Abstract:On the integrated optimization plat, the workflow of intake system optimization was constructed based on Boost which is the software of engine cycle simulation. The model was verified by experiments. At the declared speed, the design variables are geometric parameters (intake pipe length, pipe diameter, volume of resonator ) and spark advanced angle, AF rate. The engine torque and fuel consumption rate were optimized by using the DOE tests. The results showed that the length of intake pipes has a special influence on full load velocity characteristic of engine. The workflow provides an efficient method to intake system optimization.

Abstract:The performance of stream reforming for rich hydrogen co-gas by dimethyl-ether (DME）was experimental studied. The multiunit catalyst which was formed with copper-based catalyst (named CNZ—1) and aluminium/zinc based molecular sieve (named HZSM—5) by means of mechanical mixing, was used. The parameters such as flow rate of reactants including water steam and DME, the reaction temperature as well as the catalyst amount influence on the reforming performance were investigated. Results show that under normal pressure, when DME flow rate increases, the yield of hydrogen increases at the beginning and then decreases. At the range from 250℃ to 500℃, the production rate of hydrogen increases with the increasing of temperature, and the maximum conversion rate of DME almost reaches 100%; the volume fraction of carbon monoxide decreases as the reaction temperature rises; although larger amount of catalyst has no influences on hydrogen production rate under the test conditions, it can improve effectively the conversion rate of DME.

Abstract:The formation processes of fuel spray of Stirling engine under different back pressure were investigated by using high-speed camera. And the influence of several parameters, such as back pressure in the combustion chamber, the flow-rate as well as the diameter of spiral channel, on the spray performance was analyzed. Results showed that: back pressure has great impact on the formation process of fuel spray; the fuel penetration and spray angle increase with the increase of fuel flow rate; the penetration increases and the spray angle decreases as the back pressure in the combustion chamber increases; at the same flow rate, with the increase of diameter of spiral channel, the penetration increases while the spray angle decreases.

Abstract:For a V-type six-cylinder supercharged diesel engine, the transient engine speed and the pressure in each cylinder were measured under different engine speeds and loads. The correlation between the fluctuations of transient engine speed and the combustion nonuniformity of the six cylinders were analyzed. The results indicated that a wave peak of transient engine speed emerges at the point between the two peaks of cylinder pressure of two adjacent fired cylinders. And, the more the output of positive work is in one cylinder, the larger the subsequent peak value of fluctuant engine speed is. When the mean engine speed is constant, the higher the load is, the larger the fluctuation ratio of engine speed is. However, when the load is same, the fluctuation ratio is independent to the mean engine speed.

Abstract:By experimental studies for the single EUP on test bench, the low fuel supply pressures near the EUP and the high pressures in high pressure fuel pipe at different cam speeds were acquired. The high and low pressure curves of the EUP’s cyclic variation circles were analyzed. Test results showed that when the cam shaft speed is very high, the supply pressure instantaneous decreased as the plunger move downward, and the pressure wave which results from the backward flow of high pressure fuel appears in low fuel supply loop. The above two factors cause the negative pressure at low fuel supply loop, and leads to the cyclic variation. Increase in fuel supply pressure and the fuel supply pipe line’s flow area is advantageous in reduction the cyclic variation of EUP. 

Abstract:Cylinder deactivation for automotive engine, to decrease the fuel consumption, has an adverse effect on power-output of engine. The multi-body model of the crank-rod mechanism was created. Based on pressure-volume diagrams and empirical equation, the boundary conditions of the model were analyzed. Three cylinder deactivation modes were given. The simulation under the whole cylinder operation mode and the cylinder deactivation modes were investigated at different load conditions. The results showed that the engine speed fluctuations under the deactivation mode differ from the fluctuations under the whole cylinder operation mode, with respect to operating cylinder load and the firing interval angle.

