Abstract:Accurate estimation of vehicle status parameters is important to vehicle stability control. Combination of 3-DOF vehicle dynamics model and adaptive control algorithm, proposed a method that modifies adaptive law through compensation was proposed to estimate vehicle parameters correctly. Bases on the method, the vehicle dynamics model was simplified to reduce the calculation burden and improve the real time performance. The starting and acceleration driving conditon and double lane change conditon were designed for the simulation and the hardware-in-loop test. Finally, both the simulation results and hardware-in-loop test results indicate that the proposed method could estimate the vehicle mass and moment of inertia more precisely and faster compared to the adaptive algorithm without compensation and satisfy the requirement of vehicle online estimation.

Abstract:To solve the problem that vehicle mass and road grade in automatic transmission control system are difficult to measure, the state-space model of system was established based on the vehicle longitudinal dynamic model, using the optimal estimation theory. The forward Euler method was adopted for discretization of the process equation. The Jacobian of the process equation was calculated for linearization of the non-linear process function. Then, the vehicle mass and road grade estimation algorithm using extended kalman filter was developed. The simulation using road test data was carried out in Matlab/Simulink environment. The simulation results show that this algorithm could estimate vehicle mass and road grade effectively and meet the requirements of the automatic transmission control system.

Abstract:Prediction of road slope is a key technology to vehicles’ electronic real-time control system, such as ABS, AMT and hybrid torque distribution, and so on. In this paper, a real-time prediction method of road slope was put forward based on support vector machine (SVM), in which the input parameters of SVM module included engine speed, engine output torque, vehicle speed and longitudinal acceleration, and could be extracted from controller CAN network in real-time. The vehicle roadway test system and the CarSim simulation platform were built up respectively, and the samples required for SVM model learning, generalization performance test were achieved by the systematic tests. The squared correlation coefficient of SVM model from CarSim tests was 0.99, while it was 0.9 from roadway tests. The main reason for the difference could be that the GPS method in road slope test may add in a body pitch angle which could not be eliminated systematically. Furthermore, the SVM model of roadway test was imported into the real time virtual controller PXIe using LabVIEW programming method. For the equivalent prediction time of one point to the single chip computer selected by automotive electronic controller was only 1.33ms , which met the requirements of real time control . The road slope prediction method proposed in this paper is effective and practicable.

Abstract:In order to overcome the complicated structure and high prices of the hydraulic retarder and the serious thermal recession problem of braking torque of the conventional eddy current brake, a self excited and liquid cooled eddy current retarder (SL-ECR) structure was proposed. The model of braking system and generating system of the SL-ECR was established and the magnetic circuit structure was analyzed. The electromagnetic field model, the braking performance and thermal field of the SL-ECR were analyzed by using finite element method. A 2000N·m SL-ECR was produced and tested. The braking performance and the generator performance were tested. The results show that the difference between the finite element analysis results and the experiment results was 6%. The temperature of the water wipe was 85℃ when the braking power was 180kW. The braking torque decreased by 10.4% in the continuous braking stage. The braking torque could reach 2000N·m when the speed was 1500r/min and the coil current was 30A, while the excitation power was only 720W by the vehicle.

Abstract:Aiming at the special structure and steering characteristic of wheeled electric-driven articulated underground mining truck, a differential control strategy which took the equal slip rate as control target was given. The kinematic and dynamic model of electric-driven mining ADT was established and the kinematic relationship and stress condition of the driving wheels were analyzed during steering. Acceleration sensors in the sample ADT were used to test the actual speed of the vehicle. Results showed that the filtered signal had small delay and fast response and could be directly used to estimate the speed. Equal slip rate control strategy was superior to equal torque control strategy because it could make full use of the ground adhesion coefficient and achieved the reasonable distribution of drive power. Two sides wheel slip ratio could be stable on -0.08 and the sliping phenomenon was avoided in experimental turning. This control strategy has practical effect for reducing tire wear and improving driving power utilization.

Abstract:Potential energy recovery can significantly reduce the boom energy consumption produced by frequent rising and lowering operations. As a critical component, the performance of the permanent magnet generator applied in energy recovery has a strong influence on energy conversion and motion control. Therefore, it is necessary to research and design the control system of the generator. Since there exist input and output parametric fluctuations, adaptive control and disturbance compensation were proposed in the current loop and the speed loop, respectively. Experiments were implemented on a test bench which is loaded with hydraulic approach. The results show that the good current and speed control performances were realized, and anti disturb capability was also improved.

Abstract:The effects of exhaust pipe insulation on unregulated emissions of a spark ignition (SI) engine fueled with M10 (10% of methanol in blend by volume) and E10 (10% of ethanol in blend by volume) blends respectively were experimentally investigated with gas chromatography (equipped with a pulsed discharge helium ionization detector, PDHID). Experimental results show that methanol and ethanol emissions decreased after exhaust pipe heat insulation. After exhaust pipe heat insulation designed, aldehyde emissions did not change obviously at low engine load conditions (Tc<850K), but aldehyde emissions decreased significantly at middle-high engine load conditions (Tc≥850K), and the decreasing range of unregulated emissions increased with exhaust temperature rising. It is conducive to the oxidation of unregulated emissions with prolonging the reaction time of unregulated emissions in high temperature environment after exhaust pipe heat insulation designed. Unregulated emissions decreased significantly with exhaust pipe heat insulation when the exhaust temperature (Tc) was higher than about 900K. Exhaust temperature and reaction time had a greater influence on the oxidation of alcohol and aldehyde emissions.

Abstract:K-means clustering algorithm is an excellent algorithm which has been widely used in the image processing and data mining. However, the algorithm arouses a high computational complexity. This paper made a parallel analysis of K-means algorithm in detail, and proposed a partitioning and parallel K-means algorithm based on CUDA (Compute unified device architecture). In addition, some optimization strategies, e.g., coalesced memory access, parallel reduction, load balance and instruction optimization, were discussed to obtain the higher performance. Experimental results show that the parallel K-means algorithm achieves 560x speedup over the sequential C codes, while maintains the same effect. Hence it solves the bottleneck of the algorithm perfectly, which is an attractive alternative to the sequential K-means algorithm for image segmentation and clustering analysis.

