Abstract:Automatic steering control plays an important part in an automatic navigation system. A Dongfanghong-X804 tractor is used as a platform and an electro-hydraulic proportional valve is added to the original manually operated steering system. The original circuit of the tractor is improved. An electronic control unit is designed to control the valve, which is composed of a microcomputer (C8051F040), an angle sensor (KMA199), and a CAN bus network. A SD card data storage system is realized for real-time storing experimental data. The experimental results show that the largest and the average signal tracking errors are 1.1° and 0.5°, respectively, and the average delay is 0.2 s. The automatic steering system has good response and can meets the performance requirements.

Abstract:0.02m。 An automatic guidance system was developed on KUBOTA SPU-68 rice transplanter using Trimble 5700 RTK-DGPS and Crossbow AHRS500GA-227. RTK-DGPS positioning data was corrected using the heading, roll and pitch parameters acquired from AHRS500GA. A Kalman filter based on position-velocity model was developed to smooth the corrected DGPS positioning data and evaluate the bias error of the heading angle. A new trajectory tracking control method was proposed based on pure pursuit model. The determination method of the look-ahead distance was studied in detail for line tracking. Simulation result indicated that the optimized look-ahead distance could be determined for a special traveling speed based on the ITAE optimization. The test result showed that the proposed positioning and orientation evaluation algorithm could eliminate the effects of uneven field condition on GPS positioning and evaluate the bias error of the heading angle from AHRS online. The developed trajectory tracking controller was helpful to improve the tracking control performance. The maximal lateral tracking error could be kept within a range of ±0.17 m and the mean lateral tracking error was less than 0.02 m at the normal traveling speed.

Abstract:1.2085m减小到0.4861m。Since the positioning accuracy of low accuracy GPS can not meet the requirements of agricultural production, a new navigation method is studied to improve the position accuracy. The compensate model is built to compensate for the libration caused by the antenna. A Kalman filter is developed, and a VRS-based receiver is used as the low accuracy GPS. The Kalman filter is applied to the data collected from the low accuracy GPS, compass and speed sensor. The data set collected from the RTK-GPS is used as a baseline to evaluate the performance of the filter. Experiment results indicated that the mean error was reduced from 1.6019m to 0.597m straight line track, and from 1.2085 m to 0.4861 m in curve track.

Abstract:4cm。 An autonomous navigation system based on machine vision for agricultural vehicle was studied. A novel line detection algorithm was proposed for navigation directrix detection, which could decrease the cost of memory and time considerably. A 2-D fuzzy controller with the inputs of lateral error and heading error was built to determine the expected angle of turning wheel, and a turning controller based on PID was constructed to control the turning of front wheel. The simplified kinematics model of two-wheel vehicle was adopted for simulation. The results of simulation and experiments indicated that the navigation system could track the desired beeline path effectively. The maximum tracking lateral error was less than 5cm and 8cm at the speed of 0.3m/s and 0.6m/s respectively, and the average lateral error was less than 2cm and 4cm respectively.

Abstract:200ms。 Obstacle detection is a key component of autonomous systems. A obstacle detection method combined monocular vision and stereo vision is studied for the vision navigated combine harvester. For monocular vision detection, H and S components are used to segment the image acquired by the left camera mounted on the combine harvester, and then through the fixed threshold value and binary processing the potential obstacle area is located. For stereo vision, the SIFT features are extracted from the potential obstacle area, and the ANN algorithm is utilized to get matching points. According to the obtained world coordinates the obstacle and the distance from the vehicle are calculated. In order to reduce the processing time the coefficient of image size linear transform is analyzed and it shows that the matching points are enough to satisfy the system need and the processing time is less than 200?ms when the coefficient is 4.0. The experiment using various mature wheat videos indicates that the method is valid to detect obstacles in front of the vehicle.

Abstract:A navigation control system for agricultural machinery was developed based on CAN bus with the communication protocol of ISO 11783, which was the standardization for the exchange of information between different devices in the system. The system includes a control terminal, an acquisition unit of GPS signal, an acquisition unit of digital compass signal, an acquisition unit of angle sensor signal, and a steering control unit. A self-adaptive PID algorithm was adopted to perform steering control. The communication experiment proved the effectiveness of the system in collecting data and transmitting commands. Experimental results showed that the algorithm could quickly track target datum, and made the system have better dynamic response characteristics.

Abstract:0.05m。 An orchard tracked mobile robot was developed in order to raise automation level of orchard management, improve operation efficiency, and reduce the intensity of operation. A navigation method based on the slider-crank mechanism was developed, and a fuzzy PID controller was designed, which used the attitude angle and position angle of the robot guiding mechanism as the input parameters. The experiments showed that the robot could travel in a straight line with a maximum lateral error of 0.02m when the robot moved at the speed of 0.15m/s, and the maximum lateral error of 0.05m when the turning radius was 2m.

Abstract:13%～18%。Soil deep loosening operation can break the hard-pan without flipping the soil. It can effectively improve the water and air permeability performance of the soil, and provide a broader space to the plant roots. To solve the existing problems, such as insufficient loosening depth, big tillage resistance and the power consumption for general types of deep loosening machines, a new type of the lever vibrating ripper is developed. The ripper is consist of five main parts, the stander, eccentric axis, crisscross connector, deep loosening shovels and wheels for depth control. The crisscross connector makes this machine achieve double vibrations. The power is transmitted effectively and tersely by the gimbal and the lever, which can enlarge the vibration displacement and increase amplitude with the increasing deep tillage. The form of shovels is narrow chisel-type so that it can maximize the protection of the soil and reduce the moisture evaporation. Contrastive experiment of vibrating and non-vibrating subsoiling operation is carried out to analyze the impact of vibration on the traction resistance. The experimental results indicate that the operation traction resistance can be reduced 13%～18%.