Abstract:The two non-linear mount simulation models were created by using Matlab software to fit various mount experiment data based on co-simulation. The vibration isolation characteristics of automobile powertrain system was studied under ADAMS software environment along with transmitting data through information exchange interface, and different mounts’vibration isolation performance was analyzed, which could provide research foundation for optimizing analysis and matching of mount system. The results show that the vibration characteristic of powertrain system is closer to actual situation founding on non-linear mount model than on the linear.

Abstract:Power consumption (torque) tests of a single universal blade for rototilling and stubble breaking were conducted in the soil bin, to investigate the influences of the tillage depth and rotary speed of the blade as well as the working speed of the machine on power consumption. The regression equations for the relations between power consumption and the above parameters were established. Soil bin tests indicated that the parameter that had significant influence on power consumption is the rotary speed, next is the tillage depth, and the working speed had less influence. Then the universal blades were mounted on the bionic intelligent rototilling-stubble-breaking machine to perform rototilling and stubble-breaking tests respectively. Field tests showed that the stability of the tillage depth is over 93%, stubble-breaking rate, stubble coverage rate and soil-crushing rate are 81.8%, 87.2%, 87.9% on average, respectively, which meets the agrotechnical requirements.

Abstract:Aimed to the serious problem of soil compaction and grassland degradation on account of long-term grazing overload, a 9ST—460 vibration spacing scarifier for meadow was designed. The loosing soil parts of interval ladder framework were adopted. By the exciting force produced by the vibration system which is composed of connecting rod and crankshaft to loose soil, the high-solid soil was achieved to loose on the condition without damage to grassland vegetation. Experimental results showed that the scarifier has the ideal loosen effect in the forward speed of 1m/s and vibration frequency 10.0Hz. The test showed that the rate of vegetation destruction is 1.6%, tillage depth is 20.01cm, scarification ratio reaches 43.4％, and productivity reaches 0.85hm2/h. The average soil bulk density and the average firmness reduce by 30.0% and 48.8%, respectively after loosing soil. The yield of natural grassland and artificial grassland increases by 73.99% and 68.65%, respectively. The tilled soil forms the spacing cultivated horizon adapting to the growth of grass. The effect is obvious to improve the grassland ecological environment and improve grass production. 

Abstract:Now conservation tillage can not be applied on a large scale in China due to the diversity of region and the various types of this technology. Aiming at the problem, the index system of suitability regionalization for no-tillage which belongs to conservation tillage was developed. And then case study was carried out in Wuchuan County where the ecological environment deteriorated gradually. GIS was applied, combined with such methods as AHP weight, cluster analysis, and so on, to divide Wuchuan County into three parts. Finally, the division results are proved to be reasonable. This will undoubtedly provide some references for the suitability regionalization research of other conservation tillage types. 

Abstract:Now conservation tillage can not be applied on a large scale in China due to the diversity of region and the various types of this technology. Aiming at the problem, the index system of suitability regionalization for no-tillage which belongs to conservation tillage was developed. And then case study was carried out in Wuchuan County where the ecological environment deteriorated gradually. GIS was applied, combined with such methods as AHP weight, cluster analysis, and so on, to divide Wuchuan County into three parts. Finally, the division results are proved to be reasonable. This will undoubtedly provide some references for the suitability regionalization research of other conservation tillage types.

Abstract:Controlled traffic with conservation tillage (CTCT) can reduce soil compaction, thus to improve operation performance of agricultural machine, by separating wheel track and crop zone. The effect of CTCT on operation resistance force was researched in annual two crops region in Northern China. The rolling resistance, opener resistance and total draft between controlled and non-controlled traffic treatments were analyzed. In subsoiling, wheat and maize planting, compared with non-controlled traffic with conservation tillage, CTCT total draft reduced by 14.6%, 13.3% and 13.3%, rolling resistance reduced by 26.9%, 21.9% and 19.7%, averaging 22.9%, working resistance reduced by 7.5%, 7.2% and 12.4%, averaging 8.8%. Opener resistance reduced 22.0% averagely in controlled traffic treatments than that in non-controlled traffic treatments. As the resistance decreased, fuel consumption in controlled traffic treatment reduced by 17.6%, 12.4% and 9.1% in three operations. Results showed that controlled traffic conservation tillage reduces agricultural machine working resistance and fuel consumption in field operation.

