基于DRNN网络的航空发动机多变量解耦控制

通过分析对角递归神经网络(DRNN)及带动量项的梯度学习方法(GDM),针对某型涡扇发动机的性能控制,研究了基于对角递归神经网络的多变量自学习解耦控制算法及其在航空发动机控制中的应用。阐明了该方法的结构和原理。并在设计点处进行了发动机多变量解耦控制系统设计。在偏离设计点时,大量的仿真结果表明,系统具有较好解耦和自适应能力。

航空发动机多变量自学习模糊解耦控制

提出了一种自学习模糊解耦控制器,将多变量模糊解耦控制和模型参考自学习控制结合起来,利用模糊逆模型在线产生和修正模糊解耦控制系统的规则库。并研究了它在航空发动机上的应用,取得了较好的控制效果。

Two Second-Order Ecient Numerical Schemes for the Boussinesq Equations

In this paper,we construct two fully decoupled,second-order semi-discrete numerical schemes for the Boussinesq equations based on the scalar auxiliary variable(SAV)approach.By introducing a scalar auxiliary variable,the original Boussinesq system is transformed into an equivalent one.Then we discretize it using the second-order backward di erentiation formula(BDF2)and Crank-Nicolson(CN)to obtain two second-order time-advanced schemes.In both numerical schemes,a pressure-correction method is employed to decouple the velocity and pressure.These two schemes possess the desired property that they can be fully decoupled with satisfying unconditional stability.We rigorously prove both the unconditional stability and unique solvability of the discrete schemes.Furthermore,we provide detailed implementations of the decoupling procedures.Finally,various 2D numerical simulations are performed to verify the accuracy and energy stability of the proposed schemes.

Enhancing Effect of Fe^(2+) on the Formaldehyde Production from Trimethylamine N-oxide Decomposition Catalyzed by the Extract of Harpadon nehereus Kidney

The effects of Fe2+ on the trimethylamine N-oxide (TMAO) demethylating activity of the Harpadon nehereus kidney extract were studied in this research.The activity of the kidney extract was presumably inhibited by ethylene diamine tetra-acetic acid (EDTA),which indicates that the kidney extract contains an enzyme or enzyme system with metal cations as activator.Activity of the kidney extract was enhanced significantly when Fe2+ was added into the model system in vitro.As the concentration of Fe2+ increased,the decomposing rate of TMAO increased rapidly until TMAO decomposed completely.The activity of the kidney extract was also enhanced by reductant such as ascorbic acid.Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) was employed to determine the content of total iron in a number of fishery products.Significant positive correlation between the contents of total iron and endogenous formaldehyde (FA) was found,especially in marine products.

Kinematics and dynamics analysis of a 3-7R parallel decoupling mechanism

One kind of movable-pair analysis method is adopted to analyze the configuration of a 3-7R （revolute-pair） parallel decoupling mechanism, and the mechanism＇s characteristics are summarized. The mechanism has three orthogonal distributional branch-chains, and all movable pairs are rotational joints. The movable platform of the mechanism has x, y, z translational decoupling directions. Furthermore, in order to verify the mechanism＇s decoupling characteristics, the mechanism＇s kinematics analysis is solved, and the mechanism＇s direct/inverse kinematics model, input/output velocities and accelerations are deduced, which confirm its decoupling movement characteristics. Finally, one kind of mechanism link decomposed-integrated approach is adopted, and the mechanism＇s dynamics model is completed with the Lagrange method, which also proves its decoupling force characteristics. All of these works provide significant theory for the further study of the mechanism＇s control strategy, design, path planning etc.

STK simulation design for satellite formation tracking mission with bidirectional communication

The problem of satellite formation tracking control is studied by using the tool, the satellite tool kit （STK ） software.To fight against gravitational perturbation rejection, a sliding mode controller for each satellite is proposed to accomplish the orbit trace and is then verified by the STK.For the purpose of accomplishing the formation tracking mission with bidirectional communication in STK,a time-share orderly calling plug-in is designed by C ＋＋,which gives solutions to the problems of the monopolization of computing resource and no return of the satellite identifier in the calculation center. The effectiveness of the decoupling approach is tested and verified by the STK.The simulation results obtained by the STK are more meaningful than those obtained by Matlab.