Abstract:Variable rate irrigating hill-seeder can automatically adjust the amount of the irrigating water according to the variation in soil moisture content in the field to alleviate drought and save water. Mathematical models for minimizing water application and determining the control time of the electromagnetic valve are developed. Static experiment is conducted with the developed variable rate irrigating hill seeder. Changing water amount in tank and irrigating time, the water amount ejected from the electromagnetic valve varies. The mathematical models for the control time of the electromagnetic valve are established based on the relations among water amount in tank, irrigating time and water amount supplied using linear regression and artificial neural networks. Regression results show that the adjusted coefficients of determination for the linear regression models are 0.992, 0.991 and 0.998 when the tank is 100% full, 1/2 full and 1/8 full, respectively. A 2-5-1 artificial neural network is used to predict irrigating time. The network provides high prediction accuracy with a maximum deviation of 3.95ms and an average deviation of 1.46ms.

Abstract:95%。The ratio of the single seedings, which is effected by the coefficient of the absorbing seeds directly, is an important parameter. The purpose of this paper is to design the variable control system for precision magnetic drum-seeder. In order to enhance the sowing efficiency, the roller is made speed-down when it is absorbing seeds, whereas it is made speed-up when it has absorbed or is sowing seeds. The variable control system embodies a F2812DSP controller, a PS2 keyboard and a photoelectricity sensor. Experiment shows that the efficiency has been raised by 16% and the ratio of single seedings is over 95%, when the speed of absorbing seeds is up to 16 r/min and the speed of absorbed and sowing seeds is up to 20 r/min. 

Abstract:6%以内。 The droplet size distribution is evaluated by image processing. The traces of the captured droplet on water-sensitive papers are detected by a camera and then sent for segment and evaluation by a specially developed program. An improved GLV algorithm is used to separate the conglutinated droplets and compute their size data comparing to the discrete droplets. Comparison experiments are conducted to measure the droplet size distribution by a laser particle size analyzer. The evaluation result shows that the error between the data set given by image process and the data set from laser analyzer is less than 6%.

Abstract:Field information collection is the key technology of precision agriculture. To obtain the yield information, an impact-type grain flow sensor is developed for the yield monitor system. The grain flow sensor consists of a mechanical unit and an electrical unit. The mechanical unit is composed of an impact plate, a sensitive bar, some strain gauges, etc. The strain gauges are stuck on the sensitive bar. When grain flow impacts the plate, the bar bends and the bridge circuit consisted of the strain gauges outputs electrical signal. The output of the sensor is voltage signal. On the basis of the static experiments and indoor experiments, field experiments are finished in Baoding of Hebei Province and Jiamusi of Heilongjiang Province. Harvesting crops are wheat and rice. The results show that the sensor has higher linear property and the accuracy meets the requirements of the precision agriculture.

Abstract:25.4 mV降低到1 mV。Zero-drift of the grain flow sensor leads to a significant error when the combine harvester tilted. The purpose of this paper is to study the effects of combine harvester tilt on the zero-drift of the impact-based grain flow sensor，and propose an innovated grain flow sensor that can stabilize zero-drift when combine harvester titled. With the single plate impact-based grain flow sensor fixed in a combine harvester, the zero-drift voltage of the grain flow sensor is recorded while the combine harvester tilted between -15° and 15°. The test result shows that there is a linear relationship between the zero-drift and the obliquity, and the zero-drift voltage is 25.4 mV when the combine harvester tilted at 15°. A dual-plate differential impact-based grain flow sensor is developed to compensate the zero drift. The tilt experimental results show that the zero-drift of the two plates are consistent each other, and thus the overall zero-drift voltage of the sensor is reduced from 25.4 mV to 1 mV.

Abstract:A grain moisture measuring method based on DSP is studied. First, the grain is leaded-in measuring capacitance by gravity. Secondly, the grain moisture is measured through MCU and DSP, and the measured data are stored or displayed on LCD. Finally, the measured grain is ejected by a discharging screw feeder, and a measuring cycle is finished. A DS18S20 is adopted to detect and compensate the temperature in the process of measuring grain moisture. The measuring precision is higher than 1% RH, and exceeds the conventional measurement methods.

Abstract:The precise feeding system and relevant key technologies, including RFID, network based on ZigBee, measuring technique etc, are discussed. The precise feeding system is composed of central computer, precise feeding devices and wireless network used to build up the distribute system. The core of the precise feeding device for dairy cattle is identification of individual dairy cattle. The RFID, a non-contact identification technology, is integrated in the system. The electrical ring made according to ISO11785 international standard is worn by individual dairy cattle to identify each dairy cattle. The information of the cattle is checked by the system and then certain amount of forage is given. On the course of intake, all feeding data are collected by the system such as the unique electrical code, actual intake of forage, feeding time, feeding velocity, etc. The feeding formula is given by the program running on central computer connected to precise feeding device by ZigBee network. Some interfaces of system are reserved for the extending function so that it will be easy to update system. The precise feeding system can provide a solution of high efficiency and high benefit for dairy farming.

