Abstract:Based on an SI electronic-controlled engine，hydrogen generator and electronic controlled unit were developed， the control strategy for fuel switching and hydrogen mixture mode were set up to realize a smooth transition in the period of fuel switching and an automatic operation under hydrogen mixture mode. Moreover, components measurement of hydrogen mixture online and its effects of mixture concentration on performance of SI engine were performed．The results indicate that besides hydrogen and monoxide carbon, certain amount of methanol steam was found in hydrogen mixture and they account for 23.3%~46%，11.6%~23% and 31%~65% respectively. In addition，the fuel economy is also improved power with gasoline.

Abstract:A visualization unit with a proportion of the multi-hole injector nozzle for cavitating flow was developed, and by means of high-speed video camera, the pictures of the cavitating flow in a large-scale transparent nozzle were taken under various injection pressures. A three-dimensional grid model of the injector nozzles was established, and the three-dimensional numerical simulation of cavitating flow in nozzle holes of a multi-hole injector combined with these pictures from experiment was utilized to analyze flow characteristics of single-phase flow to supercavitation flow. The relationship between injection pressure, non-dimensional cavitation parameters and the discharge coefficient, as well as the critical conditions when the cavitation appeared was pointed out clearly.

Abstract:Large Flow Injector Equipped with Piezoelectric Crystal

Abstract:Intake Port Design for Low-pressure Air-assisted In-cylinder Direct Injection Gasoline Engine

Abstract:According to the structural characteristics of new-type horizontal diesel engine, the cooling jacket of forced cooling closed-loop system was designed, the temperature and pressure of inlet position and key points of cooling jacket were measured and analyzed under different working conditions. Computational fluid dynamics (CFD) software was utilized to study the fluid flow and the flow field, the pressure field and heat transfer coefficient distribution were analyzed and optimized. The results indicated that the mean flow velocity, average heat transfer coefficient and whole pressure loss of the original cooling jacket were 1.00m/s, 7767W/(m2·K) and 0.027MPa respectively. They met the requirements of engineering design. But the cooling water flow velocity and average heat transfer coefficient between two cylinder bore were non-uniform. There were big swirls in the central region in public cavity and the top region in the second cylinder block water jacket and dead flow region in the bridge of the nose area of the second cylinder head and the local area below two exhaust port. After optimization,the mean flow velocity and average heat transfer coefficient came up to 1.35m/s and 9826W/(m2·K), increased by 35% and 26.5% respectively than the original design. The mean flow velocity of cooling water came up to 1.33m/s,increased by 41.5% and the average heat transfer coefficient was greater than 5000W/(m2·K) in the bridge of the nose area of cylinder head. Compared to the original design, there was no dead flow region, no big swirls existed in new cooling jacket.

Abstract:Use the system identification to get the mathematic model of ratio-control-valve, clamping-force-valve and the clutch-control-valve, and then the CVT ratio response model, engine model and the whole vehicle model were set up by combining the theory and the experimental study. Based on the whole developed model, the hardware-in-the-loop test bench was set up. With the test data of one domestic CVT prototype vehicle taken as the example to verify the developed hardware-in-the-loop test system, comparative results between model response and the real vehicle prototype response show that the developed hardware-in-the-loop test bench can reflect all the characteristics of CVT vehicle. Therefore, the proposed hardware-in-the-loop test bench can be used for developing control strategy and diagnostic system.

Abstract:With the aim to establish the relationship between soil surface porosity and surface roughness,a fractal analysis procedure based on 3-D surface area calculation was proposed, which applied a surface unit to cover the soil roughness characteristics. Using the soil surface unevenness data measured by a laser profiler, the method could derive the fractal dimension of soil surface directly (D∈[ 2,3)). Furthermore, 3-D surface area method was also introduced into multi-fractal spectrum analysis for investigating fine scale information. The statistical analysis demonstrates that fractal dimension Dl, Dr, and multi-fractal parameters α|fmax, Δα can reflect the change process of soil surface roughness effectively regardless the influence of different tillage types. In this case, α|fmax fitted a linear relation to porosity with the value of R2= 0.7014, which showed potential to be a meaningful indictor for surface porosity estimation.

