Amirkabir International Journal of Modeling, Identification, Simulation & ControlAmirkabir International Journal of Modeling, Identification, Simulation & Control
http://miscj.aut.ac.ir/
Sun, 30 Apr 2017 11:51:06 +0100FeedCreatorAmirkabir International Journal of Modeling, Identification, Simulation & Control
http://miscj.aut.ac.ir/
Feed provided by Amirkabir International Journal of Modeling, Identification, Simulation & Control. Click to visit.Robust MRAC for a Wing Rock Phenomenon in Delta Wing Aircrafts
http://miscj.aut.ac.ir/article_825_0.html
Articles in Press, Accepted Manuscript , Available Online from 12 November 2016<br><br>Wing rock phenomenon is an undesired motion appears in high angles of attack where a rolling in the aircraft in positive and negative roll angles with specified amplitude and frequency is occurred. In this paper two adaptive controllers suggested to control the rolling dynamics under wing rock phenomenon for a delta wing aircraft with presence of disturbance. Disturbance was considered as unmatched disturbance. Classical MRAC and σ-modified MRAC are the targeted controllers. Matlab/Simulink is used to simulate the wing rock phenomenon and to test the designed controllers. The simulated results show that the modified controller gives more robust characteristics than its counterpart; as it could confine different aircraft responses within bounded limits. Moreover, the modified controller shows lower control effort than classical one.Fri, 11 Nov 2016 20:30:00 +0100Generalized Aggregate Uncertainty Measure 2 for Uncertainty Evaluation of a Dezert-Smarandache ...
http://miscj.aut.ac.ir/article_826_0.html
Articles in Press, Accepted Manuscript , Available Online from 12 November 2016<br><br>In this paper, Generalized Aggregated Uncertainty measure 2 (GAU2), as a new uncertainty measure, is considered to evaluate uncertainty in localization of an object using cameras’ images. The theory which is applied in a hierarchical decision making system to combine cameras’ images is Dezert-Smarandache theory. To evaluate decisions, an uncertainty analysis is performed in each level of the decision making system. The supervision is based on the second generalization of Aggregated Uncertainty measure (GAU2) whereas it is applicable for DSmT results. The GAU2 measure in spite of the GAU1 measure can be applied to the problems with unclear frontiers or continuous events. This measure helps to make decisions based on better preference combinations of sensors or methods of fusion. Classic DSmT and hybrid DSmT using extra knowledge, is applied and then uncertainty evaluation is carried out by GAU2 uncertainty measure. Therefore, more accurate and less uncertain results in localizing the object with high conflict sensory data are generated using the decision making system.Fri, 11 Nov 2016 20:30:00 +0100Uncertainty Measurement for Ultrasonic Sensor Fusion Using Generalized Aggregated Uncertainty ...
http://miscj.aut.ac.ir/article_827_0.html
Articles in Press, Accepted Manuscript , Available Online from 12 November 2016<br><br>In this paper, target differentiation based on pattern of data which are obtained by a set of two ultrasonic sensors is considered. A neural network based target classifier is applied to these data to categorize the data of each sensor. Then the results are fused together by Dempster–Shafer theory (DST) and Dezert–Smarandache theory (DSmT) to make final decision. The Generalized Aggregated Uncertainty measure named GAU1, as an extension to the Aggregated Uncertainty (AU) is used to evaluate DSmT. Then the GAU1 and AU as the uncertainty measures are applied to the obtained results of the decision makers to evaluate DSmT and DST accordingly. The introduced configuration for decision making has enough flexibility and robustness to use as a distributed sensor network.Fri, 11 Nov 2016 20:30:00 +0100Partial Eigenvalue Assignment in Discrete-time Descriptor Systems via Derivative State Feedback
http://miscj.aut.ac.ir/article_828_92.html
Volume 48, Issue 2, Autumn 2016, Page 65-74<br><br>A method for solving the descriptor discrete-time linear system is focused. For easily, it is converted to a standard discrete-time linear system by the definition of a derivative state feedback. Then partial eigenvalue assignment is used for obtaining state feedback and solving the standard system. In partial eigenvalue assignment, just a part of the open loop spectrum of the standard linear systems are reassigned, while leaving the rest of the spectrum invariant and for reassigning, similarity transformation is used. Using partial eigenvalue assignment is easier than using eigenvalue assignment. Because by partial eigenvalue assignment, size of matrices and state and input vectors are decreased and stability is kept, too. Also concluding remarks and an algorithm are proposed to the descriptions will be obvious. At the end, convergence of state and input vectors in the descriptor system to balance point (zero) are showed by figures in a numerical example.Sun, 20 Nov 2016 20:30:00 +0100Potentials of Evolving Linear Models in Tracking Control Design for Nonlinear Variable ...