Abstract:In order to obtain the topographic information efficiently, a tractor-mounted field 3-D topography surveying system was developed. The surveying system consisted of a measuring laser receiver, a GPS receiver, an intelligent controller and a hydraulic system. Furthermore the system could also conduct laser land leveling. The measuring laser receiver was used to obtain the elevation, and the GPS receiver was employed to obtain the longitude and latitude data. Both of them were fused in the controller so as to get the 3-D topographic information. The field experiments were carried out in different moving speeds and then the data measured by the surveying system were compared with the data from the fixed-point surveying method. The results show that the surveying system has a good consistency with the fixed-point surveying method in lower moving speed.

Abstract:In order to evaluate the leveling performance of the paddy field leveling machine, the inclination of the harrow was measured using two SensComp 600 ultrasonic sensors. The ultrasonic sensors were fixed on the harrow's end, and distances of each harrow's end to referenced horizontal were measured to calculate the gradient angle of the harrow. Some factors having effect on the measurement of the gradient angle were analyzed, such as the distance measured by the ultrasonic sensors, the measuring angles of the sensor, and the movement of the sensors. Then the angle was compared with the data from an attitude-heading reference system AHRS500GA-226 device. The results showed that the calculated inclination was quite accurate. The maximum static-error and the maximum dynamic-error were 0.08° and 1.00° respectively. Finally, estimating experiments were conducted in a laboratory. Based on the evaluation results, it was concluded that the leveling control system could measure the inclination real-time and exactly, and the whole leveling system works reliably.

Abstract:2cm。 Laser receiver was a key component of the laser-controlled land leveling system. In order to improve the quality of the laser signal, extend the operating range, and reduce the noise, a novel laser receiver based on integrated IC was developed. Red polymethyl methacrylate was used as the material of the in-light window to reduce the background light into the laser receiver. Interference filters were used at the laser receiver to further reduce the background light. Photo-electric cells were used to transform light signal into electrical signal. Integrated operational amplifiers were used in low-noise pre-amplifier and main amplifier to amplify the weak electrical signal effectively. The wave shaping circuit and the widening circuit were employed to make the signal conditioning better and perform the signal transformation from spike pulse signal to digital TTL signal. The results of the field experiments show that the receiver works stable within 150 m for all directions. The vertical workable ranger is 28.4cm which allows the 2cm of accuracy in land leveling.

Abstract:The mass layout of the cable in field brings many problems in the automatic irrigation control system such as installation, maintenance, and extension. This article suggests a wireless broadcast irrigation control system and designs a low power wireless DC solenoid valve based on OOK modulation and powered by battery. It also introduces how to design and implement the transmission control module with discrete input and digital input. Finally, it provides an application example of automatic irrigation control system based on wireless solenoid valve throughout the greenhouse irrigation in a plantation.

Abstract:In this paper, we study the effects of wavelength selection and data pretreatments, including no pretreatment, standard normal variate transformation (SNV), vector normalization, smoothing, first and second derivative transformation, on the discrimination of maize seed varieties. The performance of the pretreatment methods is evaluated on the basis of the two data sets: all-range spectral data and the data of the characteristic wavelengths selected by a standard deviation-based feature selection method, respectively. The correct acceptance rate (CAR) and the correct rejection rate (CRR) are used as the criteria for the discrimination models. The results show that the best model uses first derivative and all-range spectral and using the best model both CAR and CRR for five varieties reach 100%, and the average CAR and CRR attains 98.6% and 98%. The wavelength selection can only improve CGR of SNV and vector normalization models.

Abstract:The thermal conductivity probe system has been used in food. However, since the probe system is derived from an idealized transient heat transfer model, there are inevitable differences between the real probe and the theoretical model. The test error resulted by some experimental operating parameters including input voltage, heating time of thermal probe and size of sample was studied. The best values of input voltage, heating time of thermal probe and size of sample were obtained to minimize the test error. The optimal value for input voltage of thermal probe is in the range of 2.5～6.5V, and the optimal heating time of thermal probe is in the range of 20～50s. And then the thermal conductivities of tomato fruits at different ripeness stage were measured. The experimental data can give a reference for storage and process of tomato industry.

Abstract:The estimation of citrus yield is important to citrus precision management. Fast non-destroyed measure could be achieved using machine vision technology. Ten images of citrus were used in this experiment and yield of each tree was measured in advance. The citrus image was segmented based on the RGB color model. The segment condition for citrus and background is: (R-B>100) & (R>G). The total number, the total perimeter and total area of citrus were computed from the segmented image. The relationship between each image parameter and citrus yield was analysis. The result of experiment shows that the correlation coefficient between the total citrus number and the yield of citrus is 0.97 and indicates that it is has good prospect in the future.

Abstract:81%。 An apple recognition method based on K-means algorithm is proposed for the green apples that have similar color with leaves. The image is divided into 8×8 pixel blocks and the block is taken as the segmentation unit by the algorithm. Color difference R-B was selected as color feature and mean value, standard deviation and regional entropy of gray scale images are selected as texture features. The feature vectors including color feature and texture features are extracted. Gap statistic is applied to calculate the best number of the clusters. The recognition experiment is conducted to test the algorithm with 200 sample images taken in different illumination conditions. The experimental results show that the apple fruits can be recognized successfully both in front light conditions and back light conditions. The recognition rate reaches 81%.

