|Transponders placed in the floor allow communication with the on-board reader of the truck.|
Specialists see a great future for Radio Frequency Identification, in short referred to as RFID in the logistics industry. The smart radio labels are seen as an effective means to accelerate the flow of materials in the industry and trade, if they are used together with material handling vehicles fitted with the corresponding requirement. Currently, tracing of materials is characterised by manual input of data by handheld data scanners and a central data processing unit. The various scans of goods between reception and delivery are time consuming and prone to errors. Inter-company systems hardly exist. A survey questioning 150 logistics companies which was conducted by the Still GmbH from Hamburg in the frame of the project IdentProLog shows that there is a great interest in the use of RFID systems to register goods and to trace materials. The project scopes the flow of information between the transported good and the load carrier on one hand and the materials handling truck on the other hand, with Still being a leading provider for the equipment of warehouse trucks.
The team from Hamburg did have good reasons to accept this task. They have started to develop RFID supported material handling trucks some years ago already and by this they have provided new functionalities to fork lift trucks. In this, RFID technology is to be used far beyond the known radio label. Corresponding solutions are already available and can be realised immediately. The Hamburg based company uses RFID to localise the vehicles and optimise the operational processes.
This way the location of the goods can be calculated logically taking the status of the vehicle such as its position and its lift height. This data then determines the storage position of the goods which is in turn transmitted to the overarching materials handling system by WLAN. A manual entry of the storage position is not needed.
Indirect identification of the stored goods
The trucks equipped with RFID are able to determine their position autonomously and are by this able to provide the driver with helpful information for navigation. Unnecessary travelling is avoided. Also, many safety functions are offered. For example, depending on the current location of the truck, the speed can be reduced, the lift height can be limited or the light can be switched on automatically. Also, a communication of the truck with its environment is possible, for example operating traffic lights and gates or monitoring one-way roads. After the goods are registered at the goods reception station they are unambiguously allocated to the pallets. This way the stored goods are identified indirectly. The pallet is registered for every internal movement and the system registers every relocation and updates its position in the database.
Obligatory prerequisite for this are special tags, also referred to as transponders which are installed in the floor in a regular matrix with a distance of about one meter between the tags. This way, the position of the vehicle is always defined. The installation can be easily fitted, also in already existing warehouses and production locations.
For customers using the new Still technology, the system provides considerable advantages: A large share of the required manual scan operations is eliminated, since this is done directly by the lift truck. This not only saves the time needed to scan barcodes but it also avoids interrupting the process of the work to scan data. Altogether this generates a consistent, steady flow of work. Furthermore, the utilisation of the trucks is much better balanced, because manual scanning consumes up to two hours per work shift. The terminals are easy to read and send the necessary data by WLAN to the Still material flow management system (MMS). This way, the position data recorded by the on board reader is provided to the system.
Great increase of the safety in the warehouse
Information about the height and load distance, speed and hydraulic operations as well as the position of the truck is sent to the truck control system of the warehouse by a specific CAN-bus protocol. How does this effect the concrete situation in the warehouse? At crossroads, i.e. potential hazardous areas the travel speed is reduced and when the area of the crossroads is left the speed is increased again. The travel speed can also be reduced automatically in narrow passages. The monitoring of the driving direction ensures locking of sensible areas. Also, one way passages can be monitored this way. Altogether this considerably increases the safety.
A additional aspect is the positive effect of active routing. The Still system works similar to the navigation, in an automobile: arrows indicate the travel direction to be followed. It is therefore a great help for new drivers or temporal workers. Also, as a central unit, the truck control system knows the position of all trucks and can always select the closest and most suitable truck for a new job.
The preparatory works by Still show that RFID technology holds considerable advantages for the flow of material and for safety. However, there still is quite some need for further research and development to develop optimum solutions – especially when it comes to the flow of information between the transported goods and the load carrier on one side and the warehouse truck and the resource planning system on the other side. This is why a consortium of well-known industrial enterprises which Still belongs to started the research project “IdentProLog”. It is promoted by the Bundesministerium für Bildung und Forschung (BMBF) [Federal Ministry for Education and Research] and is a part of the programme “Forschung für die Produktion von morgen” [Research for the production of tomorrow]. The duration of the program is planned for three years.
Key role for the fork lift trucks
During the programme a system able to identify the different load carriers and the information encoded on it unambiguously is to be developed. The use of RFID technology and modern wireless data transmission on warehouse trucks permit automatic registering of load carriers such as pallets and the loaded goods and can thus serve as a link between the warehouse level, the control level and the management level.
In the frame of the IdentProLog project Still is responsible to equip warehouse trucks so that they detect load carriers reliably and can provide the stored information to the back end systems. To check the operation of the whole system and to detect possible weaknesses, different tests are to be conducted on a demonstration warehouse truck.
For preparation some 150 companies of the logistics industry were interviewed. In telephone interviews the companies were asked about the requirements of future customers for the optimum placement of RFID installations. The questions of the interviews were prepared by the specialists from Hamburg. The results are clear: About 75 percent of the companies are very interested in goods recognition and 65 percent are very interested in tracing materials by RFID. The potential users see the major advantages of this method compared to barcode reading in making a visual contact with the code unnecessary and in the high sturdiness of the RFID transponders. In the operational process the advantages are the automatic and error-free identification and the easy coordination of the stock in the warehouse and the management system. A clear 80 percent majority of the participants underline the positive aspects when managing the inventory. In this, the priority is placed on the load carriers and transport packaging and not the packaging of the individual good.
Apart from the overwhelming fundamental agreement to RFID there are additional wishes the users have: rewriteable tags are required. Also the fully automatic comparison of data without any activity of the driver is assigned great importance. The integration into the IT systems, first of all into MMS (Material Management Systems) followed by PPS (Production Planning Systems and SCM (Supply Chain Management Systems) is strongly required. On this background it is clear that Still is moving in the right direction using RFID technology to locate the positions of the trucks.
Development of components close to the market
To finish off with, the results are directly taken up by the work of the research project and will be presented to various customers – this allows to keep track of the functionalities required by the market. Still’s top goal is to develop components that are adequate to the market.
Beside STILL as an active partner for the equipment of warehouse trucks, other partners are involved in the project: Jungheinrich AG as a manufacturer of warehouse trucks and Kuka Roboter GmbH as a user. Further Gebhardt Transport- und Lagersysteme as a manufacturer of load carriers, PSI Logistics GmbH as an IT integrator and Deister Electronic GmbH as an RFID specialist participate in the project. On behalf of the research, the Institut für Transport- und Automatisierungstechnik (ITA, Garbsen) and the Institut für Fördertechnik und Logistik (IFT, Stuttgart) are involved. The executing organisation for the BMBF is the Forschungszentrum Karlsruhe (FZK) which is a member of the major research institutions of the Helmholtz association.
Still sees a good opportunity to drive forward the development from being a manufacturer of trucks to being a provider of system solutions which is well under way now. At the same time the competitiveness of the German manufacturers is sustainably strengthened in this area. By the project and the related active development of tomorrow’s standards, Still will be able to extend the RFID solutions already available today.