The estimation of accurate values of aircraft flow angles namely angle of attack (AOA) and angle of sideslip (AOSS) is a crucial step in the safe flight operation and aircraft modeling. The airdata measurement is sole...
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The estimation of accurate values of aircraft flow angles namely angle of attack (AOA) and angle of sideslip (AOSS) is a crucial step in the safe flight operation and aircraft modeling. The airdata measurement is solely dependent on the data from sensors installed on aircraft, and such sensor data is prone to errors due to flow distortion at aircraft body and sensor misalignment. Further, the online estimation of airdata measurement is more cost-effective and is of more relevance in autonomous flight applications. This work focuses on the online estimate of aircraft flow angles in the presence of atmospheric turbulence using an adaptive sequential estimation algorithm. The proposed estimator has the potential to accurately estimate the AOA and AOSS even in the adverse effect of external disturbance like atmospheric turbulence. (C) 2020, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.
The mobile network is the most establishing communication technology nowadays, In order to support its high speed data rate in real time process it often use adaptive algorithms. But in fact, the performance of freque...
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Applications have different preferences for caches, sometimes even within the different running phases. Caches with fixed parameters may compromise the performance of a system. To solve this problem, we propose a real...
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Applications have different preferences for caches, sometimes even within the different running phases. Caches with fixed parameters may compromise the performance of a system. To solve this problem, we propose a real-time adaptive reconfigurable cache based on the decision tree algorithm, which can optimize the average memory access time of cache without modifying the cache coherent protocol. By monitoring the application running state, the cache associativity is periodically tuned to the optimal cache associativity, which is determined by the decision tree model. This paper implements the proposed decision tree-based adaptive reconfigurable cache in the GEM5 simulator and designs the key modules using Verilog HDL. The simulation results show that the proposed decision tree-based adaptive reconfigurable cache reduces the average memory access time compared with other adaptive algorithms.
In this brief, a robust correntropy-based adaptive learning algorithm, called the adaptive kernel recursive maximum correntropy criterion, is proposed by considering an adaptive kernel size based on the Kullback-Leibl...
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In this brief, a robust correntropy-based adaptive learning algorithm, called the adaptive kernel recursive maximum correntropy criterion, is proposed by considering an adaptive kernel size based on the Kullback-Leibler divergence minimization. Simulation results confirm that the proposed algorithm can perform better than other adaptive algorithms especially when the environment is disturbed by non-Gaussian noises. The proposed algorithm is beneficial for using in helicopters, since the pilot speech signal is contaminated by the acoustic impulsive noises that are originated from rotor blades.
This paper introduces a new adaptive mixed differential evolution (NAMDE) algorithm for mechanical design optimisation problems. The algorithm uses a self-adaptive mechanism to update the values of mutation and crosso...
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This paper introduces a new adaptive mixed differential evolution (NAMDE) algorithm for mechanical design optimisation problems. The algorithm uses a self-adaptive mechanism to update the values of mutation and crossover factors. Moreover, elitism is used where the best-found individual in each generation is retained. The performance of NAMDE is evaluated by solving 11 well-known constrained mechanical design problems and two industrial applications. Further, comparison results between NAMDE and other recently published methods, for the first problems, clearly illustrate that the proposed approach is an important alternative to solve current real-world optimisation problems. Besides this, new optimal solutions for some engineering problems are obtained and reported in this paper. For the coupling with a bolted rim problem, the objective function improved by 10%. Whereas for the spur minimisation problem, the final design provides a reduction in gearing mass by 7.5% compared to those published in previous works.
Accurate picking of first-arrival times is important in many seismic studies, particularly in seismic tomography and reservoirs or aquifers monitoring. Many techniques have been developed, mainly for seismological pur...
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Accurate picking of first-arrival times is important in many seismic studies, particularly in seismic tomography and reservoirs or aquifers monitoring. Many techniques have been developed, mainly for seismological purposes, in order to pick first arrivals automatically or semi-automatically. However, these techniques do not reach the accuracy required in shallow seismics due to the complexity of near-surface structures and low signal-to-noise ratio. We propose here a new adaptive algorithm to automatically pick first arrival in near-surface seismic data by combining three picking methods: multi-nested windows, higher order statistics, and Akaike information criterion. They benefit from combining different properties of the signal in order to highlight first arrivals and finally to provide an efficient and robust automatic picking. This strategy mimics the human first-break picking, where a global trend is first defined at the beginning of the picking procedure. The exact first breaks are then sought in the vicinity of each point suggested by this trend. Three successive phases are combined in a multistage algorithm, each of them characterizing a specific signal property. Within each phase, the potential picks and their error range are automatically assessed and sequentially used as prior constraints in the following phase picking. Since having realistic estimates of the error in picked traveltimes is crucial for seismic tomography, our adaptive algorithm automatically provides picked arrival times with their associated uncertainties. We demonstrate the accuracy and robustness of the implemented algorithm using synthetic, pseudo-synthetic and real datasets that pose challenges to classical automatic pickers. A comparison of both manual and adaptive picking procedures demonstrates that our new scheme provides more reliable results even under different noisy conditions. All parameters of our multi-method algorithm are self-adaptive, thanks to the sequential integration
Aiming at the problem of fault diagnosis in continuous time systems, a kind of fault diagnosis algorithm based on adaptive nonlinear proportional integral (PI) observer, which can realize the effective fault identific...
