Infrastructure

The infrastructure sector is one of the most important economic sectors in Germany: with billions invested, tens of thousands of employees and a dense network of roads, railways and waterways, it forms the backbone of trade, mobility and supply. Continuous maintenance and modernisation not only ensure competitiveness and innovation, but also create important impulses for growth and employment. Other important areas of infrastructure are aerospace and the energy sector.

Reliable sensor technology is a crucial component of modern transport infrastructure. Position, distance and displacement sensors ensure precise control, monitoring and safety in applications such as river sluices, tunnel construction, bridge monitoring, harbour facilities and rail transportation. Whether monitoring the movement of bridge components or position control in goods handling, robust sensor solutions make a significant contribution to the efficiency and operational safety of infrastructure systems.

Monitoring the condition of rails is extremely important in order to recognise wear and damage in advance. Non-contact laser distance sensors can be easily mounted in measuring wagons or on traction units and measure the rail profile while in motion. Thanks to their miniaturised and robust design, the sensors can be mounted in confined spaces. Such sensors are often used in measuring wagons and continuously record the distance to the rail head in order to detect unevenness and wear points. For this purpose, several laser sensors are aligned on a measuring wagon or inspection train so that they scan the top of the rail. The sensors continuously measure the distance to the rail head at a high measuring frequency. When travelling at high speed, this creates a complete profile of the rail. Even the smallest deviations, such as chipping at the rail head or incipient wear, can be detected in this way.

In practice, automated systems compare the measured profiles with target specifications and mark worn rail sections for maintenance. With their high measurement frequency and precision, laser distance sensors such as the LAS2-TM series from WayCon deliver very tightly synchronised measurement curves so that even subtle profile alterations are reliably detected.

Another important application is track width monitoring. Here, the track width (the distance between the two rails) is continuously monitored. It is common to arrange one sensor on each rail or parallel to each other on a transverse boom so that the sensors simultaneously measure the distance to the rails. The current track width can be calculated from these measured values. The high measuring frequency of the sensors is again an advantage here, as it allows the track gauge to be determined continuously even at higher speeds. Laser distance sensors therefore enable the track cross-section to be permanently monitored, which is critical in the case of low-speed sections and points.

Bridges of all kinds, from railroad bridges to road bridges and pedestrian bridges, are subject to high and changing loads. Many types of damage are not immediately visible as they occur inside the structure. This is why permanent monitoring systems (SHM - Structural Health Monitoring) are used: distributed sensors continuously measure the condition of the bridge and can thus detect deformations and the formation of cracks, for example, at an early stage.

Vertical deviations are detected by draw wire sensors, for instance. This deviation (also known as sagging) of the roadway is caused by the load to which the bridge is constantly subjected. SX50 series draw wire sensors can be mounted parallel to the bridge bearings and detect the vertical movements of the bridge. For larger distances, sensors from the SX135 series are suitable, which, with measuring lengths of up to 42.5 m, can also be used directly below the roadway in the middle between two piers.

Draw wire sensors are also used to monitor the lifting of entire bridge sections during maintenance work, which is necessary to replace the bridge bearings, for example.

In addition to draw wire sensors, linear potentiometers are also used to monitor cracks and gaps. The sensor housing is firmly attached to the structure and the piston rod is mounted on a plate or bolt on the opposite edge of the crack. If the crack widens, the rod extends and the sensor registers the increase in crack width over time. In this way, growing cracks can be recognised automatically. A previously defined maximum width then leads to a warning or timely closure of the bridge.

By using these sensors and networked data acquisition systems, changes in the condition of bridges can be recognised at an early stage and maintenance work can be planned as required. This significantly increases the safety and service life of the bridges - and saves costs in the long term through targeted maintenance measures.

Distance sensors are used in a wide range of applications in harbour complexes: they control the lifting and turning movements of cranes, monitor filling levels and loading positions, detect gate and automatic gate positions as well as conveyor belt positions.

The use of laser distance sensors is a proven application for container ports. The LDI series from WayCon is used to measure distances of up to 150 metres with ±1 mm accuracy. Such laser sensors measure the height or position of cranes without contact and thus enable precise crane control. Thanks to their high protection class and range, the LDI series is particularly suitable for demanding outdoor applications.

Draw wire displacement transducers are used in harbours to record the positions and movements of mobile machinery. SX80 series draw wire displacement transducers measure the extension of booms on container bridges or the lifting distance on forklift trucks, among other things. The SX80 series draw wire displacement transducers are optionally available with a corrosion-resistant housing (CP and ICP options), which means they are optimally protected against sea air and splash water.

Rotary angle sensors are also essential for the automation of harbour machinery in order to detect and control rotary movements of all kinds. For example, these sensors, also known as encoders, detect turning movements of container cranes and enable their precise positioning.