Abstract:To gain a deep insight into the development tendency and the key technology of compound-structure electrical machine for hybrid electric vehicles, this paper reviews the compound-structure electrical machine and its key technologies. The composition, operating principle and topologies of different compound-structure electrical machines are analyzed, including the brush and brushless ones. Meanwhile, the advantages and key technology problems of different compound-structure machines are investigated and summarized. The results show that the purely-electrical hybrid schemes based on the compound-structure electrical machine don't have the problems of vibration, noise, wear and regular maintenance, but they also have advantages of simple and compact structure and easy control, compared with the mechanical hybrid schemes based on the planetary gear. Meanwhile, they also show that the investigation of the brushless compound-structure electrical machine must be a development tendency in this field for the brushless compound-structure electrical machines can get rid of brushes and slip rings in the brush ones as well as improve the system stability.

Abstract:In order to improve the flatness of the diaphragm and the ability of the diaphragm-based Fabry-Perot fiber acoustics sensor to detect weak acoustics signal, a large area silver diaphragm was fabricated by sputtered. The diaphragm was then transferred to the sensor head with a sacrifice layer. The diaphragm is as thin as 130 nm, while its diameter is 2.5 mm. Experimental result demonstrate that the flatness of the diaphragm is less than 20 μm. The fabricated sensor's sensitivity is about -158 dB (re 1 V/μPa) with a high linear pressure response range of 0.001-1.250 Pa. The noise equivalent acoustic signal level of 419 μPa·Hz^-0.5 at 1 kHz. The sensor exhibits a flat frequency response in the range of 0.1 kHz to 3 kHz. The diaphragm's flatness is improved by the proposed method and the fabricated sensor is suitable to be useful for highly sensitive measurement of the weak pressure and sound field.

Abstract:In order to further study the interaction mechanism and the physical nature between detection signal from electromagnetic waves and light waves and the background of irregular surface, which provided scattered model for the detection of radar target and the remote sensing of irregular surface. Two-dimensional band-limited Weierstrass function is used to simulate two-dimensional fractal rough surface. Two-dimensional rough surface scattering field is deduced based on the Kirchhoff approximation. The electromagnetic scattering coefficient and the average intensity coefficient of the rough surface is obtained under the HH polarization. The relationship between scattering characteristics and the harmonic number, the incident wavelength and dimension of fractal surface is discussed through theoretical analysis and numerical calculation. The results show that with the harmonic number and fractal dimension increases, apart from the mirror reflection point, the scattering intensity of the amplitude and its high-frequency component is increased. It provided scattering data for refactoring related statistical parameters of rough surface according to the scattering intensity.

Abstract:In order to solve oilfield pumping system with the following disadvantages:low efficiency of crude exploitation, high energy consumption, etc. Kinetic and efficiency model of pumping system has been established to calculate the pumping rod load and efficiency. A new power system transmission solution has been proposed, which use spring group to store pumping system deceleration inertial energy. Spring group releases energy when pumping system changes direction. Adding spring energy storage device reduces the impact of electrical motors' working status switch, and saves system energy consumption substantially. Spring energy-storage device designed in this paper can reduce motor torque ripple, short start-up time, and reduce motor heating, extend motor life. Compared with traditional reciprocating pumping unit, the new-designed oil-pumping system has great improvement, the energy saving rate reaches 10.46%.

Abstract:In view of the problem of automatic and high accuracy detection of space moving targets for space surveillance system, an algorithm of complementary enhancement by salience computation with optical flow detection is presented, in which the elementary detecting result by mean shift is taken as a guidance to realize high accuracy detection and segmentation through the complementary enhancement of salience computation and optical flow detection. Firstly, the salience computation by complementary enhancement of frequency tuned filter with gradient information is carried out for the whole frame of video image and various regions produced by mean shift segmentation separately so as to obtain their respective salient regions, then a proper threshold value is determined based on the mean salience of whole frame image to detect candidate targets. Meanwhile, in a concurrent way, another set of candidate targets are acquired by threshold based optical flow detection. Afterwards, a conjunction operation is used to obtain an intersection of two different distributed maps of candidate targets as confirmatory detection result, then the morphological filter is employed to enhance the confirmatory targets to achieve a high accuracy detection and segmentation of space moving targets. A series of experimental results with video images demonstrate that the proposed algorithm can accurately detect and segment space moving targets with neither priori knowledge of scene and targets nor manual intervention, which qualifies well performance of adaptability to illumination changes and noise disturbance.

