1,017 research outputs found
Nonlinear system identification and control using state transition algorithm
By transforming identification and control for nonlinear system into
optimization problems, a novel optimization method named state transition
algorithm (STA) is introduced to solve the problems. In the proposed STA, a
solution to a optimization problem is considered as a state, and the updating
of a solution equates to a state transition, which makes it easy to understand
and convenient to implement. First, the STA is applied to identify the optimal
parameters of the estimated system with previously known structure. With the
accurate estimated model, an off-line PID controller is then designed optimally
by using the STA as well. Experimental results have demonstrated the validity
of the methodology, and comparisons to STA with other optimization algorithms
have testified that STA is a promising alternative method for system
identification and control due to its stronger search ability, faster
convergence rate and more stable performance.Comment: 20 pages, 18 figure
Identification of Linear / Nonlinear Systems via the Coyote Optimization Algorithm (COA)
Classical techniques used in system identification, like the basic least mean square method (LMS) and its other forms; suffer from instability problems and convergence to a locally optimal solution instead of a global solution. These problems can be reduced by applying optimization techniques inspired by nature. This paper applies the Coyote optimization algorithm (COA) to identify linear or nonlinear systems. In the case of linear systems identification, the infinite impulse response (IIR) filter is used to constitute the plants. In this work, COA algorithm is applied to identify different plants, and its performance is investigated and compared to that based on particle swarm optimization algorithm (PSOA), which is considered as one of the simplest and most popular optimization algorithms. The performance is investigated for different cases including same order and reduced-order filter models. The acquired results illustrate the ability of the COA algorithm to obtain the lowest error between the proposed IIR filter and the actual system in most cases. Also, a statistical analysis is performed for the two algorithms. Also, the COA is used to optimize the identification process of nonlinear systems based on Hammerstein models. For this purpose, COA is used to determine the parameters of the Hammerstein models of two different examples, which were identified in the literature using other algorithms. For more investigation, the fulfillment of the COA is compared to that of some other competitive heuristic algorithms. Most of the results prove the effectiveness of COA in system identification problems
From model-driven to data-driven : a review of hysteresis modeling in structural and mechanical systems
Hysteresis is a natural phenomenon that widely exists in structural and mechanical systems. The characteristics of structural hysteretic behaviors are complicated. Therefore, numerous methods have been developed to describe hysteresis. In this paper, a review of the available hysteretic modeling methods is carried out. Such methods are divided into: a) model-driven and b) datadriven methods. The model-driven method uses parameter identification to determine parameters. Three types of parametric models are introduced including polynomial models, differential based models, and operator based models. Four algorithms as least mean square error algorithm, Kalman filter algorithm, metaheuristic algorithms, and Bayesian estimation are presented to realize parameter identification. The data-driven method utilizes universal mathematical models to describe hysteretic behavior. Regression model, artificial neural network, least square support vector machine, and deep learning are introduced in turn as the classical data-driven methods. Model-data driven hybrid methods are also discussed to make up for the shortcomings of the two methods. Based on a multi-dimensional evaluation, the existing problems and open challenges of different hysteresis modeling methods are discussed. Some possible research directions about hysteresis description are given in the final section
Coverage and Field Estimation on Bounded Domains by Diffusive Swarms
In this paper, we consider stochastic coverage of bounded domains by a
diffusing swarm of robots that take local measurements of an underlying scalar
field. We introduce three control methodologies with diffusion, advection, and
reaction as independent control inputs. We analyze the diffusion-based control
strategy using standard operator semigroup-theoretic arguments. We show that
the diffusion coefficient can be chosen to be dependent only on the robots'
local measurements to ensure that the swarm density converges to a function
proportional to the scalar field. The boundedness of the domain precludes the
need to impose assumptions on decaying properties of the scalar field at
infinity. Moreover, exponential convergence of the swarm density to the
equilibrium follows from properties of the spectrum of the semigroup generator.