Kinetics of Thermal Decomposition of Lithium Hexafluorophosphate

With on-line coupled thermo-gravimetric technique, the thermal decomposition of analyzer-Fourier transform infrared spectrometer lithium hexafluorophosphate （LiPF6） and its gas evolution at inert environment （H2O〈10 ppm） were studied under both non-isothermal and isothermal conditions. The results showed that the LiPF6 decomposition is a single-stage reaction with LiF as final residue and PF5 as gas product. In addition, its decomposi- tion kinetics was determined as 2D phase boundary movement （cylindrical symmetry） under both non-isothermal and isothermal conditions. Furthermore, the activation energy of LiPF6 decomposition was calculated as 104 and 92 kJ/mol for non-isothermal and isothermal con- ditions, respectively.

Multivariable Decoupling Predictive Control with Input Constraints and Its Application on Chemical Process

A constrained decoupling (generalized predictive control) GPC algorithm is proposed for MIMO (malti-input multi-output) system. This algorithm takes account of all constraints of inputs and their increments. By solving matrix equations, the multi-step predictive decoupling controllers are realized. This algorithm need not solve Diophantine functions, and weakens the cross-coupling of the variables. At last the simulation results demon- strate the effectiveness of this proposed strategy.

Multivariable Nonlinear Proportional-Integral-Derivative Decoupling Control Based on Recurrent Neural Networks

A nonlinear proportional-integral-derivative (PID) controller is constructed based on recurrent neural networks. In the control process of nonlinear multivariable systems, several nonlinear PID controllers have been adopted in parallel. Under the decoupling cost function, a decoupling control strategy is proposed. Then the stability condition of the controller is presented based on the Lyapunov theory. Simulation examples are given to show effectiveness of the proposed decoupling control.

Studyon hardware-in-the-loopsimulation of beer fermentation system

Beer fermentation process is a complex biochemical reaction process.It is the most important to control temperature of the wort in fermentation tank in accordance with the beer fermentation temperature curve so as to ensure the completion of fermentation.The controlled object is characterized by large inertia,long time delay and mutual coupling of three temperature areas.Based on this,a temperature control method for beer fermentation system is designed.Using digital incremental proportion integration differentiation （PID） control algorithm,the controlled quantity is transmitted to the controlled object after diagonal matrix decoupling.This simulation system can be completed in laboratory using VB and Kingview software,so it has the features of good security and low cost.It is very suitable for experimental teaching.

Photodissociation Spectra of OCS＋ via B2∑＋←X2П Transitions

In the wavelength range of 231-275 nm, we have studied the mass-resolved dissociation spectra of OCS＋ via B2∑＋←X2П3/2（000） and B2∑＋←X2П1/2（000, 001） transitions by preparing OCS＋ ions in the well-defined spin-orbit states. The spectroscopic constants of v1 （CS stretch）=828.9 （810.4） cm-1, u2 （bend）=491.3 cm-1 and v3（CO stretch）=1887.2 cm-1 for OCS＋（B2∑＋） are deduced. The observed dependence of the v2（bend） mode excitation of B2∑＋ on the spin-orbit splitting of X2П（Ω=1/2, 3/2） in the B2∑＋←-X2П transition can be attributed to the K coupling between the （000）2П1/2 and （010）2∑＋/2 vibronic levels of X2П state, which makes the B2∑＋（010）←X2П1/2（000） transition possible.

