Abstract:In order to overcome the shortage of the previous model of EPS, the dynamic model for steering system in steering and aligning condition was established, based on the combination of tire model of parking steer and 7 degree-of-freedom vehicle model with Doguff tyre model. For obtaining the characteristic of vehicle steering moment and return ability, the steer torque and return ability of manual steering system was analyzed at all operating conditions. The simulation result and road test showed the model built can accurately describe steering torque and return ability well and truly. Finally, a control strategy for controlling power assistant and self-align was framed based on sliding mode control theory (SMC). The simulation result and road test showed the sliding mode control strategy based on the model improved the steering easiness and vehicle self-align capability effectively. 

Abstract:A modeling method for virtual prototyping models of hydrodynamic torque converter with locked function, shifting clutch and vehicle transmission system was presented, and dynamics models were also established by analyzing the models based on the configuration and the principle of a hydro-mechanical transmission system widely used in vehicle transmission, to predict the performance of vehicle transmission system in design phrases. The virtual prototyping models were validated by the power input character and operating manner of start process test. Contrast of the simulation and test results shows that the virtual prototyping model is correct, reasonable and has higher accuracy. 

Abstract:The temperature change processes of functioning parts of the united braking system consist of eddy-current retarder and primary brakes were analyzed to put forward the optimal function for the braking force distribution of the united braking system, and the value of the braking force distribution parameter was suggested. The braking process simulation of an actual passenger car on a virtual multi-gradient ramp was carried out, and the results showed that the final temperature of eddy-current retarder rotor and disc brakes and drum brakes of the united braking force with optimal distribution parameter is relatively low, and varies in a uniform trend. The optimal result of braking force distribution parameter can be refered to for the engineering practice requirements.

Abstract:Based on the relationship between braking performance of permanent magnet type eddy current retarder and structure parameters, the method of uniform design and regression analysis were applied to sensitivity analysis on influence factors for braking performance of permanent magnet type eddy current retarder. The regressive models of braking torque were established concerning inside radius of rotor, circumferential length of permanent magnet, width of air-gap, axial width of rotor influenced and height of permanent magnet, the influences of structure parameters and it’s interaction of permanent magnet type eddy current retarder on braking performance were studied systematically. Based on the result of uniform experimental design and sensitivity analysis, structure parameters were optimized by means of whole-arrangement method. The conclusion can be used in the option design, enhance braking torque and improved braking performance of permanent magnet type eddy current retarder. 

Abstract:A research method of modeling hydro-pneumatic spring mechanical characteristic was presented. According to the calculation method of the sectional linear speed characteristic, the structural parameters of damping valve at the valve open point and the maximal valve open point, such as aperture width, predeformation of slice and positive retainer ring, were designed respectively by using sheet mechanics theory and fluid mechanics theory. The elastic force of hydro-pneumatic spring was deduced by the modified perfect gas equation. The correctness of the design method was validated through the comparison between performance test and simulation data. Eventually, the influence rules of different cylinder bodies and physical parameters on the speed characteristic of hydro-pneumatic spring were programmed and analyzed so as to provide reference for the research on the internal characteristic of damping equipment. 

Abstract:A coupled method based on numerical computation of heat transfer and experimental analysis was presented to estimate thermal loads on seals of the transmission. According to the working conditions of sealing rings, the transfer rule in the sealing system was investigated. Then the method to calculate the frictional heating of seal end face was put forward. Selecting reasonably boundary conditions on seal and simulating the actual operations of transmission, thermal responses such as temperature field and distribution, thermal deformation, and their variable curves between pressure and rotating speed were obtained by numerical computation of heat transfer. An experimental investigation was performed in the dynamic sealing performance test rig, by comparison of numerical and experimental results to enable an assessment of the accuracy level. Experimental results indicated that the predicted data agree well with test data. This estimation method can accord with the actual working mode, and has excellent reliability to predict sealing performances under thermal loads. 