In addition, we use the proposed coverage method to construct a
time-inhomogenous diffusion process and apply the observability of the heat
equation to reconstruct the scalar field over the entire domain from
observations of the robots' random motion over a small subset of the domain. We
verify our results through simulations of the coverage scenario on a 2D domain
and the field estimation scenario on a 1D domain.Comment: To appear in the proceedings of the 55th IEEE Conference on Decision
and Control (CDC 2016
Video Superresolution via Parameter-Optimized Particle Swarm Optimization
Video superresolution (VSR) aims to reconstruct a high-resolution video sequence from a low-resolution sequence. We propose a novel particle swarm optimization algorithm named as parameter-optimized multiple swarms PSO (POMS-PSO). We assessed the optimization performance of POMS-PSO by four standard benchmark functions. To reconstruct high-resolution video, we build an imaging degradation model. In view of optimization, VSR is converted to an optimization computation problem. And we take POMS-PSO as an optimization method to solve the VSR problem, which overcomes the poor effect, low accuracy, and large calculation cost in other VSR algorithms. The proposed VSR method does not require exact movement estimation and does not need the computation of movement vectors. In terms of peak signal-to-noise ratio (PSNR), sharpness, and entropy, the proposed VSR method based POMS-PSO showed better objective performance. Besides objective standard, experimental results also proved the proposed method could reconstruct high-resolution video sequence with better subjective quality
Video Superresolution via Parameter-Optimized Particle Swarm Optimization
Video superresolution (VSR) aims to reconstruct a high-resolution video sequence from a low-resolution sequence. We propose a novel particle swarm optimization algorithm named as parameter-optimized multiple swarms PSO (POMS-PSO). We assessed the optimization performance of POMS-PSO by four standard benchmark functions. To reconstruct high-resolution video, we build an imaging degradation model. In view of optimization, VSR is converted to an optimization computation problem. And we take POMS-PSO as an optimization method to solve the VSR problem, which overcomes the poor effect, low accuracy, and large calculation cost in other VSR algorithms. The proposed VSR method does not require exact movement estimation and does not need the computation of movement vectors. In terms of peak signal-to-noise ratio (PSNR), sharpness, and entropy, the proposed VSR method based POMS-PSO showed better objective performance. Besides objective standard, experimental results also proved the proposed method could reconstruct high-resolution video sequence with better subjective quality
Linear Regression Models Applied to Imperfect Information Spacecraft Pursuit-evasion Differential Games
Within satellite rendezvous and proximity operations lies pursuit-evasion differential games between two spacecraft. The extent of possible outcomes can be mathematically bounded by differential games where each player employs optimal strategies. A linear regression model is developed from a large data set of optimal control solutions. The model is shown to map pursuer relative starting positions to final capture positions and estimate capture time. The model is 3.8 times faster than the indirect heuristic method for arbitrary pursuer starting positions on an initial relative orbit about the evader. The linear regression model is shown to be well suited for on-board implementation for autonomous mission planning
PHM overview on battery models approaches
The Battery Management Systems (BMS) brought a new impetus to the battery energy
management which lead to an increase in battery life. But the BMS fails when the State
of Charge (SoC), State of Health (SoH), State of Life (SoL) or Remaining Useful Life
(RUL) prognostics systems do not provide the required accuracy. Despite the increase of
complexity and accuracy of battery models, the poor performance with floating
temperature and load profiles persists. With the development of innovative products on
wide-ranging applications, the battery materials, technologies, reliability and safety are
being pressed to their limits. Therefore, a huge amount of work is still necessary, not only
on the development of new battery technologies but also on the BMS, battery models and
metrics accuracy improvements. The paper gives a comprehensive overview of the
applicability, accuracy, weaknesses and advantages of the most recent battery models.
The paper will also discuss how the Prognostics Health Management (PHM) can support
a technologic impetus on battery affairs with battery models and metrics accuracy
improvements.info:eu-repo/semantics/publishedVersio
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