Abstract:In order to solve the problem of mass concentration of pesticide fog after application in airtight space, an improved container collecting the air samples was used at different locations in the level of 1.5m from ground, and curved surface of mass concentration of pesticide fog was established based on cubic spline interpolation. It was showed that the pesticide mass concentration attains maximum at 10～12m in the front of the nozzle, and the effective regional of cold aerosol sprayer is 42m, from 10m in the back of the nozzle to 32m in the front of the nozzle, in length; and the pesticide mass concentration was lower in the middle of airtight space than the sides of it, in width. 

Abstract:In order to investigate the droplet distribution of air-assisted orchard sprayer, a model for Hardi LB—255 air-assisted sprayer was developed based on CFD technology. The 2-D boundary and the model variables were defined to correspond to the tested sprayer. The trajectory of air-assisted droplets and the distribution of droplets in different layers were simulated. The relative errors of simulated results could show the droplet distribution accurately with the range less than 240 cm from the fan. 

Abstract:The performance of fine-sucking seed was controlled by the combination mode of the vacuum cylinder (VC) and the vibrating seed plate (VSP) in the precision seedling planting parts for super hybrid rice. The ebullience and vibration of the seed close to VC in VSP were highly correlated with vibration parameters. The sucking-seed capability of VC was measured on conditions of the different seeds thickness and the installation position of vibrator, respectively. In addition, the vibration characteristic of VSP was studied. The results showed that the optimal performance is obtained when the air-style vibrator is at the rear of VSP, and the regular capability of fine-sucking seed depends on the given seeds thickness close to VC and the vibrator’s frequency in harmony. The prime performance comes to 93.118% when the optimum seeds thickness 0.7cm and frequency of vibration 98Hz.

Abstract:Three kinds of anti-blocking mechanism, i.e. powered-chain, powered-disc and strip-rotating, for wheat no-till planting had different performance and adaptability, the passing ability, soil disturbance, fuel consumption, yield, etc., were analysed through field experiment. The experimental results indicated that all the three mechanism have the passing ability when the corn stalk is chopped and returned to the field. But the strip-rotating exceeds the others when 100% corn stalks residue covers the soil surface. Compared with strip-rotating and powered-disc, powered-chain has a less soil disturbance, fuel efficiency, better plant performance and yield. 

Abstract:Aimed to the problem that the transmission axis of the multiple functions of precision seed-drilled appliance is not in the center of the seeddrilled wheel, the new curve for seed pushing wheel was applied, to lower the location of seed pushing wheel, and locate the transmission axis in the center of the seed pushing wheel. Furthermore, the aperture and number of the seed pushing wheel for different seeds were investigated, and the seeds amount of per hole, the rates of broken seeds and the reliability were all measured. The new type precision seed-drilled appliance has been produced, and been applied in multiple types drills successfully in present.

Abstract:Based on the related Pro/E software and the basic principle of forage harvester, the design of a rubbing forage harvester was coordinately combined double-disk saw tooth cutter, forced and sequential feeding device with the wheel-type cutter header. A virtual assembly model had been established, and model machine had been manufactured according to the fitted position. The effects of structure parameters and mobile parameters of cutter on the working performance have been analyzed, and determined reasonable working parameter on the basis of indoor service test. Experimental results show that 4QR type of rubbing forage harvester meets design needs completely, quality silage crops and high productivity.

