Harmony search optimization for robust pole assignment in union regions for synthesizing feedback control systems

2017 ◽  
Vol 40 (6) ◽  
pp. 1956-1969 ◽  
Author(s):  
Junchang Zhai ◽  
Liqun Gao ◽  
Steven Li
Keyword(s):  
Control Systems ◽  
Discrete Time ◽  
Continuous Time ◽  
Search Algorithm ◽  
Harmony Search ◽  
Pole Assignment ◽  
Harmony Search Algorithm ◽  
Time System ◽  
Feedback Control Systems ◽  
Time Systems

This paper is concerned with robust pole assignment optimization for synthesizing feedback control systems via state feedback or observer-based output feedback in specified union regions using the harmony search algorithm. By using exact pole placement theory and the harmony search algorithm, robust pole assignment for linear discrete-time systems or linear continuous-time systems in union regions can be converted into a global dynamical optimization problem. The robust measured indices are derived for robust union region stability constraints and a robust [Formula: see text] performance. For the nonlinear, robust measured indices, a set of dynamic poles and the corresponding feedback controllers can be obtained by global dynamic optimization based on the harmony search algorithm and the idea of robust exact pole assignment. One key merit of the proposed approach is that the radius or the position of the sub-regions can be arbitrarily specified according to the transient performance request. Furthermore, the eigenstructure of the closed-loop system matrix can be optimized with better robustness for the proposed approach. Finally, the simulation results for a discrete-time system and a continuous-time system demonstrate the effectiveness and superiority of the proposed method.

Discrete-time approximationsfor continuous-time Markoviancontrol systems

1984 ◽  
Vol 16 (1) ◽  
pp. 15-16
Author(s):  
A. Hordijk ◽  
F. A. Van Der Duyn Schouten
Keyword(s):  
Decision Theory ◽  
Discrete Time ◽  
Continuous Time ◽  
Time System ◽  
Time Approximation ◽  
Discrete Time Systems ◽  
Discrete Time Approximation ◽  
And Control ◽  
Time Systems ◽  
Continuous Time System

The method of discrete-time approximation is widespread in control and decision theory. However, little attention has been paid to the conditions on parameters and control under which the discrete-time systems come close to the continuous-time system.

scholarly journals Invariance under discretization for positive systems

2021 ◽  
Author(s):  
Zbigniew Bartosiewicz
Keyword(s):  
Nonlinear Systems ◽  
Control Systems ◽  
Discrete Time ◽  
Continuous Time ◽  
Positive Systems ◽  
Time System ◽  
Fundamental Properties ◽  
Linear And Nonlinear ◽  
Linear And Nonlinear Systems ◽  
Continuous Time System

AbstractPositive dynamical or control systems have all their variables nonnegative. Euler discretization transforms a continuous-time system into a system on a discrete time scale. Some structural properties of the system may be preserved by discretization, while other may be lost. Four fundamental properties of positive systems are studied in the context of discretization: positivity, positive stability, positive reachability and positive observability. Both linear and nonlinear systems are investigated.

scholarly journals An Improved Global Harmony Search Algorithm for the Identification of Nonlinear Discrete-Time Systems Based on Volterra Filter Modeling

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Zongyan Li ◽  
Deliang Li
Keyword(s):  
Discrete Time ◽  
Search Algorithm ◽  
Harmony Search ◽  
Solution Space ◽  
Cauchy Distribution ◽  
Genetic Mutation ◽  
The Other ◽  
Volterra Model ◽  
Discrete Time Systems ◽  
Time Systems

This paper describes an improved global harmony search (IGHS) algorithm for identifying the nonlinear discrete-time systems based on second-order Volterra model. The IGHS is an improved version of the novel global harmony search (NGHS) algorithm, and it makes two significant improvements on the NGHS. First, the genetic mutation operation is modified by combining normal distribution and Cauchy distribution, which enables the IGHS to fully explore and exploit the solution space. Second, an opposition-based learning (OBL) is introduced and modified to improve the quality of harmony vectors. The IGHS algorithm is implemented on two numerical examples, and they are nonlinear discrete-time rational system and the real heat exchanger, respectively. The results of the IGHS are compared with those of the other three methods, and it has been verified to be more effective than the other three methods on solving the above two problems with different input signals and system memory sizes.

scholarly journals On the Properties of Reachability, Observability, Controllability, and Constructibility of Discrete-Time Positive Time-Invariant Linear Systems with Aperiodic Choice of the Sampling Instants

2007 ◽  
Vol 2007 ◽  
pp. 1-23 ◽  
Author(s):  
M. De la Sen
Keyword(s):  
Discrete Time ◽  
Continuous Time ◽  
Linear Time ◽  
Time System ◽  
Linear Time Invariant ◽  
The Matrix ◽  
Metzler Matrix ◽  
Time Invariant ◽  
Time Systems ◽  
Continuous Time System

This paper investigates the properties of reachability, observability, controllability, and constructibility of positive discrete-time linear time-invariant dynamic systems when the sampling instants are chosen aperiodically. Reachability and observability hold if and only if a relevant matrix defining each of those properties is monomial for the set of chosen sampling instants provided that the continuous-time system is positive. Controllability and constructibility hold globally only asymptotically under close conditions to the above ones guaranteeing reachability/observability provided that the matrix of dynamics of the continuous-time system, required to be a Metzler matrix for the system's positivity, is furthermore a stability matrix while they hold in finite time only for regions excluding the zero vector of the first orthant of the state space or output space, respectively. Some related properties can be deduced for continuous-time systems and for piecewise constant discrete-time ones from the above general framework.

scholarly journals Performance of Optimum Tuned PID Controller with Different Feedback Strategies on Active-Controlled Structures

2021 ◽  
Vol 11 (4) ◽  
pp. 1682
Author(s):  
Serdar Ulusoy ◽  
Gebrail Bekdaş ◽  
Sinan Melih Nigdeli ◽  
Sanghun Kim ◽  
Zong Woo Geem
Keyword(s):  
Control Systems ◽  
Pid Controller ◽  
Search Algorithm ◽  
Harmony Search ◽  
Harmony Search Algorithm ◽  
Flower Pollination Algorithm ◽  
Acceleration Feedback ◽  
Feedback Strategies ◽  
Structural Responses ◽  
Controlled Structures

In this study, multi-story structures with different combinations (on each floor and only the first floor) of active tendon control systems driven by a proportional–integral–derivative (PID) controller were actively controlled. The PID parameters, Kp (proportional gain), Td (derivative gain), and Ti (integral gain) for each structure, were optimally tuned by using both the harmony search algorithm (HS) and flower pollination algorithm (FPA), which are metaheuristic algorithms. In two different active-controlled structures, which are formed according to the position of the PID, the structural responses under near-fault records defined in FEMA P-695 are examined to determine the appropriate feedback which was applied for displacement, velocity, acceleration, and total acceleration. The performance of the different feedback strategies on these two active-controlled structures is evaluated. As a result, the acceleration feedback is suitable for all combinations of the active control system with a PID controller. The HS algorithm outperforms the optimum results found according to the FPA.

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