Abstract:A new approach to realize the wheel-soil interaction simulation was proposed which applied the large-scale multibody contact problem and vehicle terramechanics theory. Using this method, we developed a wheel-soil simulation module in self-developed multibody dynamics simulation platform. Based on modeling of soil and wheel-soil contact, the computational implementation for wheel sinkage was depicted in detail. According to records, it needs only 20 min to simulate the motion of wheel-soil testbed system about 30?s on a microcomputer with general configuration. Under similar conditions simulation and experimental results have good consistency. This indicates that the simulation algorithm could meet the requirement of off-road driving simulation.

Abstract:Medium-small no-till wheat planter hasn’t already satisfy power need with the development of high-power tractor in the Mongolia and Sinkiang large farms, which restricted the application of conservation tillage. Therefore, it is necessary to study the large no-till planter matching with high-power tractor. Adopted the controlled flume dense dentiform seed meter to perform precision metering, the 2BMG-24 no-till wheat planter was designed. Furthermore, the wavy disc coulters were used to cut stubble for sowing, and the double disc coulters were used to open furrow for fertilizing. The results of field test showed that the eligibility ratio of seed depth, the variance coefficient of metering equality and the seed damaged rate were 91%, 28% and 0.1%, respectively. The operating performance of this machine was equal to that of the overseas machines. At the same time, the cost was much lower than them, reduced by 60%～70%. Its application can save 16 kg/hm2 fuels and increase 15%～20% incomes. Thus, the 2BMG-24 no-till wheat planter can meet with the need of large farms, which is an indispensable equipment for the development of the China conservation tillage.

Abstract:This paper put forward the new anti-blocking principle combining residue-throwing by powered-chain finger and residue-cutting by knife type opener, and designed the powered chain anti-blocking mechanism for no-till planter according to the problem of residue blocking of no-till wheat planting in heavy corn residue cover fields in annual double cropping areas of North China plain. Furthermore, the key parameters for powered-chain, chain finger and knife type opener were determined based on the analyses of the movement of anti-blocking mechanism. The field experiment showed that the powered-chain anti-blocking mechanism could solve the residue blocking effectively, so as to ensure the passing of wheat no-till planter. Through real-time clearing of corn residues before the knife type opener, 12.3% of opening force was decreased. Compared with the strip roto-tilling wheat planter, the powered-chain wheat no-till planter could not only seed and fertilize at the suitable depths, but also decrease soil disturbance and fuel consumption by 66.4% and 8.07%, respectively, which indicates that this new planter can meet the requirements of agronomy in North China plain. 

Abstract:It is difficult to extend the conservation tillage in ridge-till areas nowadays, because of lack of no-till planter, which can work on the permanent ridge stably with corn stubble, and have anti-blocking ability and good planting quality. The 2BML-2 ridge-till and no-till planter was been designed on the base of low-bandwidth rotary tillage. Field test of fuel consumption was carried through. The result showed: when the parameters of openers, cover and press disks are invariable, the depth of rotary till is the most important factor, and the width of rotary is the second one, then is the approaching speed; in the range of fitness, with increase of the speed, the quantity of consumption becomes lower; compared to the 2BML-2 planter, the fuel consumption in traditional tillage would increase more than 32%. A fuel consumption model was obtained through the field testing, which can calculate the fuel consumption conveniently according to actual condition and make for selecting appropriate work parameters and designing similar type planter. 

Abstract:To study the effect of high voltage on the parameters of droplets motion and deposition in the state of induction charge, charged droplet’s move-motional and depositional process of 3 nozzles were tested under the same condition of spray pressure and liquid medium. By using micrograph combining with digital image processing technology, the parameters of spraying deposition were calculated and analyzed. The results showed that with the increasing distance, droplet spraying coverage rises firstly and then declines, but the droplets density is of the opposite trend; with the increasing voltage, area of deposition increases obviously, but spraying uniformity declines. The appropriate voltage depends on the practical occasions of electrostatic spraying application, and adjusting charged voltage is an important measure for adding droplet deposition and spray uniformity. 