Abstract:A new 3-DOF deflection type PM motor with a "butterfly" type rotor is proposed in this paper. In order to overcome the disadvantages of torque characteristics of the single layer structured permanent magnet 3-DOF motor mentioned in the previous research, the air-gap magnetic field and electromagnetic torque of the motor are analytically modeled using the seperation of variables method and the Lorentz force method in spherical coordinates. The space-harmonics of the magnetic field and the influence of structural parameters on the fundamental flux density and torque amplitude are defined; also the 3D finite element simulation and analysis are performed simutaneously. In the present study, the distribution characteristics and the regularities of air gap magnetic field, spin and deflection torque are investigated under different calculation methods. Simulation results show that the flux density distribution and torque characteristics with "butterfly" type permanent magnet rotor structure is superior to single layer structure. The spacial distribution of radial component of the flux density approximates the flat top waves and its maximum magnitude values appear in the middle layer of the rotor poles. The computation errors by the analytical and finite element methods are all less than 6.7%.

Abstract:In order to optimize the lower power current-mode signaling (CMS) circuit, we offered a top-down methodology to optimize the power of a dynamic overdriving CMS circuit. First, we molded the CMS scheme using a behavioral model-switched current source, which helps us determine the branch current quickly. Under the help of Matlab, we can determine the optimized branch currents, making the average power of the CMS scheme lowest. To get the accurate dimensions of MOSFETs quickly, a new design method of 2I_D/g_m methodology is introduced. Moreover the detail analysis shows that the 2I_D/g_m methodology is both practical and scientific. The simulation results using initial values calculated by this methodology are very close to the specs, demonstrating the top-down methodology improving the design efficiency of the dynamic overdriving CMS-circuit.

Abstract:Micro-grid is one of the effective means to absorb distributed generations; however, this also results in issues of voltage instability and difficulty in operation controlling of the micro-grid, especially the unbalanced three-phase voltage at the point of common coupling (PCC). This paper proposes a control for micro-grid voltage bipolar compensation at the point of common coupling, the upper level sends the control signals, these control signals relate to the positive-and negative-sequence components of the unbalanced voltage, dual the current control loop current setpoint is obtained. The lower control loop controller through dual current implementation, in view of the PCC point of three-phase voltage imbalance problem, application of dq rotating coordinate decomposition principle, proposed dual synchronous coordinate system based on improved decoupling phase-locked loop (IDDSRF-PLL) to independently control the positive and negative sequence voltage component. Furthermore, the three-phase balance voltage could be achieved by controlling the model of positive and negative sequence currents, and using the unbalance voltage compensation controller, bus voltage doubler fluctuation at point of common coupling is zero, thus realizing the three-phase control voltage unbalance compensation. MATLAB/Simulink software is used to set up the simulation model of connecting micro-grid to the main grid. The simulation results show that the hierarchical control method is effective to implement voltage control of micro-grid.

Abstract:In order to explore frost heaving properties of gravel soil containing mud in seasonal frozen region of Qinghai-Tibet Plateau, and provide the foundation for airport engineering anti-freezing expansion design, Particle analysis experiment and compaction experiment were conducted to provide the basis indoor frost heaving rate experiment. Then it improved for gravel soil particle size characteristics of large heaving rate based on traditional means of laboratory experiments, following the improved apparatus a series of sets of orthogonal frost heave indoor tests were conducted to study the influence of factors including degree of compaction, moisture content, silt content, overlying load, water replenishing on frost heaving ratio by the improved experiment device. The test results show that frost heaving ratio of gravel soil containing mud in seasonal frozen region of Qinghai-Tibet Plateau showed a trend of decrease after the first increase with the increase of degree of compaction in a sealed environment, and approaches its maximum at the compaction degree of 95%; increases linearly with the increase of moisture content, increases with the increase of silt content corresponding to a polynomial function; Gently decreases at an exponential functional with the increase of overlying load. Frost heaving ratio increases over three times under the condition of the water replenishing. Multi-factor regression forecast formula is obtained by the multiple regression analysis. The influence of various factors on frost heaving ratio decreasing order:water replenishing, moisture content, silt content, degree of compaction, overlying load. Consequently, it is the key of anti-freezing expansion design to control water replenishing, moisture content, silt content.

