Inductive sensor technology provides highly precise and reliable solutions, which can be used for a wide variety of applications.
How does the technology work?
Of the different sensor operating principles – mechanical, hydraulic, pneumatic, or magnetic – the inductive wheel sensor has proven to be the most popular due to its high reliability?
For safety reasons, a wheel sensor generally consists of two independent sensor systems in one housing. This dual channel processing allows for the possibility of other wheel detection system functions, which are based on the temporal context and the intensity of the interference. That is one of the many reasons why Frauscher wheel sensors meet the CENELEC standard up to SIL4.
Presence, speed, or the direction of travel of an axle: These and other data are reliably detected by Frauscher Wheel Sensors – under all climatic, technical, and operational conditions. Maximum availability results from a robust design, high-quality components, and an extremely reliable technology.
The wheel detection system essentially consists of a wheel sensor and an evaluation board. All analogue signals are transmitted from the sensor to the prefabricated evaluation boards and then safely evaluated. The boards can optionally be positioned either centrally in the interlocking or – in case of a decentralised architecture – in cubicles along the rail line.
The benefit: no active electronic components on the track!
Temperature and environmental influences
Our Frauscher Wheel Sensors withstand adverse weather conditions including dryness and heat, tropical humidity, extreme cold, floods or changeable weather. Due to the innovative design and IP68 ratings, a lot of issues like change of sensor current parameters are prevented.
The challenges resulting from mechanical influences affect all components of the sensors and their way of mounting. The rail claw must ensure that the position of the sensor does not change even under high loads, as deviations in their orientation can lead to errors and failure due to faulty detection. These challenges include strong impacts or vibrations caused by wheel flats, defective rail joints, or even rail breaks. In addition, the forces created by these defective train components can damage the sensor housing. This kind of damage can also be caused by influences such as metal parts hanging from the train, dropping of accreted snow and ice, or flying ballast. Our patented rail claws ensure that our sensors are not affected by mechanical influences and can resist those challenges, if needed in combination with our rail deflectors.
Frauscher Wheel Sensors
Highly available wheel detection systems are an integral part of a wide variety of railway applications, from simple switching tasks to fail-safe train detection. Modularity and flexibility of the hardware and software components are key factors in being able to guarantee optimum operation, even in the case of the most stringent requirements. This means that the presence, speed or direction of an axle is reliably detected under all climatic, technical and operational conditions.
The design of Frauscher Wheel Sensors – with two independent sensor systems in a single housing – minimises their weight. When rail claws are used for convenient and easy mounting of the sensors without having to drill into the rail, this in turn increases the service life of supporting components.
Speaking of mounting: Frauscher rail claws are very user-friendly, lightweight, and thus easier to install. Another big advantage is that no rail drilling is required. This helps ensuring that the installation time and efforts are reduced reasonably while also ensuring the longevity of the rails.
With no active electronic components on the track itself, our products ensure high availability and easy maintenance.
The compact design also enables the mounting of Frauscher wheel sensors on the inside along the track where they reliably detect the flange of passing wheels. Not least because of their design, they also supply important additional information about:
- traversing of an axle
- direction of travel
- wheel centre pulse
- wheel diameter
Innovative functions to increase availability
Counting Head Control (CHC)
The Counting Head Control principle serves to avoid errors caused by short-term influences such as tools, people, or trolleys. When configured correctly, the patented functionality matches the requirements according to SIL 4.
If the adjacent track sections are clear, the detection point enters a standby mode (however, even in standby mode, it detects debris, trolleys, etc. and supresses faults). In this idle state, a freely configurable number of undesirable instances of damping can be suppressed. Hence, no occupied track section message is generated by short-term influences, and no reset is required. Approaching vehicles in the adjacent track sections deactivate the standby mode and are safely detected, triggering an occupied indication.
Supervisor Track Section (STS)
The intelligent Supervisor Track procedure corrects the impact of unavoidable interferences in a fully automated manner. By observing the general reset conditions, availability can be further optimised without any negative effects on safety. Every two track sections can be overlaid by a supervisor section. This makes it possible for a faulty track section to be reset automatically if the corresponding supervisor section is clear.
In addition, a faulty supervisor section is reset if the two corresponding track sections are clear. This enables the system to correct short-term, system-external interferences – such as lightning strikes or people crossing the tracks.
- reduced number of reset procedures carried out by the dispatcher
- supervisor sections do not need to be integrated into the interlocking
- correction of ongoing errors
- no need for additional hardware
- reduced downtime
- reduced trackside exposure of staff