http://miscj.aut.ac.ir/article_829_92.html
Volume 48, Issue 2, Autumn 2016, Page 75-92<br><br>Evolving models have found applications in many real world systems. In this paper, potentials of the Evolving Linear Models (ELMs) in tracking control design for nonlinear variable structure systems are introduced. At first, an ELM is introduced as a dynamic single input, single output (SISO) linear model whose parameters as well as dynamic orders of input and output signals can change through the time. Then, the potential of ELMs in modeling nonlinear time-varying SISO systems is explained. Next, the potential of the ELMs in tracking control of a minimum phase nonlinear time-varying SISO system is introduced. For this mean, two tracking control strategies are proposed respectively for (a) when the ELM is known perfectly and (b) when the ELM model has uncertainties but dynamic orders of the input and output signals are fixed. The methodology and superiority of the proposed tracking control systems are shown via some illustrative examples: speed control in a DC motor and link position control in a flexible joint robot.Sun, 20 Nov 2016 20:30:00 +0100Fault Detection and Isolation of Multi-Agent Systems via Complex Laplacian
http://miscj.aut.ac.ir/article_830_0.html
Articles in Press, Accepted Manuscript , Available Online from 12 November 2016<br><br>This paper studies the problem of fault detection and isolation (FDI) for multi-agent systems (MAS) via complex Laplacian subject to actuator faults. A planar formation of point agents in the plane using simple and linear interaction rules related to complex Laplacian is achieved. The communication network is a directed, and yet connected graph with a fixed topology. The loss of symmetry in the digraph Laplacian matrix is also considered. Both the partial actuator effectiveness and the actuator bias faults are taken into account. For this purpose, a virtual agent whose dynamics structure is identical to that of the leader agent is introduced to determine the center of planar formation. The FDI scheme requires no additional fault isolation model which is a necessary part in the traditional active FDI scheme. Finally, numerical example results are presented to show the effectiveness of the proposed scheme.Fri, 11 Nov 2016 20:30:00 +0100Analysis of critical paths in a project network with random fuzzy activity times
http://miscj.aut.ac.ir/article_831_92.html
Volume 48, Issue 2, Autumn 2016, Page 93-102<br><br>Project planning is part of project management, which is relates to the use of schedules such as Gantt charts to plan and subsequently report progress within the project environment. Initially, the project scope is defined and the appropriate methods for completing the project are determined. In this paper a new approach for the critical path analyzing a project network with random fuzzy activity times has been proposed. The activity times of a project are assumed to be random fuzzy. Linear programming formulation has been applied to determine the critical path. The critical path method (CPM) problem has been solved using the expected duration optimization model and the mean-variance model, along with Liu’s definition for random fuzzy variables. Furthermore, a numerical example problem is solved for illustrating the proposed method.Sun, 20 Nov 2016 20:30:00 +0100A multi-objective integrated production-allocation and distribution planning problem of a ...
