The problem of guaranteed cost observer-based controller design for a class of singular systems time-delay with uncertainties is investigated.The design method of guaranteed cost observer-based controller is given.Based on linear matrix inequality (LMI) approach, sufficient conditions for the existence of guaranteed cost observer-based state feedback control law and corresponding guaranteed cost performance index are obtained by constructing generalized Lyapunov function.It makes that the closed-loop system is robust stable.
This thesis mainly drawed lessons from the innate immune layer and adaptability immune layer of immune system to construct the urban distribution network warning model. The model can not only analyze running state according to the real-time data of distribution network, but also can evaluate it totally and detect Power accidents quickly and efficiently, so that the distribution network can operate safely. The model also can structure the new accident detector by T cells learning principle to provide a reliable evidence for future events. Finally, this paper verified the validity of the model by the simulation test.
In this paper, we analyze the mutual relationship among parameters in the anti-surge controlling process of centrifugal air compressor; build time-varying system of air compressor for anti-surge; put forward generalized predictive control method based on cascade control; and apply to the governing system which separates the deep and cold air for a certain chemical plant. The results showed that this controlling method can restrain the interferences from uncertain things and harmful effects on the system coming from nonlinearity factors, and can prevent effectively the occurrence of surge phenomena.
As one-cycle controlled three-phase active power filters (APF) only can compensate harmonic and reactive currents simultaneously, this paper uses ip−iq method as harmonic currents detecting circuit and one-cycle control as currents tracing control circuit. The results of simulation verify that this scheme can compensate harmonic and reactive currents effectively and flexibly.
A force identification technique based on simulation models is proposed and applied to predict the concentrated force at the barycenter of an apparatus. Computation procedure of it is given, in which the model updating and verification steps are included. The mode parameters are used as the base datum for FE model updating. Two verification strategies for the force identification results are introduced, and the strategy by comparing the vibration response from simulations with the forces identified as boundary conditions and experimental results has been proved to be efficient. Numerical results showed that the proposed method is valid and can be used for dealing with the engineering problems.
An real-time temperature and humidity measurement system is designed with SHT21 temperature and humidity sensors. Communication is controlled by XC2S50-5TQ144 Field programmable gate array and measurement data can be shown in real time by the PC software. The results show that the system can not only accurately measure the real-time temperature and humidity, but also rapidly respond to the mutations in surroundings temperature. The accuracy of measurement system is up to 0.001 of the requirement and realizes the maximum balance between miniaturization and high performance of system.
This paper is devoted to study the swimming micro robot in liquid on the basis of simulation a wild aquatic animals movement, mainly based on the fish propulsion mechanism. In the paper the theoretical basis and propelling principle are introduced. With the analyzing of kinematics and dynamics of the swimming micro robot, the theoretical model is built up. The resistance during the locomotion of swimming micro robot is analyzed, and a contrast of efficiency between different propulsion modes is given. Some kinds of experimental projects are introduced. With the detailed experimental studying of swimming micro-robot, the results are provided, and the analysis of experimental rules is given.
Developed a fast handover method based on channel quality messages associated with the priority messages in mobile multi-hop relay networks. The Relay Station (RS) and attached all terminals can complete the fast handover in fixed, nomadic, mobile relay station, when add / remove relay station in the existing network, and add / remove relay station, in the existing communication path, through environmental monitoring and Ranging, as well as the new relay station login / login again. Furthermore, To ensure that the channel quality of the communication path after the fast handover, and significantly reduced delay and complexity of handover procedures of the scanning, environmental monitoring and ranging.
Three-dimensional model reconstruction of historic buildings is a hot topic of current research. In order to make a study of the modeling method of historic buildings based on laser scanning and the precision of constructed model, this paper firstly analyzes the whole technological process of building modeling by means of 3D laser scanner, and then on the basis of the comparison between laser scanning-based model and total station-based CAD model, assesses the precision of the constructed model based on laser scanning respectively from three aspects of point position error, geometric body error and the overall error. Practice has proved that building modeling method based on laser scanning is feasible.
In the field of information collection process, we not only pay attention to the environmental temperature, humidity, light, etc, but also hope to accurately locate acquisition nodes. Especially in the study of soil pH and soil nutrients, the soil pH is not uniformly distributed in different regions. In this paper, we constructed a wireless positioning sensor network based on the Zigbee technology, adopting multi-user RSSI algorithm. We designed the hardware and software of the wireless positioning system and finally performed positioning system testing in the field greenhouse.
