Abstract:With the development of aeronautical flight test telemetry technology, the requirement for flight test telemetry becomes higher and higher. The integration flight test and multifighter coordination flight test are urgent requirements for aeronautical flight test. At the same time, with the promotion of rapid development of wireless communication, telemetry transmission in aviation flight test develops gradually from the traditional "oneway, pointtopoint remote sensing" mode to "2way, multipoint to multipoint integration of space telemetry and remote network" mode. In the new mode, bidirectional wirelessbased telemetry network faces the challenges of complex channels, i.e. multipath transmission, Doppler frequency shift and the timevarying link quality. Given this, the progress and current status of telemetry technology in aeronautical flight test is introduced, and its technical challenges are discussed. We review the current research status and works. Finally, the trends, major research challenges and concerns are analyzed, which should be focused on wireless telemetry transmission in networking flight test telemetry.

Abstract:Stress concentration is the key factor that induces the damage of oilgas pipeline. It is a serious threat to the safe of pipeline. Effective test can both find the mechanical damage induced by stress concentration and achieve prejudgment of early damage of pipeline. Magnetic memory technology has been widely recognized by the customers as a method of stress testing. In this paper, magnetic memory signal character of ferromagnetic material in different stress application is analyzed in the macroscopic and microcosmic range from the point of energy balance. The theory relation model between stress and susceptibility or atomic magnetic moment is build. Force magnetic coupling process of magnetic memory in FeC metal system is simulated by CASTEP software, which is based on first principle. The results show that ferromagnetic system energy balances and achieves to stable state when the stress is applied. It also weakens the material magnetism and changes the distribution character of electron band structure and density of state. Atomic magnetic moment and susceptibility decrease linearly along with the increase of stress. Finally, magnetic memory testing experiments on pipeline contained crack demonstrate the correctness of theory analysis and effectiveness of engineering application.

Abstract:Motor current signal analysis (MCSA) based on fast Fourier transform (FFT) has its inherent drawback such as low resolution in frequency domain, thus, the detection performance becomes inaccurate for incipient broken rotor bar in squirrelcage induction motor. In this paper, a highresolution spectral analysis method is proposed to solve this issue. Firstly, data preprocessing for single phase stator current is achieved by Hilbert transform and discrete wavelet transform (DWT). Then, extended Prony algorithm is utilized for preprocessed signal qualitative and quantitative analysis. The steadystate stator current of 3kw squirrelcage induction motor can be analyzed under different fault degrees and different operating conditions. The comparison is conducted with FFT. The experimental results shows the effectiveness and superiority on incipient broken rotor bar fault diagnosis even for shorttime data sequence.

Abstract:Twodimensional cellular automata model is often applied to simulate the forest fire spreading. However, the model has many disadvantages which include numerous iteration times, unfinished evolutionary process, uncertain condition of iteration, etc. Aiming at tackling these problems, a 3D cellular space fire spread model based on genetic algorithm with multiple objectives is proposed. First, the main factors that influence the spreading of forest fire are applied to the twodimensional cellular automaton model. Secondly, to decrease the iterations of cellular automaton model of spreading forest fire and identify the termination condition of iteration, the initial mode of the twodimensional model is improved which utilizes the threedimensional spherical cell space. The genetic algorithm with multiple objectives is applied to cellular automaton algorithm for improving the prediction accuracy of forest fire spreading model. By comparing the proposed method with the traditional twodimensional cellular automaton model, Wangzhengfei model and Rothermel model, it can be seen that the proposed method in this paper can greatly reduce the number of iterations and the running time. The operation efficiency of the cellular automata is also improved remarkably. In addition, the termination condition of cellular automata is explicit. The actual forest fire spreading process has high similarity with the simulation results of the proposed forest fire spread model.

Abstract:Ultra high frequency (UHF) radio frequency identification (RFID) systems have many advantages, such as low tag cost and farther identification range. Therefore, it is meaningful in the field of intelligent transportation such as electronic toll collection (ETC), etc. However, it is difficult to accurately estimate the tag identification area in practical applications for the random multipath propagation of radio waves. For ETC scenarios often have in common geometric features. This paper firstly analyzes the constitution of the tag received multipath waves, and then proposes a prediction method of tag identification area. The method is based on geometric optics theory and takes the scenario geometric features and antenna RF characteristics into consideration. Actual tests and simulations showed that the method can accurately predict the tag received power and identification area. The prediction accuracy is higher than the empirical models, and the computational complexity is lower than the electromagnetic computation software.