Abstract:Orchard pests monitoring is very important in precise pest management. The pests trapped by high-voltage current in orchard show different postures, which increase the difficulty of image automatic identification. A posture description-based method has been proposed to automatically represent image boundary and identify certain common pests in orchards. The performance of proposed method in posture description with rotation, translation and wing scale of image edge was tested. Posture feature vector and similarity difference threshold were determined by the calculation of average normalized Fourier descriptors(FDs) and discrete degree. Three types of pests with 200 sample images were tested, and it found that correct rate of target pest Dichocrocis punctiferalis (Guenee) was 86.7% and error rate was 2.6% when discrete degree threshold was 0.02126. The experiment results indicate that this approach has a stable description ability for posture-shape and good recognition performance.

Abstract:In order to detect the broken shiitake, a automatic detection system of shiitake was developed based on machine vision. Identification algorithms based on curve evolution and shiitake edge grayscale were presented. First, the background of shiitake images was removed, the edge of shiitake was tracked and then the coordinates of shiitake boundary was obtained. A closed curve was composed of these coordinates. Two initial curves could be generated from the interior and exterior of the closed curve respectively. Two final curves were evolved on those two initial curves, which met the condition of specific termination criterion. Two parameters (Nin，Nout) were extracted from the difference of final curves and initial curve. These parameters could determine the broken extent of shiitake and shiitake edge region were sampled with the method of morphology. Then four parameters could be extracted from the sequence of the gray scale of sampled regions .These parameters were mean (μ), variance (ρ), average width of peaks (Lp) and the maximum width of peaks (Lmax) respectively. The four parameters were analyzed with the method of pattern recognition and the broken extent of shiitake was obtained from the processing results. The final result was given with the results of both curve evolution and grayscale analysis. Experiments show that the accuracy of final shiitake detection model reached up to 88.33% , and the selection speed was 98 per minute.

Abstract:In order to enrich the kind of teas being produced, and improve the utilization of fresh tea materials, a multi-functional preprocessing machine for fresh tea was developed which could realize spreading of green tea, withering of black tea, and green-making of oolong tea. The general structures as well as the working principle of some key parts like mechanical transmission system, leaf turning device, ventilation and heating system were introduced. With multi-branch pipe for air intake, the uniformity of wind field was ensured; pump with high pressure and low flow rate, together with small spray nozzle ensured the uniformity of moisture; temperature was accurately controlled according to different layers. Experimental results show that teas produced with this machine had higher physical and chemical indexes and scores compared to the control groups. The results show that the design was reasonable, and the machine was reliable.

Abstract:Biogas slurry residue has the characteristics of continuity and Large quantity. It has also a great difference with conventional liquid fertilizers. A fertilizer machinery used for biogas slurry dark field irrigation is designed based on the physical parameters of biogas slurry, and it can complete the operations of ditching, fertilizing, ridging, the suppression of process at one time. An distributor adopted by the fertilizer spreader can change continuous flow into intermittent flow and concentrate fluid energy, as a result the anti-blocking capability of the flow are improved to some extent. In addition, the maximum stress of fertilizing shovel applied the job force are in the allowable stress range. According to the calculations of the mechanical traction power for the entire fertilizer, DFH X904 tractor can meet the power demand of the fertilizing machinery when operating.

Abstract:The structures of fertilizer tube and fertilizer falling tube have an important impact on the granular multi fertilizer flows blending and fertilizing hysteresis performance in the nutrient proportion of variable rate technology (NPVRT). On the basis of the optimal structure of the blending cavity structure, the granular multi fertilizer variable rate fertilizing process was simulated by discrete element method in this paper, and the impact on particles motion under varied height of fertilizing tube and varied diameter of triangular shape of the bellows was analyzed. According to the proposed performance evaluation indexes, the structures of fertilizing tube and bellows were optimized. The computing and mechanism analysis results show that: first, the greater height of fertilizer tube was, the higher particles speed in falling, collision , mixing and the various stages were. Second, the greater the spread area after the particles colliding with the blending cavity was, the better the particles blending was, and the smaller the standard deviation of particle blending ratio was. Then, the height of triangular shape of the bellows for fertilizer dropping was in range of 4~6mm, relative to the non-bellows one, that could raise the number of collisions among the particles and bellows, thus improving the uniformity of particles blending. However, excessive height slowed down the dropping particles contacted with bellows. If the height of triangular shape of the bellows was about 2mm, that was approximately 40% to 60% the diameter of fertilizer particle, the uniformity blending of particles could be promoted, and triangular shape had smaller effect on time-lagging of particles.

Abstract:In order to solve the problems of rice seedling-growing bowl tray made of paddy-straw in the process of application, the improved structural design was made for the early rice seedling-growing bowl tray made of paddy-straw. The paper explored its structural design principle and design process. Compared with the early rice seedling-growing bowl tray made of paddy-straw (CK1), rice bowl carrier of Japanese (CK2) and actual rice production of China (CK3),the paper discussed influence on rice production by field test with rice seedling-growing bowl tray made of paddy-straw after improvement(CK). The results with CK, CK1, CK2 and CK3 as rice seedling carrier respectively showed that: the max normal stress of CK was higher than that of CK1. The seedling with CK and CK1 need not slow growth days, but the seedling with CK2 and CK3 slow growth days when they were transplanted in rice field. Rice-seedling qualities was not significantly different between CK and CK1, but which were better than CK2 and CK3. Cost of production of CK was smaller than that of CK1and CK2, but higher that of CK3. Influence of CK and CK1 on organic matter in soil profile was the same. At the soil level of 0~10cm, 10~20cm and 20~30cm, the organic matter in soil profile of CK were 7.06%, 10.08%, 2.53%, 3.34%, 0.48% and 0.11% higher than that of CK2 and CK3 respectively. Influence of CK and CK1 on dynamics of soil bulk densities was the same. Compared with CK2 and CK3, the CK could enable to reduce dynamics of soil bulk densities. The rice yield of CK was the same to that of CK1. Compared with CK2 and CK3, rice yield of CK was higher than by 10.59% and 13.54% respectively, which benefits to develop others bowl cultivation technology in China.

