per
Iranian Society of Instrumentation and Control Engineers
Journal of Control
2008-8345
2538-3752
2022-12
16
3
1
9
article
Design and Implementation of Discrete Time Observer Based Backstepping Controller for a 2DOF Servomechanism
Mostafa Darabi Moghadam
mostafadarabi@rocketmail.com
1
Ahmadreza Vali
ar.vali@gmail.com
2
Seyed Mahdi Hakimi
sm_hakimi83@yahoo.com
3
Vahid Behnamgol
vahid_behnamgol@mut.ac.ir
4
Ghasem Derakhshan
gh.derakhshan@yahoo.com
5
Islamic Azad University, Damavand Branch
Malek Ashtar University of Technology
Islamic Azad University, Damavand Branch
Malek Ashtar University of Technology
Islamic Azad University, Damavand Branch
The two degrees of freedom servomechanism has many applications, including in gimbaled seekers. These mechanisms require closed-loop control to perform properly. In this paper, an observer-based multi-input-multi-output hybrid controller is designed for a two-degree-of-freedom servomechanism. Since in the model presented in this paper, disturbances on the mechanism are considered, so an extended state observer to estimate disturbance term to improve the controller performance. Also, due to the nonlinearity and two input- two output dynamics of these mechanisms, the use of combined nonlinear multivariate control methods to control the angle in these mechanisms will increase efficiency. For this purpose, nonlinear auxiliary control inputs are first determined in the first step. Then, in the second step, the nonlinear control input vector is determined using the multi-input-multi-output linear feedback method. In this step, a discrete time observer is used to estimate the uncertainty. The simulation results show that the proposed observer accurately estimates the disturbance and provides it to the controller. The controller designed using this information is able to control the output angles. Also, the results of the controller implementation designed in the processor in the loop test are presented.
http://joc.kntu.ac.ir/article-1-921-en.pdf
2DOF Servomechanism
Backstepping Control
Discrete-Time observer
PIL test.
per
Iranian Society of Instrumentation and Control Engineers
Journal of Control
2008-8345
2538-3752
2022-12
16
3
11
24
article
A class of multi-agent discrete hybrid non linearizable systems: Optimal controller design based on quasi-Newton algorithm for a class of sign-undefinite hessian cost functions
Erfan Nejabat
erfan.nejabat@gmail.com
1
Mohammad Reza Homaeinezhad
mrhomaeinezhad@kntu.ac.ir
2
Faculty of Mechanical Engineering, K. N. Toosi University of Technology
Faculty of Mechanical Engineering, K. N. Toosi University of Technology
In the present paper, a class of hybrid, nonlinear and non linearizable dynamic systems is considered. The noted dynamic system is generalized to a multi-agent configuration. The interaction of agents is presented based on graph theory and finally, an interaction tensor defines the multi-agent system in leader-follower consensus in order to design a desirable controller for the noted system. A general undirected, simple and connected graph topology is proposed for the system. Next, a nonlinear controller is designed for the multi-agent system to track a predefined reference trajectory and maintain the formation topology. An optimal controller, based on quasi-Newton optimization method is proposed in order to minimize a nonlinear cost function with indefinite variable sign hessian matrix. The convergence of previous optimization algorithms, namely the Newton optimization algorithm, regarding to variable sign hessian matrices fails. Thus, in the present paper, a quasi-newton optimization method is proposed based on eigenvalue modification to design a controller for the system. Afterward, the controller generalized for the multi-agent system and the performance of the controller is examined in a specific scenario of indefinite, variable hessian matrix problem. Consequently, the innovation of the present paper is proposed by considering the quasi-newton optimization method in order to overcome the disadvantages of traditional optimization methods in the problem of undefined hessian cost function. An example is provided in order to illustrate aforementioned claims and declared propositions.
http://joc.kntu.ac.ir/article-1-909-en.pdf
Eigenvalue Modification
Graph Theory
Multi-Agent System
Quasi-Newton Optimization
per
Iranian Society of Instrumentation and Control Engineers
Journal of Control
2008-8345
2538-3752
2022-12
16
3
25
34
article
Designing a hybrid quantum controller for strongly eigenstate controllable systems
Tahereh Azizpour
azizpor.tahereh@gmail.com
1
Majid Yarahmadi
yarahmadi.m@lu.ac.ir
2
Lorestan University
Lorestan University
In this paper, a new quantum hybrid controller for controlling the strongly eigenstate controllable systems, is designed. For this purpose, a Lyapunov control law is implemented when the target state is in reachable set of the initial state. On the other hand, if the target state is not in the reachable set of the given initial state, based on Grover algorithm, a new interface state that the target state is in its reachable set, will be found and the given initial state is transferred to the new interface state. Then, the new interface state is transferred to the target state, based on a designed Lyapunov control law. A new algorithm, for implementing the presented method, is designed. Finally, a simulated example illustrates the applications and advantages of presented method.
http://joc.kntu.ac.ir/article-1-896-en.pdf
Hybrid Control
State Transformation
Quantum Controller
Grover Algorithm
Strongly Eigenstate Controllable.