Abstract:In this paper we discuss the tunnel safety monitoring principle, the monitoring system layout and data acquisition method using embedded FBG strain sensors in a certain practical tunnel construction project. Based on above discussion, the synchronous multidimensional strain data streams collected from the same cross section are analyzed, an abnormal data realtime diagnosis algorithm is proposed based on double slide window model technology. With the first sliding window, the current stress data gathered by the FBG sensors are combined with the historical data to form the current observation window data; then, principal component analysis is conducted on the data in every observation window, corresponding eigenvectors are extracted to obtain the dynamic characteristics of the present observation window. Next, the second sliding window is used to merge current dynamical observation vector into historical ones to get the dynamical feature matrix, and correlation analysis is performed. Finally, the variance of the correlation coefficient is computed, which is used as the criterion to judge the stability of the supervised data streams. Field observation report and comparison experiment result show that the proposed method achieves better real time monitoring effects. This method also provides a strong support for the application of FBG strain sensor in realtime engineering safety monitoring.

Abstract:In order to improve the reconstruction effect of the vibration signal in the process of blocked compressed sensing, an adaptive compressed sensing algorithm is proposed. Firstly, the signal is transformed into matrix by devising the signal into blocks, and the redundant diction is constructed by KSVD adaptively. Secondly, the complexity weight is defined by the attenuation rate, which comes from the sparse coefficients under the redundant dictionary. At last, based on the complexity weight, the observation number of different signal blocks is allotted adaptively in the guarantee of the same total sampling rate. While this algorithm is applied in the compressed sensing of machinery vibration signal, the reconstruction precision is higher than other compressed sensing algorithms.

Abstract:Aiming at targets performing uniform linear motion, the target course is obtained with intial target course angle calculated by using three azimuths at any different time, according to the relative motion model in torpedo attacking theory. Based on the simple linear regression and bearing sequence, an accurate estimation algorithm of target course is proposed. The influences of the time period of observed data and course accuracy on estimation results are analyzed. The simulation results show that the proposed algorithm is of high accuracy, which is also practicable while the measuring error is relatively large. Moreover, the target course estimation result has the advantage of high accuracy and stablity with the increasing of observed data length, the change rate of azimuth, and the precision of azimuth.

Abstract:In order to accurately measure the mechanical properties and rapidly evaluate of the mechanical life of the concentric connector during the inserting and unplugging, a concentric connector testing system of mechanical properties is developed. The system is mainly composed of the motion simulating mechanical device, the sensor measurement and the motor control subsystem, which has fourchannel test capabilities. According to the connector test standard, the system performance index is analyzed, and a testing method combining linear motion and rotary motion is proposed to make the test conditions better fit the actual use of the connector. At the same time, an adaptive flexible fixture is designed to reduce the installation error. The kinematic model is established and analyzed with which the time sequence of the linear and rotational motion is determined under ultimate speed. Multiple connector samples are tested, and the mechanical properties and the service life of the connectors are evaluated. The experimental results show that the system can meet the testing requirements and achieve the desired performance.

Abstract:The error of grating encoder may affect the position accuracy of Articulated Arm Coordinate Measuring Machine (AACMM) in different poses. The position accuracy distribution effected by grating encoder accuracy may be used to guide the calibration and measurement of AACMM. The paper studies the relationship between the precision of grating encoder and the position accuracy of 6joint measurement system. The position accuracy metric of grating encoder is defined. The distribution of AACMM in the workspace is depicted. The evaluation experiments and testing results are as follows. The comparisons of position accuracy effect of grating encoder's precision in different joints are carried out. Then, the distribution characteristic is compared with Monte Carlo method. Then, the different positions are utilized to measure the singlepoint test and standard ball radius. The experimental results show that the proposed method can describe the position accuracy distribution of AACMM more comprehensively and accurately. The optimized measurement region can be determined by the position accuracy distribution which can be used to guide the practical operation.

Abstract:When the technology of the image measurement is applied in the double secondary permanent magnet linear motor rotor position measurement, the selection of the target source image is very important for its measurement precision and anti-interference . According to the width of the standard deviation and the gray gradient sum to construct different aperiodic fence image, the original picture surface is used. The quadtree decomposition method is used to decompose the collected fence image into each piece. According to the edge texture of the block image and its constraint conditions of neighborhood pixels to distinguish as well as eliminate the influence of edge texture of noise, the noise levels of block image are achieved accurately. Each image block is weighted, the whole image with noise results from the average level. Finally, peak signal to noise ratio is used to evaluate the quality of the image, and the phase correlation algorithm is used to verify its anti-interference. Results show that the gray aperiodic fence image's peak signal to noise ratio is better and its similarity peak is higher for the width standard deviation change in ［8.1,8.3］ and thegray gradient sum change in ［18 000,22 000］, and its anti-interference is better and can realize high precision measurement of the linear electric motor rotor position.

