Amirkabir University of Technology
AUT Journal of Modeling and Simulation
2588-2953
2588-2961
48
2
2016
11
21
Partial Eigenvalue Assignment in Discrete-time Descriptor Systems via Derivative State Feedback
65
74
EN
Sakineh
Mirassadi
Ph.D. Student, Department of Mathematics, Shahrood University of Technology
s.mirassadi@shahroodut.ac.ir
Hojat
Ahsani Tehrani
Associate Professor, Department of Mathematics, Shahrood University of Technology
hahsani@shahroodut.ac.ir
10.22060/miscj.2016.828
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.
Descriptor Discrete-Time System,Derivative State Feedback,Partial Eigenvalue Assignment,Converge to Balance Point
http://miscj.aut.ac.ir/article_828.html
http://miscj.aut.ac.ir/article_828_ef3a423cf6d24473c80bbeb45cd3704d.pdf
Amirkabir University of Technology
AUT Journal of Modeling and Simulation
2588-2953
2588-2961
48
2
2016
11
21
Potentials of Evolving Linear Models in Tracking Control Design for Nonlinear Variable Structure Systems
75
92
EN
Ahmad
Kalhor
Assistant Professor, School of Electrical and Computer Engineering, University of Tehran
akalhor@ut.ac.ir
Nima
Hojjatzadeh
M.Sc. Student, Faculty of New Sciences and Technologies, University of Tehran
nhojjatzadeh@ut.ac.ir,
Alireza
Golgouneh
M.Sc. Student, Faculty of New Sciences and Technologies, University of Tehran
golgouneh@ut.ac.ir
10.22060/miscj.2016.829
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.
Evolving linear model,nonlinear time-varying systems,tracking control system
http://miscj.aut.ac.ir/article_829.html
http://miscj.aut.ac.ir/article_829_de01177a091e0b46a404606f77aa9ffe.pdf
Amirkabir University of Technology
AUT Journal of Modeling and Simulation
2588-2953
2588-2961
48
2
2016
11
21
Analysis of critical paths in a project network with random fuzzy activity times
93
102
EN
Abolfazl
Kazemi
Assistant Professor, Faculty of Industrial and Mechanical Engineering, Islamic Azad University (Qazvin Branch)
abkaazemi@gmail.com
Ahmad
Talebi
M.Sc., Faculty of Industrial and Mechanical Engineering, Islamic Azad University (Qazvin Branch)
a.talebi@yahoo.com
Mahsa
Oroojeni Mohammad Javad
Ph.D., Department of Mechanical and Industrial Engineering, Northeastern University, Boston, USA
oroojeni.m@husky.neu.edu
10.22060/miscj.2016.831
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 Liuâ€™s definition for random fuzzy variables. Furthermore, a numerical example problem is solved for illustrating the proposed method.
Critical Path Method (CPM),Activity Times,Random Fuzzy Time,Triangular Fuzzy Numbers,Normal Distribution
http://miscj.aut.ac.ir/article_831.html
http://miscj.aut.ac.ir/article_831_cf37bb9dc970e9477f154b19241c6e30.pdf
Amirkabir University of Technology
AUT Journal of Modeling and Simulation
2588-2953
2588-2961
48
2
2016
11
21
A risk adjusted self-starting Bernoulli CUSUM control chart with dynamic probability control limits
103
110
EN
Majid
Aminnayeri
Associate Professor, Department of Industrial Engineering, Amirkabir University of Technology
mjnayeri@aut.ac.ir
Fatemeh
Sogandi
Ph.D. Student, Department of Industrial Engineering, Amirkabir University of Technology
f.sogandi1990@gmail.com
10.22060/miscj.2016.833
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 patientsâ€™ risk distributions and process parameter. Simulation studies show that both proposed schemes have good performance under various shifts.
Average Run Length,Self-Starting Monitoring,Bernoulli Process,Probability Control Limits,Surgical Performance
http://miscj.aut.ac.ir/article_833.html
http://miscj.aut.ac.ir/article_833_4ffc38712924fe9b18808b580670cc7e.pdf
Amirkabir University of Technology
AUT Journal of Modeling and Simulation
2588-2953
2588-2961
48
2
2016
11
21
Time-Invariant State Feedback Control Laws for a Special Form of Underactuated Nonlinear Systems Using Linear State Bisection
111
122
EN
Rouzbeh
Moradi
Ph.D. Student, Aerospace Research Institute, Ministry of Science, Research and Technology
roozbeh_moradi_aerospace@yahoo.com
Alireza
Alikhani
Assistant Professor, Aerospace Research Institute, Ministry of Science, Research and Technology
aalikhani@ari.ac.ir
Mohsen
Fathi Jegarkandi
Assistant Professor, Aerospace Department, Sharif University of Technology
fathi@sharif.edu
10.22060/miscj.2016.836
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.
Underactuation,Feedback linearization,State bisection
http://miscj.aut.ac.ir/article_836.html
http://miscj.aut.ac.ir/article_836_444d1146e87f28f3d555f1c33007d079.pdf
Amirkabir University of Technology
AUT Journal of Modeling and Simulation
2588-2953
2588-2961
48
2
2016
11
21
Adaptive Leader-Following and Leaderless Consensus of a Class of Nonlinear Systems Using Neural Networks
123
138
EN
Bahram
Karimi
Associated Professor, Department of Electrical Engineering, Malek-e Ashtar University of Technology
bkarimi@mut-es.ac.ir
Hassan
Ghiti Sarand
Assistant Professor, Department of Electrical Engineering, Malek-e Ashtar University of Technology
hghsarand@mut-es.ac.ir
10.22060/miscj.2016.837
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.
Adaptive control,Consensus,MIMO systems,Neural Networks,multi-agent systems
http://miscj.aut.ac.ir/article_837.html
http://miscj.aut.ac.ir/article_837_5d29e3b7aa92e10bed079a8133a97d86.pdf