Abstract:Small flow high precision real-time dynamic detection and control of pesticide is a key problem which need to solve urgently for on-line mixing device. Flow rate passing the flow regulating valve is related to differential pressure between the upstream and downstream of the valve, fluid density and the valve opening. By developing the relation expression between flow rate and these three variables, real-time detection and control for pesticide flow rate can be implemented using the control valve. In order to meter and control the flow rate of water and pesticide by using flow meter and control valve respectively, the online mixing pesticide device is designed. The calibration method of control valve is proposed and the flow rate relation expressions are developed. The experiments are conducted for the designed mixing device. The experimental results show that the relative error of the pesticide flow rate is less than 4% as the pesticide flow rate is between 24mL/min and 240mL/min.

Abstract:In order to study the effect on air flow rate of air-assisted and the distance of air outlet to nozzle to the droplet diameter and droplet velocity,the air-assist boom spray field was tested and analyzed in various conditions using PDPA measurement system. According to the test results, the droplet diameter distributions, velocity distributions and the relationship between air pressure and droplet diameter were analyzed systematically. The test results indicate that under the influences of flow field,the higher the air flow rate of air-assisted is, the smaller the droplet diameter is,increasing the droplet deposition,reducing the droplet drift.And its distributions are more symmetrical.The closer distance between the air outlet to the nozzle,the better droplet penetration is,reducing the trend of droplet drift.

Abstract:In order to obtain the optimal structure and operational parameters of the threshing and separation device of tangential-longitudinal combine, rice harvest in field was conducted to study influence of tangential drum-concave gap, longitudinal drum-concave gap and speed of tangential drum and longitudinal drum on the performance of total threshing-and-separation power consumption, tangential drum power consumption, longitudinal drum power consumption and entrained loss. The combine was re-constructed- based on self-developed tangential-longitudinal combine and load test system was built for the combine. Optimal parameters are gained by quadric polynomial regress analysis and complex method, and tangential drum-concave gap is 30.99mm, longitudinal drum-concave gap is 14mm and the speed of tangential drum and longitudinal drum is 892.95r/min and 848.95r/min respectively. The test result showed that on the parameter’s condition, total power consumption was 39.03kW, power consumption of tangential drum and longitudinal drum were 11.72kW and 27.31kW respectively and the entrained loss rate was 0.50%. Mixture distribution under tangential drum and longitudinal drum was analyzed, and it provide basis for design and optimization of cleaning unit.

Abstract:In order to harvest sugarcane with machine in hilly area, a small whole stalk sugarcane harvester was designed. Virtual simulation test for cutting system was carried out using logistics simulation software FLEXSIM. The virtual test results showed that increasing the width of logistic channel and enhancing the transmission speed of the sugarcane had significant differences on avoiding blocking during sugarcane harvesting. When the width of logistic channel remained constant, enhancing the transmission speed of the sugarcane was particularly important. Then, the transmission process of the sugarcane was simulated using ADAMS software. The simulation results showed that increasing the friction coefficient between sugarcane and spiral, equipping aggressive knock down roller and adding more rubbers on the drum could increase the transmission speed of the sugarcane. Field test indicated that the feed ability was enhanced, and the times of sugarcane struck by base cutter and lifter were decreased. The cutting quality of sugarcane was improved, and the probability of blocking during sugarcane harvesting was reduced after taking the measures above. The time of sugarcane passing through the cutting system was shortened to 1.5 s from 2~3 s, and no damage rate of the base of sugarcane was increased from 17.8% to 57.9%.

Abstract:To solve the cleaning problems of portable reaper, the cleaning system test bench was designed and the wheat was chosen as the experimental object. Air flow test without material was done and analyzed the static pressure in the two stages of pipelines. The relation among the speed of first and second level winnower and the fan can be found. The test can provide the selection scope of motion parameters for the material test. In material test, the fan speed and the first and second winnower speed were selected for test factors, and the cleaning rate for test indicator. Through orthogonal test and quadratic general rotation test, the motion parameters of wheat were found out when its cleaning rate was best and the impact of individual factor on the indicator was researched by regression equation. The best motion parameters can be found through the test: when the speed of first and second level winnower and the fan was 300r/min、764r/min、3255r/min , the cleaning rate would be best. This combination of parameters will apply to portable reaper cleaning systems, and provide the system the reliable movement parameters.

Abstract:In order to study the gas-liquid two-phase flow during the gas-liquid mixing and separating process, a flow-ejecting self-priming pump named JETST-100 was chosed. Based on Eulerian-Eulerian multiphase flow model, the transient numerical simulation of the gas-liquid mixing and separating phenomena on the pump chamber was carried out using CFX software. The distributions of pressure, velocity and gas-liquid phases field inside the pump were obtained, and the change of the air volume fraction by monitoring the points on the gas-liquid separation chamber outlet and jet aerator inlet were analyzed . The test and simulation results show that the flow of liquid from the guide vane formed a large amount of velocity circulation. And the water of the pump chamber reduced with the large amount of water into the outlet channel. It was found that adding the reinforcing plate could prevent the generation of circulation on guide vane back, and improve the self-priming performance of the pump.

Abstract:Pumped storage power station was widely concerned since its important role. The running stability of the pump turbine unit as the core component was essential to the safe and stable operation of the plant. The stability tests were conducted under working condition of hydroelectric generating set. The test data were analyzed, including the lower labyrinth pressure pulsation, the guide bearing swing and the head cover vibration. It was revealed that the main frequency causing the labyrinth pressure pulsation was the rotation frequency, the blade passing frequency of runner and the vortex rope of draft tube. The signals of labyrinth pressure fluctuation were strong correlated with the signals of the turbine bearing swing and the head cover vibration and had a strong influence on the vertical/horizontal vibration and swing of turbine.