Abstract:A detailed analysis was provided based on the port impedance theory. The relationship between probe length and impedance characteristics of soil moisture sensors as terminal open or terminal short was deduced. With the aim to verify the theoretical conclusion, the simulation method by using high frequency structure simulator software (HFSS) and the experiment associated with several organic solutions as references of known dielectric constants were conducted. After a number of experiments, the result showed that the measuring range of soil moisture sensors as terminal open or terminal short, when probe length was within 0~8.3cm, could be up to 0~100%.

Abstract:The simulative study with discrete element method for the cone penetration into the sandy soil was investigated. The results of the simulations and the tests are in good agreement, and the friction on the cone side surface has little influence on the penetration resistance. The conclusion of DEM shows that the strong force chain is located at the cone tip, where the directions of particle velocities are in disorder, while the particles in other place are almost stabile. The penetration resistance increased as the increase of penetration depth, and the normal pressure on the side wall of the soil bin. However, the penetration velocity has little influence on the penetration resistance.

Abstract:Variations of photosynthesis and chlorophyll fluorescence for winter wheat leaves under limited irrigation were analyzed. Meanwhile stomatal and non-stomatal limitations of photosynthesis in winter wheat under limited irrigation were also discussed. The results indicate that mild limited irrigation does not significantly affect photosynthesis and chlorophyll fluorescence. At the flowering and early grain filling stages, stomatal limitation resulted from moderate and severe limited irrigation is the major factor resulting in the reduction of photosynthesis rate. However, at the late grain filling stage, the maximum photochemical efficiency of photosystem II is significantly reduced due to moderate and severe limited irrigation, and non-stomatal limitation becomes the major factor in reducing the photosynthesis rate. 

Abstract:With the aim to evaluate the influence of soil hardness to corn growth and calcium absorption, five levels of soil hardness (soil bulk density: 1.1, 1.2, 1.3, 1.4 and 1.5g/cm3) were established in the pot experiment. There was no significant influence of soil hardness to corn growth in the first 15d after seeding, however, it inhibited aboveground corn growth in the following days. Root dry mass and activity both decreased because of the high soil hardness which had a negative effect on calcium absorption. The highest calcium content (1.67%) occurred in the treatment with 1.2g/cm3 soil hardness. The increase of soil hardness caused root activity decrease which led to the decrease of calcium absorption, thus, lower crop resistance to disease and cause in senescence in advance. It was concluded that too high or too low density of soil bulk was disadvantage to the crop growth.

Abstract:Based on the results from 18-year long-term location experiment in dryland experimental area of northern China, the effects of various kinds of straw return to field such as no straw returning (CK), straw mulching (SM), straw crushing (SC), cattle manure (CM) and different fertilization time i.e. spring and autumn on corn yield and water use efficiency were studied. The results showed that the experiment of combining autumn fertilizing with returning stalks to field could increase the yield and water use efficiency of spring maize significantly compared to the spring fertilizing, meanwhile, it decreased the accumulated water consumption and increased the soil water storage amount. The results showed that autumn fertilizing increased 9.71～15.58t/hm2 in yield, compared with spring fertilizing. The range of increased in yield was 8.33%～16.19%. The total corn yield and water use efficiency in the past 18-year decreased in the following order: CM＞SM＞SC＞CK. In different rainfall years, the corn yield and water use efficiency were very different. In normal years, the corn yield was highest. In dry years, the water use efficiency of spring maize was highest and yield increasing effect from straw mulching combining with autumn fertilizing was striking. 

