2004 zyxwvu IEEE zyxwvu International zyxw Conference on Industrial Technology (ICIT) zy Industrial applications of wireless networks: A bridge crane distributed control system based on Bluetooth Juan V. Capella, Albert0 Bonastre and Rafael Ors Department of Computer Engineering Polytechnic University of Valencia Camino de Vera s/n, 46022 Valencia, SPArN Cjcapella, bonastre, rors}@disca.upv.es zyxwv Absfruct- This paper shows the possibility to use Bluetooth for wireless short range communication in an industrial environment. In this line a distributed control system based on Bluetooth has been proposed for a bridge crane system. Its configuration is mainly based on the use of distributed nodes connected by means of Bluetooth. Traditionally many types of devices have been delivered as mechanical devices and more or less all or the intelligence and control has been added. Nowadays there is a growing trend towards a higher level of built-in intelligcnce in the devices, constituting the intelligent nodes. This type of systems allows the impkmentation of highly flexible control systems capable of adapting themselves to different situations. With the introductioii of Bluetooth, another dimension is aggregated, the possibility to wirclessly connect to the devices. The technology makes it possible to easily access the built-in user interfaces through portable devices but also to access the device data without the need for a physical connection. Bluetooth is one of the most promising personal wireless network technologies. The automation industry is showing interest in using Bluetooth for many industrial applications. zyxwvu Key Words: Bluetooth, distributed contrul systems, wireless nehuurks, industrial systems. 1. Introduction The application of distributed control systems to industrial systems has grown in a spectacular way. One of the current challenges in this field is the application of the wireless technology, because the following reasons: In the first place, it is looked for that the industrial-systems are flexible, so that they can be adapted easily to the process modifications. This would atlow, in turn, the definition of generic modules that could be adapted to concrete problems. On the other hand, the modern industrial systems consist of mobile devices or machine parts. Then, it seems very important, the application of-wireless control systems distributed, so that without cables we have a much greater freedom to physicalIy distribute the nodes. It is possible io place actuators and sensors without worrying about the location of the control node. For example, it allows us the place the sensor and actuator on a mobile object and still run the controlier from a standstill platform. However, going wireless can have some inconvenience that should be studied. This work is a study of the Bluetooth [I J application in industrial environment. The motivation for this work is the fact that short-range radio communication in factories can reduce the use of cables and are in some case a good alternative to wired connections. When transmitting or receiving from rotating and moving machine parts, it is of great advantage to use wireless communication. The Bluetooth short-range radio systems need for a research effort, before it can be used effectively in factories 121. Especially when there are high demands for safety and real- time performance. Bluetooth in industry impose new requirements on the technology, while it at the same time opens up new and interesting possibilities for using wireless communications in industrial applications. This paper will discuss some of the issues which should be considered in order to utilise Bluetooth in industrial plants. Another challenge for the distributed systems implementation is the necessity of facilitating the system programming. As answer to this issue, the traditional control systems also should advance [3]. A marked tendency is appreciated to the application of expert systems to the industrial control [4], because it offers some interesting advantages. In this field; some of the techniques that probably offer the most interesting perspectives are those coming from Artificial Intelligence, and within them the so- called expert systems, which attempt to simulate the reasoning of a human technician. Most of them consist on the denominated rule-based systems, since they express the desired system behaviour by means of simple production rules like: zyxwv “IF antecedents THEN consequents”. In this case we can add the ff exibility and easiness of programming, so that an user does not require a solid computer background to specify the desired knowledge base. This is why the expert systems, simulating the knowledge of a human operator, are considered one of the best bets when implementing these control systems [SI. On the other hand, the most used devices in those systems have an ever-increasing capability of processing data and transmitting them through wireless communication networks. In this way, apart fiom soIving the problem associated to the distance among the system, elements and mobility, it is also possible to build generic modules that will be assembled to meet specific requirements. ‘It also allows the implementation of fault-tolerant systems by means of replicated nodes. 2. Bluetooth Biuetooth is a standard for short-range radio and personal area networks, developed by the Bluetooth Special Interest Group(S1G). The Bluetooth SIG is supported by a number of large multinational companies, This group of companies co- operate, to make the Bluetooth standard accepted and compatible worldwide. Different profiles are being specified 0-7803-8662-0104/$20.00 02004 IEEE 824