Abstract:20％。High-voltage electrostatic spray tester was designed through combination of high-voltage electrostatic spraying and axial-flow air-assisted techniques with the fluid director applied for the experiment of spray. Experimental study for air flow field, droplet size, and deposition were performed. Results indicated that technology of axial-flow air-assisted electrostatic spraying can effectively decrease the droplets diameter, makes droplets distributing more uniform and deposition better，which reduces the environmental pollution. At the same time, the electrostatic function makes the droplets more activated, and improves the ability of absorption, with the increase in sterilization efficiency by about 20%.

Abstract:Based on theoretical analysis of nonlinear jump of the grain on the existing reciprocating screen, movements of grains on screen working in reciprocal and two new dimensional motion modes were researched respectively by using procedure LS-DYNA, and a dispersion measure was designed to reflect the diversification of grains on the screen, in light of which, the comparative analysis of sifting efficiency of theses three screens was performed. The research established the analytical model according to the real structure and material characteristics of screen and grains. Considering effect of friction and collision of screen to grains and grain to grain, the law of motion of grains was solved out. Results of research showed that the two new dimensional movements of vibration screen make for increase in sifting efficiency. 

Abstract:L、a、b色差ΔE仅为5.95。An air-impingement rotary dryer was designed, with a high coefficient of heat transfer, uniform heating of materials, energy conservation, high-volume loading compared to conventional rotary dryer. Some special structural design was used in thermal insulation, recycling of hot air, and dehumidification. The technical and structural parameters of this dryer such as hot air temperature, relative humidity, wind speed, rotary speed, branch nozzle diameter, height and angle, can be adjusted according to different materials properties and products requirement. Herbage seeds (Elymus dahuricus) and carrot cubes were adopted to test the performance of air-impingement rotary dryer. The results of drying can reach national first-class seed quality standard for Elymus dahuricus, and the value of L, a, b color difference, ΔE, between rehydration and raw materials of carrots was only 5.95. 

Abstract:The vertical separation principle of alfalfa in alfalfa rotary drum dryer was studied, and the wind field of separation exit of the three pass rotary drum dryer was optimized by using CFD based on the range of separation velocity when the gas temperature was about 90℃. An optimum structural dimension between the bottoms of the middle and outer drums of a triple pass rotary drum dryer, modified to achieve drying and leaf-stem separation of alfalfa in one process, was recommended based on the CFD simulation results of a series of the contours of velocity and wind field of velocity vectors at different dimensional conditions. 

Abstract:A mobile heat pump drying system driven by a diesel generator was designed to meet the need of the agricultural mechanical harvest. A horizontal multi-room fluidized bed serves as the drying chamber, and a vapor compression heat pump (R134a as refrigerant) supplies heat for this system. Heat exchangers are installed along the air duct to recover the waste heat from the cooling water and flue gas in the diesel generator, which increased the primary energy ratio(PER).A mathematical model for the system composed of fluidized bed, heat pump and diesel generator was also presented. Modeled results showed that the value of drying system’s specific moisture extraction rate (SMER) was firstly up and then down, with air temperature in the range of 60～90℃, and reached a peak value around 70℃. Testing experiments of the prototype dryer showed that under the designed conditions, the mean coefficient of performance (COP) is 4.66, PER is 1.09 and SMER reaches 3.08 kg/(kW?h). The model is in good agreement with experimental results, and this grain dryer is significantly energy saving.

Abstract:Labyrinth channels have a great influence on the hydraulic performance of the drip irrigation emitter. With the help of CAD and NC, sample piece of the labyrinth channels was produced. The application of refined machining-tools resolved the problem of measuring the channel size. The methods of hot modeling and hot embossing process were used to achieve the fast design and manufacture of labyrinth channels. 

