A novel type of discrete-time fractional-power nonlinear autoregressive with exogenous input (FPNARX) model is introduced for system identification, modeling and prediction. Parameter estimation of such a model is a n...
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A novel type of discrete-time fractional-power nonlinear autoregressive with exogenous input (FPNARX) model is introduced for system identification, modeling and prediction. Parameter estimation of such a model is a nonlinear optimization problem. A harmony search algorithm is then applied to solve such fractional models. Examples of both simulated and real data are provided.
This paper reports on a new Mamdani data-driven fuzzy modelling approach, which makes use of interval type-2 fuzzy sets and employs a multi-objective evolutionary algorithm to optimise the structure and parameters of ...
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This paper reports on a new Mamdani data-driven fuzzy modelling approach, which makes use of interval type-2 fuzzy sets and employs a multi-objective evolutionary algorithm to optimise the structure and parameters of interval type-2 fuzzy models with respect to the predictive accuracy and the complexity of fuzzy models. In order to reduce the computational burden of the interval type-2 fuzzy modelling, a computationally efficient type-reduction technique is developed based on the center-of-sums defuzzifier. As the clustering-based method is utilised to elicit the initial fuzzy model, a new objective function is also introduced to improve the distribution of membership functions in each variable domain. The proposed modelling approach is then tested on a benchmark problem, where it is shown to be able to conduct an interpretable interval type-2 fuzzy model while maintaining a good predictive accuracy. This approach is also applied to the problem of prediction of the mechanical properties of alloy steels, and is shown to perform well.
In this paper, the load and/or grid connected to an inverter is modelled as the combination of voltage sources and current sources at harmonic frequencies. As a result, the system can be analysed at each individual fr...
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ISBN:
(纸本)9781457710957
In this paper, the load and/or grid connected to an inverter is modelled as the combination of voltage sources and current sources at harmonic frequencies. As a result, the system can be analysed at each individual frequency, which avoids the difficulty in defining the reactive power for a system with different frequencies because it is now defined at each individual frequency. Moreover, a droop control strategy is developed for systems delivering power to a constant current source, instead of a constant voltage source. This is then applied to develop a harmonic droop controller so that the right amount of harmonic voltage is added to the inverter reference voltage to compensate the harmonic voltage of the harmonic current dropped on the output impedance. This forces the output voltage at the individual harmonic frequency close to zero and improves the THD of the output voltage considerably. Simulation results are provided to demonstrate the excellent performance of the proposed strategy.
P systems (PSs) are powerful computing models based on the structure of a biological cell and on the way chemicals interact in complex biochemical reactions which take place in various compartments (or membranes) of t...
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Functional Electrical Stimulation (FES) driven cycling using single muscle group, the quadriceps, is achieved using PID controller with a novel assisting mechanism represented by a flywheel with an electrical clutch. ...
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Functional Electrical Stimulation (FES) driven cycling using single muscle group, the quadriceps, is achieved using PID controller with a novel assisting mechanism represented by a flywheel with an electrical clutch. This mechanism is useful for disabled individuals whose muscles are weak and unable to push a fix-geared flywheel. The flywheel is engaged and disengaged by the clutch when necessary to assist or retard the cycling without imposing additional load on the person's leg muscle. A comparison between this new mechanism and a previously proposed method show positive results of the new mechanism towards reducing the number of muscle stimulation which leads to delay muscle fatigue and consequently promoting prolonged FES driven cycling for paralyzed people.
A novel structural health monitoring strategy is proposed in this paper. A baseline model between the operating parameters and measurement features is established firstly to generate the baseline working feature and v...
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A novel structural health monitoring strategy is proposed in this paper. A baseline model between the operating parameters and measurement features is established firstly to generate the baseline working feature and validated. Then a tolerance range of deviation of practical working features from the baseline model is computed based on normal distribution. Furthermore, health probability is defined as the proportion of the number of working status in the corresponding tolerance range. Finally, the effectiveness of such novel structural health monitoring strategy is validated by simulation study and experimental work.
In this paper, an improved multi-objective particle swarm optimization algorithm (mPSO-DHA) with a dynamic hypercube archive (DHA), mutation and population competition is presented to enhance the performance of PSO in...
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ISBN:
(纸本)9781467315104
In this paper, an improved multi-objective particle swarm optimization algorithm (mPSO-DHA) with a dynamic hypercube archive (DHA), mutation and population competition is presented to enhance the performance of PSO in solving multi-objective optimization problems. The proposed algorithm considers a modification of the hyper-cube archiving method originally proposed in 2002 by Coello and Lechuga, and changes the bounds of the objective space dynamically in the optimization process. When the particles are trapped in local Pareto fronts, the algorithm introduces a mutation process in order to help the particles jump out. Also, weight adaptation and pool selection techniques are introduced in order to enhance the local searching ability. The proposed algorithm is applied to a series of wellknown benchmark problems, and results show that it can successfully find the true Pareto front with a good diversity of the solutions. In comparison to several other multi-objective particle swarm optimization algorithms, the proposed scheme showed better performance in solving benchmark functions.
The goal of this paper is to develop a new approach for the Free Flight concept based on neighbouring Optimal control (NOC) that can deliver an aircraft to its designated position safely and reliably when faced with c...
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ISBN:
(纸本)9781467315593
The goal of this paper is to develop a new approach for the Free Flight concept based on neighbouring Optimal control (NOC) that can deliver an aircraft to its designated position safely and reliably when faced with conflicts, and to have some form of recovery measure when the pilot is faced with uncertainty that are due to wind and other uncertainties in the FF environment. The benefits of the algorithm are that it reduces fuel consumption, and it achieves optimal safe inter-aircraft separation while maintaining near-optimality under disturbances.
T In this paper we propose two networked control strategies for a 3 dimensional crane system. The purpose of this approach is enabling the use of Linear Quadratic Regulator (LQR) and Model Predictive control (MPC) for...
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ISBN:
(纸本)9781467345033
T In this paper we propose two networked control strategies for a 3 dimensional crane system. The purpose of this approach is enabling the use of Linear Quadratic Regulator (LQR) and Model Predictive control (MPC) for a fast system by using parallel data acquisition and actuation. By fast systems we understand those which must be sampled at short time rates due to the high dynamics in the system. We first implement an LQR controller which however is not able to keep the physical constraints of the system between the imposed boundaries. Then, we specialized our network control architecture to an MPC scheme such that it is able to take into account the time spent on solving online the optimal solution to an optimization problem. In order to validate our proposed control strategies we have used a laboratory system (a 3 dimensional crane) and the Ethernet communication network. The results show that our network control architecture enables the use of LQR and MPC for fast systems and moreover the desired performances are achieved..
Wound care skills are essential for patients in stable condition after surgery. A nurse must teach wound care skills and explain infection symptoms and signs to patients or their families before discharge to help woun...
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