per
Iranian Society of Instrumentation and Control Engineers
Journal of Control
2008-8345
2538-3752
2022-12
16
3
35
46
article
Hybrid model predictive control of a nonlinear three-tank system based on the proposed compact form of piecewise affine model
Mohammad Bitarafan
m.bitarafan@modares.ac.ir
1
Amin Ramezani
ramezani@modares.ac.ir
2
Tarbiat Modares University
Tarbiat Modares University
In this paper, a predictive control based on the proposed hybrid model is designed to control the fluid height in a three-tank system with nonlinear dynamics whose operating mode depends on the instantaneous amount of system states. The use of nonlinear hybrid model in predictive control leads to a problem of mixed integer nonlinear programming (MINLP) which is very complex and time consuming to solve. One way to solve this problem is to approximate nonlinear equations with linear or piecewise affine (PWA) expressions. The linear approximation often has a large error in calculating the operating modes and the system states. The PWA approximation produces less error than the linear approximation, but its computational load is much higher. In this study, with the aim of reducing the computational load, a closed form model has been obtained for the equations of the three-tank system in each of the modes. The resulting system is an PWA, each mode being described by an PWA expression. Predictive control of this system is a mixed integer linear programming problem that can be solved by conventional solvers. To evaluate the performance of the proposed method and the possibility of using it online, the optimal control input sequence is calculated using MOSEK commercial solver in MPT toolbox, and at any sampling time only the first member of the sequence is applied to the precise modeled three-tank system in the Simulink/Stateflow environment. The simulation results indicate that the proposed controller performs the tracking efficiently and the constraints on the system states are also satisfied.
http://joc.kntu.ac.ir/article-1-900-en.pdf
Model predictive control (MPC)
Hybrid system
Three-tank system
Piecewise affine (PWA) approximation
Mixed logical dynamical system (MLD)
per
Iranian Society of Instrumentation and Control Engineers
Journal of Control
2008-8345
2538-3752
2022-12
16
3
47
58
article
New Optimal Observer Design Based on State Prediction for a Class of Non-linear Systems Through Approximation
Majid Hajatipour
hajatipour@kashanu.ac.ir
1
Saeed Kashefi
s.kashefi@grad.kashanu.ac.ir
2
University of Kashan, Kashan
University of Kashan, Kashan
This paper deals with the optimal state observer of non-linear systems based on a new strategy. Despite the development of state prediction in linear systems, state prediction for non-linear systems is still challenging. In this paper, to obtain a future estimation of the system states, initially Taylor series expansion of states in their receding horizons was achieved to any specified order and then an analytic solution was developed for the prediction error problem, which resulted in a closed-form for non-linear optimal observer. In the proposed observer, the observer gain was optimally chosen among gains obtained from the analytic solution of the prediction error problem and satisfied the stability condition. Finally, the qualitative simulation results showed the effectiveness of the proposed method in the state observation.
http://joc.kntu.ac.ir/article-1-923-en.pdf
Non-linear systems
Optimal observer
State Prediction
Stability analysis
per
Iranian Society of Instrumentation and Control Engineers
Journal of Control
2008-8345
2538-3752
2022-12
16
3
59
69
article
2-DoF Self-tuning Fuzzy PID Controller for Under-actuated Inverted Pendulum System with Uncertainties in Model
Sama Nazeran
samanazeran@yahoo.com
1
Mohammad Farrokhi
farrokhi@iust.ac.ir
2
Iran University of Science and Technology
Iran University of Science and Technology
In this manuscript, the laboratory inverted pendulum mounted on a cart has been controlled using 2-DOF self-tuning fuzzy PID controller. The robustness of the proposed method is investigated against the uncertainties in the system’s parameters and external disturbances. Moreover, the proposed method is tested against measurement noises. Stability of the proposed method is investigated using Bode diagrams in frequency domain. Performance of the 2Dof-fuzzy-PID controller is compared with the 2-DoF PID controller. The practical results indicates better performance of the proposed method.
http://joc.kntu.ac.ir/article-1-848-en.pdf
2 DOF PID controller
laboratory inverted pendulum
parametric uncertainty
external disturbance
fuzzy system
per
Iranian Society of Instrumentation and Control Engineers
Journal of Control
2008-8345
2538-3752
2022-12
16
3
71
82
article
Back-stepping calibration algorithm for three-axial magnetometer applied to autonomous underwater vehicles with magnetic deviations
Hossein Nourmohammadi
hnourmohammadi@mut.ac.ir
1
Mohammad Taghi Sabet
sabet_mt@mut.ac.ir
2
Malek Ashtar University of technology
Malek Ashtar University of technology
Heading estimation is one of the main challenges in low-cost inertial navigation systems (INSs). Non-observability of heading angle with gravitational acceleration vector as well as inaccessibility of radio/satellite navigation in underwater vehicles increases the value of this challenge. Applying three-axis magnetometer and heading estimation from earth magnetic field components is one of the main approaches to accuracy enhancement of the low-cost inertial navigation systems. However, in order to achieve accurate heading estimation, the magnetometer must be appropriately calibrated for both sensor errors and presence of magnetic deviations. This paper aims to develop back-stepping algorithm for magnetometer calibration applied to measure the earth magnetic field components. In the proposed algorithm, the results of the prevalent spherical magnetic calibration are corrected based on vertical channel decomposition and magnetic field components in the horizontal plane. The algorithm is evaluated in the field tests executed on an Autonomous Underwater Vehicle (AUV).
http://joc.kntu.ac.ir/article-1-920-en.pdf
Three-axis magnetometers
Back-stepping calibration
Underwater vehicles
Low-cost inertial navigation