ESO-based decoupling control with multi-objective optimization for boiler-turbine unit

A model-assistant extended state observer(MESO)-based decoupling control strategy is proposed for boiler-turbine units in the presence of unknown external disturbance and model-plant mismatch. For ease of implementation, the decoupling compensator is reduced to the proportion integration(PI) decoupler with the frequency domain analysis, where the decoupling error in collusion of uncertainties and disturbances can be estimated by the proposed MESO and then compensated. To decrease the sensitivity of the dynamic error for the decoupling control and fulfill various requirements of constraints, such as safety operation, energy conservation, emission reduction, etc., the plant is transmitted through a scheduled steady state region which is achieved from the optimized reference governor in advance. Simulation results show that the proposed control strategy can well suppress various disturbances including a decoupling error, and multi-objective optimization can meet multiple requirements with the premise of safety production.

Disturbance decoupled fault diagnosis for sensor fault of maglev suspension system

A disturbance decoupled fault diagnosis strategy is proposed.This disturbance decoupled fault diagnosis is both robust to disturbances and sensitive to sensor faults of magnetic levitation control system.First,a robust controller based on a novel disturbance observer is devised to improve the disturbance attenuation ability,which greatly enhances the robustness of the system.Second,a fault reconstruction technique with adaptive method is presented,along with a strict verification for guaranteeing the robustness of fault.This fault reconstruction technique provides an accurate sensor fault reconstruction.From the results of simulation and experiments conducted on the CMS-04 maglev train,the integrated strategy is robust to model uncertainties of the system and the fault reconstruction algorithm is able to reconstruct the dynamic uncertain faults.

Nonlinear decoupling controller design based on least squares support vector regression

Support Vector Machines (SVMs) have been widely used in pattern recognition and have also drawn considerable interest in control areas. Based on a method of least squares SVM (LS-SVM) for multivariate function estimation, a generalized inverse system is developed for the linearization and decoupling control of a general nonlinear continuous system. The approach of inverse modelling via LS-SVM and parameters optimization using the Bayesian evidence framework is discussed in detail. In this paper, complex high-order nonlinear system is decoupled into a number of pseudo-linear Single Input Single Output (SISO) subsystems with linear dynamic components. The poles of pseudo-linear subsystems can be configured to desired positions. The proposed method provides an effective alternative to the controller design of plants whose accurate mathematical model is un- known or state variables are difficult or impossible to measure. Simulation results showed the efficacy of the method.

Decoupling Relationship Between Cultivated Land Occupation by Construction and Economic Growth in China During 1998-2007

With the rapid development of economy,the conversion of cultivated land into nonagricultural land occurs more frequently and makes cultivated land sparser.This article based on the decoupling theory takes the situations of cultivated land occupation by construction and economic growth in China from 1998 to 2007 as an example to evaluate and analyze the decoupling.The conclusions are drawn as follows.First,the article applies IU curve and gross method.The decoupling status by gross method,in contrast to that by IU curve,can express the pressure from cultivated land occupation better and is similar to the decoupling status based on the model of decoupling in this article.Second,in most provinces of China,the relationship between the cultivated land occupation by construction and economic growth has transformed from expansive negative decoupling to strong decoupling.In general,the transformation was firstly from economically advanced eastern municipalities under the central government directly,then to economically advanced eastern coastal provinces,and lastly to central,western and northeastern regions.Third,the decoupling status was relative to contemporaneous policies and laws on cultivated land protection and regional development planning.Their effect is obvious and positive.

Neural adaptive PSD decoupling controller and its application in three-phase electrode adjusting system of submerged arc furnace

Taking three-phase electrode adjusting system of submerged arc furnace as study object which has nonlinear, time-variant, multivariable and strong coupling features, a neural adaptive PSD(proportion, sum and differential) dispersive decoupling controller was developed by combining neural adaptive PSD algorithm with dispersive decoupling network. In this work, the production technology process and control difficulties of submerged arc furnace were simply introduced, the necessity of establishing a neural adaptive PSD dispersive decoupling controller was discussed, the design method and the implementation steps of the controller are expounded in detail, and the block diagram of the controlled system is presented. By comparison with experimental results of the conventional PID controller and the adaptive PSD controller, the decoupling ability, adaptive ability, self-learning ability and robustness of the neural adaptive PSD dispersive decoupling controller have been testified effectively. The controller is applicable to the three-phase electrode adjusting system of submerged arc furnace, and it will play an important role for achieving the power balance of three-phrase electrodes, saving energy and reducing consumption in the process of smelting.