Abstract:The paper is intended to analyze the correlation of traffic performance index and bus performance index, for which time series analysis of econometrics is used. Granger causality test, co-integration test, vector auto-regression model, and vector error correction model are employed to investigate the relationships between the two indexes in the short run and the long run. The results indicate that there exists a Granger causality between traffic performance index and bus performance index. The two indexes are correlated in the short run while they are not significantly correlated in the long run. The two indexes remain relatively independent as short-run co-movement effect dissipates.

Abstract:Aiming at the limitations of 5℃ ductility on evaluating the low-temperature properties, in order to find an index to evaluate the low-temperature properties of rubber asphalt more accurately, based on the bending beam rheometer test, the research on the low-temperature evaluation indexes of TFOT-aged and PAV-aged rubber asphalt which processed in the laboratory were carried out. The analysis was made on the low-temperature evaluation indexes of rubber asphalt based on the bending beam rheometer such as stiffness modulus, the rate of stiffness modulus, performance grade temperature, continuous grade temperature, k value and the S_A index which take asphalt modulus and relaxation capacity into consideration. Test results showed that, with the rubber powder adding into asphalt, its low temperature crack resistance improved significantly, one-sidedness was existed to evaluate the low-temperature properties of rubber asphalt by a single S index or a single m index; indexes which take asphalt modulus and relaxation capacity into consideration including C_T index and k index and S_A index were better applied to evaluate the low-temperature properties of rubber asphalt. By doing correlation analysis between these low-temperature evaluation indexes of rubber asphalt with the bending strain energy density of rubber asphalt mixture and by doing comprehensive comparison, conclusions were made as follows, on the substantial projects we gave priority to recommend k value and C_T index as the low-temperature evaluation indexes, while undertaking research work, we gave priority to recommend S_A index as the low-temperature evaluation index of rubber asphalt.

Abstract:To facilitate residents travel along inter-city expressway, the setting method of passenger sites on inter-city expressway was proposed. In accordance with the operating features of passenger lines on inter-city expressway, an algorithm was proposed to achieve full coverage for all settlements by seeking the minimum number of settlement sets. Optimization model was established with the target of minimizing total walking distance to determine the best place of each passenger site corresponding with settlement set. In order to improve the operational efficiency of passenger lines, grey clustering method was introduced and the quantitative clustering index system was established to optimize the number of sites by assessing the important degree of each site. Finally, the above method was validated by a case study. The results show that it is an effective approach for setting sites. The method achieves dual optimization for the location and the number of passenger site, meets the demand of the most residents along the intercity expressway, and makes site layout more reasonable on inter-city expressway.

Abstract:In order to improve road cement concrete deformation and small toughness traditional defects, rubber grain was mixed into concrete to form the rubber particles concrete; flexural modulus of rubber particles of concrete and ordinary concrete was comparative studied, two kinds of concrete damping change was analyzed by using the finite element, through three point concrete trabecular bending test, the fatigue properties were comparative researched, the rutting test methods were used in proving the rubber particles of concrete of erosion performance. According to the mechanical parameters of acquired in experiments, adopted the MEPDG 2002 design method, the road surface damage states were fore-casted of the two kinds of concrete pavement in the end period of design. Study results show that rubber particles cement concrete flexural modulus reduced by 12% than that of ordinary cement concrete, the damping ratio increased by 30%, the fatigue life have greatly improved, and surface erosion phenomenon did not happen, the rubber cement concrete slabs breakage was lower 30% than ordinary concrete. Therefore, the rubber particles concrete slabs can overcome the traditional defects of cement concrete pavement and with has excellent road performance.

