Implementation of Model Based Networked Predictive Control System

Networked control systems are made up of several computer nodes communicating over a communication channel, cooperating to control a plant. The stability of the plant depends on the end to end delay from sensor to the actuator. Although computational delays within the computer nodes can be made bounded, delays through the communication network are generally unpredictable. A method which aims to protect the stability of the plant under communication delays and data loss, Model Based Predictive Networked Control System (MBPNCS), has previously been proposed by the authors. This paper aims to demonstrate the implementation of this type of networked control system on a non-real-time communication network; Ethernet. In this paper, we first briefly describe the MBPNCS method, then discuss the implementation, detailing the properties of the operating system, communications and hardware, and later give the results on the performance of the Model Based Predictive Networked Control System implementation controlling a DC motor. This work was supported in part by the Scientific and Technological Re search Council of Turkey, project code 106E155

Realization of reactive control for multi purpose mobile agents

Mobile robots are built for different purposes, have different physical size, shape, mechanics and electronics. They are required to work in real-time, realize more than one goal simultaneously, hence to communicate and cooperate with other agents. The approach proposed in this paper for mobile robot control is reactive and has layered structure that supports multi sensor perception. Potential field method is implemented for both obstacle avoidance and goal tracking. However imaginary forces of the obstacles and of the goal point are separately treated, and then resulting behaviors are fused with the help of the geometry. Proposed control is tested on simulations where different scenarios are studied. Results have confirmed the high performance of the method

Wireless model-based predictive networked control system over cooperative wireless network

Owing to their distributed architecture, networked control systems (NCSs) are proven to be feasible in scenarios where a spatially distributed feedback control system is required. Traditionally, such NCSs operate over real-time wired networks. Recently, in order to achieve the utmost flexibility, scalability, ease of deployment, and maintainability, wireless networks such as IEEE 802.11 wireless local area networks (LANs) are being preferred over dedicated wired networks. However, conventional NCSs with event-triggered controllers and actuators cannot operate over such general purpose wireless networks since the stability of the system is compromised due to unbounded delays and unpredictable packet losses that are typical in the wireless medium. Approaching the wireless networked control problem from two perspectives, this work introduces a practical wireless NCS and an implementation of a cooperative medium access control protocol that work jointly to achieve decent control under severe impairments, such as unbounded delay, bursts of packet loss and ambient wireless traffic. The proposed system is evaluated on a dedicated test platform under numerous scenarios and significant performance gains are observed, making cooperative communications a strong candidate for improving the reliability of industrial wireless networks

Modele dayalı öngörülü ağ baglantılı kontrol sistemi

Ağ bağlantılı kontrol sistemlerinin endüstriyel alandaki ihtiyaçları karşılayan çeşitli avantajları vardır. Uygulamalar karmaşıklaştıkça ağ bağlantılı kontrol sistemlerinin kullanımının kaçınılmaz hale gelmesi beklenmektedir. Ancak haberleşme ağının neden olduğu belirsiz gecikmeler ve veri kayıpları, çevrim dinamiklerini olumsuz etkilemekte ve kararsızlıklara sebep olabilmektedir. Bu çalışmada veri gecikmesi ve kaybı ile algılayıcı gürültüsü gibi ideal olmayan durumlarda da çalışabilen bir ağ bağlantılı kontrol sistem mimarisi tanıtılacaktır. Yapı olarak, kontrol edilen sistemin bir modelinin, kontrolörün de içinde bulundurulması sayesinde haberleşme ağının neden olduğu kayıplar ve gecikmelerin kompanze edilmesi sağlanmaktadır. Model sayesinde, öngörülmüş kontrol çıktıları hesaplanıp haberleşme gerçekleşemediği durumlarda sistemin bunlarla kontrolü sayesinde yüksek derecede veri kayıplarında bile kararsızlıg˘ın önlenmesi amaçlanmaktadır. Önerilen yöntemde kontrol edilen sistemin durumu ile kontrolör içindeki modelin durumunun eşleştirilmesi önemli bir problem haline gelmektedir. Bu yapı bilgisayar, kontrol ve haberleşme dallarının özelliklerini kullanarak her birinin eksiğini tamamlamaya yönelik olup, çeşitli kontrol metotlarıyla kullanılmaya açıktır. Önerilen Modele Dayalı Öngörülü¨ Ağ Bağlantılı Kontrol Sistemi (MODOAKOS) benzetim yolu ile bir doğru akım motorunun kontrolüne uygulanmıştır. Normal ağ bağlantılı kontrol sistemin kararlılığını bozucu gecikme ve kayıplar varken bile önerilen sistem altında kontrol uygulandığında kararlı çalışma bozulmamış ancak referans girişine olan cevabın geciktiği gözlenmiştir