http://miscj.aut.ac.ir/article_832_0.html
Articles in Press, Accepted Manuscript , Available Online from 12 November 2016<br><br>Supply chain management (SCM) is a subject that has found so much attention among different commercial and industrial organizations due to competing environment of products. Therefore, integration of constituent element of this chain is a great deal. This paper proposes a multi objective production-allocation and distribution planning problem (PADPP) in a multi echelon supply chain network. We consider multi suppliers, manufacturers, distribution centers, customers, raw materials and products in the multi-time periods. Three objective functions are minimizing of the total costs of supply chain between all echelons, the delivery time of products to customers with decrease flow time in chain, and the lost sales of products in distribution centers. Since the under investigation model is proved as a strongly NP-hard problem, we solve it with two meta-heuristics algorithms, namely genetic algorithm (GA) and particle swarm optimization (PSO). Also, to justify the performance and efficiency of both algorithms, a variable neighborhood search (VNS) is addressed. Design of experiments and response surface methodologies (RSM) have been utilized to calibrate the parameters of both algorithms. Finally, computational results of the algorithms are assessed on some classified generated problems. Statistical tests indicate that proposed GA and PSO algorithms has better performance in solving proposed model in compared to VNS.Fri, 11 Nov 2016 20:30:00 +0100A risk adjusted self-starting Bernoulli CUSUM control chart with dynamic probability control limits
http://miscj.aut.ac.ir/article_833_92.html
Volume 48, Issue 2, Autumn 2016, Page 103-110<br><br>Usually, in monitoring schemes the nominal value of the process parameter is assumed known. However, this assumption is violated owing to costly sampling and lack of data particularly in healthcare systems. On the other hand, applying a fixed control limit for the risk-adjusted Bernoulli chart causes to a variable in-control average run length performance for patient populations with dissimilar risk score distributions in monitoring clinical and surgical performance. To solve these problems, a self-starting scheme is proposed based on a parametric bootstrap method and dynamic probability control limits for the risk-adjusted Bernoulli cumulative sum control charts. The advantage of the proposed control charts lies in the use of probability control limits when any assumptions about the patients’ risk distributions and process parameter. Simulation studies show that both proposed schemes have good performance under various shifts.Sun, 20 Nov 2016 20:30:00 +0100Adaptive Control of a Spin-Stabilized Spacecraft Using two Reaction Wheels and a 1DoF ...
http://miscj.aut.ac.ir/article_834_0.html
Articles in Press, Accepted Manuscript , Available Online from 12 November 2016<br><br>In impulsive orbital maneuvers, a large disturbance torque is generated by the thrust vector misalignment from the center of mass (C.M). The purpose of this paper is to reject the mentioned disturbance and stabilize the spacecraft attitude, based on the combination of a one degree of freedom (1DoF) gimbaled-thruster, two reaction wheels (RWs) and spin-stabilization. In this paper, the disturbances are assumed to be unknown and reaction control systems (RCS) are not employed. The nonlinear two-body dynamics of the proposed system is formulated and validated by the Simmechanics model. The closed-loop controller includes a full state feedback controller based on the gimbal actuator, a self-tuning controller (STC) based on the two RWs and a least squares based disturbance estimator. The simulation results are given by which the applicability of the proposed method is illustrated.Fri, 11 Nov 2016 20:30:00 +0100Integrated production-Inventory model with price-dependent demand, imperfect quality, and ...
http://miscj.aut.ac.ir/article_835_0.html
Articles in Press, Accepted Manuscript , Available Online from 12 November 2016<br><br>In practice, manufacturing systems are never perfect and may have low quality outputs. Therefore, different decisions such as reprocessing, sale at lower prices or diminishing are made according to industry and market. This paper investigates the importance of supply chain coordination through developing two models in centralized decision-making for an imperfect quality manufacturing system with probabilistic defect rate. Moreover, two types of errors in inspection process are considered: Type I error (classifying perfect products as defective ones) and Type II error (classifying defective products as perfect ones). Moreover, a cost function for investment on products quality as well as selling price is considered. The algorithms to find the optimal solution for both models are suggested. Numerical results show that even by less consumer prices; more profit, more satisfied customer, and improved quality can be achieved through coordination in supply chain.Fri, 11 Nov 2016 20:30:00 +0100Time-Invariant State Feedback Control Laws for a Special Form of Underactuated Nonlinear ...
http://miscj.aut.ac.ir/article_836_92.html
Volume 48, Issue 2, Autumn 2016, Page 111-122<br><br>Linear state bisection is introduced as a new method to find time-invariant state feedback control laws for a special form of underactuated nonlinear systems. The specialty of the systems considered is that every unactuated state should be coupled with at least two directly actuated states. The basic idea is based on bisecting actuated states and using linear combinations with adjustable parameters to stabilize the unactuated states. These linear combinations make the underactuated system virtually fullyactuated, making it suitable to be stabilized with well-known nonlinear control methods, like feedback linearization. In addition to its simplicity, one of the main contributions of this method is that it can be applied to systems with more than one unactuated state. Three underactuated systems are considered: an asymmetric rigid body, a planar rigid body with an unactuated internal degree of freedom and a system with two degrees of underactuation. It is shown through simulations that the proposed control laws can be effectively used to stabilize the special form of underactuated systems considered.Sun, 20 Nov 2016 20:30:00 +0100Adaptive Leader-Following and Leaderless Consensus of a Class of Nonlinear Systems Using Neural ...
