Aiming at the multivariable coupling characteristics and the complexity of its control inside the concrete curing box,this paper firstly analyzes the coupling relationship between temperature and humidity in the curin...
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Aiming at the multivariable coupling characteristics and the complexity of its control inside the concrete curing box,this paper firstly analyzes the coupling relationship between temperature and humidity in the curing box, and uses the decoupling strategy of the feedforward compensation algorithm. The simulation results show that the decoupling effect is good. Then, based on the principle of the self-adjusting function on the transient performance of the system, a self-adjusting factor fuzzy controller is designed, which combines the decoupling method and the self-adjusting function to improve the control effect of the coupling variable of temperature and humidity inside the concrete curing box.
A new concept of a synchronous detector for Giant Magneto-Impedance(GMI) sensors is presented. This concept combines a lock-in amplifier, with outstanding capabilities, high speed and a feedback approach that ensure...
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A new concept of a synchronous detector for Giant Magneto-Impedance(GMI) sensors is presented. This concept combines a lock-in amplifier, with outstanding capabilities, high speed and a feedback approach that ensures the amplitude detection with easily adjustable gain. The synchronous detector is capable of measuring high-frequency and very low amplitude signals without the use of diode-based active rectifiers or analog switches. In comparison with most of the commercially available diode-based peak detectors, the linearity of the synchronous detector is generally better, especially for low level amplitudes. The synchronous detector has been used for the amplitude measurement of single frequency sine signal and for the demodulation of amplitude-modulated signal. It has also been successfully integrated in a GMI sensor prototype. Magnetic field measurements in open-and closed-loop of this sensor have been conducted. The measured sensitivity was about 1.02 V/Oe in open-loop while it was 0.12 V/Oe in close-loop. The above research provides technical accumulation for the design of sensor nodes based on GMI sensor wireless sensor networks.
Deep drilling is a costly project and efficiency is of paramount importance. The weight on bit is one of the main operating parameters that influences the drilling efficiency and it was controlled by manual before. Bu...
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Deep drilling is a costly project and efficiency is of paramount importance. The weight on bit is one of the main operating parameters that influences the drilling efficiency and it was controlled by manual before. But after people saw the giant potential of an auto-drilling system in increasing the drilling efficiency, more and more studies on the feed back control of weight on bit have emerged. This paper mainly studied weight on bit dynamic under the variational formation based on a lumped parameter model and a self-tuning PID controller for weight on bit control. The parameters of the PID controller are tuned by using gradient descent method and RBF neural network identification.
In this paper, a new unscented Kalman filter(Unscented Kalman filter, UKF) for nonlinear system with both one-step randomly delayed measurements and colored measurement noises is proposed. Firstly, the first-order Mar...
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In this paper, a new unscented Kalman filter(Unscented Kalman filter, UKF) for nonlinear system with both one-step randomly delayed measurements and colored measurement noises is proposed. Firstly, the first-order Markov sequence model is used to whiten colored noise, at the same time, an independent and identically distributed Bernoulli variable is used to model the delay of measurement data transmission, then the model of nonlinear one-step randomly time delay system with colored noise whitening is established. Secondly, filter recursion formula of UKF under the above model is proposed through unscented transformation(Unscented transformation, UT) to calculate the posterior mean and covariance of the nonlinear state based on the Bayesian filter framework. The proposed new UKF method can effectively deal with the issue that traditional UKF is failure under the condition of one-step randomly delayed measurements and colored measurement noises. The efficiency and superiority of the proposed method are illustrated in a numerical example for a target tracking problem.
For the control problem of redundant manipulators with joint limits constraints, a novel method combining the simplified clamping weighted least-norm method and the typical gradient projection method is proposed in th...
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For the control problem of redundant manipulators with joint limits constraints, a novel method combining the simplified clamping weighted least-norm method and the typical gradient projection method is proposed in this paper. The method solves the problem that the manipulability of the redundant manipulator is poor caused by the clamping weighted least-norm method and makes the joint velocity change more smoothly. The proposed novel method is implemented on a kinematic redundant manipulator with four degree-of-freedom(DOF) which belongs to the dulcimer music-playing robot. The numerical simulation results show that the joint positions are well-bounded within the joint limits and the manipulator has a good performance for tracking a given trajectory.
This paper presents a novel single-parameter optimization method for extracting coupling matrix from either measured or electromagnetic simulated S-parameters of a narrow band coaxial-resonator filter with losses. Hav...