Abstract:To find traffic conflict identification indicator which can reflect driver's mental load and traffic conflict identification method based on the indicator, the correlation between the conflict stimuli and the pupil diameter is identified by comparative analysis, a pupil diameter based GSA-T fast traffic conflict identification method is proposed to remedy the defects of original GSA to meet the requests of traffic conflict identification. The result of construction conflict shows that the computation and the identification time of the GSA-T is shorter than the Enumeration method, thus the low time complexity and space complexity are testified. It is proved that GSA-T can meet the requests of traffic conflict identification and road safety evaluation, and can lay foundation for further study of relationship between traffic conflict severity and pupil diameter.

Abstract:In order to investigate the mechanical behavior of steel reinforcing bars (rebars) after corrosion fatigue, axial tensile tests of rebars which were removed from corroded reinforced concrete (RC) beams after fatigue loading tests was carried out. Combined with the experimentally obtained stress-strain curves of the rebars after corrosion fatigue, constitutive relation model for the rebar after corrosion fatigue was quantitatively presented. And the model was verified by comparing the calculated values with the test ones. Test results show that, after cyclic loading to 2 million times, uncorroded rebars have the same ductile failure characteristics as the original ones without corrosion fatigue. Fatigue effect has no substantial influence on mechanical behavior of uncorroded rebars. Stress-strain curves for the rebars after corrosion fatigue changed obviously:characteristics of yield plateau changed, percentage of elongation shortened and yield strength decreased. The magnitude of variation correlated with the degree of corrosion fatigue. Mild steel changed into hard steel to varying degrees. The emergence of fatigue crack in rebar caused tensile failure in very low percentage of elongation, great reduction of yield strength and almost complete loss of ductility.

Abstract:The mechanics property near interface crack tip is studied in order to strength analysis, which interface is between GFRP and asphalt mixtures. Bimaterial Brazilian Disk specimens with prefabricated interface crack are designed. 27 Brazilian Disk specimens are tested by loading angle in the range of 25 degree to 90 degree, and experimental data are recorded, such as ultimate load, crack propagation path, fracture form, etc. Finite element model of GFRP asphalt mixtures Brazilian Disk is built, considering the GFRP orthotropic property. Interface stress intensity factors (SIF) are calculated applying numerical extrapolation method, and fracture mechanics performance of GFRP asphalt mixtures Brazilian Disk is studied by theoretical analysis and experimental research. The results show that the bimaterial Brazilian Disk specimens with prefabricated interface crack can fully reflect fracture types of GFRP and asphalt mixtures, which is an efficient experiment method, that interface SIF acting as mechanics evaluation parameter, can well explain experiment phenomena, and that GFRP and asphalt mixtures Brazilian Disk specimens with prefabricated interface crack are in accordance with elliptic strength criterion.

Abstract:The BPR model was used to release the law between the characters of parking vehicle and speed of the main road. This paper focuses on the rightmost lane on the main road at the sections of off-street parking access in the city. An impedance function model describing the off-street parking vehicle enters or not was established through the analysis of theory and specific cases based on parameters. Some conclusions can been drawn as follows:firstly, speed of the rightmost vehicle is only related to its flow and proportion of the lane been utilized is only 0.384, while there is no off-street parking vehicle; secondly, speed of the rightmost vehicle is related to the influence time, frequency of parking, deceleration distance and its flow, while the off-street parking vehicle entry into the access. Meanwhile, sensitivity analysis of influence of relative factor on the speed of the social vehicles was conducted. Results show that the parking vehicle's deceleration distance is contrast to the average speed and it's influence time is in proportion to the average speed, while the off-street parking vehicle affected the vehicles on the rightmost lane. Moreover, the social vehicles would be deeply affected by the off-street parking vehicle, while the deceleration distance is less than 10 m.