http://miscj.aut.ac.ir/article_837_92.html
Volume 48, Issue 2, Autumn 2016, Page 123-138<br><br>This paper deals with leader-following and leaderless consensus problems of high-order multi-input/multi-output (MIMO) multi-agent systems with unknown nonlinear dynamics in the presence of uncertain external disturbances. The agents may have different dynamics and communicate together under a directed graph. A distributed adaptive method is designed for both cases. The structures of the controllers simplify their implementation and reduce computational cost. Unknown nonlinearities are estimated by a radial basis function neural network (RBFNN). The ultimate boundness of the closed-loop system is guaranteed through Lyapunov stability analysis by introducing a suitably driven adaptive rule. Finally, the simulation results verify performance of the proposed control method.Sun, 20 Nov 2016 20:30:00 +0100A Genetic Network Programming Model for Pricing of Basket Default Swaps (BDS)
http://miscj.aut.ac.ir/article_838_0.html
Articles in Press, Accepted Manuscript , Available Online from 12 November 2016<br><br>The credit derivatives market has experienced remarkable growth over the past decade. As such, there is a growing interest in tools for pricing of the most prominent credit derivative, the credit default swap (CDS). In this paper, we propose a heuristic algorithm for pricing of basket default swaps (BDS). For this purpose, genetic network programming (GNP), which is one of the recent evolutionary methods with graph structure as a subgroup of machine learning methods, is applied to assess basket default swap spreads. Here GNP is an alternative way for modeling the default correlation structure among different reference entities in a basket default swap. In order to improve the efficiency of the proposed algorithm, GNP with vigorous connection (GNP-VC) is developed and used for the first time in this paper. To implement our model, we consider a basket consisting of 25 entities of the CDX.NA.IG.5Y index. We compare the heuristic results with the Monte Carlo ones and discuss the efficiency of the proposed algorithm. The impact of vigorous connection on the performance of GNP is also reported.Fri, 11 Nov 2016 20:30:00 +0100PDC Control of Time Delay Fuzzy T-S modeled HIV-1 System through Drug Dosage
http://miscj.aut.ac.ir/article_839_0.html
Articles in Press, Accepted Manuscript , Available Online from 12 November 2016<br><br>This paper proposes a Time Delay nonlinear dynamic model of HIV-1 (Human Immunodeficiency Virus type 1), introducing the drug consumption efficiencies as the controlling input for the model. The paper also represents the fuzzy T-S representation and the corresponding Fuzzy T-S controller. The controller parameters are tuned using LMIs (Linear Matrix Inequalities). The main focus is on the stabilization problem for the resulting T-S fuzzy system with time-delay. In particular, it aims to present delay-dependent design of state feedback stabilizing fuzzy controller for the mentioned T-S fuzzy system with state delay. The design of the controller is based on the parallel distributed compensation.Fri, 11 Nov 2016 20:30:00 +0100Thermo-Electro Mechanical Impedance based Structural Health Monitoring: Euler-Bernoulli Beam ...