Abstract:Black liquor pyrolysis/gasification is a promising alternative for conventional combustion method. The swelling of kraft black liquor was tested at 400～800℃ under nitrogen atmosphere with a visualized single droplet reactor. The main permanent pyrolysis gas components of three kraft black liquors were investigated at temperatures up to 850℃. The measurements of hydrogen sulfide release during pyrolysis were realized by iodometry, the total sulfur release was evaluated through char analysis. At the runs which temperatures higher than 500℃, the droplet volumes began decrease after the droplets swelled to the maximums. Water contents of the black liquors had no significant effects on the hydrogen yields under the reaction atmosphere where nitrogen was used as carrier gas, so nearly all the hydrogen was generated from organic components at the considered experimental conditions. The hydrogen sulfide release has similar trend to total sulfur release, i.e., the release contents reached to the maximums at about 650℃, and below or above this temperature range they decreased. 

Abstract:Based on thermodynamic properties of agro-residues and engineering parameters related to briquetting equipment, the energetics of densification briquetting fuel from main agro-residues in China was compared with that of coal. The results indicated that energy required for producing densification briquetting fuel from agro-residues straw is so high that this type of briquetting fuel had similar energetically advantageous to coal for locations at a distance of above 4?000?km. In contrast, densification briquetting fuel from agro-residues husk consumed lower energy consumption and had a smaller critical transport distance. More specifically, densification briquetting fuel from agro-residues husk was found to be more energetically advantageous, similar energetically advantageous, and less energetically advantageous than coal for locations at a distance of above 2200 km, between 1500 and 2200 km, and below 1000 km from the coal pithead, respectively.

Abstract:The change of dielectric properties on Fuji apples with red-dot disease stored at constant temperature was investigated, which provides a new theoretical basis for revealing its pathogenetic mechanism at electrical properties. By applying LCR electronic measure instrument, the fruits’ dielectric properties, which include the impedance, reactance and inductance, were determined at 100 Hz, 1, 10, 100 kHz and 1 MHz at 20℃. The results indicated that the dielectric constant, impedance, reactance and inductance for all fruits decrease with the increase of frequency at the same stored days. Moreover, there was a significantly positive correlation among impedance、reactance and inductance, the value of the loss tangent and dielectric constant is significantly different (P<0.05), but the value of the impedance, reactance and inductance is not significantly different (P＞0.05) between the diseased and normal fruits from 100?Hz to 1 MHz. This research revealed that the loss tangent and dielectric constant could reflect the quality of apples in some extent. 

Abstract:The dynamic changes of the oxygen and carbon dioxide volume fraction of Agaricus bisporus which were packaged in three kinds of film with different thickness were studied at 2℃ and 20℃. The results indicated that low temperature and MAP could inhibit the respiration of mushroom. A respiration model, based on Michaelis-Menten type enzyme kinetics, was proposed for predicting respiration rates of Agaricus bisporus as a function of O2 and CO2 volume fraction at the storage temperature of 2℃ and 20℃, which is essential to the design of modified atmosphere package.

Abstract:The technology of vacuum pre-cooling was applied to the broccoli's keeping fresh at 5℃, whose effect on the physiological activities of broccoli was studied. The results showed that the respiration rate and ethylene production florets were inhibited, and sensory quality was improved. Weight loss was decreased by 2.18% at the end of storage. At the same time, the degradations of chlorophyll and vitamin C were delayed by vacuum pre-cooling followed. Chlorophyll content fall by about 50% of the original in a vacuum pre-cooling group had been postponed for 12 days. Vacuum pre-cooling also delayed senescence of broccoli by regulating the activity of antioxidant enzymes.