Abstract:Aiming at the problem that precision, efficiency, security and cost could not be balanced with existing inertial parameters measurement methods of powertrain, a fast integration system for measuring inertial parameters was designed. All the inertial parameters can be measured by this system in one installation and less than 90 min. A small sloping angle method was proposed to ensure the measurement security of products in comparison with traditional vertical, side lying and suspensory installation method. The actual measurement results of standard specimen show that the relative error of mass measurement is 0.024%, the maximum absolute error of centroid measurement is -0.2 mm, the maximum relative error of moment of inertia measurement is 0.91%, the maximum deviation of orientation angles of principal inertia axis is -1.79°.The comparisons with 4 common measurement methods show that the measurement precision is improved significantly, the efficiency and security is higher, and the cost is moderate. This system can easily be applied in real application and adapted in multiple products’ inertia parameters measurement.

Abstract:Loadbearing structures are the most common structural components in highend equipment. The loading and stress concentration easily initiates cracks, leading to structural failure. Meanwhile, the realtime monitoring of strain is essential for the health evaluation of structures. In this paper, the influence on the natural resonant frequency by the size of the Rectangular Microstrip Patch Antennas (RMPA) is revealed, based on microwave nondestructive testing technology. Furthermore, the interaction mechanism between the resonant frequency of RMPA and the strains is explored. RMPA can radiate at one or two resonant frequencies. The resonant frequency shifts as the length or width of RMPA varies. Thus, when a tensile stress is applied on the grounded metal sheet of RMPA, the geometrical dimension changes, which induces the resonant frequency shift. This phenomenon can predict the strain of the grounded metal sheet inversely. This is of great importance to the strain and crack monitoring of key loadbearing structures.

Abstract:Area coverage of directional sensor networks (DSNs) has been a research hotspot in recent years. This paper studies the relationship between VORONOI cell and corresponding virtual sensing circle (the circle with its location as center and sensing radius as radius), according to which it firstly ascertains the possible working direction to maximize coverage ratio in each of VORONOI cells. Then, in order to decrease overlap coverage between neighbor nodes, it adjusts the direction of node with the maximum overlap area, which is changed to the cell vertex with the minimum overlap coverage area. Finally, in order to avoid invalid coverage ratio, the directions of sensors close to the overall sensing field boundary are readjusted. Simulation results proved that this algorithm could improve the valid coverage area and decrease the invalid coverage ratio.

Abstract:For a low energy density piezoelectric transducer which powers wireless microsensors, it harvests little energy, and its output voltage is low. When the storage capacitor is charged by conventional management circuit, the energy transmission in low power leads to a high proportion of harvested energy dissipated in rectifying circuit, and little energy is transferred to the storage capacitor, which means low charging power. To overcome the large power dissipation and low charging power issues in low energy density environment, a novel management circuit is proposed, which involves quartz crystals with the high quality factor. The circuit uses quartz crystals to accumulate the harvested energy in little consumption. When the energy stored in the quartz crystal is high enough, it is released quickly, and then a higher input power is produced for the rectification circuit, which can reduce the proportion of energy dissipated in rectifying circuit. Hence, more energy is transferred to the storage capacitor, and a larger charging power can be obtained. Experiments show that for a piezoelectric transducer which harvests 50 Hz energy and produces 8 V voltage, the proposed circuit can improve the charging voltage and the charging power by 163% and 110% respectively, compared with the management circuit just using frequencyconversion matching technique.

Abstract:In order to improve the accuracy of FBG threedimensional shape sensing reconstruction, this paper proposes a temperature compensated detection method based on nonorthogonal curvature, utilized three FBG arrays to constitute sensor networks. Based on analysis of the system error components and the error causes, the influence of each component error on the 3D reconstruction accuracy is obtained with simulation model. The results show that the key issueto reduce the installation angle error can improve the 3D reconstruction accuracy. A new calibration method is proposed due to that the difference between the calibration direction and the installation direction brings the change of the measurement calibration parameters. The experimental results indicate that the proposed method can reduce the maximum error ratio of 3D reconstructed to 0.16%, which provides a reliable detection method for high precision 3D shape sensing system.