Abstract:A typical acid hydrolysis residue (AHR) was adopted as material to make char in a tube reactor with low heating rate. Proximate analysis was carried out to show component differences between AHR and the char. The crystal structure and morphology of char samples were characterized by X-ray diffractometry (XRD) and scanning electron microscopy (SEM), and were analyzed to explain changes of CO2 gasification reactivity. The CO2 gasification reactivity of acid hydrolysis residue was studied in the view of the rate of weight loss by a thermal gravimetric analyzer. The results showed carbonization increased as pyrolysis temperature rised, increase of final pyrolysis temperature enhanced the degree of crystallike ordering, and the degree of char deconstruction increased with final pyrolysis temperature increasing. The CO2 gasification reactivity showed a decrease tendency when final pyrolysis temperature increases.

Abstract:A new method was explored to predict the total nutrient content in organic fertilizer products using near-infrared reflectance spectroscopy (NIRS) with linear support vector machine regression (SVR), compared with partial least-squares regression (PLSR). 120 commercial organic fertilizer samples were collected from 22 provinces in China. Spectra of orient and dried (passed 1 mm screen) samples were scanned with a SPECTRUM ONE NTS (PerkinElmer, New Jersey, USA) from 10000 to 4000cm-1,respectively. NIRS—PLSR models for total nutrient in organic fertilizer products samples on orient and dried basis were developed with the following results: the determination coefficient of validation (Rv2), the standard error of prediction (SEP) and RPD (SD/SEP) on orient and dried basis were 0.96, 7.95g/kg,2.47 and 0.93, 8.02g/kg, 3.58, respectively. The validation results of NIRS—SVR model for total nutrient content on dried basis were Rv2 0.93, SEP 7.38g/kg and RPD 3.88.Results showed the feasibility and potential of NIRS to predict total nutrient content in organic fertilizer products, and NIRS-SVR method on dried basis is the best choice.

Abstract:The methodology of life cycle assessment was applied to analyze the primary energy consumption and environmental emissions of biodiesel deriving from residual frying oil, compared with conventional diesel pathway. The conclusions are as follows: fossil energy consumption decreases by 65.7%, especially oil consumption decreases by 91.8%, and the criterion emissions also decreases; the total greenhouse gas emissions decreases by 86.6% with CO2 emission decreasing by 88.1%, according to conversion by means of global warming potential. It fully showed that this kind of biodiesel is an environmental friendly fuel in line with the trend of energy saving and emission reduction.

Abstract:A soft braking system was designed based on the mathematic model of wind turbine braking, and a semi-physical simulation test-bed for wind turbine was really formed. Analog simulation experiment for wind turbine soft braking was performed on the test-bed. Experiment results indicated that, when the wind turbine was regularly stopped, soft braking controls the high-speed switch valve on-off time by means of varying the PWM output of PLC, to adjust brake force through, which can make rotor speed fall down gently and minish the gearbox torque wave. 

Abstract:The effects of different dose UV—C treatments on main physiological and quality parameters of shiitake mushrooms during storage were investigated. The experimental results indicated that 2.0kJ/m2 and 4.0kJ/m2 UV—C treatment significantly inhibits the increase in firmness and malonaldehyde (MDA) contents, delays the decrease in reducing sugar and vitamin C contents, and promotes synthesis and accumulation of flavonoid, therefore maintaining better quality, nutrition and extending the shelf life of shiitake mushrooms compared with the control treatment. The results suggested that UV—C treatment has the potential to apply on extending the shelf life of shiitake mushrooms.

Abstract:The gas permeability coefficients of different material films at 2,4,8 and 20 ℃ were measured by small bags method. The influences of temperature on the gas permeability coefficient and gas permeability coefficient ratio were analyzed. The results suggested that the gas permeability coefficients of films increases with temperature; as the temperature increased, the gas permeability coefficient ratio of LDPE significantly increases, while the gas permeability coefficient ratio of PVC shows different changing trends at the experimental temperature. The relationship between permeability coefficients and temperature well accords with Arrhenius equation, and a linear relationship lies between nature logarithmic of gas permeability coefficient and the reciprocal of temperature.

