Abstract:The cascade structure of control system consisting of yaw-moment controller and wheel slip controller was adopted to develop vehicle stability control (VSC). An ideal model with the best performance of side-slip angle and yaw-rate was established. The strategy of both the forward-feed control and back-feed control of tracking the desired model was employed. The linear quadratic regulator (LQR) theory was exploited for yaw-moment controller. Ideal slip assignment model was proposed to determine the ideal value for slip controller from the yaw moment acquired from the yaw-moment controller. The fuzzy logic control theory was applied to slip controller. An 8-DOF nonlinear vehicle model was constructed based on Matlab/Simulink platform, and then simulation was performed under low friction and high friction road condition respectively. The results show that the proposed control algorithm can achieve the desired yaw-moment, the side-slip angle and yaw-rate can track the ideal model effectively. It can achieve good transient and steady response, and improve vehicle handling stability.

Abstract:A detailed multi-body dynamic model of a heavy truck was established by using SIMPACK software, which included front suspension, rear balance suspension, steering system, tyre system etc. The harmony superposition method was used to simulate stochastic road with a specific spectrum, and an integrated environment with different road roughness was built to study the relationship between vehicle dynamic tyre loads with three directions and different road grading and vehicle speed. Simulation results indicated that, the front axle’s vehicle longitudinal dynamic tyre load was less than the middle and the rear axles, and the front axle’s vehicle side and normal dynamic tyre load was more than the middle and the rear axles. For the middle axle and the rear axle, the vehicle dynamic tyre load was roughly the same. At 60～90km/h driving, on grade A～D road, the front axle’s vehicle normal dynamic tyre load coefficient was more than the middle and the rear axles, and the front axle’s vehicle normal tyre force was less than the middle and the rear axles.

Abstract:Considering the high uncertainty for vehicle working environment, multi-degree of freedom four-wheel steering vehicle model was proposed. Structural singular value μ theory is adapted to design robust controller. By specifying an imaginary uncertainty module, the behavior robust property was inverted into a generalized system to resist the exterior disturbance. A HILS platform based on Matlab/Simulink/dSPACE was developed to real-time carry out the virtual testing by constructing different vehicle surrounding. The four-wheel steering automobile was modified successfully and the developed 4WS controller was then applied in the vehicle field test for validation and further modification. The test data proved that the modified four-wheel steering is prior to front-wheel steering and the former has an excellent maneuverability and stability. Furthermore, the whole procedure of rapid development for 4WS including off-line simulation, real-time simulation, hardware-in-the loop simulation and the validation of the vehicle field test, based on the control development system, was investigated by the 4WS rapid development system. Therefore it was demonstrated by theoretical and experimental results that the 4WS rapid development system is an extended powerful tool for the development of vehicle chassis electronic controllers.

Abstract:It is difficult to formulate exact mathematical model of hydrostatic transmission due to nonlinear and time-varying characteristic, thus fuzzy control was performed to the system. To improve the traditional fuzzy controllers, a novel fuzzy control scheme was studied. By generating a new compensation amount with the product of original one and its absolute value, a fuzzy controller with variable scale factor was formed. The simulation and test results showed that the new controller can achieve high speediness response, restrain the overshoot effectively and obviously improve the dynamic and static characteristics of the system. It is suitable for the high speed tracked vehicle hydrostatic transmission.

Abstract:3-DOF vibration reduction platform using 3-PRRP（4r） parallel mechanism and the elastic damping devices were established. A semi-active controller was designed with LQR law to control the system. Then, an experiment system was constructed to test the vibration of on control and off control. The result showed that it has good effectiveness for multi-dimension vibration control of instrument carried in vehicle.

Abstract:The vehicle driving cycle was taken as a stochastic Markov process with time, which was divided into 6 different states by maximum likelihood estimation (MLE). And every driving segment, as the modal event reflecting acceleration variations, finely preserved the speed variation characteristic in tiny time segments of the vehicle driving process. Therefore, the selection approach of candidate cycles was put forward by combination of the states transition probabilities with similarity tests, and the new evaluation criteria with 13 characteristic parameters was established. The actual application analysis was carried out with an example of typical roads driving cycles in Hefei and the independent test was performed to validate the rationality of the Markov method for the driving cycle. The results showed that the similarity levels of the Markov method, on the K-S test of modal events acceleration distribution with experimental data, were 0.998, 0.989, 0.994, contrasting the traditional method, 0.788, 0.036, 0.992. Resultingly, the Markov method more accords with driving cycles of real roads.