Abstract:An auto threshold adaptive algorithm is suggested for image segmentation of the eggplant images acquired in natural light. The segmentation is conducted with the gray-scale, three orthogonal feature vectors based on R, G, B's linear transformation, and the hue component of HSV color model. The experiment result of the segmentation with Matlab shows that the target and background have a good separation based on Otsu algorithm and the optimization of the gray-scale histogram. However, it is also observed that there is the impact of area light reflection on the region of eggplant surface. A new segmentation experiment based on improved Otsu algorithm is conducted with the color feature vector of (2G-R-B)/4 and the result shows that the new algorithm can partially eliminate the impact of light reflection. Finally, the improved Otsu algorithm with hue are tried in the segmentation and the result shows the impact of light reflection completely is effectively removed. The segmentation effect is further improved by removing the noise of hue-segmented binary image through mathematical morphology.

Abstract:94.74%、94.44%、92.31%。 The nondestructive discrimination of the shelled chestnuts was studied with near infrared spectra, which could provide a new method for quality detection of other shelled agricultural products. 178 chestnut samples were prepared and the diffuse spectral reflectance of the samples were collected in the wave number range of 12000～4000cm-1. First，six preprocessing methods including smooth、vector normalization、min-max normalization、standard normal variate transformation、multiplication scattering correction and first derivative were used to improve the original spectrum. Then，principal component analysis was applied to compress thousands of spectral data into several variables and to collect spectral information. The principal components extracted by PCA were employed as the inputs of the BP neural networks. Effects of the six preprocessing methods on the models based on BP neural network were compared. The results show that prediction precision varied to different preprocessing methods. The optimum network structure of 7-4-1 was obtained after vector normalization method. Discriminating rate of qualified chestnut, surface moldy chestnut and internal moldy chestnut in prediction reached 94.74%, 94.44% and 92.31%, respectively.

Abstract:A method for classification of Xi-hu-long-jing tea in four grades was introduced based on machine vision of multi-spectral imaging technique. Firstly, three monochrome images at 540，670 and 800 nm wavelengths were simultaneously obtained based on 3CCD multi-spectral camera, then image features including 18 shape features and 15 texture features were extracted based on image processing technology. These two groups of features were adopted for cluster analysis with principal component analysis of the four grades tea. However the result was not satisfactory. In order to obtain a more effective separation model, the two groups of features were combined, and the cluster analysis was conducted again based on the combined features. The result was better than the former. After optimization of these three groups of features, three classification models were developed by means of multiple stepwise discriminant analysis (MSDA). It was found that model based on the combined features had the best performance with accuracy of 85% for prediction of unknown samples. The most important two features for classification were correlation and energy of 800 nm wavelength monochrome image.

Abstract:It is a big problem for China to have not enough workforces in picking tea sprout today, which usually result in missing the tea sprout's optimum picking period. The picking machine currently used improves the picking efficiency indeed. However, the old leaves are picked together with the sprout, and the sprout is damaged at some time. Hence it is necessary to develop an intelligent picking machine that can recognize and pick the sprout with the minimum sprout damage. This paper presents an image process method based on the tea sprout color and shape features, which was used to recognize the “Wuzi Xianhao” (a famous green tea of Shaanxi, China) tea sprout grown at Xixiang County of Shaanxi Province. Firstly, the green component of the tea leaf image in RGB color space was extracted. Secondly, green component image was segmented using double threshold method. Finally, the edge of tea sprout is detected according to its shape feature. Experimental results indicate that this recognizing method of the tea sprout based on color and shape features can reach the right detection rate of 94%, and provide an effective method for automatic tea sprout picking.

Abstract:An apparatus of climatic information acquisition and wireless transmission is developed for frost protection of tea farm. The hardware of the system is made up of a microcomputer AT89C52, an A/D convertor, a TC35i GSM module, a RAM, a liquid crystal displayer, a keyboard, a printer, a power supply and several sensors, which can measure meteorological parameters such as air temperature & humidity, radiation, wind speed and so on. The software is programmed with assembly language and the function includes system setting, SMS receiving & sending, data storage and inquery, result display and printing management. The apparatus can be used for on-line information acquisition and wireless transmission with high reliability in remote tea field in order to provide the basis for tea plant management decisions, especially for the early warning of late spring cold.

Abstract:It is a bottleneck of transparency of the agricultural traceability system to acquire environmental parameter of agricultural products in the supply chain real-time and accurately .Radio frequency identification (RFID) technology has been a research hotspot in recent years as a new automatic identification technology. It is significant to combine RFID tag with sensor to the agricultural products traceability system. It can detect and record temperature, humidity and other important parameters, and it can be identified by wireless communication. The current development status of this kind of tag was reviewed both in China and other countries. The key technology is analyzed, and the existing problems and solutions are pointed out. It provides a reference for further research on RFID tags integrated sensors.