Abstract:‘Whangkeumbae’ pear was treated with 1-MCP at different levels, along with the control atmosphere and modified atmosphere packing, to study browning inhibition and fresh-keeping. The results showed that gas composition of 3.0% O2 and 0.5% CO2 is suitable for storage of ‘Whangkeumbae’pear, keeping higher firmness, inhabiting black skin completely, reducing core browning index significantly. The concentration of 1.0μL/L 1-MCP induced CO2 injury to fruits stored in control atmosphere. Fruits with 0.5μL/L 1-MCP treatment had good effect of browning inhibition and fresh-keeping, whatever stored in unpacked thick bags or packed thin bags. Application of only packed thick bags applied gains a good modified atmosphere effect, while treatment with 1-MCP results in CO2 injury fruits at different levels.

Abstract:With horse mackerel as experimental material, the temperature distribution and migration characteristic of moisture during fish fillets drying by heat pump dehumidifier (HPD) were studied. The results showed that temperature distribution inside horse mackerel fillets is uniform during the great part of drying periods, and the regular temperature gradient along the direction of fish fillets thickness doesn’t occur. During horse mackerel drying by HPD, an obvious moisture gradient along the direction of thickness of fillets is found with drying temperature and velocity. In the initial stage of drying, drying rate of fish fillets is mainly depended on moisture evaporation. In the next stage of drying, drying rate of fish fillets is mainly depended on moisture diffusion. The moisture migration is mainly controlled by moisture content gradient.

Abstract:A three factors quadratic regression rotation combination design was adopted to study the effect of moisture content of pre-dried carrots, super heated stream temperature and treating time on the specific volume of puffed carrots and product rehydration ratio. Results showed that all the three factors have significant effect. Long treating time increases specific volume of puffed carrots while decreases product rehydration ratio significantly. The optimized result is 23% moisture content of pre-dried carrot, 150℃ puffing temperature and 50s treating time. Puffing dried carrot at the above condition has small a shrinkage, a high rehydration ratio, and a appropriate hardness. Super heated stream puffing drying has a higher efficiency comparing to hot air drying, which could decrease drying time near 40%.

Abstract:The interior quality of Shanxi ‘Fuji’ apple including soluble solid content (SSC), sugar content (SC), titrated acidity (TC) and firmness was determined by acousto-optic tunable filter (AOTF) near infrared (NIR) apparatus. The dubitable outlier samples were analyzed by Cook values, Mahalanobis, leverage and studentized residual. In order to avoiding falsely estimating outlier samples, twice-detection diagnosis method was applied to keep more valid samples. The estimated number of outlier samples for SSC, SC, TC and firmness were 11, 11, 11 and 6, respectively. After outlier samples elimination, the correlation coefficient (r) of SSC, SC, TC and firmness models were improved from 0.868, 0.791, 0.443, 0.693 to 0.904, 0.849, 0.501, 0.718, respectively. The RMSEC of SSC, SC, TC and firmness were decreased from 0.882 °Brix, 9.213g/L, 0.805g/L, 0.105MPa to 0.733 °Brix, 7.300g/L, 0.687g/L, 0.097MPa，respectively. Moreover, the presented models of apple quality became more robust and stable.

Abstract:An efficient method was presented to select wavelength regions of NIR (near infrared spectroscopy) based on WT(wavelet transform) for building a PLS(partial least squares) calibration model. Wavelet approximation coefficient (WAC) is similar matrix of original NIR. By linking the correlation coefficients of the optimal WAC with original NIR data, a research space with the all combinations of strong correlativity wavelength was selected as final wavelength regions to build a PLS calibration model of NIR. This selecting method considered the influence of density matrix on wavelength selection, filtered wavelet detail coefficient entirely, and avoided the interference of high frequency noise. The running time of building model was reduced enormously so that the final model is of higher accuracy. Compared with other traditional wavelength selecting method, This method is validated in the measurement of rice apparent amylose content by NIR. The apparent amylase content test results showed that the number of wavelengths for building the models can be reduced to 20% of the original method, the calibration model and the prediction precision are greatly improved by wavelet transform algorithm.