Abstract:In order to study erosion rule of engineering slope runoff and provide scientific and theoretical basis for control of water and soil loss of slope in Pisha sandstone region, the hydrodynamic characteristics of slope runoff under the different EN—1 soil stabilizer contents, curing ages and compaction degrees treated with soil stabilizer were studied by using indoor runoff scouring experiment. The results showed that flow velocity of slope runoff of Pisha sandstone stabilized soil increased with the increase of soil stabilizer contents, curing ages and compaction degrees under the soil stabilizer contents, curing ages and compaction degrees in this experiment and it had a fluctuant and decreased tendency with scouring time. The Reynolds number (Re) of slope runoff decreased with the increase of soil stabilizer contents, curing ages and compaction degrees and it had a fluctuant and increased tendency with scouring time. The Froude number (Fr) of slope flow runoff had the opposite trends. The flow regimes were turbulent flow and subcritical flow when scouring proceeded to the later period at smaller compaction degrees. The flow regimes were all laminar flow and supercritical flow at the other treatments. The Darcy—Weisbach drag coefficient (f) of slope runoff decreased with the increase of soil stabilizer contents, curing ages and compaction degrees, and had a positive correlation with sediment transport rate.

Abstract:To overcome the poor hydraulic performance problem of impact sprinkler when operating at low pressure, a program of modifying the shape of outlet nozzle was put forward. It was used to reduce the droplet impact strength and improve the uniformity coefficient. Impact sprinkler typed PY115 was chosen and three improved nozzles were designed. One, two or three notches were to be added in the outlet nozzle, respectively. All the notches were 0.5 mm in width and 0.3 mm in height and they were set at bottom, left or right side of the outlet nozzle. Experiments were carried out under the low operating pressure of 200kPa. When the rectangular spaces were 13m to 18m, Matlab was used to establish a program to simulate the hydraulic performances. The results showed that with the increase in the number of notches, the flow-rate increased, the wetted radius were shortened by 8.1% to 9.4%, the reduced coefficient of droplet diameter was 2.9% to 6.8%, the average irrigated intensity increased and complied with national requirement. The combined uniformity coefficient was improved for all the improved nozzles. The effect was more obvious when three notches were added in the outlet nozzle and the maximal uniformity coefficient can be more than 90％. Modifying nozzle shape was proved to be an available program as a result.

Abstract:In order to understand the flow pattern of salt-out particles in a vortex pump, PIV was adopted to measure the particle flow field. The quasi three dimensions velocity field of the particles was obtained. The particle flow characteristics were primarily known under several running conditions. It is indicated that velocity distributions are obviously different on various axial sections in the impeller. The forced and free vortexes were both existed in the vaneless volute. When the pump flow rate increased, particle relative flow velocity increased at the impeller inlet, as well as the relative flow angle at the impeller outlet. Near the small radius area of vaneless volute, radial velocity component increased with the flow rate changed. There is also portrait vortex of particle flow, and the vortex center is located around the centre of impeller flow passage. It is almost no change with the flow rate.

Abstract:In order to rebuild 3D models of pump impeller, ICT fault images in high quality of two typical impellers were collected at first, and format conversion from RAW to BMP was fulfilled though a developed program. On the platform of VC++ 6.0, MFC, OpenGL, ADO were used, and with the technologies of fault images pre-processing, 2D image processing and 2D geometric processing, noise to these images was removed and image definition was greatly improved. Development tools like 3D model in surface were reconstructed, transformation from surface model to solid model was also realized by triangular facets and B—Rep model. Living rebuilt examples fulfilled on ReImpeller3D showed that the way of reconstruction can supply geometrical models for numerical simulation, FEM, RP, digitized production, and optimization design, so it is feasible to use ICT fault images to rebuild 3D models of the impellers.