Abstract:In order to develop a fast and efficient method to determine the freshness of bee pollen, visible and near infrared (Vis/NIR) spectroscopy combined with least square support vector machine (LS-SVM) was applied to identify the samples of bee pollen under the different storage temperature. Five storage temperatures including -20, 4, 15, 25 and 40℃ were set. The Camellia pollens stored for 60 days at different set temperatures were investigated. Spectra were acquired by an ASD fieldspec spectrometer. As the pretreatments of the optimal smoothing way, moving average with three segments and multiplication scatter correction (MSC) were applied to reduce the noise of the spectra. After the principle component analysis of the spectra from 400 to 1000 nm, 4 to 20 principal components (PCs) were chosen as the inputs of LS-SVM models. Results show that the r2p of the LS-SVM model with 20 PCs was more than 0.9919 in validation set, and was better than the traditional PLS model. The results also indicated that the PCs could reflect and represent the main characteristics of bee pollens stored at different temperatures, and the LS-SVM model could be used to discriminate the samples of bee pollen under the different storage temperature.

Abstract:An embedded electronic nose is developed including three modules, a sensor array, an A/D system, and a microprocessor. The sensor array composed of three gas sensors, TGS813,TGS825 and TGS880 produced by Figaro company, is used to collect sample signal. A MAX1270 chip produced by MAXIM company is used as A/D converter. The S3C2410 microprocessor produced by SAMSUNG company is used as CPU with the embedded operating system WINCE. The signal is simulated by a logarithm curve by designed software, and BP neural network is used to train the curve parameters and build the model to identify the samples. This system is used to identify Italian Ambrosi cheese with four different production dates, and the recognition accuracy reaches 100%. To identify pure milk in three different companies, the recognition accuracy reaches 100% too. The results show that the system has several advantages such as small size, light weight, easy to use, high recognition accuracy etc.

Abstract:Mid-infrared spectroscopy combined with chemometrics was used to determine total sugar content in Chinese rice wine. A total of 30 samples were collected. Calibration models were developed in the range of 1000cm-1 to 1500cm-1 and 2500 cm-1 to 3000cm-1 to exclude the influence of water absorption. Stepwise multiple regression (SMLR), principal component regression (PCR) and partial least squares regression (PLSR) were used to develop the models in TQ analyst software. And derivative pretreatment method was used to test the impact of accuracy of the models established. The best model was obtained by PLSR with second-order derivative pretreatment. The correlation coefficient of cross validation (rcv) was 0.984, RMSECV to 0.765g/L, RPD to 5.75. The result indicates that mid-infrared spectroscopy (MIR), combined with chemometric methods, can be used as a fast, simple and exact method to measure total sugar content in Chinese rice wine.

Abstract:The performance of a newly-developed portable rapid detector of contamination in fruits and vegetables (PRD) was tested in lab, by detecting the content of nitrite, heavy metal and pesticide in different samples. The detection ranges of nitrite, lead, phoxim, trichlorfon, carbofuran and methomyl were 1.5～150, 0.5～4.0, 0.005～2.0, 0.005～0.5, 0.005～0.3 and 0.005～1.0μg/mL, respectively. Precision tests, made on different concentration levels, gave values of RSD in the ranges of 2.6%～8.9% for lead, and less than 2% for nitrite, and the sensitivity of the four pesticides ranged from 31.368 to 62.05. The results show that the accuracy and precision detecting the three kinds of contamination can meet the requirement of rapid detection compared with Optizen 2120V-FT machine. The PRD is more simple, rapid, portable and feasible for application.

Abstract:。 The tide salt clay in Zhejiang Province was selected as research object, and the soil N and soil P were analyzed with NIR spectroscopic techniques. Six group samples were collected from a rice farm. Several kinds of nutritional water with different concentrations were added to the six groups, and then the samples were dried and rubbed. At last, 120 samples were got from six groups equably. Standard normal variate (SNV), multivariate scatter correction (MSC) and smoothing of moving average were used to process the spectral data. Different calibration models were established and the performance of these models was compared with different pretreatment methods. After comparison, smoothing of moving average was found to be the best spectral pretreatment method. 96 samples were randomly selected from 120 samples as the calibration set, and the other 24 samples were used as the validation samples. Two discriminating analysis models were developed using partial least squares (PLS) method and least squares-support vector machine (LS-SVM) method respectively. The correlation coefficients (r) between the measured data and the predicted data from PLS were 0.9454(N), 0.9327(P) respectively, and 0.0321(N),0.9547(P) from LS-SVM, respectively. The root mean standard error of prediction (RMSEP) were 0.0321(N),0.0089(P) from PLS, and 0.0378(N),0.0101(P) from LS-SVM. The results showed that NIRS could be used to evaluate the soil N and soil P.

Abstract:Characterization of three source clay minerals, illite, kaolin and montmorillonite, were made using three mid-infrared spectroscopic techniques (attenuated total reflectance (FTIR-ATR), transmittance spectroscopy, and photoacoustic spectroscopy (FTIR-PAS)). For the FTIR transmittance spectra, there are three main absorption regions: 3000～3800cm-1,1300～1800cm-1, and 500～1200cm-1, and sharp differences can be found in each region. For the FTIR-ATR spectra, there are absorptions with main difference in the region of 800～1200cm-1. For the FTIR-PAS spectra, there are also three similar absorption regions as FTIR transmittance spectra. However more information is found in the FTIR-PAS spectra comparing with FTIR transmittance absorptions. The FTIR-PAS was applied to identify three soil types and the results revealed that: Hailun soil was characterized as montmorillonite type soil with medium calcium carbonate content, Changwu soil was characterized as montmorillonite/illite type soil with high calcium carbonate content, and Qiyang soil was characterized as kaolin type soil with low calcium carbonate content