Abstract:To explore the mechanics of vacuum cooling and optimize vacuum precooling instrument, the real-time measurement of the variation of multi-parameters such as the pressure in the vacuum chamber, temperature of the condenser, temperature and mass of fruits and vegetables during vacuum cooling was necessitated. The self-designed vacuum cooling set up and the data acquisition processing system were presented. It was the weight sensor innovatively taken into the vacuum chamber that realized the online measurement of product quality during vacuum cooling.

Abstract:The mechanism of infrared radiation drying was introduced, and the intrinsic and external factors influencing infrared radiation drying kinetics for fruits and vegetables were synthetically analyzed. The relationships between dehydration and the controlling factors, including interior moisture removal and diffusion process of materials were discussed. Characteristics of heat and mass transfer in wet materials were investigated. Further research direction and development trends of infrared radiation drying for fruits and vegetables were presented based on seeking the regularities of drying. 

Abstract:0.25%。Influences of five factors which were size of pear particles, concentration of pear particles, ratio of potato starch to CMC-Na, concentration of colloidal solution and citric acid content respectively, on ohmic heating rate for colloidal solutions with fruit granules, as well as optimization process were studied. Heating rate models was established and optimized parameters were obtained by quadratic orthogonal rotation combination design with five factors and regression analysis. Results showed that effect order of five factors on ohmic heating rate is, according to priority, colloids concentration, ratio of potato starch to CMC-Na, citric acid content, size of pear particles, and concentration of pear particles; the optimal parameter is size of pear particles of 1.0 cm, pear particles concentration of 30%, ratio of potato starch to CMC-Na of 40%, colloids concentration of 4% and citric acid content of 0.25%.

Abstract:In this paper, the synthesis of porous superabsorbent was performed using sodium bicarbonate, acetone, and sucrose as porosity generators. Compared to the superabsorbent prepared under porous-free condition, the results showed that porosity generators can improve absorbency rate effectively, and that sodium bicarbonate has a better effect than others. Morphological studies with scanning electron microscope (SEM) showed that the superabsorbent has the loose and porous structure. 

Abstract:OMS部分。Edible oils, odorless mineral spirits (OMS), chromium hexacarbonyl (spectral marker) taken as raw materials, by using spectral reconstitution (SR-FTIR), the marker’s ability to predict the true volume fraction (TVF) of OMS was evaluated and 2-D correlation spectroscopy was employed as a means to determine whether solvent bands could substitute for the marker. The results indicated 9 spectral wavelengths can be used to quantify the TVF in a single system of rapeseed oil. However, with the introduction of additional variables, including differing oil types and the presence of free fatty acids, the number of useful wavelengths was reduced to 4. The optimal wavelength exceeds the marker band in predicting OMS TVF and was insensitive to polarity changes associated with TVF changes. It was demonstrated that a very consistent, representative edible oil spectra can be derived using either marker or solvent wavelengths to remove the solvent spectral contribution. 

Abstract:Effects of modified Lactobacillus helveticus 6024 by using heat-shock treatment on its biochemical properties and Cheddar cheese ripening were investigated. Results showed that the cell acidification activity was only 6.4% at 6 h cultivation when cells were subjected to the heat treatment of 10 s at 70℃. However, the average level of aminopeptidase activity is maintained at around 25%. The cheese chemical compositions were not apparently affected by adding the heat-shock cells, but the levels of soluble nitrogen were found to be different. The level of WSN% was not significantly different between experimental cheese and control, and there was a 2-fold increase in the level of 5% PTA-SN% at 3 months ripening when compared to control (not adding the heat-shock cells). The results of TPA profiles and microstructure also indicated that the ripening of Cheddar cheese is accelerated as a result of the heat-shock cells. 