Abstract:To investigate the influence on bridge scour from environments, a K-ε turbulence model was applied in the present study to simulate the complicated flow filed and local scour around bridge pier. Four key problems for a fine 3D scour simulation were discussed in details and the corresponding solutions were also given. More attentions were especially paid to the dynamic updating of boundary condition and the optimized iteration convergence of programing algorithm. The accuracy of the proposed simulation was fully verified by comparing to the classic B. W. Melville experiment from the viewpoint of 3D performance during the scour. By re-developing the CFD Fluent program following the proposed solution, a parametric study was conducted by varying several scour environment parameters. The results show that the maximum scour depth has an approximate linear relationship with the pier measurements and average velocity of flow. A good selection of pier shapes, a narrow effective pier width, a slow average velocity of flow, and a proper water depth would all reduce the scour depth of piers. A conclusion can also be drawn regarding the influences of different environment parameters on the 3D scour development, which should be a rational theoretical basis for the active anti-scour design for piers.

Abstract:To analyze the effect of non-motorized vehicle flow caused by curbside parking on segregated bicycle lane, this study draws an analogy between travel time and duration data of survival analysis. A proportional hazard-based duration model is proposed to establish travel time and speed models of non-motorized vehicle flow. The speed model extracts and screens the influential factors related to curbside parking, including the effective width of bicycle lane, the inbound and outbound parking maneuvers, the time influence rate, electric bike and bicycle flow and so on. The parameters of model are calibrated by using the survey data. The results show the distribution characteristic of speed estimated by the model would give a quantitative analysis of the influence of curbside parking; the model could pass goodness of fit tests and make prediction effectively; the events of inbound and outbound parking maneuvers, the rate of bicycle and the time influence rate show a negative effect on speed whereas the effective width of non-motorized lane shows a positive effect on travel speed; the hazard of non-motorized vehicle speed decreases with the increase of the effective width of bicycle lane.

Abstract:In order to research influences of hydrodynamic effect on asphalt mixture anti-fatigue performance under different material composition, laboratory equipment is developed for simulating the asphalt pavement affected by water, load and temperature. Seven types of asphalt mixture are generated with void ratio of 6%, 10% and 14%, gradation of AC-16, SMA-16 and SAC -16 and asphalt of A-90, A-110 and A-130; stress-fatigue equation parameters change of these mixture after hydrodynamic effect are analyzed by comparison. The results have shown that anti-fatigue performance of the asphalt mixture is reduced after hydrodynamic effect. Under fatigue load, asphalt membrane of mixture after hydrodynamic effect is easier to spalling. 10% is unfavorable void ratio of AC concrete, it can cause fatigue life reduction and stress sensitivity increase. When the void ratio is 10%, suspension structure of the asphalt concrete follows the larger influence of hydrodynamic effect on anti-fatigue performance than the skeleton structure and high penetration asphalt concrete is larger than low penetration in the influence.

Abstract:In order to accurately segment the coarse aggregate adhesion images in the CT X-ray asphalt mixture slice image during the classification of materials, an improved morphological multiscale algorithm with structural element radius of 1, 2, 3 and 4 was introduced to study the segmentation of the coarse aggregate adhesion images, respectively. By judging the number of the segmentation lines, the segmentation image with the maximum number of segmentation lines and minimal structural element was identified as the final segmentation. Then image segmentation was completed by overlapping the independent particle image and the segmented adhesion images. Study of effectiveness and accuracy were carried out to evaluate the improved algorithm. The test results showed that the improved morphological multiscale algorithm not only effectively separated the adhesion images of asphalt mixture X-ray CT slices, but also effectively reduced the over-segmentation and less-segmentation problems. The segmentation remains significantly higher in effectiveness and accuracy through this method which will reduce the difficulty of numerical modeling of the sample.