Abstract:In the car-following process, there are some uncertain parameters in the vehicle brake system and the driver, such as the brake acceleration, the action time of the vehicle arrester and the response time of the driver, etc. Generally, the ranges of these uncertain parameters are easy to be found, but the effect of them on the car-following process is one of the hard issues. This paper used the interval number to describe the uncertain parameters in the car-following process. Based on the approximate computational method of the safety distance, the interval analysis was employed to calculate the safety distance of vehicles under two typical conditions. The results show that the safety distance calculated by the interval analysis method is not a certain value, but an interval value. Therefore, the interval analysis method can forecast the effects of the uncertain parameters on the safety distance in the car-following process.

Abstract:190～210 kg/m3。The basic structure and work principle of large rectangular baler were introduced. To satisfy the bundling compression property of maize straw and the load system require of burning straw generate electricity, gearbox, materiel collect and feed system, mechanical pre-compressing unit, baler plunger and hydraulic control system were design and computed. Collect and feed parameter, second pre-compressing principle and hydraulic control system were reasonably adopted to ensure the work dependability. The result indicated that the fully bale rate of 4YF-1300 large rectangular baler can achieve 97.2%, the regular bale percent is 94.4%, and bale density can achieve 190～210 kg/m3, which can satisfy the performance request of large rectangular baler.

Abstract:20％。Ensilage maize combine can ingather corn ear, as well as bundle and ensilage corn stalk when it is used for corn harvest. In order to enhance operation efficiency of ensilage harvester, and to reduce the operating burden of driver, an automatic control system on feedstock and rope-send was designed, composed of three parts, i.e., sensor detection element, control circuit and implementation mechanism. Four-way change-over switch was used as detection element of sensor, and combined with RS de-twitter circuit, to improve the reliability of the control system effectively. The implementation components that were composed of two electromagnetic clutches responded to the control circuit output, and ultimately actualized the real time control of feeding stalk and sending rope. Experiments show that the designed system can work accurately and reliably, with the baling rate to 100%, compared with manual control, the veracity of bale density control is strengthened effectively, and operating efficiency of the machine is improved by 20%.

Abstract:In order to optimize parameters of threshing system of seed corn thresher with different speeds threshing parts, and to decrease mechanical damage of corn seed kernel in the course of threshing, the process of feeding and threshing origination of single seed corn ear was analyzed by using high-speed photograph method. The testing results show that damage rate of kernels subjected intense impact is large in the feeding origination of seed corn ear; with threshing, impact changes more and more feeble, and damage rate of kernels becomes smaller and smaller too. Under state of ordinal threshing, large amounts of kernel is threshed and the moving track of threshed kernel follows the tangent direction of contacting dot of straight roller and ear, while under state of out-of-order threshing, the amount of kernel is small and the moving of threshed kernel presents disordering. Furthermore, large rotating speed of spiral roller results in the larger out-of-order threshing of ear, which influences the threshing quality and threshing efficiency of seed corn ear.

Abstract:In order to analyze the working performance of the rethreshing separation unit combined with a tangential-threshing and an axial threshing, including losing rate, distribution of the mixture along the axial of cylinder, the rate of impurity and power consumption, three threshing drums, i.e., the spike tooth, the rectangular tooth or the spike-short-rasp-bar tooth, were developed and test on the rig of the axial-threshing separation performance with axial feeding. The results show that three drums have low losing rate. Compared with the spike tooth and the rectangular tooth, the drum with spike tooth and short-rasp-bar tooth has uniformal distribution of the mixture along the axial of cylinder, less impurity contents and lower power consumption while threshing wheat.

Abstract:The total structure of a new transverse axial flow threshing and separating unit with double cylinder was described in detail, along with the design scheme of the threshing cylinder and concave. The frontal threshing device was made with the structure of short-rasp-bar, plate teeth, the small distance grid concave, and the posterior threshing device was composed with the structure of the spike tooth cylinder with helical blades and the large distance grid concave. The bench test showed that this device was applied for the large capacity and the difficult threshing rice. It also has the following advantages as higher threshing, lower cleaning loss, the well-proportioned distribution of threshed stuff, and the little trash content, and so on. The field experiment showed that the total loss rate is 1.94%, the threshing loss rate is 0.89%, the broken rate is 0.84%, and the ration of trash content is 0.20% when the feed rate is 4.32kg/s. Various technical indexes have reached to the national standard.