Abstract:Described herein are the principles for automatically arranging, and separating granules via an inclined turntable, the foundations of which have been established through the design and manufacture of a turntable-inclined scratch style photoelectric apparatus that can count granules or weigh up to 1000 of them. The unorganized granules enter an inclined trough and onto a turntable, the bottom of which automatically migrates, sorts and arranges the granules into space from each other, to get the reliable light-trough gaps, at which point a photoelectric apparatus accurately preset, counts and verifies the collection of granules. This type of instrument provides several advantages over other designs: the counting mechanism is extremely precise, for every round, the preset counting error is less than 1~2 granules, and the re-examination counting error rate is less than 0.04%; the counting speed is as high as 30~50 granules per second; the valid range of diameters is from 0.5 mm to 18mm; no seed damage was found during tests; the simple and reliable structure enables no electromagnetic vibration or noise; and the principles underlying the device have a wide range of potential applications beyond precise counting and sorting granules, especially for some devises with no-damage counting.

Abstract:Energy analysis was applied to evaluate three typical straw-based power generation systems: 1MW gasification and power generation system, 5.5MW gasification and power generation system, and 25MW combustion and power generation system. Based on the concepts of energy costs and energy benefits, two indicators were employed: environmental yield ratio (EYR) and net energy. The results show that the 5.5MW system is the most efficient one in recovering energy from straw (the highest EYR) and is capable of saving the greatest quantity of energy per MJ of straw used (the highest net energy); the 1MW system is the best one in terms of energy costs, but the worst in terms of energy benefits. Compared with the 1MW system, the 25MW system has a lower EYR but higher net energy.

Abstract:Pyrolytic lignin was separated from bio-oil. The structure and pyrolysis characteristics of pyrolytic lignin were compared with an alkali lignin. The content of main elements in two kinds of lignin was the same level, but the content of carbon was higher and the content of oxygen was lower in pyrolytic lignin compared with alkali lignin. It was shown that alcoholic hydroxyl group in pyrolytic lignin was less than alkali lignin with Fourier transform infrared spectroscopy(FTIR) analysis. Thermogravimetric analysis (TGA) revealed that the rate of weight loss of pyrolytic lignin was quicker at low temperature and the thermal stability was worse compared with alkali lignin. It was observed that the composition of pyrolysis products of two kinds of lignin was largely different by the experiments of pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The contents of aromatic compounds in pyrolysis products of pyrolytic lignin were both higher than alkali lignin at two temperatures. The main components in pyrolysis products of alkali lignin were alcohols, while the content of aromatic compounds was low at 250℃. However the content of aromatic compounds in pyrolysis products of alkali lignin increased at 550 ℃, the content of alcohols decreased, and large numbers of acetone were formed.

Abstract:The preparation of nanocrystalline cellulose using crops and agricultural residues has attracted wide attention recently. The primary composition of agricultural fibers was introduced. Research progress of nanocrystalline cellulose prepared from crops and agricultural residues was reviewed in terms of raw material kinds, preparation method, properties and application of nanocrystalline cellulose. The main problems in terms of dimensional measurement, surface modification, preparation technology and application were analyzed. The corresponding solution ways were put forward. The preparation of nanocrystalline cellulose is a high value-added application for crops and agricultural residues.

Abstract:The design principle of automatic high hydrostatic pressure equipment, its structural characteristics and major technical difficulties were introduced. The structure and the optimum parameters of high pressure intensifier, check valve, relief valve, sealing system and temperature sensor system were studied and confirmed. The results of performance test prove that it has the advantages of reasonable structure, easy operation, steady performance and reliable security. Furthermore, several batches of fresh peach juice were processed by using this equipment, and the results showed that commercial sterilization was achieved after treated by HHP at 600MPa for 5min.

Abstract:Twelve kinds of semi-empirical and empirical mathematical drying models were analyzed. Using experimental data of the heat pump cabbage seeds drying from the finding references, the twelve kinds of drying models have been studied according to the considerations or no considerations of dry air’s temperature and relative humidity. Four statistical indexes including coefficient of determination R2, root mean square error ERMS, reduced mean square of the deviation χ2, mean relative percent deviation EMD, have been used as the criterion for selection and analysis of different models. Results showed that after considering influences of both temperature and humidity of dry air, most of the twelve models have higher R2, lower χ2, ERMS and EMD. The models of modified Henderson and Pabis, Midilli et al and Two-term exponential are more accurate than others.

