A. Bonastre

Software-based EDF message scheduling on CAN networks

In this paper, a CAN-based communication system has been used to transmit data between different kinds of sensors and the drive control of an electrical vehicle. Software-based earliest deadline first (EDF) scheduling has been applied to order the data, making possible that more relevant measures meet with their delivery time and, discarding, if necessary, less relevant ones are discarded. The messages use their time-to-deadline as their priority level. With this mechanism, alongside with the discard of data that has lost its deadline, is it possible to deal with saturated that would require a bus utilization well above 100%.

New challenges in wireless sensor networks: fault tolerance and real time

The wireless communications field is in continuous growth and revolution. The current trend toward the use of distributed wireless systems is due to these systems have demonstrated to be a good option due to its flexibility and power. In this line, nowadays there is an enormous demand of wireless connectivity for any industrial control applications, included critical systems. In this paper we discuss the possibilities and necessary developments to set up wireless communication for industrial applications in general and critical systems in particular. Furthermore, an abstract definition of a layered architecture for the development of intelligent and distributed control systems based on wireless sensor networks is proposed

Industrial applications of wireless networks: a bridge crane distributed control system based on Bluetooth

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 intelligence in the devices, constituting the intelligent nodes. This type of systems allows the implementation of highly flexible control systems capable of adapting themselves to different situations. With the introduction of Bluetooth, another dimension is aggregated, the possibility to wirelessly 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.

Distributed and mobile systems based on wireless networks: definition of a generic control architecture

The tendency toward the use of distributed systems is due to these systems have demonstrated to be a good option for the industrial control systems implementation, because of their flexibility and power, which can be increased with the application of artificial intelligence techniques. In this line, our research group has developed several distributed systems applied to chemical analysis and industrial automation. For these implementations the CAN network was used. Nowadays there is a market for technical tasks like distributed control, monitoring or data acquisition where there is a need for wireless connectivity. Thus, in this paper we want to discuss possibilities and necessary developments to set up wireless communication for industrial applications. Also, an abstract definition of a new layered architecture for the implementation of intelligent and distributed systems interconnected by means of wireless networks is proposed. Several techniques of discrete control may be used, from Petri nets to an expert system based on rule nets, while continuous control loops may be implemented by means of from traditional PID devices to distributed neural network approaches. Finally, for the communication layer implementation, a wireless network such as Bluetooth or ZigBee could be used.

An advanced and distributed control architecture based on intelligent agents and neural networks

A new layered architecture for the implementation of intelligent distributed control systems is proposed. The proposed architecture distinguishes four layers in a distributed control system. Upper layer consists of a digital control layer, where high level decisions are taken. This level is implemented by means of intelligent agents that carry out the discrete control functions, system supervision as well as diagnosis and fault tolerance. Third layer deals with numeric values, performs analog operations and implement analog control loops. It is also in carry of the conversion from numerical variables values to evaluated expressions. This layer has been implemented by means of neural networks. Communications network appears in the second layer. Selected network was CAN (controller area network) because of its particular characteristics. Finally, every node should implement a hardware interface with the process to control. Some interesting characteristics provided by this architecture are its low-cost implementation, easy distribution through a communication network, distributed execution in virtual generic nodes-with no hardware dependency-, bounded response time and fault tolerance mechanisms

Integration and application of emerging RF systems formed by wireless sensor networks: exhaustive experiment to their implantation in different environments

This paper shows the possibility to use Bluetooth for wireless short range communication in an industrial environment. 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 intelligence in the devices, constituting the intelligent nodes. This type of systems allows the implementation of highly flexible control systems capable of adapting themselves to different situations. With the introduction of RF systems, another dimension is aggregated, the possibility to wirelessly 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 RF systems for many industrial applications.

A CAN Fieldbus Based Architecture for Distributed Control Systems Implementation

Abstract The application of distributed systems theory to the implementation of industrial control systems is one of the best options to develop simple, scalable and physically distributed control systems. Following this line, our group has proposed a new architecture based on Rule Nets (RN) as an HLP over CAN fieldbus for the implementation of Distributed Systems. This architecture has been applied to several control applications, obtaining excellent results. The most outstanding feature of the architecture was its simplicity in the control systems design, without any efficiency loss. New capabilities have been added to improve its features and develop new analysis tools, in order to increase its power and simplicity. In this work these new architecture features are presented.

Enabling ubiquitous wireless sensor networks: A new fault tolerant RF architecture with perpetual electrical power based on 802.15.4 and RFID

The wireless communications field is in continuous growth and revolution. The current trend toward the use of distributed wireless systems is due to these systems have demonstrated to be a good option due to its flexibility and power. In this line, nowadays there is an enormous demand of wireless connectivity for any industrial control applications, included critical systems. In this paper, we want to discuss possibilities and necessary developments to set up wireless communication for industrial applications in general and critical systems in particular. Furthermore, an abstract definition of a layered architecture for the development of intelligent and distributed control systems based on wireless sensor networks is proposed.

A New Web Interface for Distributed Control Systems: Application to the Chemical Monitoring of a Wort Fermentation Process

A new Web interface for rule net-based distributed control systems is proposed. It is applied to the monitoring of a chemical analysis system coupled with a wort fermentation process. A complete description of both the chemical and the informatics system is presented. This interface offers the possibility of accessing the process from any Internet-connected device (PC, PDA, etc.), using a standard browser as the only software required. The evolution of the results obtained in the FIA monitoring (and consequently of the process) can be analyzed by means of this interface; on the other hand, the process itself can be directly controlled through the modification of the different working parameters, even from a remote location.

Distributed system for pollution analysis based on GPRS mobile communications

In this paper the implementation of a distributed system for the control of a chemical analysis system is proposed. This work presents the design of the proposed distributed system, describing the nodes architecture, communications system, control strategies, etc. as well as the chemical implementation aspects, such as selection of parameters to be monitored, analysis techniques, acceptable values, and so on. From the chemical point of view, the parameters to be controlled and their acceptable levels are based on the current legislation. As for the methods of analysis for the detection of pollutants, well-known electrochemical methods are proposed. The communication among the nodes that form the distributed system is implemented by means of the utilization of data transmission services (like GPRS) provided by a mobile telephone operator. The information is processed, integrated and stored in a control centre. These data can be retrieved-through the Internet-so as to know the real-time system status and its evolution.