Abstract:The experimental area was selected in Lingxian County of Shandong Province. Based on the GPS positioning data, soil moisture content, chlorophyll content and wheat dry matter production was measured. Geostatistical analysis was conducted combined with geographical information system (GIS) and the semivariogram models were established. It was found that a spherical model fit semivariogram model of soil moisture content better, and a Gaussian model was the better model for wheat chlorophyll content and dry matter production. The results showed soil moisture content and wheat chlorophyll content had the strong spatial autocorrelation, and the ratio of structural variation was 97.3% and 81.3%. Wheat dry matter production has the medium spatial autocorrelation, and the structural variation was 50%. Block Kriging was applied, and the spatial distributing maps and maps of standard deviation of Kriging estimates were drawn. From the distribution types, it was observed that the Kriging estimates maps of soil moisture content and wheat chlorophyll content had obvious slabby and plaques characteristics while the map of wheat dry matter production had ribbon characteristics.

Abstract:The composition and implement of NTRIP (networked transport of RTCM via Internet protocol) are studied and discussed, a GPS receiver based on NTRIP/VRS are developed and experimented with the low-cost and low-accuracy GPS OEM board. The GPS receiver mainly includes a microprocessor, a wireless communication module, a GPS OEM board, a LCD module, an USB module, and so on. It can receive and process RTCM correction signals from VRS system via GPRS and GPS data. And then more accurate positioning data can be calculated and real-time displayed. The data can be also stored in the USB flash disk or sent to a PC for afterwards processing. The designed interface is friendly and easy to use so that it is convenient to change the parameters of storage, receiving and GPRS. Experiment results indicate that the accuracy of low-cost GPS receiver based on NTRIP/VRS is about 1.24m (95%), and can provide reliable GPS data resource for field information sampling.

Abstract:The technical frame of agriculture mobile management system for interactive management in the field was designed based on the mobile terminal, embedded GIS, and wireless communication. The related technologies of wireless collection for field information, image capturing based on GPS location, differential data collection from GPS virtual reference stations, and wireless communication for field information were developed. The prototype of the agriculture mobile system was also developed for experiments. The mobile terminal has the functions of GPS positioning and navigation, images capturing based on GPS, image editing and viewing, thematic map making, properties indexing, field grid making, and so on. The prototype system was experimented for information collection and site management in 2008. The result shows that it is practical in agriculture mobile management.

Abstract:In order to acquire field information in precision agriculture, a new measurement method of grain yield distribution is suggested based on weighing device. The new method could increase the accuracy of grain flow monitoring. According to grain transmission characteristics of the traditional combine harvesters, a new kind of grain flow sensor is developed with spiral propulsion weighing device. The device solves the several problems in present measurement system of grain flow such as direct power transmitting and effective signal detecting. Together with GPS positioning information, dynamic measurement of yield distribution information for grain combine harvester is realized.

Abstract:Weighted fuzzy clustering algorithm is proposed and applied in management zones of soil nutrients. In the algorithm, the determination of the weight of different soil nutrients is a key step. Two methods are used to determine the weight. One is the principal component analysis (PCA). The other is coefficient of variation (C.V).To verify above methods, soil nutrients of N, P, K were sampled at the experimental site, a field in Yushu City of Jilin Province, and then the weighted fuzzy clustering algorithm was used and the number of the management zones was determined. The effectiveness of the weighted fuzzy clustering method was validated by comparing with the traditional fuzzy clustering method. The results show that the weighted fuzzy clustering method is more reasonable and more practical and can be used to support precision fertilization.

Abstract:560ms。 The effect of the weed environment on the path recognition is investigated. On the basis of the conventional path recognition method, a new method based on the BP neural network for the path recognition in the weed environment is proposed. Experimental results prove that the new method is effective for the path recognition in the weed environment, and can obtain the target navigation path rapidly, reliably and accurately. The recognition correct rate is 97%, and the average cost time is 560 ms.

Abstract:99%。A navigation algorithm was studied, which as used to extract navigation route by machine vision based on agricultural non-structural characteristic. Firstly, a new algorithm was used to detect the ending region of farmland based on cluster's method. And then moving window was used to examine white pixels of the binary image to definite target regions. Finally, improved Hough transformation was used to extract navigation routes. The experiment proved that this algorithm can accurately extract the column information of green crops. The average time required for processing a 320×240 pixels color image was 57.404ms and the accuracy of the recognition reached 99%.

Abstract:In order to provide an effective tool for light distribution calculation within crop canopy on Windows platform, a light distribution calculation system derived from RGM model was developed using C++ language and OpenGL library. A maize canopy geometrical model was taking as the experimental example. Parameters were selected on the basis of feasible RGM model. The related methods were improved according to the characteristics of crop canopy. On the basis of 3-D maize canopy model, the light distribution situation of each organ facet could be calculated in real time by using parameters input via human-computer interaction. The system had user-friendly interface and was easy to operate. It only needed few input parameters and most parameters were meaningful in botany and agriculture.