Abstract:The rice hardness is one of the most important qualification to scale the rice quality. Nowadays the rice taste meter is employed to detect the rice eating quality, which is NIR-based to beget the controversy about precision. In virtue of the measurement of engineering theory, the design of the automatic measurement of the rice hardness was carried out. The experiments prove that the instrument can detect the rice hardness accurately, with the result consistent with that of the rice taste meter. The simple, accuracy and reliable method has the value of application for the measurement and estimates of the quality of the rice.

Abstract:Damping of a multidimensional vibration isolation device for transporting eggs was discussed. The air cylinder was used as a damper and its coefficient of damping was measured with CNC lathe. The accelerations of up-platform with different coefficients of damping were measured and compared by means of ADAMS simulation and experiments. Studies indicated that it’s inappropriate to design the damping of the device according to the classic amplitude-frequency chart. It was proposed that the damping should be decided according to performance index of transient response of second order system. The conclusion showed that the multidimensional vibration isolation device for transporting eggs isolates vibration present a favorable effect when the damping ratio of 0.707 is adopted for the coefficientof damping of the air cylinder. 

Abstract:Gelatin and arabic gum were used as the wall material to prepare protease microcapsule with freeze drying technique through Box-Behnken design and response surface methodology. The microencapsulated protease were added to cheese to determine the ratios of pH 4.6 soluble nitrogen to total nitrogen and water soluble nitrogen to total nitrogen, as well as of 12% TCA soluble nitrogen to total nitrogen in ripened cheese. SDS—PAGE analysis, texture analysis and scanning electron microscope examination were also employed to analyze ripened cheese. It was shown from the analysis results that the optimum conditions for protease microcapsule preparation is that the concentrations of gelatin and arabic gum are 3.8% and 3.7% respectively, core material (protease) is 6.4mg/(100mL), and microencapsulation efficiency is 93.4%. The ratios of pH 4.6 soluble nitrogen to total nitrogen, water soluble nitrogen to total nitrogen, and 12% TCA soluble nitrogen to total nitrogen in ripened cheese are all increased when protease microcapsule is incorporated in cheese, indicated that degradation of casein into small peptides occurs and lead to the improvement in texture. The microstructure of proteins in cheese was destroyed after 60 days of ripening.

Abstract:Based on single factor experiment, response surface methodology was used and orthogonal experiment was designed to investigate the effect of extruding parameters on soybean oil yield extracted with enzyme-assisted aqueous extraction processing and cellulose degradability after extrusion and expansion. Statistical analysis system (SAS) was employed to establish regression model and interaction of factors was analyzed. Results showed that the optimal total soybean oil yield is 93.02%±0.29% on response surface with the die length of 20mm, moisture of material of 14.5%, rotate speed for screw of 105r/min, and sleeve temperature of 90℃. Furthermore, There existences a optimal cellulose degradability value of 40.28%±0.43% on response surface when die length is 18 mm, moisture of meal is 15%, rotate speed of screw is 100r/min, and sleeve temperature is 95℃. The degree of cellulose degradability has a significant effect on total oil extraction yield during extrusion and expansion period, total oil extracti on yield during extrusion and expansion was not only dependent on cellulose degradability.

Abstract:Bitter almond shell was pyrolyzed to prepare wood vinegar. The vinegar was studied in term of the antibacterial activity, physical characters and the chemical components, to offer the theory base for almond shell wood vinegar used as a botanic antiseptic. Based on pyrolysis theories, wood vinegars were collected rang from 90～170℃, 170～370℃, and 370～500℃ respectively, and refined by standing, adsorptions by charcoal and filtration. Physical and chemical characters were tested. Antibacterial activity of the obtained wood vinegar on germina was also investigated. The results showed that the generating temperature ranges of bitter almond shell wood vinegar is 90～500℃; the maximum amount of the wood vinegar was collected at the range of 170～370℃, which also showed the strongest anti-pathogens activities, the minimum pH and the highest organic acid content. GC/MS analysis showed that the main compositions of wood vinegar collected at 170～370℃ is hydroxybenzenes, organic acids, aldehydes, ketones, alcohols, furans and esters etc. Among all the components examined, the content of acetic acid was the highest (22.41%), next the furfural and the phenol. Based on the preliminary analysis, it was considered that phenols, acetic acid and furfural are the active components of antibacterial activity. 

