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Manufacturing systems are developed and configured using different design tools, e.g. CAD for mechanical construction, CAE for electronic engineering and IDE for software development. These tools work on different views of automation units, which are the basic blocks of manufacturing systems. With this, tool dependent data is generated that relates to automation units involved in the manufacturing...
A static control system architecture cannot meet the demand for continually introducing new parts into manufacturing systems while maintaining high quality and throughput for existing parts; a reconfigurable control infrastructure is needed. Control authority in the factory is typically allocated to three levels: the machine, cell, and system. The machine controllers must be reconfigurable to process...
Tumultuous and dynamic markets demand faster changes in their production systems. Frequent changes in order to implement new functionality is time consuming. Reconfigurability could offer a solution by using standard and open methods to represent information. Machines setup time could be decreased obtaining tested and dependable control modules from the device designer. In this way, control modules...
Automatic fault detection and diagnosis has always been a challenge when monitoring rotating machinery. Specifically, bearing diagnostics have seen an extensive research in the field of fault detection and diagnosis. In this paper we present two automatic diagnosis procedures-a fuzzy classifier and a neural network-which deal with different implementation questions: the use of a priori knowledge,...
This paper discusses a new approach to the development life-cycle of agent-based production control applications, from the design to the operation, based in a catalogue of high-level Petri nets. The high-level Petri net-based approach facilitates the conception, definition and formal specification of an "encapsulation process" in industrial production systems. The catalogue includes elements...
The transfer lines dealt with in this paper are equipped with multifunctional spindle heads, capable to realize several operations in the same time (in parallel) on the same work-piece. Each such multifunctional spindle head is called a block and is fully described by its set of operations, operating time and cost. The reconfigurability concerns here the possibility of realizing a family of products...
This paper outlines the perspectives opened by the application of the service-orientation paradigm for realizing high-level communications between next-generation, increasingly intelligent embedded devices - it indicates how this approach can benefit the manufacturing industry - and outlines the issues and approaches for cohesively coordinating manufacturing services at various levels of the manufacturing...
In this paper we consider a quantized discrete-time linear quadratic regulator (DLQR) problem, namely a DLQR problem where the input u may only take values in a given finite set 14. Eased on our previous results on the optimal control of hybrid systems we show that the optimal control law for the quantized DLQR problem takes the form of a feedback control law, that can be obtained from a partition...
The paper introduces a new event-based criterion for discrete representations of continuous-time signals, which can be used in intelligent sensors to report the current state of the observed object. The criterion is based on the control of the sampling error energy. The analytic approximation of the mean sampling rate for a given sampling resolution is derived. The formula for the reduction of sampling...
The paper presents a layered architecture for real-time surveillance systems. Each layer includes objects that model the "real world" at a specific abstraction level, from raw data up to domain concepts. Each layer performs abstractions on perceptions coming from the lower layer and formulates timed hypotheses about domain objects. The failure of a hypothesis causes a perception to flow...
Localization is essential to modern autonomous robots in order to enable effective completion of complex tasks over possibly large distances in low structured environments. In this paper, a extended Kalman filter is used in order to implement self-localization. This is done by merging odometry and localization information, when available. The used landmarks are colored poles that can be recognized...
This paper presents some new work concentrated on methods and strategies to gain basic features for scene analysis, based on distance measurements with ultrasonic sensors. While in former works object classification is sometimes carried out with special sensor arrangements, our methods are based in principle on continuous movements of single sensors. Sequences of measurement values are analyzed whether...
This paper presents the SC-MER, safety control for Mars exploration rover, an innovative traction control scheme for wheeled mobile vehicles. The system is thought to be used on space mission rovers and is based on fuzzy logic and competitive neural networks to achieve optimal navigation on rough terrain with variable morphology. The main goal of this research is to minimize the power consumption...
Time-triggered systems are advantageous for embedded applications, when determinism, hard real-time behavior, and a straightforward way for certification are required. However, when it comes to flexibility, time-triggered systems often require that possible extensions have been planned in advance, which makes it difficult to apply unforeseen changes to such a system. This paper presents an approach...
The efficient use of the limited energy resources is the key challenge in the design of wireless sensor networks. Due to the paramount importance of the energy conservation, all protocols for these networks have to be designed taking into account their energy consumption. When simulation is used to analyze the performance of any energy-aware algorithm, it is necessary to have the information about...
A reported liability of the controller area network protocol is that it does not provide a clock synchronization service. Therefore, whenever a CAN-based distributed embedded system requires its nodes to have a common time base, clock synchronization has to be implemented by means of an external mechanism. In a previous work, we proposed a fault-tolerant and high-precision clock synchronization protocol...
The precise and "cost-efficient" localization is of particular interest in large wireless sensor networks. For this purpose, the pertinent literature proposes various algorithms, which significantly differ in localization precision, energy consumption, and hardware requirements. One of those algorithms, also known as coarse-grained localization with centroid determination, has received particular...
In this paper we present a new approach to calibrate sensors in sensor networks in an uncontrolled environment. The proposed algorithm makes a model of the distribution of the measured quantity. This model can be used to estimate and correct the bias of the sensor. The proposed, centralized calibration algorithm is a macro-calibration algorithm which tries to improve the system response as a whole,...
The geographically distributed system can be interconnected via an overlay multicast network. In this overlay network the multicast data are routed and replicated on the application layer along a multicast tree. This paper presents the techniques of the network reduction and the multicast tree construction. The multicast tree in the form of shortest path tree (SPT) can be build up upon the linear...
Generally speaking, information usually just gains significance only when it is being processed in the context of own experience and being linked to other information. This article describes the development of a generic model for an IT service catalog which could for instance be adapted and utilized by an IT provider in the field of a service management project. The fundamental idea for developing...
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