Abstract:In order to improve the occupant protection in coach rollover accident to reduce or avoid injury of occupants, according to the occupant's body motion behaviors, injury mechanism and injury level, an ARS (active-tilting restraint system) safty seat is originally proposed. A compound finite element model (FEM) combining coach body segmental structure, restraint system and occupant is developed via the items of ECE R66 to analyze and realize different occupant injury protection capability of the two kinds of seat restraint systems, with and without the ARS. The comparative calculation and analysis results express that during coach rollover the ARS seat effectively guarantees occupant motion within residual space, avoiding occupant body impact side going beyond it to be injured; and making HIC (head injury criteria) and TTI(thoracic trauma index) improved. The research concludes that the ARS seat can keep the occupants within the residual space preventing from impacting coach body by initiative pulling back against rollover to restrain the body's motion, and enhance occupant protection of coach body.

Abstract:In order to better understand the long-term effects of bearing pile foundation on close subway tunnel, by improving the pile load and test monitoring equipment of centrifugal field, use geotechnical centrifuge model test to analyze the deformation of adjacent existing tunnel by pile foundation in the process of bearing load with change of parameters(different loads and pile foundation pile and tunnel structure spacing), and the interaction of pile-soil-tunnel was discussed based on the test of test results, the results showed that:blocking and reinforced effect of tunnel structure change the transmission path of the additional soil load and displacement surrounding the bearing load pile, lead to stress concentration of the tunnel body. Both sides arch waist of subway tunnel are the main areas where bear the additional load caused by bearing load pile, lead to the sinking of the subway tunnel structure. The settlement is main tunnel deformation form, horizontal displacement is small, which lead to smaller transverse cross section of the tunnel. The bearing load pile exist in one side of tunnel cause moment distribution of tunnel structure deflection to pile foundation, while the direction of the tunnel structure to the foundation piles have some distortion. A relationship between relative pile-tunnel location and the pile bearing load at which tunnel displacements occurred is presented, which provides useful guidance to tunnel design engineers.

Abstract:In order to simplifying the analytic method of bending problem of rectangular thick plate, the decoupling method and the modified Navier method are combined for accurate bending analysis of rectangular thick plates with all edges clamped supported. By using the transition function, the basic governing equations for Mindlin plates are first decoupled into independent differential equations which can be solved separately. With the different series corns unified by modified navier method, analytic solution of rectangular thick plate with all edges clamped supported is derived simply. Numerical comparisons show the correctness and accuracy of the results at last. The method used in this paper leaves out the complicated derivation for calculating coefficients and obtain the solution to problems directly.

Abstract:A method of determining the stage of geomorphic development is built up in complicated mountainous river basin, which can also be used to regional assessment of the regional severity of collapse-landslide caused by earthquake or heavy rainstorm. Based on the theory of the erosion cycle and the theory of river's developing by stages, the stage of geomorphic development is estimated by combining the Strahler's integral (HI) and the stream-gradient indices (SL indices). Then regional severity of collapse-landslide is estimated by development stage with DEM (digital elevation model) and ArcGIS technique. Both of the change point of HI of branch basins and the breakpoint of SL indices can be the cut-off point of development stage. In the same development stage, HIs are very similar. HI of the whole same development stage can be the representative HI of all the HIs of branch basins. The basins in development stage of late youth and maturity have the severest regional disasters, with HI change from 0.45~0.6.

Abstract:The use of the vehicle information system and the complex road traffic control information make the mental workload of drivers increased. In order to recognize driving mental workload efficiently, provide the basis of automatic auxiliary driving and integrate the traffic information, the method use the EEG signal δ(0.5-4 Hz), θ(4-8 Hz), α(8-13 Hz), β (13-30 Hz) as the input features and SVM model to establish the recognition model for state of driving mental workload. Meanwhile, combine with examples based on EEG data from the simulator to test the model, the result shows that the average recognition accuracy rate was between 93. 8% and 96.5%. The modle shows good accurancies for driver's mental workload recognition and can be used in actual driving.