Abstract:The effects of freezing-thawing cyclic (FTC) treatment on the condensed state structure and N-deacetylation of chitin were investigated. The mixture of chitin and concentrated NaOH solutions (40%) was frozen at -18℃ and thawed at 40℃, repeatedly. Slowly freezing and low temperature thawing cycle process can thoroughly destruct the condensed state structure, especially the crystalline state structure, as a result of the ice crystals’ repeatedly formed and recrystallizated. Furthermore, via three times FTC treatment at -18℃, chitin was completely dissolved in NaOH aqueous solution and the homogeneous solution with a chitin concentration about 4% and a final NaOH concentration of approximately 10% formed, which is likely applied to prepare partial N-deacetylated water-soluble-chitin.

Abstract:Aiming at the problems of selective harvesting-tomato for robot according to various purposes, feature extraction and analysis of tomato image from artificial selection were firstly performed. Proceeding from camera perspective geometry of tomato, difference value between rendering area ratio of red hue to whole tomato region and rendering area ratio of other hue to whole tomato region was presented by way of main grouping feature of judgment model to describe maturity of tomato. An automatic judgment model on maturity of tomato based on BP NN was built up by using above feature combined with hue mean and variance of whole rendering region of tomato. Validation test and noise level test of models show that the model can keep higher accuracy and nicer anti-interference when difference value of area ratio and hue mean are selected as two inputs of BP NN. The accuracy of validation test and noise level test is 97.5%. The accuracy can reach above 95.26% when noise level is under0.05. The model can provide theoretical reference of automatic harvesting-tomato for robot.

Abstract:5 mm以内。By analyzing characteristic information of depth image for robotic fruit-picking, a combinatorial optimization matching algorithm based on epipolar geometry and gray correlation constraints was discussed, to improve target precision with convergent binocular stereovision system. Furthermore, a light analysis model was established by comparing the influence of illumination intensity variation on the navigation detection under different time scale, which was beneficial to the processes of robotic autonomous navigation. The experimental results showed that the visual system can detect the target of cucumbers with the positioning error in a ±5 mm range.

Abstract:In order to study the growth behavior of greenhouse tomato with different density, GreenLab, the functional-structural model, was improved. On the basis of improving the degree of fitting, the growth parameter of tomato with different density was obtained. Environment was connected with tomato plant growth behavior through the analysis of the parameter. The results show that the density influences production and distribution of assimilate, which was characterized by the exterior morpha such as leaf appearance rate, leaf thickness, fruit set rate and so on, and GreenLab model can reproduce this feedback relationship. 

Abstract:，选出率为80.7%。A cotton seed on-line separation system based on computer vision was designed to realize the automatic separation of red-brown and black cotton seeds produced in Xinjiang Province. In the system, the seeds were projected horizontally, separated by compressed airflow in the air. Meanwhile, a method of capturing seed images was studied in an unordered arrangement. And the corresponding relationship between unordered seeds and the airflow nozzles was resolved by region subdivision of seed image. Lastly, a seed tracking and separating algorithm was proposed which memorized the position of each inspected seed until the seeds reached the separation region. The experiment results show that when the speed of the conveyer belt is 0.50 m/s, the inspecting accuracy is 88.6%, and the separating ratio is 80.7%.

Abstract:A positioning method of a variable rate fertilizer applicator with sensors is introduced, to replace GPS in precision agriculture. In the positioning system, the controller receives pulse signals from the sensor and calculates the working distance of the variable rate fertilizer applicator, thus the grid in which the fertilizer applicator is working is identified by the algorithm of automatic grid recognition. The accumulative error of the system from the sensor is corrected by the error revising algorithm, and the correction results were tested in field. The experiment results showed that the accumulative errors for the photoelectric encoder and the proximity transducer are 2.32 m and 2.34 m, within 250?m of working distance, respectively, i.e. the positioning errors is less than 6%. Under the above conditions, a variable rate fertilizer applicator can be applied in a larger working field if the working grid is divided longer.