A Novel Resource Allocation Algorithm based on Downlink and Uplink Decouple Access Scheme in Heterogeneous Networks

Traditional cellular network requires that a user equipment(UE) should associate to the same base station(BS) in both the downlink(DL) and the uplink(UL). Based on dual connectivity(DC) introduced in LTE-Advanced R12, DL/UL decouple access scheme has been proposed, which is especially suitable for heterogeneous networks(Het Nets). This paper is the pioneer to take the DL/UL decouple access scheme into consideration and develop a novel resource allocation algorithm in a two-tier Het Net to improve the total system throughput in the UL and ease the load imbalance between macro base stations(MBSs) and pico base stations(PBSs). A model is formulated as a nonlinear integer programming, and the proposed algorithm is a sub-optimal algorithm based on the graph theory. First, an undirected and weighted interference graph is obtained. Next, the users are grouped to let users with large mutual interferences to be assigned to different clusters. Then, the users in different clusters are allocated to different resource blocks(RBs) by using the Hungarian algorithm. Simulation results show that the proposed algorithm can provide great promotions for both the total system throughput and the average cell edge user throughput and successfully ease the load imbalance between MBSs and PBSs.

Optimal Boundary Control Method for Domain Decomposition Algorithm

To study the domain decomposition algorithms for the equations of elliptic type, the method of optimal boundary control was used to advance a new procedure for domain decomposition algorithms and regularization method to deal with the ill posedness of the control problem. The determination of the value of the solution of the partial differential equation on the interface——the key of the domain decomposition algorithms——was transformed into a boundary control problem and the ill posedness of the control problem was overcome by regularization. The convergence of the regularizing control solution was proven and the equations which characterize the optimal control were given therefore the value of the unknown solution on the interface of the domain would be obtained by solving a series of coupling equations. Using the boundary control method the domain decomposion algorithm can be carried out.

Genetic Optimization Algorithm of PID Decoupling Control for VAV Air-Conditioning System

Variable-air-volume (VAV) air-conditioning system is a multi-variable system and has multi coupling control loops. While all of the control loops are working together, they interfere and influence each other. A multivariable decoupling PID controller is designed for VAV air-conditioning system. Diagonal matrix decoupling method is employed to eliminate the coupling between the loop of supply air temperature and that of thermal-space air temperature. The PID controller parameters are optimized by means of an improved genetic algorithm in floating point representations to obtain better performance. The population in the improved genetic algorithm mutates before crossover, which is helpful for the convergence. Additionally the micro mutation algorithm is proposed and applied to improve the convergence during the later evolution. To search the best parameters, the optimized parameters ranges should be amplified 10 times the initial ideal parameters. The simulation and experiment results show that the decoupling control system is effective and feasible. The method can overcome the strong coupling feature of the system and has shorter governing time and less over-shoot than non-optimization PID control.

Multi-loop Constrained Iterative Model Predictive Control Using ARX -PLS Decoupling Structure

A multi-loop constrained model predictive control scheme based on autoregressive exogenous-partial least squares(ARX-PLS) framework is proposed to tackle the high dimension, coupled and constraints problems in industry processes due to safety limitation, environmental regulations, consumer specifications and physical restriction. ARX-PLS decoupling character enables to turn the multivariable model predictive control(MPC) controller design in original space into the multi-loop single input single output(SISO) MPC controllers design in latent space.An idea of iterative method is applied to decouple the constraints latent variables in PLS framework and recursive least square is introduced to identify ARX-PLS model. This algorithm is applied to a non-square simulation system and a stirred reactor for ethylene polymerizations comparing with adaptive internal model control(IMC) method based on ARX-PLS framework. Its application has shown that this method outperforms adaptive IMC method based on ARX-PLS framework to some extent.