Abstract:The walking office, harvests and threshing system of combine was analyzed, and the fundamental mathematical model of system was proposed. Since this model was high order, nonlinear system, without the accurate system parameter. The difference equation of model was decomposed into two parts. The first part had a bearing on the control signal, another part did not. By using the RBF neural network technology, the two parts was separately identified online. Then, the controller functionated according to the identified result. Under the dissimilar condition, simulation and experiment was carried out which proved that using the RBF network can fit the controlled plant effectively. When the controlled plant parameter changes, the system can track it, achieving the good control effect.

Abstract:The abrasive testing machine with operation process similar to the pelleting circular mold was used, taking the alfalfa grass powder as abrasive material. The influences of alfalfa powder on the abrasive properties of four kind of metal materials were examined, by measuring the rigidity and chemical components of the abraded surfaces and analyzing of the microstructures and surface morphologies of the abraded surfaces. It is shown that the abrasive quantities of four samples as below are orderly increased, 3Cr13, 9SiCr, 45# steel, and HT200, some physical and chemical changes take place on the abraded surfaces, and “the soft abrasive wear” is accompanied by “the hard abrasive wear” feature due to the micro-cutting and strain fatigue.

Abstract:Under rainfall-irrigation-evaporation, 2-D soil moisture movement mathematical model including root water uptake function was established, and solved by finite element method based on soil hydrodynamics theory and root zone soil moisture movement characteristic. The model was verified by the data of the measured soil moisture content in filed. The computational results were in accordance with the measured, which indicated that the mathematic model of soil water movement is correct, and that solving of the model with finite element method is feasible. The model can be used to simulate the soil moisture distribution rule.

Abstract:A new type lightweight and small irrigation machine with dual purpose of sprinkling irrigation and hose irrigation dual purpose was introduced, whose height and sprinkling breadth was adjustable. The water distribution uniformity of machine was studied by theoretical analysis and experimental validation, primary factors of which were analyzed, and sprinkling intensity and uniformity coefficient were calculated when the machine collocated sprinkling irrigation and hose irrigation system. The result show that primary factors effecting water distribution uniformity of machine are water distribution uniformity and collocating space of sprinkler, stepped speed, soil and landform, as well as wind speed. In lab experiment, the sprinkling uniformity coefficient exceeded 95%, and hose irrigation uniformity coefficient reached 90%, which fully met irrigation demand.

Abstract:Bulb tubular pumps have small hydraulic loss and high pumping system efficiency, which especially suit to the low lift head, large discharge and long running time situation. Bulb supporting units which including manhole and bottom supporting are important flow-passage components of bulb tubular pump. The turbulent flow in a bulb tubular pump with different supporting shapes was simulated by CFD method. The results of the calculation indicated that the shape of supporting has a marked influence on hydraulic loss in the discharge passage and flow pattern. Therefore, reasonable shape of supporting can improve the turbulent flow pattern, reduce the circumference velocity and increase the pumping system efficiency.

Abstract:The three-dimensional, unsteady Reynolds-averaged Navier-Stokes equations with shear stress transport turbulent (SST) models were solved to investigate the flow field and the characteristic of pressure fluctuations in the double volute. The results show that the pressure fluctuations are strong in the double volute. The pressure fluctuations in the volute are relatively low at the design flow rate condition. The blade passing frequency dominates the pressure fluctuations near the volute tongue and the clapboard at the design flow rate condition. The amplitude of the pressure fluctuation is largest at the beginning of clapboard, which is 25 times larger than at the volute tongue. At the large flow rate condition, the blade passing frequency is also dominative in the pressure fluctuations, but at the small flow rate condition the rotation frequency becomes dominative. The radial force on the impeller is unsteady especially at the small flow rate. At three flow rates, the radial forces all point at the beginning of clapboard.

Abstract:To the doubt whether steady flow is endowed with global representativeness, the numerical simulation was performed for a low specific-speed centrifugal pump at multi-phase position, under the designed operating conditions, by multiple reference frame model. Changes of the total head were investigated in detail, due to the relative position of impeller passage to volute. The important flow information, such as velocity, the pressure fields and characteristics of swirling flow and its developing process on the eighth cross-sections of the volute casing, were also gained. It was concluded that the result of steady numerical simulation with multi-phase position truly reflects the unsteady flow features in the pump flow field to a certain degree.