Linear motor for multi-car elevators, design and position measurement

Multi-car elevator is an emerging technology consisting of two or more elevator cars moving independently in an elevator hoistway, which has become more appealing as building heights increase. In this paper, the design and drive methodologies for a linear motor driven multi-car elevator system with independently moving cars is introduced together with experimental results. Additionally, a safety method developed for the linear motor elevator and the conditions necessary for its proper operation are discussed. The new results introduced in this paper are in the areas of the design method of the linear motor for multi-car elevator system, and the preliminary results for the position measurement system

Design and implementation of a linear motor for multi-car elevators

The multi-car elevator system is a revolutionary new technology for high-rise buildings, promising outstanding economic benefits, but also requiring new technology for propulsion, safety and control. In this paper we report on experimental results with new components for linear motor driven multi-car elevators. We show that linear synchronous motors with optimized design and with our new safety and control system can be considered as core components of a new generation of elevator systems. The main new results concern the development of a safety system integrated into the propulsion system, the design methodology of a linear motor optimized for the multi-car elevator task, and the motion control system that is expected to be usable for extra high-rise buildings

Threat Construction and Framing of Cyberterrorism in the U.S. News Media

This research aims to explore the influence of news media on the fear of cyberterrorism and how cyberterrorism is framed in the media. Using a mixed-method approach as a research strategy, this paper reports on two studies that explore the influence of news reading on the fear of cyberterrorism. The first study analyzed survey responses from 1,190 participants and found that increased exposure to reading news media was associated with increased fear of cyberterrorism. The second study, built on the first, sought to investigate how cyberterrorism is framed and constructed as a threat by the US local and national newspapers. The framing and portrayal of cyberterrorism in US newspapers are discussed

Tuning scaling factors of fuzzy logic controllers via reinforcement learning policy gradient algorithms

In this study a gain scheduling method for the scaling factors of the input variables to the fuzzy logic controller by means of policy gradient reinforcement learning algorithms has been proposed. The motivation for using PG algorithms is that they can scale RL problems into continuous high dimensional state-action spaces without the need for function approximation methods. Without incorporating any apriori knowledge of the plant, the proposed method optimizes the cost function of the learning algorithm and tries to find optimal solutions for the scaling factors of the fuzzy logic controller. To show the effectiveness of the proposed method it has been applied to a PD type fuzzy controller along with a nonlinear model of an inverted pendulum. By performing different simulations, it is observed that the proposed method can find optimal solutions within a small number of learning iterations

Protective Effects of Rosuvastatin on Kidney in Experimental Hypertension Rats Models

Purpose: Hypertension is responsible for approximately 30% of patients who reach end-stage renal disease. Statin is known to reduce the risk of developing kidney disease. In this study, the changes in caspase-3 and fibrillin1 in the kidney tissue of rats with hypertension using L-NAME were investigated along with how rosuvastatin affected the changes caused by hypertension on these proteins. Materials and Methods: 18 Wistar Albino male rats weighing 200-220 g were used in the study. The rats were divided into 3 groups with 6 animals in each group (1.Control, 2.Hypertension, 3.Rosuvastatin).To induce hypertension, rats were given L-NAME for 7 weeks. After the second week, rosuvastatin was given by oral gavage for 5 weeks. Blood pressure values were evaluated on days 0, 14, 28, 42. At the end of the experiment, all rats were sacrificed and caspase-3 and fibrillin1 levels were evaluated. Results: Blood pressures were found to be higher in the hypertension group on the 14th, 28th, and 42nd days (p=0.001). Rosuvastatin caused a decrease that was found to be insignificant at 28th, 42nd days. Caspase-3 (p=0.001), fibrillin1 (p=0.001) immunoreactivity were found to be increased in the hypertension group. Compared with the hypertension group, caspase-3 (p=0.031), fibrillin1 (p=0.030) immunoreactivity were decreased in the rosuvastatin group. However, caspase-3 (p=0.036) and fibrillin1 (p=0.041) immunoreactivity was increased in the rosuvastatin group compared to the control group. Conclusion: Although rosuvastatin didn’t significantly decrease blood pressure, it is thought that caspase-3 and fibrillin1 may mediate its protective effect on hypertensive kidneys