Abstract:The catalytic removal function and mechanism of ultrasonic treatment coupling with TiO2 on pyrethroid pesticides in apple juice were investigated, the main quality change of apple juice and mechanism of catalytic removal were researched. The response surface method was applied to optimize the process parameters and the results were as follows: the TiO2 amount was 0.5g／L, the ultrasonic power was 416W, the treatment time was 18min, the ultrasonic temperature was 37℃. Under this condition, the removal rate would reach to 62.17%. The main chemical and physical indexes of apple juice processed by ultrasonic treatment coupling with TiO2 have no significant change, all accord with the export standards of apple juice.

Abstract:Ultrasound-phosphorylation was used to modify soybean proteins to improve the emulsification property. Based on the single factor experiments, technology was established and optimized by central composite design theory of Box-Behnken. The response model was valid in analyzing and predicting the extent of EAI due to its higher fitting degree and less experimental error. The effect on emulsifying properties of soybean proteins modified by ultrasound-chemistry phosphorylation (UP—SP) were analyzed, and the optimized conditions of preparation of UP—SP were as follows: STP 9.65%, ultrasound power 490 W,and time of reaction 34 min, then the emulsifying activity and emulsion stability of UP—SP, were 70.8 and 30.2min, 2.18 and 1.57 fold against control experiment respectively. The results show that ultrasound-phosphorylation is an efficient method to improve the emulsification properties of soybean proteins.

Abstract:In order to establish a kinetics model on pulsed ultrasound-assisted extraction of protein and polysaccharide from defatted rice bran, protein and polysaccharide concentration changes in the extracting solution were determined in the experiments. The results of the experiment have established a second-order kinetics models on pulsed ultrasound-assisted extraction for both protein and polysaccharide from defatted rice bran. The study showed that the extracting temperature had a remarkable effect on protein and polysaccharide leaching. There was a sharp increase in concentration of protein in the extracting solution when the extracting temperature reached 45℃ whiles the sharp increase in concentration for polysaccharide occurred at 50℃. There was a linear increase in protein equilibrium concentration as the extracting temperature increased. The equilibrium concentration of the polysaccharide in the extracting solution increased sharply beyond 45℃. The initial extracting rate of protein and polysaccharide initially showed a downward trend and then began to increase.

Abstract:With the aim to optimize the technology parameter of subcritical water extracting protein from rice bran, the single factor and orthogonal experiments were conducted by taking protein yield as index, and the function characteristics of protein from rice bran were studied. The results were as follows: the ratio of protein in the extracts was 55.9% at 8.0MPa, pH value 9.0, 200℃ for 25min with the liquid-solid ratio of 15mL/g, the emulsion activity index of rice bran protein was 119.8mL/g, and the emulsion stability indicator was 81.3min; the foamability and the stability of foam were 71.5% and 37.4% respectively; the water/oil absorption and the solubility were 5.6%, 3.7% and 68.4% respectively. The extract time and the protein yield of rice bran extracted by the methods of alkaline water and ultrasonic assisted alkaline water were 120min, 35.6%, and 30min, 48.1% respectively. Compared with the previous two methods, subcritical water extracting protein from rice bran has obvious advantage in saving time and extraction ratio.

Abstract:Changes in volatile compounds during aging process of yak meat were determined by HS-SPME and GC/MS. The results showed that 54, 58, 63 kinds of volatile compounds were detected 0d, 3d, 8d during aging process respectively. Volatiles from the Maillard reaction, which enhanced characteristic flavor of yak meat, increased during aging process, among them content of 3-hydroxyl-2-butanone, 2-methyl-3-furanthiol and 2-methylbutanal after 8d of aging markedly increased by 183.17%, 128.40% and 190.10% respectively compared to those at 0d of aging. While volatile components formed through lipid oxidation which reduced fatty flavor of yak meat such as aldehydes decreased during aging process; meanwhile volatile compounds from herbage decreased by 20.30%. 