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This paper presents a novel single-parameter optimization method for extracting coupling matrix from either measured or electromagnetic simulated S-parameters of a narrow band coaxial-resonator filter with losses. Having had the polynomials of the S-parameters of a filter by the Cauchy method with removing phase shift, the rational polynomials can be *** the rational polynomials having been determined, a single-parameter optimization method is proposed to obtain ε and the coupling matrix with an assigned topology, which can be extracted using well established techniques. The measured Sparameters compared with the S-parameters obtained from the coupling matrix, and the attenuation factor K is easily *** loss effects will be removed after obtaining the value of the attenuation factor K. The approach is useful and can be used in computer-aided tuning of microwave filters. Example is presented to illustrate the validity of the proposed method.
Aiming at the detection of moving objects in video series, a moving object detection algorithm based on background difference method and inter-frame difference method is proposed. A new background update method is pro...
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Aiming at the detection of moving objects in video series, a moving object detection algorithm based on background difference method and inter-frame difference method is proposed. A new background update method is proposed to update the unchanged background area into the background frame. Experiments show that this method overcomes the problems of false detection and empty in the previous detection algorithms. The method can meet the need of real-time detection and tracking of moving targets with the advantages of high accuracy and fast calculation speed.
Remote sensing hyperspectral imaging can obtain rich spectral information of terrestrial objects, which allows the indistinguishable matter in the traditional wideband remote sensing to be distinguished in hyperspectr...
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Remote sensing hyperspectral imaging can obtain rich spectral information of terrestrial objects, which allows the indistinguishable matter in the traditional wideband remote sensing to be distinguished in hyperspectral remote *** image has the characteristics of "combining image with spectrum". Making full use of spectral information and spatial information in hyperspectral image is the premise of obtaining accurate classification results. At present, most of hyperspectral data feature extraction algorithms mainly utilize local spatial information in the same channel and spectral information in the same spatial location of different channels. However, these methods require a large amount of prior knowledge, it is difficult to fully grasp the hyperspectral data of all spatial and spectral information, and the model generalization ability is poor. With the development of deep learning, convolutional neural network shows superior performance in all kinds of visual tasks, especially in the two-dimensional image classification, and could get a high classification accuracy. In this paper, an image classification method based on three-dimensional convolution neural network is proposed based on the structural properties of hyperspectral data. In the proposed method, first the stereo image blocks of hyperspectral data are intercepted, then multi-layer convolution and pooling operation of extracted blocks by convolutional neural network are implemented to obtain the essential information of hyperspectral data, finally the classification of hyperspectral data is completed. The experimental results show the proposed method could provide better feature expression and classification accuracy for hyperspectral image.
The traditional wired seismograph has disadvantages such as cumbersome cable, complicated wiring, crosstalk and noise between adjacent transmission lines. In addition, the dynamic range of the instrument is small, and...
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The traditional wired seismograph has disadvantages such as cumbersome cable, complicated wiring, crosstalk and noise between adjacent transmission lines. In addition, the dynamic range of the instrument is small, and the observation of seismic signals is not intuitive, which can not meet the needs of high-precision seismic exploration. In order to solve these problems, the design of distributed three component seismic data acquisition system based on Lo Ra wireless communication technology is proposed. The system uses Lo Ra long-distance wireless communication technology and 24 bit Σ-Δ ADC, which realizes long-distance wireless communication and large dynamic range seismic data acquisition. Besides, the system has manmachine interaction interface, which can observe the parameters of seismic waveform in real time and adjust sampling rate directly. The whole circuit has the advantages of simple design, high precision and good stability. To sum up, the design has certain practical value and application prospect.
This paper presents a two-stage position control strategy based on the differential evolution(DE) algorithm for a planar second-order nonholonomic manipulator,which has one passive joint and this passive joint is not ...
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This paper presents a two-stage position control strategy based on the differential evolution(DE) algorithm for a planar second-order nonholonomic manipulator,which has one passive joint and this passive joint is not the first joint(planar APA manipulator for short,where m≥1,n≥0).An offline DE algorithm is used to calculate all link target angles corresponding to the target *** to these target angles,a Lyapunov function is constructed to design the controllers A for the control stage 1,which are used to control all active links to their target *** to the constraint equation of the planar APA manipulator,an oscillatory trajectory is planned for the first active link based on the online DE *** the first active link tracks the oscillatory trajectory,it will back to its target angle ***,the passive link will be jointly controlled to its target angle ***,the other Lyapunov function is constructed to design the controllers B for the control stage 2,which are used to control the first active link tracks the target trajectory and control the remaining m+n-1 active links maintain in their target *** results of a planar AAPA manipulator demonstrate the effectiveness of the proposed control strategy.
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