http://miscj.aut.ac.ir/article_841_0.html
Articles in Press, Accepted Manuscript , Available Online from 12 November 2016<br><br>In recent years, the use of piezoelectric wafer active sensor (PWAS) is increasing as impedance measurement method for non-destructive evaluation (NDE). In this method, the electrical impedance of a bonded PWAS is used to detect any structural defect. The original principle of this method is based on the electromechanical coupling of PZT materials, so any change in a structure lead to a change in mechanical impedance of the structure and electrical impedance of the PWAS can sense this change. Since environmental temperature generate a thermal stress on a structure, therefore electrical impedance of PWAS changes with temperature variation. The thermal stress that affects the output impedance of PWAS is also developed. In addition of considering the temperature dependency of PWAS and structure material properties, a temperature dependent model is considered for a PWAS bonded to an Euler Bernoulli clamped-clamped beam. The Rayleigh-Ritz and spectral element methods have been studied and verified by 3D finite element method (FEM).Fri, 11 Nov 2016 20:30:00 +0100Turbo Expander System Behavior Improvement Using an Adaptive Fuzzy PID Controller
http://miscj.aut.ac.ir/article_842_0.html
Articles in Press, Accepted Manuscript , Available Online from 12 November 2016<br><br>Turbo-expanders are used in industries for cooling, liquefaction and also power generation. An important part of these turbines is the variable angle nozzle causing a nonlinear behavior that is not well recognized among the prime movers of the dispersed generators. In this paper, at first, the turbo expander system is evaluated in details and its nonlinear behavior is investigated. Then, the system is linearized and variations of its eigenvalues are investigated by a system modal analysis for some changes in input gas stream parameters. Afterwards, variations of nozzle angle and output pressure are studied using a conventional PID controller. Due to system nonlinearity, adaptive PID and fuzzy controllers are then designed to improve the system behavior by controlling mechanical parts of turbine nozzle actuator. An adaptive controller uses fuzzy system as a nonlinear tuner that specifies the coefficients for conventional PID controller of the system. A comparison of controllers’ effects is presented. Simulation results show that the turbine response to step changes in gas flow rate or pressure would be more steady when the adaptive or fuzzy controllers are used.Fri, 11 Nov 2016 20:30:00 +0100A New Control for Series Compensation of UPQC to Improve Voltage Sag/Swell
http://miscj.aut.ac.ir/article_843_0.html
Articles in Press, Accepted Manuscript , Available Online from 12 November 2016<br><br>Voltage sag/swell is one of the most frequently power quality problems which affects the power systems with sensitive loads. The unified power quality conditioner (UPQC) is capable of mitigating the effect of voltage sag/swell at the load or point of common coupling (PCC). In this paper, a new control of UPQC is proposed based on combining the sag detection and voltage injection established on d-q frame. The voltage sag is detected based on vector control which can immediately discover all of voltage sag in different directions. This method is used the phase-locked loop and positive-negative sequence to detect the sags and the injected voltage in produced by series converter. The proposed UPQC is investigate in two case studies including the different sags/swells in main bus and forward and backward sags in main and load buses. Also proposed control can improve the other power quality phenomena such as voltage and current harmonics and power factor in the main bus. The simulation results show the accuracy the proposed method.Fri, 11 Nov 2016 20:30:00 +0100NGTSOM: A Novel Data Clustering Algorithm based on Game Theoretic and Self-organizing Map
http://miscj.aut.ac.ir/article_850_0.html
Articles in Press, Accepted Manuscript , Available Online from 15 November 2016<br><br>Identifying clusters is an important aspect of data analysis. The main goal of clustering is to generate compact groups of objects or data that share similar patterns within the same cluster, and isolate these groups from those which contain elements with different characteristics. This paper proposes a novel data clustering algorithm to increase the clustering accuracy. A modified game theoretic self-organizing map (NGTSOM) and neural gas (NG) are used in combination with competitive Hebbian Learning (CHL) to enhance the quality of the map and provide a better vector quantization (VQ) for clustering data. Different strategies are proposed to provide a competitive game for non-winning neurons to participate in the learning phase and obtain more input patterns. The performance of the proposed clustering analysis is evaluated and compared with that of the K-means, the original SOM and NG methods using the different types of data. The clustering results of the proposed method and existing state-of-the-art clustering methods are also compared which demonstrates a better accuracy of the proposed clustering method.Mon, 14 Nov 2016 20:30:00 +0100Conjugate problem of combined radiation and laminar forced convection separated flow
http://miscj.aut.ac.ir/article_853_0.html