Abstract:In order to discuss the characteristics of pressure fluctuation in a scaled axial flow pump at different flow rate conditions, the dynamic pressure fluctuation data of six pressure monitoring points on the pump casing was measured at different flow rates, and the law of pressure fluctuation in impeller was revealed. The experimental results show that waveform of pressure fluctuation at impeller inlet P1 was the normal sine shape, and the peak to peak value of pressure fluctuation at the measuring point P2 in the impeller reached the maximum, and then decreased at monitoring point P1 located in impeller inlet. Time domains of pressure fluctuations in impeller had four peaks and four valleys which were consistent with the impeller blade number, due to the alternating pressure gradient. The secondary flow and tip leakage vortex induced the second harmonic wave significantly at the middle of impeller at small flow rate conditions. Based on Fast Fourier Transform, the main frequencies of pressure fluctuations at three measuring points in the impeller region in different flow rate conditions were all blade passing frequency(BPF), and the harmonic frequency was the multiples of BPF. The amplitudes of harmonic frequency decayed exponentially. However, the low frequency which was induced by the reversed flow and flushing occured in the frequency domain of pressure fluctuations in the guide vane, and the BPF and its harmonics coexisted.

Abstract:A software for automatic parameter estimation (PEST) was used to estimate 24 parameters in the root zone water quality model (RZWQM2) and analyze the sensitivity of each parameter by controlling the proportion of function values of simulation difference from various observation variables in the objective function, including soil moisture, soil nitrate, leaf area index and yield of crop. The results show that parameters of PHW, P1VW and PHM were the three most influential parameters to the overall simulation performance of the RZWQM2 model when the proportion of simulation difference for each observation variable was closest. In contrast to the trial and error method, RZWQM2 model after calibrated with PEST could accurately simulate the moisture and nitrogen transport in soil profile and crop growth in a rotation system of waxy mazy and winter wheat. This study could help estimate RZWQM2 parameters in different agricultural management practices and could also provide a reference for the application of PEST in other models for parameter optimization.

Abstract:The present method for allocating the nutrient of livestock manure from the scale raising farms is simply allocating the total amount of statistical data of scale raising farms according to the area of farmland taking administration cell as unit. In this method, it is thought that there are no differences among the farmlands and the amount of statistical data of scale raising farms is only closely related to the area of farmland in a administration cell. The specialization algorithm of statistical data of scale raising farms was constructed based on the spatial differences among the farmlands and the particularity of livestock manure from the scale raising farms, when it applied as the fertilizer to farmland using theory and technique of GIS spatial analysis. With the maximum nutrient load of farmland, the statistical data of scale raising farms were transformed to the supply of regional nutrient of livestock manure. Finally, the specialization algorithm was carried out at the town of Shangjie to realize the application. The results of practical application show that the maximum values of nitrogen and phosphorus load of farmland were 169994kg/hm2 and 34973kg/hm2,which both were below the threshold value of 170kg/hm2 and 35kg/hm2 respectively. And it also shows that the method could reflect the spatial differences between the farmlands and was closer to the practical results of livestock manure than the present method.

Abstract:Distribution uniformity (DU) and Christiansen uniformity coefficient (CU) are two important indicators for evaluating the hydrodynamic performance and irrigationg quality of sprinkler irrigation system. In order to research the impact of the pressure, sprinkler combinations and interpolation methods on the distribution uniformity and Christiansen uniformity coefficient, CU and DU were computed by linear interpolation, cubic interpolation, cubic spline twice interpolation, inverse distance weighting method and plane interpolation method with two combinations (rectangular and regular triangle), and 1m sampling space. Using the experimental data of FY RB-471 sprinklers without wind simulated the water distribution under different pressures. The results showed that CU calculated form rectangular combination date were less than form regular triangle combination date by 1.56%~4.77%. Similarly, DU calculated form rectangular combination date were less than form regular triangle combination date by 4.26%~9.19%. Different interpolation methods for the calculation results of CU and DU are not obvious, while the pressure is an important factor for affecting the sprinkler uniformity.

Abstract:130 soil samples from farmlands in Weibei dry-land mining area were collected and analyzed for the content of Cd, Cr, Cu, Pb, Zn. The results indicated that the average contents of Cd, Cu, Pb were higher than those of Shaanxi Province soil background, while Cr and Zn contents were lower than those. The geostatistical analysis results suggested that the heavy metal contents decreased from west to east, and had the highest contents all around cement factory. There were significantly positive correlation among Cd, Cr, Cu, Pb and Zn. The principal component analysis was applied to estimate the sources of heavy metals. Cd in factor 1 was associated with anthropogenic activities, whereas Cr in factor 2 was mainly controlled by parent material, Cu，Pb and Zn were affected by both two factors. The quality of soils were evaluated with pollution load index (PLI) and potential ecological risk index(PER), respectively. The results show that coal mine area was clean or slightly to moderately polluted, while the cement factory area was moderately polluted. Heavy metals in soil were ranked by pollution index as Cd,Pb,Cu,Cr,Zn.

Abstract:The study investigated spatial variability of spring wheat ET and uses regression analysis to identify the ET main factors. Furthermore, the ET main factors were taken into account in the ET space research. Results showed that the geo-spatial coefficients of variation of spring wheat ET ranged from 0.328 to 0.495 at various growing stages even for homogeneous farm fields. During the spring wheat growing season, the spatial variability of cumulative ET estimates was high at the tillering-shooting stage, and then reduced at the shooting-heading stage. Comparing to leaf area index (LAI), spring wheat ET had a significant relationship with surface soil moisture content change at all the growing stages. When the rainfall infiltration depth was less than 20cm, the soil moisture (0~20cm)was the ET main factor. Compared with the ground-based observations, the ET estimation precision with 42 ET ground sample data was better than 90%.

Abstract:Shallow brackish water is widely distributed throughout north and northwest China and could be rational used. To evaluate the spatial distribution and variability of cotton field salinity under mulched drip irrigation with brackish and fresh water in southern Xinjiang, electromagnetic induction EM38-MK2 was applied to measure the apparent soil electrical conductivity. Statistical characteristics of soil salinity from the interpretation models of soil salinity showed that the scenario of brackish water irrigation had the higher salinity level and the lower variation coefficient than the fresh water irrigation. The optimal semi-variance models of brackish water and fresh water irrigation were exponential and Gaussian models respectively. Both models were characterized by strong spatial correlation. Compared with fresh water irrigation, the scenario of brackish water irrigation with the higher salinity level had the lager range variation and increased the spatial dependency of soil salinity. The spatial distribution of field salinity interpolated by Kriging method showed that both scenarios of brackish and fresh water irrigation had some filed parts with high salinity level, which would affect cotton emergence. EM38-MK2 would be suggested to investigate the field salinity distribution. According to soil salinity levels of different parts, amount of fresh water of flood irrigation for leaching salinity could be defined to save water and ensure the agriculture production.