Abstract:A novel digital controller solution was proposed, according to the actual driving of PV pumping system. To reduce freewheeling power consumption, MOSFET was used as freewheeling current path instead of diode based on synchronous rectification, which was helpful to reduce temperature of the controller and to improve the system reliability. The deadbeat digital controller was designed based on adaptive UKF, to identify and modify system parameters on line. Simulation and experimental results show that the designed scheme is easy to digital implementation, valid for parameters identification, and has higher current control precision. Therefore, it is effective to improve the performance of PV pumping system.

Abstract:The hygroscopicity of the yellow dextrin/straw fiber composites at different relative humidity conditions was researched. The model of hygroscopicity and its variational rate was set up. The favorable water resisting property for the composites was obtained, on the two following groups conditions: the straw fibers of 100 g, the water of 40 g, the yellow dextrin of 20 g, the hot pressing temperature of 170℃, the hot pressing pressure of 4.2 MPa, the hot pressing time of 30 min; and the straw fibers of 100 g, the water of 40?g, the yellow dextrin of 10 g, the hot pressing temperature of 170℃, the hot pressing pressure of 9.8 MPa, the hot pressing time of 20 min respectively. The hot-pressing temperatures of two groups were both higher than in common. So the preparation process should focus attention on hot-pressing temperature factors. The research can provide reference for applying of the moisture absorption properties of the yellow dextrin/ straw fibers composites.

Abstract:Straw fiber wall structure is a new structural system with properties of lightweight and energy-saving, heat preservation and sound isolation. Firstly, the impact of chemical component, structure on basic thermal performance such as activation energy, heat productivity, heat release rate was studied in details. Secondly, the chemicophysics reaction in high temperature were studied through TG-FTIR experiment. Finally, the linear stepwise regression model about fire temperature and loss on ignition was established based on loss on ignition experiment and DRS2.6 software analysis system. Furthermore, a 200mm thickness straw fiber external thermal insulation plate was chosen and burned in independent designed ISO9705 standard fire test room in order to verify the accuracy of the regression model. The results show that the model is correct and can be applied to the real engineering computation and assessment.

Abstract:The micro-structure parameters of the actual porous media through mercury intrusion experiment were obtained, and the fractal dimension of pore distribution was calculated, taking frozen-dried potato for example. The result showed that the pores in the freeze-dried potato presented the remarkably fractal properties. A two-dimensional fractal pore network model of porous media was constructed based on the theories of homothetic reduction, fractal geometry, Voronoi diagram, along with the structural parameter of potato. Since pore microstructure characteristic was considered into the model, the parameter of network model can well reflect the microstructure of porous materials, and the reasonable fractal dimension was obtained.

Abstract:By taste analyzer, the physical and chemical data of brown rice was obtained. And then, employing the model of white rice, the correlation between the main compositions and taste value was gained by parameter estimation. Base on the paddy moisture falling to 15%, a mathematical model for taste value of the brown rice was built by using quadratic orthogonal rotation combination design to evaluate the rice taste quality and develop the vacuum drier. The research results showed that drying temperature, original moisture, and vacuum degree are the key factors affecting the taste value during paddy vacuum drying, according to priority. The taste value is negatively related to the two former and is positively related to the latter.

Abstract:In order to validate the model of reference, a corn drying experimental study was conducted, and numerical simulation was carried out under the same environmental condition. The experiment and simulation results indicated that the pore network model could explain the drying process of corn material well. There was a significant difference between the temperature of corn and of pore air, hence it was unreasonable to confuse the two kinds of temperature. The pore coordination number had a great effect on the drying process. The greater the pore coordination number was, the faster the material was dried. When the pore coordination number was small, a wet cluster phenomenon appeared in the drying bin.