Abstract:In view of the phenomenon of clustering effect and energy constraints, a weighted scalefree network model is propsoed with high clustering and balanced energy consumption characteristics,in which the relationship between node energy and node weights is modeled. In the evolution process, a new edge weight is established with the probability according to the triad formation mechanism and with the probability according to weight priority connection mechanism. Therefore, the energy factor balances the network energy consumption , and the triad formation improves the clustering coefficient of the network, and then improves the faulttolerance of the network. Theoretical proof shows that the distribution of the node weight and the node degree of the network all obey the powerlaw distribution. Simulation results indicate that the proposed model has a high clustering coefficient and great fault tolerance performance, and balanced network energy consumption. Moreover, the energy balance of the model is verified by the real test experiments.

Abstract:Based on the equivalent transformation of measurement model and geometric meaning, an equivalent twostep algorithm is proposed for the calibration of threeaxis magnetic sensor. The calibration is divided into two steps: the equivalent sensor frame calibration and the equivalent misalignment calibration. The significance and characteristics of the equivalent transformation analysis method are described in the study. The calculation formula of the parameters in the equivalent sensor coordinate system is derived and the geometric meaning of parameters calibrated by the ellipsoid method is defined. The principal component analysis is utlized in the equivalent misalignment calibration, correspondingly, the sign inversion and nonorthogonality defects are analyzed as well as; the correction algorithms are studied. The equivalent twostep algorithm can calibrate threeaxis magnetic sensor without external attitude information, geomagnetic information and auxiliary sensors. Experiments show that its calibration accuracy is close to that of dot product invariance algorithm.

Abstract:The planar inductive angular position sensor is popular in recent years for its low cost, high precision, and being well applicable in extreme environments. The decoding of the sensor’s output is focused to acquire angular position and velocity of objects. The sensor output signals need to be transformed into two signals: the sine and cosine signals by the demodulation module. Generally, the sine and cosine signals are unbalanced, i.e., they are not in the same amplitude and ninety degrees phase difference. The traditional decoding method synchronizes reference frame phaselocked loop (SRFPLL) can only be capable of acquiring correct angular position and velocity from balanced sine and cosine signals, which can not operate under unbalanced condition. In this work, a decoding method is proposed, termed double synchronous reference frame phaselocked loop (DSRFPLL), to acquire correct angular position and velocity under the unbalanced condition. Effectiveness of DSRFPLL decoding method is verified by simulation and experimental results.

Abstract:Based on some priori knowledge such as the feature information of prostate magnetic resonance images (MRIs) and its special zone different diseases often occur, aiming at the segmentation of prostate outer and inner contours, a twostep prostate MRI segmentation method based on edge distance regularized level set evolution (DRLSE) is proposed. On the basis of constructing a unified level set energy function, the first step is to realize the outer prostate contour segmentation based on the T1 (longitudinal relaxation time) image of MR. The second step is to realize the inner prostate contour segmentation based on the T2 (transverse relaxation time) image of MR under the condition of outer contour constraint; and then the effective whole segmentation of the prostate outer and inner contours is achieved. The humanmachine interactive interface of the prostate segmentation was designed, and the image segmentation experiment study on ten prostate cases (including 30 images of normal, hyperplasia and cancerous prostates) was conducted. The Dice similarity coefficient (DSC) is used to evaluate and analyze the segmentation results, and the DSC value reaches to above 90%. The experiment results show that the proposed twostep prostate MRI segmentation method based on edge DRLSE can effectively realize the whole segmentation of prostate outer and inner contours, and the results are very close to the ideal ones obtained by clinic experts manually, which has good reference value for the clinical diagnosis and treatment of prostate diseases.

Abstract:The traditional camouflage pattern design is too single, and mostly depends on the designer's experiences, as a result, the camouflage performance is not satisfied in war field. Thus, a novel bionic camouflage pattern design method by genetic evolutionary algorithm is proposed in this work. The comprehensive parameter model is obtained according to the principle of human visual reconnaissance and photoelectric imaging reconnaissance. The camouflage pattern is processed by fine selection, crossbreeding and variancebreeding based on zebra stripes camouflage pattern. The proposed bionic camouflage pattern can counter imaging reconnaissance to improve the traditional camouflage pattern design. The comparative experiments by several camouflage methods indicate that the proposed method can reduce detection and recognition feature of target superior to the others traditional camouflage patterns. Comprehensive feature parameter is reduced by more than 23% of initial value, which is better than other traditional camouflage patterns. An integrated model of reconnaissance, genetic evolutionary and camouflage theory is achieved in the proposed method, which provides a novel approach for scientific and felicitous camouflage pattern design.

