards will significantly facilitate these tailor-made solutions, saving time and budget while strengthening safety and economic outcomes.”