Abstract:Analysis of physical properties and nutrient components of the carrot micro-powder showed that the carrot micro powder gained by the hot air drying and the microwave drying had the larger bulk density than by the freeze drying. Water solubility of the carrot micro-powder gained by the microwave drying was higher than gained by the freeze drying; water solubility of the raw carrot micro-powder was higher carrot than the cooked. The amino acid mass ratio of the raw carrot powder was higher than the cooked carrot powder, the freezing and thawing powder. Treated with the freeze-drying, the amino acid mass ratio of the raw carrot powder was the highest, and the powder granularity was smaller than 240 mesh. The vitamin C mass ratio of the carrot micro-powder processed by the freezing and thawing was higher than the raw and the cooked carrot powder. The vitamin C mass ratio of the carrot micro-powder processed by the freeze drying was the highest, and then the vacuum drying. The smaller the granularity was, the less the carotenoids mass ratio was; the carotenoids mass ratio and the vitamin C mass ratio ware the highest when the freeze-thaw carrot was processed by the freeze drying, and the granularity was 80 to 120 meshes.

Abstract:4.55～10.4℃。 Both thermal infrared imaging and thermocouples were applied to real time measurement of cut gerbera during vacuum cooling. Surface temperatures of the ligule-shape petal, tubular petal and stem were detected. Results show that there is a significant difference of different parts in average cooling rate, and for the petal and stem, the temperature distribution is nonuniform. The average final temperature obtained with thermal images is 4.55～10.4℃ lower than the thermocouple.

Abstract:To explore the effect of prestorage mild heat treatment on mechanism of senescence and softening and storage quality of minimally-processed grape, lightly processed Red Globe grape were treated at either 45℃ for 8min or 55℃for 5min before stored. The respiration and endogenous hormone of the treated table grapes were investigated. Results indicated that heat treatment had significant effects on the respiration rate of grapes during storage as follows. Contents of IAA and GA3 were negatively correlated with decay rate of lightly processed grape, and the correlation coefficients were 0.9035 and 0.8416, respectively. The ABA content during the storage of the grapes changes in parabolic shape, developed from lower to higher and then to lower. Heat treatment can delay the appearance of peak and decline the peak value. ZR content was not significantly affected by heat treatment, and didn’t present change rule during the lightly processed storage.

Abstract:Box-Behnken model was used to optimize the glycation process of egg white protein. The emulsifying properties of glycated egg white protein (GEWP) were determined and analysed in various conditions. The results showed that the optimized condition of glycation reaction was as follows: 9% of ratio of dextran, 48 hours of time of reaction, 60℃ of temperature of reaction. Then, emulsifying activity and emulsion stability of GEWP, are 1.328 and 9.63min, 3.7 and 8.75 fold against egg white protein respecitvely. The correlation between degree of glycation and emulsifying activity or emulsion stability of GEWP accords with Lerentz function. The emulsifying properties of GEWP were not affected in acidic pH value and high ionic strength. The results show that glycation is an efficient method to improve emulsifying properties of egg white protein.

Abstract:0.3%时提高了21.1%。 Cross-linking of casein catalyzed by horseradish peroxidase was studied, which was demonstrated by SDS-PAGE analysis, spectroscopic analysis and capillary electrophoresis analysis. The cross-linking degree of casein was measured by capillary electrophoresis with an area normalization method. Response surface method was applied to optimize the reaction conditions for cross-linked casein. The optimal cross-linking conditions obtained were that enzyme addition level was 4.73μkat per gram protein, temperature was 37℃ and reaction time was 2.9h. Under these optimal conditions, the cross-linking degree of casein prepared was about 6.9%. Evaluation results show that emulsifying activity index of cross-linked casein at concentration of 0.01% has an increase of 8.7%, while emulsifying stability index of cross-linked casein at concentration of 0.03% has an increase of 21.1% comparing to that of native casein, which indicates the improvement in emulsifying properties of cross-linked casein.

Abstract:86％。 By using single-factor test and orthogonal test, the optimized seed medium and feeding medium were obtained, with the aim to study the stability of the production of lactic acid by Rhizopus oryzae though semi-continuous fermentation. The optimization culture medium was as follows: glucose 120g/L，(NH4)2SO4 2g/L，NaH2PO4 0.16g/L，KH2PO4 0.14g/L，MgSO4?7H2O 0.2g/L，ZnSO4?7H2O 0.22g/L，CaCO3 60g/L; the feeding medium was as follows: glucose 100g/L，（NH4）2SO4 2g/L，KH2PO4 0.1g/L，ZnSO4?7H2O 0.33g/L，MgSO4?7H2O 0.15g/L，CaCO3 50g/L. In flask culture 30 repeated stable fermentation were carried out, and 20 batches were carried out in a 5 L stirred tank fermentor. The highest lactic acid yield from glucose was up to 86%.

