D - 73252 Lenningen
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6 m below the university hospital of Münster a large automatic goods transport system was going in operation.
The old electric overhead conveyor is replaced by an modern driverless transport system, which was built in
cooperation of the companies TMS and Siemens. The TMS Produktionssystem GmbH is responsible as general contractor
for the plant parts of the whole project Siemens provides the control software and hardware.
Containers with all goods needed in modern clinic operation are transported: laundry, food and dishes, medicaments, files, surgical instruments, Waste and much more are moved from the care center to the single clinic blocks and back.
The containers are moved from the clinic via elevators to the basement, taken over by free navigating, radio-controlled floor transport vehicles (Picture 1) and transported to the target points – laundry, waste disposal, kitchen and so on. Once there the are unloaded, then sterilized in a washing line and stored in stock for the next mission in the other direction. A daily amount of about 2500 transports are done, 38 floor transport vehicles are in use.
RFID technique from Texas instruments is used when the container enters or leaves the installation. Every container has a glass tag 134,2 kHz where the container ID and a type number is stored mounted at the bottom. If the container is moved to the elevator at one of the user levels in the clinic area, the tag is read through the antenna which is embedded in the floor. (Picture 2)
The Tiris S251 reader is mounted in the control panel. The data is evaluated there and shifted to the CP-control unit form Siemens. This unit hands the data over to the PLC. Then container is introduced to the system and an according transport order is submitted to the next standing floor transport vehicle. The user enters the target for the container at the elevators but some type numbers like waste containers who will always be targeted to the waste disposal have fixed targets. The reversed action is started at the transport from the care center to the bed buildings as soon as a container is unloaded at the base of the elevator and pulled in the elevator. The transponder is read and the transport order is finished.
The company GiS - Gesellschaft für Informatik und Steuerungstechnik mbH – was involved to this project as VAR (Value added Reseller) and has adapted the Texas Instruments products to the requirements of the system.
So the transponders had been poured in plastic blocks (Picture 3), so they are robust enough to get through the sterilization process. Also the standard antennas could not be used because a very low height of only 8 mm was required. GiS developed a special antenna which is also trimmed to allow a supply line of 12 m.