Abstract:A kind of unsupervised segmentation processing method based on parallelized firing PCNN algorithm was proposed. The color images of corn disease were segmented by improved parallelized firing PCNN which the normalized L+U as external stimulus input, the integrated information of the geometric distance and the color difference between neighboring pixels as the PCNN coupling value, the minimum color contrast of color vector as the criteria of the best segmentation results, in parallel with improved disease of maize PCNN to segment color images. The segmentation experiments which 100 images of four kinds of diseases showed that the method could better segment the diseased regions with high fitness and low complexity parameters.

Abstract:In order to avoid damaging apples and branches caused by manipulator during the picking operation, for the absence of attitude information, an apple’s attitude estimation method was put forward. After the apple object was segmented from background with the two-step algorithm based on the characters of color and texture, the freeman chain code algorithm was used to extract one-pixel fruit contour. Then least distance method, least slope variance method and three collinear points’ method were given, and the recognition rates of three methods were compared. At last, for the purpose of improving recognition rate, decision method based on fusion of four methods was proposed. The research results showed that the recognition rates by using four methods were higher than using any one of methods separately, and the right recognition rate could reach to 90%.

Abstract:Corn root is separated into a series of root elements. According to the statistical measured parameters, the random 3-D model of corn root was constituted based on coordinate transformation. In the model building, the measured data was fitted to NURBS curve, shape and surface of the model were expressed by NURBS curve and NURBS surface respectively. Matlab and 3-D CAD software were used as main tools. The model was saved in IGES file format which can be import into 3-D CAD software and FEA software for further analysis of mechanical properties of the corn root. The corn root modeling method is different in principle from the other existed methods and has great significance for mechanical analysis of the root system in the crop root treatment, plants reinforcement of soil and etc.

Abstract:According to the low accuracy and low stability of the single feature-based method for weed recognition, a multi-feature fusion method based on SVM and D—S evidence theory was proposed. Firstly, three types of visual features such as color, shape and texture were extracted from the plant leaves after a series of image processing. Then, the plants were classified according to each type of features utilizing SVM and the results were used as evidences to construct the basic probability assignment (BPA). Finally, using D—S combination rule of evidence to achieve the decision fusion and giving final recognition results by classification thresholds. The experimental results show that the accuracy of multi-feature fusion method is over 97% and it has good performance on accuracy and stability compared to the single feature-based method in weed recognition.

Abstract:In order to solve the problems encountered in analyzing crop nitrogen concentration by chemical methods, such as high cost, long and complicated process, etc., a new four-waveband crop canopy analyzer was developed based on optical principle to obtain some vegetation indices to evaluate the crop growth status. The analyzer was designed to work as a wireless sensor network with a control unit and a measuring unit. As the coordinator of the whole wireless network, the controller was used to receive, display and store all the data sent from different sensor nodes. The measuring unit which consisted of several optical sensors was designed to collect, amplify and transmit the optical signals. Each sensor node contained four optical channels, which allowed the instrument work at the wavebands of 550nm, 650nm, 766nm and 850nm. Calibration test was conducted and the result showed a good performance. An experiment in maize field was also performed, and the correlation between measured N and predicted N in crop leaves had high significance with R of 0.884. Those results showed the potential of the instrument in crop nutrition level diagnosis.