This paper describes new models for portfolio selection under uncertainty with risk and vagueness aspects which are solved by fuzzy-stochastic methodology. And the corresponding optimal portfolio is derived using minimizing Value-at-risk(VaR). The VaR concept has been extended to the portfolio value-at-risk measure used for managing risk and returns under a multiple-asset portfolio. An approach to modeling risks by VaR under imprecise and fuzzy conditions is discussed. It is supposed that the input data and problem conditions is difficult to determine as real numbers or as some precise distribution functions. Thus, vagueness is modeling through the fuzzy numbers. A numerical example of a portfolio selection problem is given to illustrate our proposed approaches.
The purpose of this paper is to improve the performance of the traditional optimum space-time adaptive processing (STAP). The signal model and the basic idea of the STAP are given, and then a robust STAP algorithm is propounded. In this algorithm, a linear estimation is used to estimate the direction of arrival. Theoretical analysis and simulation results show that the Robust STAP can improve the SINR and robustness of the algorithm.
The estimation of fundamental matrix is one of the most crucial steps in many computer vision applications such as 3D reconstruction, autocalibration and motion segmentation. In this paper, we give a new method for nonlinearly estimating the fundamental matrix from point correspondences using global optimization. We firstly parameterize the fundamental matrix in 7 unknowns in a way that the rank-two constraint is satisfied. Then, the fundamental matrix is estimated by globally minimize non-convex formulation in term of convex (linear matrix inequality) LMI relaxation and standard LMI techniques. In order to obtain robustness, we perform the computation in a RANSAC framework and consider nonlinear criteria minimizing meaningful geometric distances. The iterate process leads the estimation to a more accurate level. Experimental results show the effectiveness of the proposed method.
Quantization index modulation (QIM) technology was always applied to inserting watermark in an additive way formerly. In this paper, we propose the concept of multiplicative distortion-compensated quantized projection (MDC-QP), which differs from the conventional DC-QP in working in a multiplicative way. The locally most powerful (LMP) detector is used to judge whether or not a watermark exists. Its detection performance is characterized by the probability of miss at a given probability of false alarm. Theoretical analysis agrees well with realistic experiment on detection performance.
Product conceptual design has been recognized as a critical decision. It aims at the selection of modules to offer near-optimal solutions of product design scheme and assist designers in product decision-making. It constitutes a combinatorial optimization problem. Conventional enumeration-based optimization techniques become inhibitive given that the number of possible combinations may be enormous. Genetic algorithms have been proven to excel in solving combinatorial optimization problems. This paper develops a genetic algorithm for solving the product conceptual design problem of intelligent instrument more effectively. A binary encoding scheme is presented to represent compositional model of modules. In order to avoid prematurity and convergence out of optimized point for genetic algorithm, a fitness normalization formula is introduced.
For solving level alarm of high pressure vessels or corrosive liquid vessels, a new non-contact level alarm device was designed by using ultrasonic wave. The attenuation characteristics of ultrasonic echo wave remained in the wall of vessels is analyzed when the medium in vessels is liquid or gas. A new method for measuring fixed-point liquid level was proposed by using this principle, and the system of level alarm was proposed. In this way, the transducer is only needed to touch to the outside surface of the wall of vessels. The device is very suitable for measuring fixed-point liquid level of high pressure vessels or corrosive liquid vessels, and has the merits of high sensitivity and reliability.
To the deficiency of marine refrigeration system simulation, marine refrigeration dynamic simulation system was developed based on real-time operation and management. Dynamic mathematical sub-models of marine refrigeration equipment was established by using the MATLAB. Then each sub-model was integrated as a dynamic composite model. In addition, the fault diagnosis, real-time operation and autoevaluation was developed . The result shows that: marine refrigeration system simulation model have the high accuracy and running speed. And the system can satisfy the operation and management requirement of marine refrigeration system in the STCW convention. It has the advantage of good realtime and fully operation function.
A disc shaped Magnetorheological Fluid (MRF) clutch with low idle and high transmittable torque and good long term stability designed and characterized. The torque-transmit ability equations of disc shaped clutch were derived. The problem of particle centrifuging was discussed, and a nondimensional parameter was also put out which clearly specifies the influence of different variables on the stability against demixing of MRF. Experimental results of the designed clutch concerning transmitted torque are presented. It was demonstrated that the clutch is capable of producing high controllable torques.