Abstract:The e-nose system and Gaussian process (GP) classifier were used to accurately monitor physical and chemical changes in solid-state fermentation (SSF) of crop straws to replace off-line chemical analysis in laboratory. The SSF experiment cycle is seven days and the gas monitoring data sets were collected by e-nose every 24 hours. In this experiment 20 data sets corresponding to 20 batches of fermentation processes were collected, and ten of which were used for training GP classifier, while the rest for testing the performance of it. Test results show that the e-nose system could effectively monitor SSF process of crop straws and the classification accuracy of GP classifier was higher than that of support vector machine classifier or neural networks classifier. So the e-nose system combined the GP classifier method could be an effective strategy to monitor SSF process of crop straws.

Abstract:The crack width of sludge return crack for the three-phase separator (TS) plays a key role in the separation process. To evaluate the effects of crack width on the separation efficiency of solid, liquid, gas in TS of USAB reactor, a 3-D CFD simulation was adopted based on Eulerian multi phase model. Five typical crack width settings as 80mm, 95mm, 110mm, 125mm, 140mm were investigated for a typical UASB reactor. The result shows that the average flow speed of three phases in the TS region was much higher than the UASB’s designed up-flow speed, and the flow speed of solid phase exceeded that of gas and liquid. Circulation pattern turbulence dominated the liquid flow in TS region. The crack width had more obvious effect on solid phase than on gas and liquid. The separation efficiency was much effective for solid phase in five cases through one platewhile only 60% for gas. The separation efficiency of gas and solid phases became lower with a wider crack gap. With the supplement of precipitation layer in the top of TS, the solid phase could separate completely, while the highest separation efficiency for gas was obtained with gap width of 95mm.

Abstract:Porous polystyrene divinylbenzene was prepared by suspension polymerization, and then sulfonie acid ion exchange resin was obtained by sulfonated porous polystyrene divinylbenzene. The resin’s morphology and degree of sulfonation were characterized with SEM/EDS, BET, IR respectively. Esterification of waste frying oils with acid value of 63.0mg/g was studied using cation exchange resin as catalyst to investigate its catalytic activity. 40.0% dosage of porogen was preferred when the polymerization conditions were 360r/min, 1.0% dispersant, 1.0% initiator, 75℃ for 4h and the heat to 85℃ for 6h,while the sulfonation conditions were 1.0mL/g dichloroethane, 5.0mL/g sulfuric acid, 70℃ sulfonated for 1h and the heat to 80~85℃ for 3h, the optimum swelling time was 1h, and the concentration of sulfuric acid was 98%. The maximum exchange capacity of the cation exchange resin W2 was 5.2mmol/g in that condition. When the esterification was performed in the condition of 40.0% methanol, 10.0% W2, 70℃ stirring for 1.5h, the crushing rate of W2 was only 10.0% and the conversion rate of FFA reached to 86.8%. W2 is better than commercially available cation exchange resin PC101, and could be reused for 5 times.

Abstract:A novel pitch control system is proposed for wind turbine to stabilize the drive-train power and torque fluctuations. This system is based on a constant pressure network and a hydraulic motor with variable displacement. The desired pitch control motions and directions can be achieved by regulating the displacement of the hydraulic motor to adapt to the varying loads acting on the blade. Mathematical model and a detailed analysis for the control characteristics of the system are provided. Further, a double control loop for position feedback is proposed to accurately track the desired pitch angle which is obtained based on fuzzy reasoning. Experimental results have demonstrated that this system can effectively control the power and driver torque, and consequently maintain the output power and torque on the rated values. In addition, this novel system has the advantages of high power versus volume, energy-saving and is particularly suitable for large scaled individual pitch controlled wind turbine.

Abstract:Traceability systems gain more attention in worldwide as an effective method for controlling agricultural products and food quality safety. The concepts of traceable and traceability system were discriminated. Key technologies for establishment traceability systems, such as coding and identification, real-time record keeping in the supply chain, intelligent decision making and early warning and data exchange and query, were summarized. Combined IOT（internet of things） technology, the technology framework of traceability system including one kernel, two axes and three chains was constructed. One kernel means to implement the goal of agricultural products and food quality safety traceability. Two axes are the supply chain from farm to table as the horizontal axe and the IOT technologies from information sensing, information transmission to intelligent decision as the vertical axe. Three chains include products chain for supply lifecycle, service chain for supply chain actors and technology chain for IOT. Furthermore, the urgent problems for implement the traceability system were put forward, which included unified encoding, low cost and quick information collection equipment, application system with intelligent decision model and collaborative traceability platform.

Abstract:The simultaneous ultrasonic/microwave assisted extraction (UMAE) technology of extracting antioxidants from clove was optimized and the reason for high-efficiency of this method was analyzed. The results show that the optimal parameters of the UMAE technology were as follows, ethanol concentration was 50%, ratio of extracting solution to sample was 30mL/g, ultrasonic power was 50W, the microwave power was 100W and the extracting time was 12min. Comparative study show that the extraction ratio of antioxidants from clove by UMAE was significantly improved compared with water bath oscillator extraction (WBOE) in the same conditions. It was also found that the superiority of UMAE was simultaneously acted and mutually reinforced by ultrasonic and microwave through interaction analysis. A comparison of scanning electron microscopy images from the clove powders by UMAE, WBOE, microwave assisted extraction (MAE) and ultrasonic assisted extraction (UAE) indicated the extraction efficiency was higher by UMEA with the more serious disruption of cell structure and the more sufficient interaction.