Abstract:In order to carry out the near and far-field seismic vulnerability, the seismic vulnerability model of a certain typical irregular highway continuous rigid frame bridge of China was created. Considering the uncertainty of near and far-field earthquake and bridge parameters, by adopting sampling method, the model sample database was generated to carry out bridge seismic vulnerability analysis. In order to obtain the structural near and far-field dynamic response respectively, every model in the database was calculated by using nonlinear time history analysis by using the software such as OpenSees. And the pier and bearing damage index were obtained. Then based on the above studied results, and then the near and far-field fragility curves of bridge dangerous members were obtained by using the probabilistic seismic demand analysis method and then a comparative study analysis for near and far-field seismic vulnerability for the structural damage state was determined. The results showed that, the vulnerability condition of the bridge component was closely related to spectral characteristics of ground-motion and irregular structure, and the near-field damage probability was significantly higher than the far-field's; so it was very necessary to carry out vulnerability research according to near and far fault ground motion. Finally the fragility curves obtained can be used to evaluate the seismic performance of irregular bridges, and can provide the basis for post-earthquake damage assessment.

Abstract:To investigate the effect of impulsive disturbances on the dynamical behavior of the equilibrium point of complex-valued neural networks, the globally exponential stability of a class of the system with mixed delays and impulsive disturbances was studied in this paper. Assume that the neuron states, activation functions and interconnected matrix were defined in the complex domain. Some sufficient conditions for assuring the existence, uniqueness and globally exponential stability of the equilibrium point of the system were obtained by applying the M matrix theory, the mathematical induction and the vector Lyapunov function methods. Meanwhile, the exponential convergence rate was proposed. It can be concluded from the established sufficient conditions that the exponential convergence rate of the neurons is reduced by both time delays and the impulsive disturbances. The stability criteria established in this paper generalize the existing results. Finally, a numerical example with simulations was given to show the correctness of the obtained results.

Abstract:In order to measure the motor parameters. This paper presents a new and improved SLIM equivalent circuit parameter identification, the motor thrust using different frequencies, the inverter output voltage and current, static stall characteristics, combined with suitable control algorithms calculate the equivalent circuit of SLIM primary resistance, leakage i_n ductance, secondary equivalent resistance and leakage inductance parameter. By finite element simulation experiments show that the amplitude of the dynamic parameters of each amendment to increase the motor speed identification accuracy is beneficial, conduct experiments on low-speed maglev simulation platform, validated under T-improved model, the motor status identification results show the current state of reconstruction, not only in the dynamic process of change or steady-state accuracy, and has a guiding significance to the future design of motor parameters.

Abstract:In order to further improve and enrich penetration grouting theories of power-law fluid, its column penetration grouting mechanism is researched. According to combining with the rheological equation and seepage motion equation of power-law fluid, carrying out theoretical analysis and experimental, column penetration grouting mechanism based on power-law fluid is deduced. Scope of application and method to determine the parameters are analyzed respectively. Then they are validated by means of designing grouting verifying experiments. Research results show that equivalent diffusion radius of actual measurement values in the indoor grouting experiments have about 30%-35% differences with that of theoretical values calculated by column penetration grouting mechanism based on power-law fluid, but they are all within the acceptable error limits. Therefore, it may have good indication to column penetration grouting diffusion laws of power-law fluid in the injected medium, so research achievements may not only can provide theoretical basis for perfecting the penetration grouting mechanism, but also play a reference guiding role for design and construction on grouting technique.

Abstract:In order to analyze the characteristic of particle coagulation from vehicle exhaust under constrained dispersion conditions and the effect of coagulation on dispersion in an underground parking lot, the study numerically simulated the particle concentration fields under steady-state constrained dispersion conditions using Realizable k-ε model and field functions based on the theories of particle dispersion and coagulation, and then analyzed the characteristics of particle decrease half-time due to coagulation and variation of particle size distribution. The simulation results demonstrated that particle decrease half-time was shortest near the tailpipe exhaust. In the area lower than 2 m in vertical direction in an underground parking lot, when idling cars were not more than 2, half-time decreased linearly with the increase of distance above the ground; when idling cars were not less than 4, half-time decreased logarithmically with the increase of distance above the ground. The effect of coagulation on variation of particle number concentration in the middle and large size categories was more obvious than that in the small size categories. Particle size changed from small to large due to particle coagulation. The uneven distribution of particle size was more obvious as the number of idling cars increased.