Articles in Press, Accepted Manuscript , Available Online from 22 November 2016<br><br>This paper presents a numerical investigation for laminar forced convection flow of a radiating gas in a rectangular duct with a solid element that makes a backward facing step. The fluid is treated as a gray, absorbing, emitting and scattering medium. The governing differential equations consisting the continuity, momentum and energy are solved numerically by the computational fluid dynamics techniques. Since the present problem is a conjugate one and both gas and solid elements are considered in the computational domain, simultaneously, the numerical solution of Laplace equation is obtained in the solid element for temperature calculation in this area. Discretized forms of these equations are obtained using the finite volume method and solved by the SIMPLE algorithm. The radiative transfer equation (RTE) is also solved numerically by the discrete ordinate method (DOM) for computation of the radiative term in the gas energy equation.The streamline and isotherm plots in the gas flow and the distributions of convective, radiative and total Nusselt numbers along the solid-gas interface are presented. Besides, the effects of radiation conduction parameter and also solid to gas conduction ratio as two important parameters on thermo hydrodynamic characteristics of such thermal system are explored. It is revealed that the radiative Nusselt number on the interface surface is much affected by RC parameter but the radiation conduction parameter has not considerable effect on the convective Nusselt number. Comparison between the present numerical results with those obtained by other investigators for the case of non-conjugate problems shows good consistency.Mon, 21 Nov 2016 20:30:00 +0100Near-Optimal Controls of a Fuel Cell Coupled with Reformer using Singular Perturbation methods
http://miscj.aut.ac.ir/article_872_0.html
Articles in Press, Accepted Manuscript , Available Online from 05 December 2016<br><br>A singularly perturbed model is proposed for a system comprised of a PEM Fuel Cell (PEM-FC) with Natural Gas Hydrogen Reformer (NG-HR). This eighteenth order system is decomposed into slow and fast lower order subsystems using singular perturbation techniques that provides tools for separation and order reduction. Then three different types of controllers, an optimal full-order, a near-optimal composite controller based on the slow and fast subsystems, and a near-optimal reduced-order controller based on reduced-order model, are designed. The comparison of closed-loop responses of these three controllers shows that there are minimal degradations in the performance of the composite and the reduced order controllers.Sun, 04 Dec 2016 20:30:00 +0100Output Consensus Control of Nonlinear Non-minimum Phase Multi-agent Systems Using Output ...
http://miscj.aut.ac.ir/article_873_0.html
Articles in Press, Accepted Manuscript , Available Online from 05 December 2016<br><br>This paper concerns the problem of output consensus in nonlinear non-minimum phase systems. The main contribution of the paper is to guarantee achieving consensus in the presence of unstable zero dynamics. To achieve this goal, an output redefinition method is proposed. The new outputs of agents are functions of original outputs and internal states and defined such that the dynamics of agents are minimum phase. However, since the main objective is to achieve consensus on original outputs of agents, the consensus invariant set in the new coordinate of the agents dynamics should be defined such that if the new states of the agents converge to this invariant set, the output consensus in original system is achieved. On the other words, achieving consensus in minimum phase system with redefined output is equivalent to output consensus in original system. After defining the proper invariant set, a consensus protocol is designed to guarantee that the redefined outputs and the internal states to this set. Theoretical results are mathematically proved based on Lyapunov criterion. Numerical examples are employed to show the effectiveness of the proposed approach.Sun, 04 Dec 2016 20:30:00 +0100A Survey on Dynamic Replication Strategies for Improving Response Time in Data Grid Environment
http://miscj.aut.ac.ir/article_874_0.html
Articles in Press, Accepted Manuscript , Available Online from 06 December 2016<br><br>Effective data management is a key issue in a large-scale distributed system such as distributed DBMS, Peer-to-Peer System (P2P), Data Grid, and World Wide Web (WWW). This can be achieved by using a replication technique, which efﬁciently reduces the communication cost and improves the data availability and response time. Different replication strategies can be proposed depending on when, where, and how replicas are created and removed. In this paper, different replication strategies are studied to determine which attributes are considered in a given strategy and which are ignored. A tabular representation of all those parameters is presented to facilitate the future comparison of dynamic replication strategies. This paper also presents some discussion about future work in this direction by proposing some open research challenges.Mon, 05 Dec 2016 20:30:00 +0100A hybrid modeling for continuous casting scheduling problem
http://miscj.aut.ac.ir/article_891_0.html
Articles in Press, Accepted Manuscript , Available Online from 14 January 2017<br><br>This paper deals with a multi-agent-based interval type-2 fuzzy (IT2F) expert system for scheduling of steel continuous casting. Continuous caster scheduling is complex, extensive and needs the expert staff. Therefore, in this study, a distributed multi-agent-based structure is proposed as a solution. The agents used herein can cooperate and coordinate via various communication protocols. To facilitate such communication, an appropriate negotiation protocol (i.e., contract net protocol) is proposed. The due dates specified by expert staff, are represented by IT2F membership functions (MFs). As a part of the objective functions, a simple procedure is proposed for calculating the total earliness and tardiness penalty, when the due date’s MFs are IT2F. The proposed hybrid multi-agent-based system, combines multi agent systems with type-2 fuzzy concepts which conforms to the real-world continuous casting problem.Fri, 13 Jan 2017 20:30:00 +0100Saturated Neural Adaptive Robust Output Feedback Control of Robot Manipulators: An Experimental ...