Abstract:A 3-dimension vision sensor for red Fuji apple harvesting robot was presented. Lasers with sensitive wavelength were selected as active lamp-house according to the reflectance characteristic of apple plant, to scan apple plant under the drive of stepping motors. And recognition of apples depended on laser reflectance difference of plant, positioning of apples was accomplished based on triangulation. ARM7 microchip LPC2114 was used as the CPU, PSD was used as the signal receiving sensor. In order to eliminate the noise of environment, optimal design of circuit and mechanism was considered. The result of experiment indicated that the output signal of system was stable ranging from 150mm to 750mm, with the maximum error of 13mm.

Abstract:An algorithm for walking goal line detection was hereby proposed based on improved randomized Hough transform (RHT) for harvesting robot. A camera was fixed on the top of the combined harvester in order to capture images of farmland scenes in the process of harvesting. By virtue of statistic analysis and edge detection, the target location of walking goal line as well as the optimal points in the straight-line direction were determined according to different color features of harvested areas, non-harvested areas and areas without farmlands respectively. The optimal points selected as the point set, complete line detection was accomplished by applying RHT, which avoids invalid sampling and accumulation in comparison with the traditional algorithm of RHT. Through processing various pictures, it was well proved that the algorithm can effectively detects the linear parameters, with the processing time of about 200ms. 

Abstract:Aimed at the trajectory tracking control problem for the kinematics model of three-wheeled AGV with nonholonomic constraint, a cascade tracking control algorithm was proposed. The algorithm broke the system down into two nonlinear time-varying systems and finally realized the global asymptotic stability of the control system using cascade control method and state derivative feedback control method. Furthermore, the noise problem of state estimation was solved successfully by using a Kalman filter, which improved the localization precision and enhanced the control effectiveness. The designed control algorithm is of strong robustness and generality for kinematics model of other wheeled mobile robots. Computer simulation results showed that the system can be stable in a short time which verifies its effectiveness. 

Abstract:Using the gray image of color difference G-B, Otsu algorithm was employed to segment the images of mature citrus and background. Then the occluded fruits and overlapped fruits were separated by watersheds method with distance transform. Convex hull algorithm was used to repair the occluded regions. Roundness threshold was set to remove the error segmented regions. After the citrus contours were extracted, the contours was fitted by means of the least-squares circle fit with Tukey weight function, and the centroid coordinates and radius were gained. The recognition results of 592 fruits in 87 images showed that the total correct recognition rate is up to 87.2%, and the correct recognition rate of occluded citrus and overlapped citrus are more than 80%. 

Abstract:None of the traditional methods for extracting contour has the good self-adaptive ability. To solve this problem, a method based on ant colony optimization algorithm was presented for extracting seed’s contour in digital image. The digital image was taken as a two-dimensional grid. The seed’s contour was the food for ant. The gradient and direction in the preceding step were the heuristic information which guided the ants to search the real contour together with pheromone intensity. Reasonable heuristic information and pheromone update mechanism was defined to increase the speed of convergence and raise the search ability. The relationship between the parameters in the algorithm was also studied. At last, the acquired images under two different kinds of illuminations were used to test the algorithm. The experiment result showed that the algorithm not only has nice robustness and parallelism, but also has preferable self-adaptive ability, and extract contour more accurately than the traditional methods. 