Abstract:Chlorophyll content of cucumber leaf in vivo was detected by reflectance laser-induced fluorescence (LIF) spectrum analysis technique in this research. Fluorescence spectrums, which was induced by four power (2.5 mW，5.0 mW，7.5 mW，10.0 mW) of center wavelength 473 nm and 660 nm laser respectively, were analyzed in the experiment. Results showed that the fluorescence spectrum has a favorable precision and stability under the condition of 7.5 mW and 473 nm laser, and there is a significant linear correlation between the ratio of chlorophyll fluorescence at 732 nm to 685 nm (F732/F685) and the chlorophyll content. Furthermore the regression model was established (R2>0.93, p<0.001) in this excitation light source condition. This research doesn’t only extend the scope of the application of chlorophyll fluorescence detection technology, but also provides a theoretical basis of the development of portable and non-destructive plants chlorophyll content detection equipment. 

Abstract:5.9%。Based on the water vapor balance in greenhouse, a dynamic forecasting model of humidity directly as a function of the inside and outside climate, greenhouse structure, crop growth, and soil moisture was presented. Meanwhile, some physical processes correlative with the water vapor change such as crop transpiration, soil evaporation, covering material condensation, and natural and mechanical ventilation were quantitative analyzed. To validate the correctness of the model, an experiment was carried out in the plastic multi-span greenhouse in North China during winter. The inner relative humidity forecasted agreed well with the measured data, with the root mean square error of 5.9%. 

Abstract:Catching insect flexible lamp with light emitting diode (LED) which can be controlled light intensity was designed, frequency and wavelength. In order to verify performance of the lamp, the experiment about phototaxis action of drosophila was performed, which shows that drosophila inclines to weak compound light of yellow and green at the 560 nm.

Abstract:A high precision pneumatic proportional pressure valve was designed. The plunger-type structure with two-stage poppet was adopted for the valve. A proportional electromagnetic actuator was used as control component and the control method was electric closed-loop feedback. The output pressure can be adjusted continuously within 0.6 MPa absolute with the steady-state precision of less than 0.25 kPa. A completely nonlinear dynamic model was developed to analyze the effects of main physical and geometrical parameters on the valve’s dynamic behavior and control performance. A self-adaptive fuzzy proportional plus integral controller with adjusting output scaling factor was designed for high precision and quickly control of different pressure target values, and carried out based on single chip-microcomputer ATmega16. Experimental results indicated that the valve has a good performance in pressure and flow characteristics under the designed pressure. Compared to traditional PI controller, the proposed fuzzy algorithm can improve the response and control stability of the system as well as the steady-tate precision drastically, which has better efficiency and robustness. 

Abstract:A disturbance observer was proposed to estimate and to compensate the load disturbance of the variable frequency pump-control-motor speed governing system. In order to improve the robustness and performance of the system, a sliding mode variable structure controller was designed to weaken the impact on the system of the disturbance. The proof on robustness of the system was conducted. Simulation results verified that the designed controller shows good robustness to the load disturbance and system parameters uncertainty, which effectively improves the precision of speed control and meets the requirements of the pump-control-motor speed governing system. 

Abstract:Considering the characteristics of valve controlled asymmetric cylinder system, a multiple sliding mode robust adaptive controller was designed. First, backstepping technique and state feedback linearization method were used to attain a multiple sliding mode controller. Next, based on Lyapunov stability theory, the uncertain parameters adaptation laws were presented and a robust adaptive controller combined with sliding mode method was designed to track piston displacement accurately. Experimental results show that the multiple sliding mode robust adaptive control approach has a strong robustness and enhances the tracking performance remarkably.

Abstract:Aiming at job-shop scheduling problem with a view of minimizing the maximal makespan, an improved adaptive genetic algorithm based on hormone modulation mechanism was employed. This algorithm has such characteristics as avoiding inbreeding efficiently, no needing reproductive operation, overcoming premature phenomenon and slow evolution. An operation-based code was applied to job-shop scheduling problems along with the satisfied results. Numerical simulation demonstrated that within the framework of the newly designed improved adaptive genetic algorithm based on hormone modulation mechanism, the needed time for new optimal scheduling project and the minimal makespan were decreased, therefore the NP-hard job-shop scheduling problem can be solved efficiently.