Abstract:12.89%和56.6%。 The technology relating to extruded corn grist degermed with enzyme preparation at low temperature which was liquefied, saccharified, fermented, distilled directly for production of ethanol, was studied. The influence of main parameters of extrusion-saccharification-fermentation system for above extrudate on main evaluation indexes of ethanol mash was researched. These parameters include the added dosage of high temperature resistant α-amylase into corn grist degermed before extruding, the added dosage of glucoamylase in saccharifying of extrudate, saccharification time, the added dosage of high temperature resistant α-amylase in liquefaction, and the dosage of yeast in ferment. The main indexes include the ethanol degree, utilization ratio of starch and residual total sugar of ethanol mash. The results indicate that under the condition of optimum value for system parameters, the ethanol degree and utilization ratio of starch of ethanol mash after fermenting for 48h are respectively 13.45% and 59.21%. These values are more than 13.08% and 57.85% of ethanol mash for contrast extruded corn without enzyme preparation. These values are also more than 12.89% and 56.6% of ethanol mash for corn grist degermed with traditional ethanol productive technology.

Abstract:Two major components of soybean proteins, β-conglycinin (7S) and glycinin (11S), were fractioned by a two-step technique based on the addition of different levels of Ca2+ and NaHSO3 at refrigeration temperature and pH value adjust to induce protein precipitation. The suitable preparation conditions were studied herewith. Fractioned soybean protein I containing glycinin about 57.4% and fractioned soybean protein Ⅱcontaining β-conglycinin 61.4% were prepared with the optimal conditions. The evaluation results show that fractioned soybean protein I has a better gelation property and foam powder than soybean protein isolate, while fractioned soybean protein Ⅱ has a better emulsion property than soybean protein isolate. It can be found that fractionation of soybean proteins basing on Ca2+ induced-precipitation may be applied in food industry to exploit functional property of soybean protein components more effectively.

Abstract:To solve the uncertainty of sensor information for intelligent vehicle navigation, a 2-level sensor information fusion method based on both BP neural network and fuzzy neural network was presented. A BP neural network was used to fuse information from multi-ultrasonic sensors so that the uncertainty of the sensors’ information can be decreased and high accuracy of obstacle distance can be obtained. In order to realize preferable decision control of navigation, a fuzzy neural network controller was employed for tracking obstacle avoidance to fuse the obstacle distance and the error information between the vehicle and the marked line. High performance of robustness and flexibility for intelligent vehicle navigation can be achieved with the 2-level information fusion method. Simulation and experiment results verified the effectiveness of the proposed approach.

Abstract:67.3%。 A method of branch identification for citrus harvesting robot was proposed. According to the characteristics of obstacle that citrus harvesting robot met, such as branch, the 3-D information of obstacle was restored by extracting and processing the skeleton of obstacle image. The branch region was obtained using image segmentation, morphologic processing and region labeling. Then the skeleton of obstacle was extracted by thinning, and the feature points such as endpoint and branch point of the skeleton was found out, to record their connecting relationship. Finally the 3-D information of obstacle was restored by stereo matching on feature points. Experimental results showed that the identification accuracy of obstacle can reach 67.3%, and the identification error ratio is increased when the actual distance of obstacle is more than 1.5m.

Abstract:10.2%。 A grading method of mangosteen at size and color was proposed based on computer vision. Taking the blue rollers as background, the mangosteen images were pre-segmented by double thresholds in RGB color space. Through morphological operation, contour trace and region fill, the whole mangosteen target was obtained. Lastly, the peduncle, pedicel and pericarp were identified by 2G-R-B and G factors. According to the centroid of peduncle and pedicel and the centroid of pericarp, the fruit posture was evaluated, and the diameter was extracted as the size grading criteria. Meanwhile, the difference of saturation and hue of pericarp area in HIS color space was the color grading criteria. A grading experiment was carried out for 200 mangosteens. The results indicated that the accuracy of diameter measurement is ±1.8mm, and the maximal scale of neighbor grade mixed by color is 10.2%.

