11,615 research outputs found
Fuzzy Feedback Scheduling of Resource-Constrained Embedded Control Systems
The quality of control (QoC) of a resource-constrained embedded control
system may be jeopardized in dynamic environments with variable workload. This
gives rise to the increasing demand of co-design of control and scheduling. To
deal with uncertainties in resource availability, a fuzzy feedback scheduling
(FFS) scheme is proposed in this paper. Within the framework of feedback
scheduling, the sampling periods of control loops are dynamically adjusted
using the fuzzy control technique. The feedback scheduler provides QoC
guarantees in dynamic environments through maintaining the CPU utilization at a
desired level. The framework and design methodology of the proposed FFS scheme
are described in detail. A simplified mobile robot target tracking system is
investigated as a case study to demonstrate the effectiveness of the proposed
FFS scheme. The scheme is independent of task execution times, robust to
measurement noises, and easy to implement, while incurring only a small
overhead.Comment: To appear in International Journal of Innovative Computing,
Information and Contro
Intelligent systems in manufacturing: current developments and future prospects
Global competition and rapidly changing customer requirements are demanding increasing changes in manufacturing environments. Enterprises are required to constantly redesign their products and continuously reconfigure their manufacturing systems. Traditional approaches to manufacturing systems do not fully satisfy this new situation. Many authors have proposed that artificial intelligence will bring the flexibility and efficiency needed by manufacturing systems. This paper is a review of artificial intelligence techniques used in manufacturing systems. The paper first defines the components of a simplified intelligent manufacturing systems (IMS), the different Artificial Intelligence (AI) techniques to be considered and then shows how these AI techniques are used for the components of IMS
Feedback scheduling of real-time control systems with resource constraints
This thesis observes the emerging trend of convergence of control with computing and communication. By exploiting control and scheduling codesign, we study some practical and open problems in RTCSs from a unique viewpoint of dynamic resource management. Considering constraints on three representative kinds of resources, i.e. CPU time, energy, and network bandwidth, we present a set of feedback scheduling methods that exploit a unified technological framework. They provide enabling technologies for closed-loop dynamic resource scheduling, and tackle some essential problems in the emerging field of feedback scheduling. Meanwhile, this thesis holistically addresses the problem of dynamic allocation of bottleneck resources within RTCSs, thus providing flexible QoC management mechanisms and achieving overall performance optimization under dynamic environmentsFacultad de Informátic
Fuzzy Logic Control Based QoS Management in Wireless Sensor/Actuator Networks
Wireless sensor/actuator networks (WSANs) are emerging rapidly as a new
generation of sensor networks. Despite intensive research in wireless sensor
networks (WSNs), limited work has been found in the open literature in the
field of WSANs. In particular, quality-of-service (QoS) management in WSANs
remains an important issue yet to be investigated. As an attempt in this
direction, this paper develops a fuzzy logic control based QoS management
(FLC-QM) scheme for WSANs with constrained resources and in dynamic and
unpredictable environments. Taking advantage of the feedback control
technology, this scheme deals with the impact of unpredictable changes in
traffic load on the QoS of WSANs. It utilizes a fuzzy logic controller inside
each source sensor node to adapt sampling period to the deadline miss ratio
associated with data transmission from the sensor to the actuator. The deadline
miss ratio is maintained at a pre-determined desired level so that the required
QoS can be achieved. The FLC-QM has the advantages of generality, scalability,
and simplicity. Simulation results show that the FLC-QM can provide WSANs with
QoS support.Comment: 13 pages, 8 figures; Open Access at http://www.mdpi.org/sensor
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