Abstract:To solve the problem of the automatic disassembly path planning for waste mechanic-electronic products in remanufacturing, one of automatic disassembly path planning methods based on assembly restraint and model interference examination of product assembly model was proposed. In this method, the direction collection was expressed by Gauss sphere which can be disassembled freely in unassembled parts. The possible disassembly direction set can be figured out through calculating the intersection of all assembly restraint Gauss sphere in parts. To verify the availability of the disassembly direction, the disassembled parts were scanned to be tool body along these directions, and the interference examination was performed through calculating the intersection between tool body and unstripped parts. The method is adapted to the needs of CAD/CAM integrated development system, and is effective and feasible by the software programming and practical engineering applications. 

Abstract:The 3-D point data of the clypeus surface of the dung beetle (Copris ochus Motschulsky) were simplified, and a 3-section wedge model was used for analyzing the applied force of the half clypeus surface in several directions. It was found that the advantageous mode of the clypeus in soil cut is the sliding cutting as a result of the optimized geometrical configuration of the clypeus of the dung beetle, through evolution over millions of years, which plays an important role in cutting resistance reduction of the clypeus. The potential applications of the clypeus in bionic cutting resistance reduction were analyzed.

Abstract:The machine machining coordinate system of spiral bevel gear cutting machine was established by analyzing the machining mechanism of the spiral bevel gear and the relationships between the structure and motion of the traditional mechanical spiral bevel gear cutting machine. The 3-D structure model of the heavy duty spiral bevel gear cutting machine was built, using the cutter spindle feed method instead of the traditional workpiece box feed method or the machine cradle feed method so as to increases the machine’s manufacture efficiency and machining precision, according to the machining characteristic of heavy duty spiral bevel gear. And the numerical control machining model of the heavy duty spiral bevel gear cutting machine was also proposed, by analyzing the shift principle from the traditional mechanical spiral bevel gear cutting machine’s adjustment parameter to the heavy duty numerical controls spiral bevel gear cutting machine. Finally, the instantaneous position of the heavy duty numerical control spiral bevel gear cutting machine’s kinematic axis was obtained through the example computation. The machining machine model of the heavy duty spiral bevel gear machine was built, and the simulation machining was also carried out. The functional verification requirement of spiral bevel gear machine can be satisfied by the simulation results.

Abstract:The structure and drive principle of the cycloid ball planetary transmission was introduced. The mathematic models for the tooth surfaces of epitrochoid and hypotrochoid enclosed grooves generated by cone milling cutter were proposed. According to space meshing theory, the meshing equations and the undercut limit functions were deduced. The variational regularity of undercut limit functions with the fundamental design parameters were analyzed through the numerical method. The analytical results showed that the undercutting phenomenon of the tooth surfaces of hypotrochoid and epitrochoid enclosed grooves occurred orderly corresponding to the variation of fundamental design parameters, and the first undercut point always occurred on inside tooth surface of hypotrochoid groove. Consequently, a simpler dimensionless inequality which can avoid the undercut was derived from the proposed analysis. Then, the conclusion was verified by the design examples and the computer simulations. The research results offer a theoretical basis for designing and manufacturing of the cycloid ball planetary transmission. 

Abstract:On the basis of characteristic analysis of the sheet metal CNC incremental forming, the problems of current incremental forming method based on contour line motion were proposed put forward, at the same time，an incremental forming method based on helix motion and the algorithm for generation of helix forming path based on STL model were presented. The isometric model of STL model was generated by using vertex offset method, and was intersected with a series of horizontal plane along with the planes that were parallel with the Z axis respectively. Then the points of the intersection lines were obtained which were linked to be the spiral tool path of forming. The case study indicated that the algorithm can generate non-inference spiral tool path of forming. 