Abstract:Differential evolution (DE) is one kind of evolution algorithm based on difference of individuals. DE has exhibited good performance on optimization. However, for the high dimension and perplexed function, the algorithm is apt to fall into premature convergence, its performance is strongly influenced by the value of each strategy parameter including scale factor. Therefore, a modified differential evolution algorithm (MDE) was proposed to solve the optimization problems. First, the scale factor was randomly initialized and calculated by chaos each generation, which decreases the participation of user and balances the convergency speed and global optimal capability. Next, disaster factor was introduced to eliminate the individual of a small probability, along with a new individual generating, which can increase the diversity of population and global optimal capability. Simulated results and engineering optimization design example showed that MDE outperforms standard DE in global optimal capability. 

Abstract:A new method was proposed for improving the performance of the Wigner Ville distribution. The WVDs of the subbands gotten by DCHWT (discrete cosine harmonic wavelet transform), was concatenated to obtain an overall WVD, significantly free from the existence of cross-terms was applied to reduce the Gibbs effect from the truncation of the Wigner Ville distribution kernel. Examples of application demonstrated that this proposed method obeys the desirable properties of time-frequency resolution and strikingly reduces cross-terms. This method can realize the simple and fast algorithm through DCT discrete cosine transform and is suitable for joint time-frequency analysis of non-stationary engineering signal.

Abstract:Fault feature was always hidden by strong noise background in rolling element bearing fault signal. Based on morphological undecimated wavelet decomposition (MUWD), a novel approach was proposed to extract rolling element bearing fault feature. MUWD possess both the characteristic of morphological filter in morphology and multiresolution in wavelet transform. Signal length was maintained invariable and information loss could be avoided in MUWD. Multi-scale MUWD was developedbased on the characteristic of impulse feature extraction in difference morphological filter. The method was used to extract impulse feature in bearing fault signal. Experiment results showed that the presented method can achieve a better performance than traditional wavelet packet. MUWD algorithm includes addition, subtraction, maximum and minimum operations, and does not involve multiplication and division. It is suitable for on-line monitoring and fault diagnosis of bearing.

Abstract:Based on the single-opened-chain (SOC) unit theory, a new parallel mechanism with two translational and one rotational（2T1R）degrees of freedom was put forward. First, the degrees of freedom and the motion output characteristic were analyzed, and then both the forward and the inverse analytical solutions of the moving platform’s position were obtained. The singular configurations of the mechanism were also discussed; the change of the position with respect to the pose angle in singular configuration was obtained through programming with Matlab software. All the above analysis provides foundation for the further research on properties and dynamics of the mechanism. 

Abstract:Through the kinematic analysis approach of mechanism with closed loop vector equations, three kinds of link units, including link vector unit, Jacobian unit and Jacobian differentiation unit, were proposed. Since they are only relative to sizes and shapes of link, these units can be programmed with link drawing subprograms together. Using the effect factors, the units were combined together to build Jacobian matrix and differentiation Jacobian matrix of whole mechanism, and a new automated modeling approach to analyzing planar linkages motion was gotten. This paper also discussed general method analyzing closed loops in complex linkages, as well as algorithm for automated modeling and kinematic analysis. Programming the kinematic analysis and testing with many planar linkages showed that the approach is suitable for automated solving kinematics of complex mechanism due to its modular property. 

Abstract:A newly hybrid technique for silicon wafer edge polishing of ultrasonic-vibration and chemical mechanical was presented, and the design, performance testing for the polishing tools, were discussed along with establishment of experimental system for the hybrid polishing. And then, the traditional chemical mechanical polishing, as well as the polishing tool with different forms of ultrasonic vibration was investigated on polish for the edge of silicon wafer. Experimental results showed that in the same polishing condition, the hybrid polishing of ultrasonic-elliptic-vibration and chemical mechanical has a favorable effect to improve wafer edge polishing. As ultrasonic-elliptic-vibration is put in polishing tool, the roughness Ra of silicon wafer polished surface decreases from the traditional polishing method of 0.059μm down to the 0.043μm, material removal increase by 22%, and the polished surface morphology is significantly improved.