Abstract:To achieve precision application of pesticides and fertilizers to fruiter, a real-time measuring system for fruiter canopy parameters is developed to guide precision spraying in orchard. It can reduce the negative impacts on the environment as well as improve fruit safety. The system consists of crop identification system, vehicle attitude system, master control unit and data logger unit，and a CAN bus is used to connect the microprocessors involved. Primary experiments are conducted on five adjacent trees with regular cylinder-shaped canopy on the campus for three times. Four independent ultrasonic sensors are used to measures the canopy of the target trees on a time-division basis. System sampling rate is 5 times/s; and the tractor-traveling speed of 0.3 m/s is selected. Experiments show that the system can detect fruiter canopy size in real-time, and provide a good measuring and controlling platform for precision spraying based on tree canopy.

Abstract:With the aim to achieve the quantified and visualized expression of crop growth, taking corn as an example, a simulation framework, which integrated parametric keyframe animation with the skeleton model was proposed. At first, a skeleton model for its topological structure was adopted, which was defined based on a precise geometric model. The dynamic creation of the parabolic curve of blade midrib integrated time variant was used to stimulate the elongation of leaf skeleton. With parametric keyframe technique, of which each keyframe parameters was acquired from the observed data or the output of corn growth model, the animation could be obtained by manual interaction. Experimental results showed that the proposed method could simulate the basic movements of corn growth visually with highly realistic rendering effects. It provides a simple and general dynamic process simulation for plant growth.

Abstract:The root is an important plant organ for nutrient and water uptake from the surrounding soil. To solve the technical problem of 3-D observation for plant roots in situ, sequence images of plant roots in situ were acquired at first with using X-ray CT scanner, and then the 3-D visualization of roots in situ was implemented in computer using image and graph processing methods. In order to improve the accuracy of segmenting root CT images, a compositive segmentation algorithm was proposed and implemented based on the spatial geometrical and morphological features of root systems. The algorithm could clean markedly up the pixels of non-root regions of which the gray levels were very similar to roots regions and the positions were very closed to roots regions. 3-D surface models of plant roots were reconstructed with marching cubes (MC) algorithm, and 3-D visualization of plant roots in situ was implemented with the tool box of VTK. It was proved by programming experiment that the approach and methods proposed were feasible and effective for 3-D visualization of plant roots in situ.

Abstract:To solve the problem of multi-focus image fusion, a new multi-focus image fusion algorithm based on the visual perception feature was proposed. Because the threshold of human visual contrast sensitivity was proportional to the image background brightness, the visual uniform parameter was adopted to separate clear objects from fuzzy objects obtained by different image sensors. Firstly, the image was decomposed at RGB level separately. Secondly, the R,G,B single gray image was divided into sub-blocks. Thirdly, the sub-blocks with higher uniform value were selected as the corresponding sub-blocks of fusion image. Then, the retained sub-blocks were reconstructed to compose the fusion image. The immune genetic algorithm was applied to calculate the optimal number of sub-blocks, and the image quality criterion data, root-mean-square error and image entropy, were chosen as the affinity function of the optimal algorithm. The results have shown that the image fusion algorithm proposed was suitable to multi-focus image fusion and easy to realize.

Abstract:An acquiring platform of near-ground remote sensing images is developed to collect visible image and NIR image synchronously and then get the reflectance information from crop images. The platform contains: a 2-CCD multi-spectral camera, two collecting boxes, a field computer with two gigabit net interfaces and an image processing system. First, a true color image of plants is processed with 2G-R-B gray and median filtering algorithm, and the Otsu algorithm is used to separate plants from ground. Then the binary image is returned back to original R gray image and the average gray value of R image is acquired. Finally, using the linear model between reflectance and gray value the reflectance of crop in red waveband is calculated. Test results show that the acquiring platform works well and there exists remarkable correlation between results by above image processing method and that of ASD spectrometer. It provides the theoretical basis for crop status monitoring with digital image processing.

Abstract:A novel technique of fault diagnosis on greenhouse environment control system (GECS) was developed for more reliability. Major faults of actuators, sensors, switch board and control software in GECS were analyzed and listed. All GECS faults were divided into four grades according to their damage levels, and were treated respectively with different strategies and solutions. Two working modes, ‘fast fault diagnosis’ and ‘complete fault diagnosis’, were proposed to meet the requirement of both higher accuracy and rapidness. The idea of one-key setting was applied for different users. The intelligent programming was completed to carry out the fault diagnosis on GECS. The test results show that the faults are correctly detected and identified.

Abstract:The control net with 1-wire technology is discussed. According to special need in greenhouse, the characteristics of integrating technology for control are analyzed, and with the 1-wire advanced technology, the performance of control net and integrating technology used in greenhouse control system is analyzed. On the other hand, the control system net using 1-wire is constructed according to the control requirement of greenhouse.

Abstract:To inspect weight and growth of pigs in real time，an web-based inspecting system based on binocular stereovision technology was developed. Hardware and software related to this inspecting system were established in laboratory condition. The calibration algorithm with non-linear camera model and coordinate inspecting arithmetic based on least square methods was developed. Calibration mode about different numbers, parts and rotating angle of the calibration board images was collected and the inspecting results were analyzed. Results showed that more than 19 calibration board images should be used to get steady system parameters. Collecting the calibration images in all parts of inspecting zone could improve the inspecting precision. There was no obvious difference in inspecting precision at different rotating angle, but a large rotating angle was not conducive to extract all coordinates of the calibration points.