Abstract:In order to obtain the optimum red edge parameters for using rapid detection of the lettuce leaf nitrogen content, the response feature of red edge parameters for leaf spectra under different nitrogen levels and the relationship between red edge parameters and leaf nitrogen contents were investigated. Visible and near infrared (Vis—NIR) spectroradiometer was used to collect the leaves’ spectral data of water culture lettuce, and the chlorophyll meter (SPAD 502) was used to measure the leaf chlorophyll content. Red edge parameters, which included red edge position (λred), red edge area (Sred), red edge differential (Dλred), the minimum of red edge differential (Dλmin) and the ratio of Dλred to Dλmin (Dλred/Dλmin), were calculated based on the first derivative reflectance spectra in the red edge region. The results showed that the dynamic characteristics of red edge parameters changed with different nitrogen nutrition levels in water culture. It was concluded that λred, Dλmin,Sred and Dλred/Dλmin had significant relationship with the leaf chlorophyll content, respectively. In all red edge parameters, the correlation degree of λred was the highest with correlation coefficient 0.9420. And the root mean squared error was the lowest with 1.803. Therefore, it was demonstrated thatλred could be a predictor for lettuce leaf nitrogen content.

Abstract:A kind of portable device for measuring concentration of pesticides used with enzyme sensor was designed. It included screen-printed enzyme electrode, signal conditioning circuit and MCU C8051F040. The preparation of enzyme electrode made the coated resistance of charge transfer reduced, charge transfer accelerated; and a reliable liner relationship between the inhibition of enzyme and log ［carbaryl］ was obtained from 5ng/mL to 2μg/mL, with the detection limitation of 1.7ng/mL. Response time of the device was less than 161s. The size of the device was small and the power was supported by battery. It provided a portable device for rapid measuring and spotty concentration of pesticide in μg/L level.

Abstract:A dynamic process management approach based on conditional design structural matrix was proposed. Considering the possibility of the conditional constraints during the design process, the conditional constraint model was constructed based on the references of the design knowledge and condition parameters, the conditional knowledge dimension was brought into the traditional DSM model, and then the 3D conditional DSM model was obtained. Using the dynamical superimposed conditional DSM view in the model mentioned above, the consequence of the reconstruction in the design process could be reconstructed again and again. The approach presented was finally used in the general variant design system supporting the vehicle CVJ shafts design process modeling, an example was provided and the results demonstrated the higher efficiency and automation degree of the approach presented.

Abstract:The target working space of bionic eye was firstly determined. The worst dexterity for bionic eye with the maximum condition number of Jacobian matrix was defined. Then, a differential evolution (DE) algorithm was used to optimize the maximum of the worst dexterity index. Dynamic scaling factor was determined according to the overcome premature evolution and enhance the probability of finding global optimum. Reasonable structural parameters were chosen in the case of satisfying the special requirements of bionic eye structure and making arbitrary posture dexterity of target working space better. Finally, the experimental results show that bionic eye with the optimized parameters are good coinciding with the design requirements.

Abstract:Focused on the similarity between the kinematics of decoupled parallel mechanism and serial mechanism, a unique method of structural synthesis was presented, which was used to synthesize the decoupled parallel mechanism. The kinematic chains of decoupled parallel mechanism were consisted of by the basic kinematic chain and the driven-chains. The structural condition of decoupled spherical parallel mechanism was deduced, and a series of novel spherical parallel mechanism were synthesized. The kinematics analysis verified that the mechanism had three fully decoupled rotational DOFs, and each rotational DOF was driven by a single actuator.

Abstract:A systemic methodology for structural synthesis of fully-isotropic two-translational and one-rotational (2T1R) spatial parallel robotic manipulators was proposed. According to the prescribed characteristics of each mechanism limb, the actuation screws, actuated screws and mobile unactuated screws of every limb were confirmed at first based on the reciprocal screw theory. Then the structural synthesis of each kinematic chain for fully-isotropic 2T1R spatial parallel robotic manipulators was performed in the light of different connectivity of the limbs. Finally, the anticipant manipulators were synthesized by connecting the moving platforms to the fixed bases and a lot of new mechanisms were attained. Kinematical analysis about one of manipulators designed here showed that the method is reasonable and correct. The kinematic Jacobian of the mechanism is an identical matrix, so it performed very well with regard to motion and force transmissions.