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Aiming at the problem of fault diagnosis in continuous time systems, a kind of fault diagnosis algorithm based on adaptive nonlinear proportional integral (PI) observer, which can realize the effective fault identification, is studied in this paper. Firstly, the stability and stability conditions of fault diagnosis method based on the PI observer are analyzed, and the upper bound of the fault estimation error is given. Secondly, the fault diagnosis algorithm based on adjustable nonlinear PI observer is designed and constructed, it is analyzed and we proved that the upper bound of fault estimation under this algorithm is better than that of the traditional method. Finally, the L-1011 unmanned aerial vehicle (UAV) is taken as the experimental object for numerical simulation, and the fault diagnosis method based on adaptive observer factor achieves faster response speed and more accurate fault identification results.
The STM32 series single-chip microcomputer is used as the controller to control the stepping motor through the L9110S motor drive module, thereby affecting the gap of the cone valve. At the same time, the Wheatstone b...
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ISBN:
(纸本)9781728167824
The STM32 series single-chip microcomputer is used as the controller to control the stepping motor through the L9110S motor drive module, thereby affecting the gap of the cone valve. At the same time, the Wheatstone bridge and the amplifier are used to form a differential amplifier circuit to collect the platinum resistance temperature signal. Use adaptive algorithm to ensure the temperature of the water is stable while taking into account the temperature regulation. The cold water inlet is reasonably restricted to make the temperature of the thermostatic valve constant under variable flow conditions.
Efficient and accurate simulation of unsteady flow presents a significant challenge that needs to be overcome in computational fluid dynamics (CFD). Temporal discretization method plays a crucial role in the simulatio...
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Efficient and accurate simulation of unsteady flow presents a significant challenge that needs to be overcome in computational fluid dynamics (CFD). Temporal discretization method plays a crucial role in the simulation of unsteady flows. To enhance computational efficiency, we propose the implicit-explicit two-step Runge-Kutta (IMEX-TSRK) time-stepping discretization methods for unsteady flows, and develop a novel adaptive algorithm that correctly partitions spatial regions to apply implicit or explicit methods. The novel adaptive IMEX-TSRK schemes effectively handle the numerical stiffness of the small grid size and improve computational efficiency. Compared to implicit and explicit Runge-Kutta (RK) schemes, the IMEX-TSRK methods achieve the same order of accuracy with fewer first derivative calculations. Numerical case tests demonstrate that the IMEX-TSRK methods maintain numerical stability while enhancing computational efficiency. Specifically, in high Reynolds number flows, the computational efficiency of the IMEX-TSRK methods surpasses that of explicit RK schemes by more than one order of magnitude, and that of implicit RK schemes several times over.
For a coal-fired boiler, it is always a difficult problem to reconstruct the internal temperature field. Due to the complex environment inside the furnace, the traditional reconstruction methods are not suitable for t...
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For a coal-fired boiler, it is always a difficult problem to reconstruct the internal temperature field. Due to the complex environment inside the furnace, the traditional reconstruction methods are not suitable for the furnace, so the current mainstream methods are based on the characteristics of the furnace internal flame image to reconstruct the temperature field. But the flame image inside the furnace is easily affected by external factors, especially the background. Therefore, it is very important to detect the edge of the flame image and extract the separate flame image for the subsequent temperature field reconstruction. For this purpose, a new edge detection method is proposed in this paper. First, a new rule is designed for color image to gray *** rule can improve the gray difference between flame target and background area. Then the threshold segmentation algorithm is used to preprocess the flame gray image, and a new weighted edge image calculation method is designed to capture more details of the flame edge. Finally, an adaptive double threshold algorithm is used to remove the false edge in the flame edge. The simulation results show that the method is effective and can detect the continuous flame edge very well. It is of great practical value for the temperature field reconstruction in the furnace.
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