Abstract:0.5s。A method using intensity and color information for separating adjoined apples was proposed. First, Lab model was employed to segment the apple images, followed by each segmented area was calculated to judge whether they were adjoined area or not. Then the intensity information was added to the adjoined area, and the light spot of apple was used to separate the adjoined apples. Thus, the noise from intensity information was screened by the Lab information in the area besides adjoined apples, and the adjoined apples was segmented using the unique intensity information in the adjoined area. The result of segmentation showed that the success rate is over 92.89%. It is useful to use the algorithm in practical recognition of apple fruits.

Abstract:An electronic nose system was developed for detecting beef freshness. An array of gas sensor was selected correctly according to beef smell and sensor experiments. To enhance the sensitivity of electronic nose sensors, purchased sensors were improved. By using the research achievements of biological olfaction, a bionic nasal meatus was designed. In order to improve the recognition rate of the electronic nose system for small samples, appropriate recognition algorithm of support vector machine (SVM) was adopted. Identification experiments of different freshness of beef that had been stored for 7 days were carried out, and results showed that the recognition rate of this system is 99.25%, the feasibility of identifying beef freshness with electronic nose was confirmed.

Abstract:Against the background of implementing load spectrum data management system of the typical agricultural machinery, the load spectrum data management system was designed and implemented using the technology of .NET in the mixed model of C/S and B/S. Then overall plan and structure model of the system were worked out according to actual situation and detailed requirements of engineering application. Finally, each system module was coded and debugged. Thus, it can be implemented for the modernization management of load spectrum data, adding communication channels and improving efficiency of structural fatigue research.

Abstract:There exist periodic order non-smooth structures like ridge and ditch in butterfly scales, small difference of which such as form, density, size, space, thickness, layer number, distribution style, can effect the different surface colors. The analysis on microstructure of butterfly scales is the theoretical foundation of stealth research on structural color of living creatures. From the macroscopical viewpoints and microcosmic ones of surface configuration and cross-section structure, the microstructure of scales were contrastively analyzed by electron microscope, the optimized model of distributing, configuration and structure of butterfly scales were built, and then two kinds of bionic models of butterfly scale’s microstructure were optimized and designed.

Abstract:Based on contact fractal theory and micro-contact size distribution function, a fractal model of normal contact stiffness of joint interfaces was proposed, considering the influence of the domain extension factor for micro-contact size distribution. Furthermore, numerical simulation was carried out to obtain the nonlinear relationships between normal contact stiffness and characteristic parameters of joint interfaces. And the effect of these parameters on the normal contact stiffness was also analysed. The results show that the normal contact stiffness of joint interfaces increases with the normal load on joint interface, decreases with the fractal characteristic length scale parameter G, however, complicatedly varies with the fractal dimension D.

Abstract:It is very important to develop a more effective and objective method to get more quantified information of coherent structures from the turbulent signal. Based on wavelet and bi-spectrum analysis, a reasonable method was put forward. The large eddy signal including the information of coherent structures was extracted by the bi-spectrum and cross correlation analysis, and multi-scale coherent structures were detected by the wavelet transform. Besides, by using wavelet analysis, a new identification criterion of energy-containing scale was established. The reliability and rationality of the method was verified by an example with the sample data from the experiment on the mechanism of rib-lets drag reduction. Furthermore, this research has also led to the conclusion that the multi-scale characteristics of coherent structures can be gotten by the above method.

Abstract:A novel spatial parallel robotic mechanism with three degrees of freedom (DOF) was proposed, whose moving platform of the mechanism had two-translational and one-rotational DOF. Based on the screw theory, kinematics output property and mobility of the manipulator were analyzed, respectively, and analytical solutions of position and velocity for both direct and inverse kinematics were derived. Furthermore, the singularity and the dexterity were discussed. Since the Jacobian matrix, mapping the input velocity vector space into the output, is an identical matrix, the present mechanism is a free-singularity fully-isotropic one, which has good performances in motion and force transmission and potential applicable future.

Abstract:A 6-DOF 6-CPS orthogonal parallel manipulator was presented, based on the theory of the structure synthesis for parallel robot mechanisms. The forward kinematics of the manipulator was studied to analyze the positive positional solutions. With the restrict condition of the lengths of six actuated limbs, the constrained equations were established, and the nonlinear equations (NLEs) were obtained to solve forward positional problems of the mechanism. Based on the Chen-Lai algorithm, by means of which chaos was generated or modified, a discrete-time dynamical system was feedback controlled to be transferred to a chaotic system that has the expected Lyapunov exponent and good ergodicity. The chaotification-based Newton iterative algorithm (CBNIA) was utilized to solve NLEs for forward displacement analysis of 6-CPS orthogonal parallel manipulators. The results of numerical verification show that through the CBNIA, all forward solutions can be quickly found that are very coincident with the inverse ones.