Abstract:Lactic acid bacteria (LAB) are recognized as probiotics worldwide. The cell itself and all kinds of metabolites are essential parts of the human life processes. The bacterial biofilm has been described as sessile bacterial communities that attached to surfaces aggregating in a hydrated polymeric matrix of their own synthesis．LAB biofilm has broad perspective for their particularities. Lactobacillus pentosus, which isolated from the traditional dairy products of Xinjiang and had a strong positive biofilm formation, was taken as the research subjects. Semi-quantitative assay was performed to examine effects of different physical and chemical factors and several food additives on biofilm formation by L. pentosus. The results showed that the optimum physical and chemical conditions for biofilm formation of L. pentosus were inoculation volume at 1∶200, incubation temperature at 37℃, culture period at 48h, glucose concentration at 2%, pH value at 5.8~6.8, and so on. The addition of Ca2+ and lactic acid obviously inhibited biofilm formation by L. pentosus completely.

Abstract:The rice bran protein was extracted using stabilized rice bran by ultrasonic combined with acid alkali soluble. Selecting the ultrasonic time, ultrasonic power, ultrasonic temperature and solid liquid ratio as studying factors, the yeild of rice bran albumin and rice bran glutelin were chosen for single factor experiment. Rice bran albumin and rice bran glutelin were from stabilized rice bran under the best ultrasonic conditions ,which were tested amino acid composition, microstructure, secondary structure and thermal stability. The results shows that the yeild of rice bran albumin and rice bran glutelin both reach the maximal value under the condition of ultrasonic time 10min, ultrasonic power 160W, ultrasonic temperature 50℃ and liquid-solid ratio 10mL/g. Amino acid composition, microstructure and secondary structure showed the two protein had the typical characteristics of albumin and protein, and had higher thermal stability.

Abstract:Hyperspectral imaging technology was used to determine total flavonoid content distribution map on different color ginkgo biloba leaves (green, green yellowish, yellow). Firstly, 120 Ginkgo biloba leaves were used to collect hyperspectral image data cube and determine total flavonoids concentrations. Secondly, the average gray value of each band in hyperspectral image data cube was calculated as spectal data of Ginkgo biloba leaf. The spectal data and total flavonoids concentrations were used to bulid calibration model (R=0.9307) by using multiple stepwise regression method. Finaly, the calibration model was used to predict the total flavonoid content of each pixel in the hyperspectral image. This enables construction of a distribution map of total flavonoid content on the ginkgo leave. Distribution maps of total flavonoid content in three color groups (green, green yellowish, yellow) were calculated. Results indicate that the level of total flavonoid for green, green yellowish, and yellow were in an increasing order. Higher level of total flavonoids could be noticed at the margin area of the leaves, while lower levels occured at the area near the leafstalk of the ginkgo leaves. This research provided a method to determine major constituent of food and agricultural products.

Abstract:Infrared drying experiments were carried out and the temperature data of yam were collected under different infrared intensities and infrared distances. The experiment results showed that the infrared intensity, infrared distance and drying time played an important role on the surface temperature and internal temperature of yam. Thus, infrared intensity, infrared distance and drying time were chosen as the input layers vectors of BP neural network model. A 3×9×1 single hidden layer BP network model was established. The model was trained by steepest gradient descent method and Levenberg-Marquardt algorithm respectively based on temperature data of yam. The maximum prediction error of optimized network model using Levenberg-Marquardt algorithm was 1.3℃, while the traditional algorithm of BP neural network was 5.7℃. It was indicated that Levenberg-Marquardt optimization method was superior to the steepest gradient descent method in the predicting temperature of yam with high precision. Therefore, it is feasible to predict temperature variations of materials during infrared drying process by using BP neural network model optimized by L-M algorithm.

Abstract:A remote sensing system based on the unmanned aerial vehicles (UAV) was designed and established. The garden plot in Beijing was selected as a research object and the major growing period of Chinese chestnut was monitored. Based on this system, the experiment monitoring for the major growing period of Chinese chestnut was achieved and a large number of high resolution images was obtained. The preprocessing including selecting, band separation and calibration and so on was made and finally three main band (red, green, near infrared) reflectance data of Chinese chestnut in the major growing period was generated. According to the analysis of difference for spectral signature between vegetation and soil in the band range of 400～1200nm, the ratio of total number of vegetation pixels was counted for the imaging range, that was fractional vegetation cover (FVC). The fractional vegetation cover of unmanned aerial vehicles images could be computed rapidly. The annual variation of fractional vegetation coverfor Chinese chestnut was monitored using multi temporal unmanned aerial vehicles remote sensing images. The simulation scenes were formed by computer simulation method and the characteristic of statisticsscalefor Chinese chestnut fraction vegetation cover was analysed. The availability and effectiveness of the fractional vegetation cover computed from remote sensing images of unmanned aerial vehicles were validated.

Abstract:To get the straight flight features of agricultural UAV(unmanned aerial vehicle)，and to verify and evaluate the artificial path planning and the actual operating results in visual remote flight mode, a wireless transmission system based on GPS was designed. The handler took the straight boundary of paddy field as a reference by using remote control UAV based on visual and experience. Straight flight experiment and the real time path planning flight experiment were implemented on the base of the paddy field boundary. The results showed that it was difficult to control the UAV flying in a straight line in visual remote control mode, and the artificial planning route deviated from the ideal flight path significantly for the reason of no reference. It was estimated that the skip rate was 17.1%, duplication operation occupied 8.2%, and outside wasted region accounted for 0.7%. Meanwhile, the height and speed of the UAV had a characteristic of erratic randomness in visual remote flight mode. Therefore, in case of no navigation, it is difficult for handler to implement precise operation by means of visual and experience alone. Autonomous flight mode with GPS navigation, intelligent optimization and generates flight trajectory, is the direction for future development of UAV applied in precision farming.