Abstract:In recent years, energy saving technology becomes more and more important in greenhouse in the world, due to the higher price of energy. Many greenhouse producers changed their produce mode and made the strategies more flexible. Wireless sensor network (WSN) is increasingly popular in the field of environmental monitoring due to its promising capability. WSN offers permanent online access to the environmental condition. The system integrated embedded technologies，GPRS and wireless sensor network. The large amount of data of greenhouse environment is acquired, and then communicated by the wireless sensor network. The design gives a new way to collect the data of environment instead of the traditional way using wires.

Abstract:1年以上。 According to the requirements for precision agriculture applications, the commonly-used node power supply in sensor networks and its characteristics are analyzed. To extend the node lifecycle powered by ordinary dry-cell batteries, an application layer operated node dormant/synchronization mechanism is proposed and a duty cycle computing method depending on the node lifecycle expectation and data acquisition demands is also provided, based on the node energy analysis. Finally, this dormant/synchronization mechanisms is realized on actual sensor networks nodes, and a large number of experiments were executed at Xiaotangshan agricultural bases of the National Engineering Research Center for Information Technology in Agriculture. The experimental results show that the node with dormant design increases its lifetime from about 150 hours to more than one year.

Abstract:A new smart sensor node to monitor soil temperature, including hardware and software, is developed through modular method. The hardware system is developed based on a CC2430 micro-controller and DS18B20. The software system includes the temperature collection and information transmission. The results show that the node can collect soil temperature data and then send the data to the upper network node. This node possesses compact structure, stable performance and low energy consumption. The effective communications distance among nodes reaches 80m and the error ratio is approximately 1%, which meets the requirement of precision agriculture. The node provides a better hardware platform for further study on the communication protocols of wireless sensor networks.

Abstract:Measurement accuracy of agricultural soil has important significance in crop growth. ARM-based wireless transmission system of soil moisture was developed. Based on μCLinux operating system, GPRS wireless data transmission terminal including the data collection system and embedded system software was designed. In terms of characteristics of wireless transmission system of soil moisture, system application could improve the agricultural product quality.

Abstract:The method of data management and transmission for the mobile and intelligent agriculture information service system is studied, and the application layer protocol for wireless data transmission between the mobile terminal and the upper computer is designed based on the TCP/IP. The type, format, and content of the wireless data transmission are studied. The application layer protocol considers the collection and transmission characteristics of agricultural information. Initial applications indicate that the application layer protocol is suitable to the mobile and intelligent agriculture information service system, and has certain versatility and expansibility. The application layer protocol standardization is advantageous in sharing agricultural information.

Abstract:A portable solar-induced chlorophyll fluorescence monitor based on this principle was developed and tested. The instrument uses sunlight as its light source. There are two sets of photoelectrical detectors with the center wavelength at 760nm and 771nm respectively and the bandwidth of each detector is 1?nm. Both sets of detectors are composed of an upper detector which are used for detecting incidence sunlight and a bottom detector which are used for detecting reflected light from the canopy of crop. The detector is the core of the monitor to measure the spectrums at special bands. The microprocessor calculates solar-induced fluorescence value based on the A/D values obtained from detectors. And the value can be displayed on the LCD, stored in the flash memory and uploaded to PC through the PC's serial interface. The prototype was tested in the crop field at different view directions and the results demonstrated that the instrument could measure the solar-induced chlorophyll value accurately with the correlation coefficients higher than 0.9 compared with the values obtained from analytical spectral devices FieldSpec Pro NIR spectrometer.

Abstract:0.52。 In order to real-time detect the plant nitrogen content, a non-destructive crop growth analyzer is developed. It is made up of a sensor and a controller. The optical part of the sensor is made up of four optical channels and four photodiodes. Two channels receive the sunlight and the other two receive the reflected light from the crop canopy at the wavebands of 610nm and 1220nm. The circuit part of the sensor is made up of power supply unit, amplifying unit and a wireless module. The controller has functions such as keyboard input, LCD display, data storage, data upload, and so on. Calibration tests show that the optical part has a high accuracy and the wireless transmission also has a good performance. The field tests comparing with a commercial spectrometer (Quality Spec made by ASD Co.) also show an acceptable correlation of 0.52.

Abstract:A new mathematical model for detecting the contents of chlorophyll, nitrogen and water of plants at the same time was established. Combined with the theory of spectroscopy, a portable meter for detecting the contents of chlorophyll, nitrogen and water in crop leaves was developed, which could avoid the error caused by different measuring time and different measuring location on the leaves when the three measuring parameters were accomplished by different instruments. The measurement result could give a better suggestion to precision fertilization and irrigation. The developed meter was composed of NIR (near infrared) LED (light emitting diode), interference filter, photodetector and microprocessor system.

Abstract:SVM has already shown its successful application on the CCP discovery for HACCP implementation. However, the classic non-incremental SVM method is not an effective algorithm due to the thoroughly re-study for those samples are gradually added. We propose a new incremental algorithm. It makes use of the heuristic mode so that training can be firstly applied on the cases with greater possibilities to be SVs, and the training set can be reduced. The experiments show that the training speed is visibly improved without losing the precision of the classification.

Abstract:Tracing and identifying animal is an important means of enhanced animal food tracing regulations in the world. Animal tracing and identification system based on RFID was introduced. Based on the system function, the design of GPRS wireless data transmission terminal based on ARM was put forward. According to the functions and characteristics, database of data center was detailed designed. Combining characteristics of animal tracing and identification system, significance of system application was described.