Abstract:By substituting the straight tooth profile for the involute one, the internal gears with hard tooth face was easily grounded in form grinding. By means of the tooth contact analysis(TCA) technology and loaded tooth contact analysis(LTCA) technology, stress condition, load share between teeth, transmission error were studied, when meshing the internal gear with straight profile with involute external gear. The noise of the planetary reducers with both straight tooth profile internal gear and involute tooth profile was collected respectively by rig experiment. By analysing the collected data, the dynamic transmission performance of internal gear with straight tooth profile was studied. The internal gear with straight tooth profile has the performance of “edge trimming” and a much smaller transmission error variations under loading than no-loading, as a result, it is fully feasible to use the internal gears with straight tooth profile in industry.

Abstract:Transformation principle and method for machine settings from cradle-type hypoid generator to Free-From CNC one was studied. Appling coordinate transformation, the mathematical model of tilt method process for hypoid gears was proposed, which can be used for simulation face milling and face hobbing process. By auxiliary coordinate systems, the relative position and motion between the head-cutter and the workpiece during the two generation process was established, and transformed to Free-Form coordinate system, to obtain and to expand the expression of 6 CNC axes. A numerical example was also employed to verify the proposed method, and the TCA results proved that transformation is feasible.

Abstract:In order to emerge the surface fracture of auto body panel, four kinds of experimental dies containing class A surface feature of auto body outer panel was designed. The fracture phenomenon was observed during the stamping experiment. At the same time, numerical simulation based on an independently developed commercial CAE software KMAS/UFT of sheet metal forming was carried out. Comparison between experimental and simulated results based on LS-DYNA3D was made which showed good consistence. And then a universal formability theory called UFT was introduced to optimize the adjustment amount of metal flow and the stamping dies for fracture. Some suggestions were given by investigating the adjustment amount and modification of the stamping die.

Abstract:Adopting the Benchmark test scheme of a cylindrical cup deep drawing proposed by NUMISHEET2002, the deep draw ability, anisotropic behavior and wrinkling of aluminum alloy 6111-T4 sheet were researched under different blank holder force (BHF) conditions. The results show that the formability of aluminum alloy sheet is hardly influenced by small anisotropic coefficient, and wrinkling can be eliminated effectively by increasing BHF, therefore aluminum alloy 6111-T4 sheet has excellent stamping formability. Based on the platform of KMAS, self-developed sheet metal forming CAE software, Benchmark test was simulated, and the results were compared with that of the test. KMAS software, adopting Barlat-Lian anisotropic yield criteria and dynamic semi-explicit algorithm, is able to simulate aluminum alloy sheet forming accurately.

Abstract:More traditional die-face designs are carried out according to experience without considering the mapping function between design parameters and finite element simulation results. So it is difficulty to optimize the design parameters. In the present research, the basic principle of the sheet metal forming optimization by the response surface method was discussed, along with the replacement model of finite element simulation results. Specially, the design variables, the objective function, constraints and the multi-objective optimization approach in sheet metal forming optimization were introduced. Based on the response surface method, the inner panel of automotive suspension was studied, and the optimal model of the die-face-geometric parameters was established with the least blank thickness as the object, the die-face-geometric parameters as the variables and the constraints as the FLD. Finally the die-face-geometric parameters were optimized. With the optimal parameters, the pressing test was carried out to verify the optimization result.

Abstract:Four kinds of cemented carbide tools were used to turn Iron-based superalloy GH2132 at high-speed under dry cutting condition. Wear morphology of cutting tool was observed by SEM, and element distribution of tool surface was analyzed by EDS. Adhesive wear, oxidation wear and diffusion with micro-chipping were the main wear mechanisms of the cemented carbide tool .The rake face wear of the cutting tools in high speed machining was different from that in conventional speed machining. Namely, the rake face was not characterized by crater wear but by slope-plane-wear with the maximum wear at the cutting edge. Furthermore, the worn area of the rake face decreased with cutting speed and the wear depth increased correspondingly.