Abstract:The aim of this study is to seek out the most suitable image fusion algorithm for OLI image of Landsat 8 satellite acquired in June 9, 2010, taking Yuyang country in Shaanxi Province as study area. Five kinds of image fusion algorithms have been employed, which are Brovey transform, High pass filter transform, HIS transform, PCA transform and LBV wavelet RF. The effectiveness of the five fusion algorithms has been evaluated based on spectral fidelity, high spatial frequency information gain, and supervised classification accuracy. Firstly, by visual evaluation this study evaluated whether fused images preserved spectral information of original multispectral image well, and whether retained texture and edges information of panchromatic image and avoided texture blurring. Secondly，by quantitative evaluation, spectrum character of fused images was analyzed by using gray average difference and gray root mean square error. Integration of the high frequency detail information of panchromatic images to fused images was analyzed by using correlation coefficient average and correlation root mean square error. The supervised classification accuracy of fused images was evaluated by using Kappa coefficient and overall classification accuracy. Results showed that LBV wavelet RF was the best method in retaining spectral information of original multispectral image, and not causing spectral distortion, as well as achieving the highest SVM supervised classification accuracy. Overall classification accuracy and Kappa coefficient of fused image using this method were 84.01% and 0.787，achieved noticeable growth of 13.45% and 15.91% than original multispectral image. The proposed OLI image fusion algorithm could provide far more detailed topographic information compared with original multispectral dates and better service for improving visual interpretation and supervised classification accuracy.

Abstract:The crop net primary productivity is inversion using HJ-1 CCD and IRS remote sensing images in Zhuozhou and Gaobeidian, Baoding City, Hebei Province. This inversion is done based on surface energy balance algorithm for land model. There are two important components in this inversion process: efficiency for solar energy utilization and absorbed photosynthetic active radiation (APAR). Firstly, HJ-1 CCD and IRS remote sensing images, DEM, meteorological data are used to estimate net radiation flux, soil heat flux, sensible heat flux to the air. These three fluxes are used to compute instantaneous evaporative fraction, which is used to inversion efficiency for solar energy utilization. Secondly, extraterrestrial radiation is computed using DEM. At the same time, crop absorbed photosynthetic active radiation is computes based on the fraction of photosynthetically active radiation (fPAR). And the fPAR is computed using normalized difference vegetation index and spectral ratio index resulting from HJ-1 CCD remote sensing images. At last, the inversion APAR and efficiency for solar energy utilization are used to estimate crop net primary productivity. Experiment results indicate that the inversion result of 24 hour actual evapotranspiration is from 4.43mm/d to 8.18mm/d, mean value of which is 6.28mm/d. This value is close to 7. 15mm/d, which is the computed result using Penman-Monteith formula. This indicates our inversion accuracy can meet our application requirements. The mean value of crop NPP 31.02g·m-2·d-1, the highest value is 139.29g·m-2·d-1, the spatial pattern is same to land cover type. These indicate that this study is reasonable and feasible.

Abstract:Support vector machine was used to invert nitrogen content of processing tomato early blight leaves in Xinjiang. The spectrum characteristic of processing tomato of difference disease level was analyzed. Then nitrogen content was found to be strong correlation with the spectral reflectivity on 218~357nm, 384~587nm, 1033~1141nm,1499~2500nm, because the correlation coefficients were more than 0.8. The vegetation index, SR705, ND705, GMI-2, RI-half, and PTEBc were chosen through K-CV cross validation, and SVM model was used to invert the nitrogen content with the vegetation index. The results show that the precision the SVM model of radial basis function kernel was the highest in linear kernel, polynomial kernel, radial basis function kernel and Sigmoid kernel. The value of MSE was 0.0124. The value of R was 85.916%. The value of average relative error was 0.175. SVM model with multi-vegetation index improved the precision of inverting nitrogen content of processing tomato early blight leaves.

Abstract:Low-power wireless measurement network of dissolved oxygen concentration based on LEACH （Low energy adaptive clustering hierarchy）protocol and intelligent inverter control in aquaculture were introduced. In LEACH protocol, the measured data were fused by the cluster head and then sent to the base station. As the dissolved oxygen concentration changed slowly，it was set that when changes in dissolved oxygen concentration were less than 0.1mg/L, node was no longer send data to the cluster head in each frame. Simultaneously head node adjusted the transmission slot of each node in the frame. Sleep time of cluster head and node was extended and power consumption was reduced. When dissolved oxygen concentration was not less than 5.0mg/L during the day, PLC controlled aerator automatically “farming water” at low speed through inverter. That fully took advantage of natural wind energy, solar energy and algae photosynthesis to improve water quality. When the dissolved oxygen concentration was less than 5.0mg/L, fuzzy variable frequency control was used to reduce errors rapidly. When approaching the control target value, the inverter outputted stability to ensure the stable operation of the aerator motor. Statistics show that this control method saved more than 42.3% of the electricity, increased the production by 11.8% and increased the comprehensive economic gains by 41.3%.

Abstract:Based on bit plane and adaptive binary arithmetic coding, a wavelet coefficients coding scheme which could match the line-based wavelet transform efficiently was proposed. The MCU of the image sensor node read image data from FIFO line by line, executed multi-level wavelet transform, determined the quantization value according to the probability distribution of the wavelet coefficients in different level, performed adaptive binary arithmetic coding based on four binary probabilistic model and realized image compression based on wavelet transform with a low cost of SRAM. The image compression method was applied to handle a 320 pixels×240 pixels gray image of piglets. Experimental results show that the SRAM cost, time cost and the PSNR was 5749KB, 16312s and 39.72dB respectively when the quantization value was set to three. This study established the foundation for agricultural image transmission over the low bandwidth WMSN efficiently.

Abstract:To improve battery energy efficiency and reduce power consumption of wireless collection nodes for greenhouse environment, hardware design for Greenhouse Wireless Acquisition nodes is achieved by low-power 16bit MCU (MSP430F149) and RF module CC1101. Power management module is designed based on chip TPS63031 to implement dual-power supply, which allows nodes’ power supplied respectively by three Nanfu AA batteries and one 3V button battery under working and sleeping mode. And 22.8% usable energy of batteries is improved effectively by using the DC-DC conversion. FSM module is adopted to software protocol design, implementing nodes’ task scheduling between working mode and sleeping mode. When the LPM3 mode is entered, node’s power consumption is greatly reduced. The discharge experiment of batteries and test of nodes performance show that design of power supply scheme in this paper guarantees node work for 110198h (about 4592d),with the setting of 30min acquisition cycle.