Abstract:Crevice is a serious defect on wood surface which influences the process and usage of wood seriously. However, the mineral streak of the crevice on wood surface is similar. Hence, how to identify the crevice texture accurately is an urgent problem to be solved. A detection method based on texture ridge line features fusion is proposed. Firstly, the basic model of extracting texture ridges line grayscale characteristic and shape feature is formulated. Secondly, all wood surface texture regions are segmented and the strip texture is extracted according to the fuzzy rules, including crevice and the mineral streak. Finally, these two ridge line features of striped texture are extracted by the model established. The composite discriminant factor is obtained through feature information fusion. The crevice is identified by analyzing the relationship of fusion result and the predetermined threshold value. The proposed method is evaluated by the selfbuilt atlas. The experimental results show that the Equal Error Rate (EER) of crevice defection is 4.64%. Compared with the other classical feature extraction and texture recognition methods, the EER of the proposed method is decreased by 10.06% at least. The efficiency and the practical application value of this method is proved.

Abstract:To overcome the limitations of small fieldview and nonintelligent of traditional monitoring systems, this work combines panoramic imaging and computer vision technology to establish an automatic intrusion detection system in unmanned environment. The proposed system can achieve fast and accurate moving object detection and tracking in panoramic monitoring field. To solve the key challenge on effectively extracting moving objects in complex and dynamic background, this paper presents an adaptive background updating algorithm based on dynamic matching between feature blocks. On the basis of target detection using the fusion algorithm with frame differencing background subtraction, the torque information is utilized for tracking the target so as to avoid the lack of color and contour features under the panoramic view. The feature block si then extracted according to the outline and position of the target, in which the local matching of feature area is conducted between video sequences of each frame image and the initial background image. The color feature of the feature block is firstly analyzed, and a RGB color histogram is established based on interval statistics. Thus, the colour feature sequences are obtained.wWhether the region background updates is then determined by calculating the correlation between the two sequences to reducethe computation of a single pixel to be updated. Experiments show that the proposed algorithm is robust and feasible, and it can effectively improve the stability of the monitoring system.

Abstract:Fully utilized the detection signal, phased array ultrasonic total focus method (TFM) imaging can achieve high imaging precision and identify defects, which is one of the most promising future phased array imaging algorithms. However, the TFM imaging can not achieve high resolution imaging of defects, and can not make accurate qualitative and quantitative analysis. Therefore, in this paper, the finite element method (FEM) is used to simulate the full matrix capture (FMC) process of phased array sensors. A TFM imaging program is designed based on the full matrix data. TFM imaging is performed on two typical defects of circular hole and crack, and the TFM imaging law of typical defects is studied. The factors affecting phased array ultrasound imaging are analyzed from the perspective of the defect scattering. The results show that phased array ultrasonic sensor can only receive the partial scattering information of the defect in the actual detection. Moreover, the scattered field distribution of phased array ultrasound is related to the type, size, angle of the defect and incident wave type, and incident angle and so on. Thus, the main energy of the defect scattering can be received is the key factor to the accuracy of the TFM imaging.

Abstract:Aiming at the problems of large number of redundant points, poor realtime performance and low ability to resist geometric transformations for the scene matching algorithm based on traditional local invariant feature, an unmanned aerial vehicle (UAV) scene matching algorithm based on CenSurEstar is proposed. Firstly, the CenSurEstar filter is adopted to extract the feature points in the reference image and realtime image, and then FREAK binary descriptors are generated. Secondly, the Hamming distance is taken as the similarity measurement of the feature points, and the KNearest Neighbor distance ratio method is used to extract the matching point pairs. Finally, the positioning model based on RANSAC is utilized to obtain the space geometric transformation relations, the image matching is achieved, and the latitude and longitude coordinates of the positioning points are obtained. The algorithm performance evaluation experiments show that compared with SIFT, SURF and ORB algorithms, the proposed algorithm has better robustness in dealing with various image transformations; and compared with the improved SIFT and SURF algorithms, the processing time of the proposed algorithm is greatly shortened. The positioning error of the algorithm is within 0.8 pixels, the scale error is within 0.02 times, and the rotation angle error is within 0.04 degrees. Based on the proposed algorithm, a field flight experiment was conducted. The experiment results prove that the proposed algorithm has high positioning accuracy, can adapt to the environment with less landform information, and meets the requirements of UAV vision aided navigation.

