Tough exterior, precise core – cylinder path measurement with VSE
Volume sensors from VSE are known for use in hydraulic inspection and testing systems, but above all in metering and process engineering processes. With their high-precision measuring technology, they reliably meter, measure and mix plastics, resins, paints, greases, oils and many other liquids.
What is less well known is the use of what is referred to as cylinder path measurement: The VSE sensors are required to measure the amount of fluid displaced in the cylinder – usually hydraulic oil – to be able to determine the exact position of the piston in the cylinder. One process with numerous application, in particular the control of heavy equipment and in extreme conditions.
For example, Mark Zellerhoff and a research team from the Aschaffenburg University of Applied Sciences demonstrated that a normal mini-excavator can become a self-controlling construction machine with the help of VSE flow sensors and the cylinder path measurement method. The student of electrical engineering and information technology reported in detail on the results of this research project at the Echterhage Holding after-work meeting in September. The VS series volume sensors installed on hydraulic cylinders of the excavator arm provided data on the position of the excavator arm and the bucket via cylinder path measurement.
Based on these and other values as well as various control systems, construction machines were actually able to work completely independently. Excavators and bulldozers, working day and night and on weekends, construction sites that come and go in a jiffy...all this still remains a dream at the moment as the technology is still too expensive for productive use on construction equipment.
There are other applications, however, because unlike other measuring devices, VSE volume sensors are built to withstand harsh conditions. The measuring technology lies inside a robust housing. Influences, such as heat, dust, pressure, salt water or moisture, do not present any issues. They are so well protected that they have proven themselves in the extreme environment of mines, quarries and mine shafts.
Here, the measuring devices are used on what are referred to as jumbo drills. Imposing machines that drill blast holes into the hard rock with multiple arms. There are many requirements for a blast and just as numerous are the parameters that the blast engineers have to calculate and set up in advance. For example, the exact location of the explosive charge in the rock and the depth of the drill holes.
The precise measuring technology of the volume sensors on the jumbo driller drilling arms monitors the work via cylinder path measurement; the device stops when the desired depth is reached.
Due to the high precision, the volume sensors from VSE are also installed in control units for the stabilisation of motorboats. This controls the position of the boat at higher speeds. Each change in position is registered by the volume sensors and forwarded to the control unit. It restores the optimal position in a matter of seconds.
Volume sensors register the smallest changes and are therefore also used for safety-relevant tasks such as in steel mills. In a special casting process, the liquid steel is given its shape during the casting process. The red-hot steel flows as one piece into a guide system mounted on hydraulic rollers. This steel strand slowly cools down via this roller system and is moved on for further processing. The hydraulically mounted rollers undergo significant stress due to the high weight of the steel and temperatures of over 1000 degrees. To detect hydraulic oil leaks in the system promptly, volume sensors are used. This means that defective rollers can be replaced immediately.
Although the use of volume sensors described here is a niche application that only accounts for around 5 percent of VSE sales, it does show how versatile VSE's high-precision technology can be.