Abstract:3-D unsteady mathematical model of natural ventilation condition in Venlo type greenhouse was built up by CFD method. The boundary conditions were based on solar radiation, external air temperature, wind velocity and direction changing over time. The result shows that the inside temperature change had the same variation tendency with the outside temperature change during the whole simulation period. The mean temperature difference of the indoor and outdoor temperature was 3.09℃. RMSE of the simulated and measured value was 0.688℃. The maximum relative error and the average relative error was 8.9% and 2.8%, respectively. The CFD-based model could accurately represent the temporal and spatial variation of indoor temperature. When the outside wind speed changed from 0.81m/s to 1.2m/s and the wind direction changed from south southwest to west, the local airspeed near the west windward entrance firstly increased and then decreased. The airflow speed in the east area was markedly increased. The average temperature of x=1.5m cross section at the entrance of ventilation and crop canopy dropped 1.87℃ and 0.92℃ in 180s. Cooling effect of natural ventilation was remarkably affected by wind speed and direction.

Abstract:Fans assessment numeration system (FANS) was taking for testing the ventilation for each fan at the range of static pressures from 5.0Pa to 61.5Pa under different operating conditions. The results suggested that the existence and cleanliness of the fan safety guard reduced ventilation by less than 5%. The ventilation and efficiency of fans fitted with plastic shutters were 13.1% and 15.1% higher than the fans with aluminum shutters. The most difference of fans efficiency with same parameters reached to 12.7%. The average ventilation was reduced by 38.7% when the rotational speed drove by belt reduced by 16.1%. The energy consumption significantly increased when static pressure was more than 30Pa.

Abstract:The primary goal of this paper is to analyze the kinematic and dynamics of a 3PUS-S(P) parallel spherical metamorphic mechanism. It consists of a moving platform, base platform, three PUS legs and one middle S(P) metamorphic leg. A complete description of the position and orientation of the moving platform requires six variables. Since the parallel metamorphic mechanism has three degrees of orientation freedom in 1st configuration and extra one degree of translational freedom in 2nd configuration, which implies that only three variables are independent in 1st configuration and four variables in 2nd configuration. Firstly, the constraint equations describing the six motion coordinates of moving platform are derived and kinematic equations are established based on vector algebra method. Secondly, inverse dynamics equations of this metamorphic mechanism are established based on the Newton-Euler formulation. According to geometric and physical parameters of real mechanism, required driving and constraint forces can be obtained when the motion of moving platform and working load are given by solving the inverse dynamics equations. Furthermore the simulation result illustrates that 3PUS-S(P) parallel metamorphic mechanism can avoid impact damage by activating the constrained prismatic pair in middle leg.

Abstract:Through kinematic analysis of the H shaped parallel mechanism, the degree of freedom was derived. The inverse and forward position model of this mechanism were established by employing kinematic superposition principle and the analytical solution was obtained. The condition number of Jacobian matrix was derived and the workspace was analysed. The result of the calculation shows that this mechanism had perfect isotropic properties and specious workspace. Further analysis of the inverse position solution adopting homogeneous transformation and matrix decomposition indicated that the trajectory between the input and output coordinate was geometrically similar. Based on that, a control strategy for fine interpolation only using general motion controller was proposed. A model machine was developed and a series of experiments were carried out, such as line/circle interpolation, continuous interpolation and etc. The results suggest that the mathematical model established for this parallel mechanism was correct.

Abstract:The frequency domain of ultrasonic pulse echo signal obtained from carbon fiber reinforced polymer (CFRP) was studied. First the frequency domain feature of reflection coefficient for the fiber layer and resin layer in CFRP laminate was analyzed. The result shows that normal and porous fiber layer, and normal and thick had different influence on the acoustic reflection coefficient. Based on the result above, the frequency domain model for the pulse echo signal acquired from CFRP laminate was established. The pulse echo signal spectrum was composed of normal fiber/resin layer response, porous fiber layer response, thick resin layer response, probe response and noise signal response. Then the numerical simulation of CFRP laminate was implemented based on the model. The simulation signal spectrum of CFRP laminate with voids as well as the spectrum of CFRP laminate without voids was obtained. The results show that the simulation signal spectrums had the same main frequency components with the corresponding experimental signal spectrums.

Abstract:A new type of flexible pneumatic bending joint (FPBJ) and its mathematical model were proposed. To implement its real-time closed-loop control system, its mathematical model was simplified, and the mechanical characteristics were studied experimentally. An experimental platform for mechanical characteristics testing was set up, and two FPBJs with different length(40mm and 60mm) were tested. The experimental results were analyzed with Matlab curve and surface fitting toolbox, and the FPBJ empirical model was derived. The model showed a non-linear relationship among the bending angle, the FPBJs internal and external pressure difference, joint length and the output force of the FPBJs. Contrast to the simplified mathematical model, the empirical model was more precise, the mean relative error of output angle model was less than 6.7%, and the mean relative error of output force model was less than 2%. Meanwhile, an error, the joint length is proportional to the bending angle in the mathematical model, was avoided in the empirical model.

Abstract:A valveless piezoelectric micropump applying Coanda effect has been developed. The dynamic mesh method and numerical simulation were applied for studying the fluid field and performance of micropump. The results show that due to the Coanda jet, the volume efficiency η of the micropump was able to reach over 0.5 at zero pump pressure, which was larger than the traditional diffuser/nozzle valveless micropump. The effect of the flat cone tube and the concaved surface was discussed and the results show that the length of flat cone tube must be larger than dcot(θ/2), and when c2/c1=1,L1/d=9, the flowrate of micropump reaches a maximum at zero pump pressure. And the comparison of η with the different c2/c1 and pump pressures shows the large width of the concaved surface could enhance the performance of micropump at a high pump pressure, but reduce the performance of micropump at a low pump pressure. Response surface methodology was utilized to optimize the structural parameters. When the pump pressure was 5kPa, the recommend region was 4≤L1/d≤5 and 0.75≤c2/c1≤0.85. When L1/d=4.3 and c2/c1=0.80, the maximum volume efficiency was 0.323 and the difference was 1.89% comparing with the value of simulation which was 0.317.