Abstract:Pantographcatenary system has complex coupling property of electric and machinery. Improving the current collection performance of the pantographcatenary is a critical issue for the present high speed train system. The pantograph active control is an important mean to stabilize the contact load and improve the current collection for the pantographcatenary. From the control theory point of view, this paper proposes a backstepping precise control method for pantographcatennary contact load based on fuzzy system, considered the influence of wind load and parameters uncertainty. Specifically, virtual control laws are utilized to select appropriate Lyapunov function with stepbystep backstepping approach. And the fuzzy interfere systems are designed to approximate the uncertainty and differential of virtual control laws, in which the relevant stability analysis is provided. Simulation and experimental results show that the proposed method can decrease the effects of uncertainty, and greatly restrain the contact load fluctuations of pantographcatenary, and improve the current collection performance.

Abstract:In order to relieve the wear of brake shoe and guarantee the safety of PMSMdriven rail vehicles with demagnetization fault, a novel healthoriented optimal control strategy is presented through similarity based modeling (SBM). The proposed methodology estimates the flux of PMSM and generates the Fv profile of pneumatic brake with the similarity operation between historical data and online monitoring data. The feasibility and benefit of the developed scheme is validated through a simulated experiment of the Syntegra PMSM rail vehicle. Simulation results show that accurate alarm monitoring and damage prognosis of demagnetization and realtime control optimization can be reached, which can effectively relieve the brake shoe wear.

Abstract:To accurately establish the soft sensor model of cement fineness, the selection of input variables is easily influenced by time delay. Thus, this paper proposes a soft sensor modeling method based on mutual information and least square support vector machine (MILSSVM). In the proposed method, the correlation of variables is represented by mutual information, which can be used to determine the time delay of each auxiliary variable. Furthermore, the twoway selection algorithm is proposed to obtain input variables, and a soft sensor model of cement fineness is built based on least squares support vector machine with these selected input variables. Finally, the proposed model is trained with actual operational data of a cement plant. The experimental results show that the model can achieve high precision and generalization.

Abstract:The construction method of the heat release signal of a supercritical boiler is proposed, which can accurately measure the calorific value of coal in the furnace. The thermodynamic property standard, IAPWSIF97 is adopted to partition the supercritical boiler water cooled wall, which solves the difficult problem of judging the working fluid state within the water cooled wall under supercritical condition; and the boiler heat storage coefficient is calculated in detail. According to the structure parameters and actual operation data of a certain 1000MW unit,the heat release signal of the structure was verified. The results show that the heat release signal can rapidly response to the unit load change, at the same time accurately reflect the changes of the calorific value of coal in the furnace, which lays a foundation for the design of the direct energy balance coordinated control system of supercritical units.

Abstract:Aiming at temperature effect on stripping peak current of water cadmium analyzer based on anodic stripping voltammetry, a modified simultaneous calibration method is proposed. In the proposed method, standard solutions are simultaneously measured in the period of sample measurement. And sample concentration is calculated by linear comparison of standard solutions and sample stripping peaks. Experimental results indicate the current of cadmium stripping peaks gradually enhanced with temperature increased, while the current of stripping peak increases about 2.3 times from 5.0°C to 43°C. Diffusion rate of cadmium ions within diffusion layer on working electrode surface is dominated by the solution temperature, which is the main mechanism of temperature effect on stripping peak currents. A modified simultaneous calibration method used for analyzer is introduced to eliminated this effect. Test results show that the measurement errors are less than 10% ranged from 5.0°C to 43°C with this simultaneous calibration method, which proves the efficiency in avoiding environmental effect on measured values.

Abstract:Pneumatic amplifier is not only the commonly used independent electrical attachment but also one of key components of the valve positioner. Here, a mass flow mechanism model of the typical pneumatic amplifier is presented, and the method of parameter identification is proposed. Firstly, according to the working principle and structural characteristics of the pneumatic amplifier, the mass flow model of the pneumatic amplifier is established by using the principle of thermodynamics and fluid mechanics. Secondly, a new sub model is established for the important equivalent orifice area in the experiment, and the parameter identification is carried out. Finally, the model is verified by the experimentalplatform of the control valve. Results show that the accuracy of the model is up to 90% compared with the actual typical pneumatic amplifier.