Abstract:An accurate and simple method for dynamic modeling of general flexible parallel robot was proposed. According to the structural character of the parallel robot, it was devided into rigid sub-structure and elastic sub-structure, and the rigid-flexible coupling system was formed. The static platform and mobile platform were treated as rigid sub-structure because its deformations were smaller compared to the other part. The chains were treated as flexible sub-structure. The dynamic equations of each sub-structure were obtained, respectively. The dynamic equations of elastic sub-structure were obtained by using the finite element method and mode synthesis method. The dynamic equations of rigid sub-structure were built accounting for the effects of deformation of flexible sub-structure. The geometrical constraint relationship between three flexible sub-structures and the rigid platform was investigated to obtain a simple displacement and dynamic relation between them. The equations of all sub-structure were assembled to get the system dynamic equations. The comparative analysis of dynamic characteristics of a high-speed parallel manipulator show that the method is correct and feasible. Due to introducing the rigid sub-structure and application of the mode synthesis, the number of system freedom was reduced and the computational modeling was simplified. It provided a practical method for flexible parallel robot.

Abstract:Base on the space engagement theory, a design method of eccentric—high order elliptical bevel gear pair was presented, the mathematical model of eccentric—high order elliptical bevel gear drive was established, pitch cone and spherical pitch curve of the eccentric elliptical bevel gear and the high order elliptical bevel gear were derived; the position of the cutter in the space during tooth profile of eccentric—high order elliptical bevel gear was generated analyzed. Secondary development based on Solidworks (API) and VB, which made the pseudoentity and assembly model of eccentric—high order elliptical bevel gear pair was obtained; and then the transmission characteristics of eccentric—high order elliptical bevel gear pair was analyzed，the change laws of eccentric—high order elliptical bevel gear pair, angular velocity and angular acceleration of driven wheel during the transmission were acquired.

Abstract:Based on the moving least squares method, a method for extracting feature curves from point clouds was presented. Firstly the algorithm calculated projection residuals and potential feature points were identified in point cloud model. The potential feature points were then smoothed by employing a modified version of the principal component analysis approach. Subsequently, a feature-polyline propagation technique was used to approximate the feature points by a set of polylines. Finally the feature curves were optimized by the algorithm to resolve gaps and recover the junctions. Experiments show that the algorithm is very robust, and it can extract feature curves from various point clouds.

Abstract:A 3-D coordinate measuring machine (CMM) touch trigger probe based on fiber Bragg gratings was developed. The sensing system and the control box of the probe were described respectively. The error of the probe may arise from the mechanical structure, the sensing signal demodulation system, the measuring speed and the approaching distance during the process. Experiments showed that probe positioning accuracy in single direction could reach 20nm, sensitivity came up to 50nm and a measuring force was less than 5mN. 

Abstract:Focusing on the problems existing in the biochip microarray manufacturing methods such as low maintenance in bioactivity, microjet head blockage and high consumption in biological reagent and so on, the ultrasonic transducer and spherical acoustic lens based on ultrasonic focusing microjet head as well as the downward isolated jetting mechanism was designed. Based on this, no nozzle, non blockage, non contact, low consumption and high accuracy was gained in the microarray manufacture. To verify the biocompatibility of the microjet system, the F0F1—ATP molecular-motor assembled liposome microarrays with regular shape and accurate location was prepared. Furthermore, the ATP hydrolysis activity and the ATP synthesis activity of the liposome microarrays were tested respectively. Experimental results indicated that the liposome microarrays fabricated this way showed favorable ATP hydrolysis activity and synthesis activity, which confirmed that the ultrasonic focusing microjet method has favorable biocompatibility in manufacturing biological microarrays. The investigation elaborated here explored a new manufacturing approach for biological microarrays.