http://miscj.aut.ac.ir/article_927_0.html
Articles in Press, Accepted Manuscript , Available Online from 27 February 2017<br><br>In this research, an extension of the output feedback tracking controller is proposed and evaluated experimentally for the trajectory tracking of robot manipulators with input saturation. Compared with the output feedback controllers, a radial basis function saturated observer-based controller has been introduced. This technique helps the controller produce feasible control signals for the actuators. As a result, it effectively reduces the risk of the actuators saturation and consequently a better transient response is obtained. Semi-global uniform ultimate boundedness stability of the tracking errors and state estimation errors is guaranteed by Lyapunov stability analysis. Experimental results illustrate the efficiency of the proposed control system.Sun, 26 Feb 2017 20:30:00 +0100Developing a model for measuring the severity of effects caused by interconnected units in ...
http://miscj.aut.ac.ir/article_928_0.html
Articles in Press, Accepted Manuscript , Available Online from 27 February 2017<br><br>For many electronic supply chain networks that can comprise hundreds of companies with over several tiers of suppliers and intermediate customers, there are numerous presenting risks to consider and tackle. In the electronic supply chain, the conditions are even worse, for the characteristics of this supply chain: excessive lean management, global sourcing and the rather more uncertain market demand, electronic companies are forced to manage their supply chains effectively in order to increase efficiency and reactivity. This paper proposes a common mathematical model for estimating severity of interactions between supply chain’s units and how they effect entire supply chain. Based on the model, scholars can model supply chains easily considering interconnected units. Basic characters of supply chains are considered in the model. Units, who are used to simulate the members of supply chains, produce appropriate products by intelligent choices. The relationships among units are connected by their activities then an experimental example is applied in model the proposed model gains its numerical parameters and answers by means of Lingo software.Sun, 26 Feb 2017 20:30:00 +0100Partial Observation in Distributed Supervisory Control of Discrete-Event Systems
http://miscj.aut.ac.ir/article_929_0.html
Articles in Press, Accepted Manuscript , Available Online from 27 February 2017<br><br>Distributed supervisory control is a method to synthesize local controllers with systematic observation of the plant. Since the set algebra preserves relationships between variables and provides a simpler way to develop theories, the observation properties are redefined and corresponding propositions are proved by set algebra, in this paper. Moreover, we use local observation properties, i.e. local normality and local relative observability in order to investigate observation properties of local controllers, which are constructed by any localization algorithm that preserves control equivalency to the monolithic supervisor with respect to the plant. These properties enable us to investigate the observation properties from monolithic to distributed supervisory control. Furthermore, observation equivalence property is defined corresponding to the control equivalence in distributed supervisory control with partial observation. It is proved that, providing observation equivalence of the local controllers to the monolithic supervisor, the control equivalence is satisfied, if and only if the intersection of local events sets is a subset or equal to the global observable events set.Sun, 26 Feb 2017 20:30:00 +0100Adaptive Control for a Telerobotic Surgery System Interacting with Active Soft Tissues
http://miscj.aut.ac.ir/article_931_0.html
Articles in Press, Accepted Manuscript , Available Online from 05 March 2017<br><br>In this paper, stability and control of a bilateral teleopeartion system, interacting with a non-passive soft tissue, for the application of robotic surgeries is considered. Although there are many researches on improving the performance of a teleoperation system, none of them considered an appropriate model for this kind of tissue. First, a new model that indicates major characteristics of a moving soft tissue as the environment of a teleoperation system is presented. The model consists of a viscoelastic passive part and a non-passive part that acts in parallel to the passive part. In prior works, a proper model for the active behavior of tissue was not presented to the best of our knowledge. After that, by considering communication time delays and uncertainties in the master and slave robot dynamics, ultimate bounded-ness of the master and slave trajectories while interacting with this non-passive environment is guaranteed using an adaptive controller and the ultimate bound is calculated. Moreover, some simulations are done to demonstrate the effectiveness of the proposed approach.Sat, 04 Mar 2017 20:30:00 +0100