Search

Shutters-style shielding and protective device for windscreen is the shutters installed outside the external position of the vehicle windscreen with the function of shelter and protection. It does not only avoid the enemy reconnaissance due to the reflective glass, but also withstands the damage from all kinds of bullets and shrapnel, and it does not affect the normal running of the vehicle.

Classical control theory method often cannot obtain good static and dynamic performance in speed control system of asynchronous motor that is multivariable, nonlinear and strong coupling. However, with the application of modern control theory, it can effectively improve the operating performance of system in a complicated environment. This paper introduces the basic principle of vector control system and establishes the simulation model of vector control system of asynchronous motor. Meanwhile, according to fuzzy control theory, this paper shows a design of fuzzy controller and it is applied to the vector control system of speed adjusting module. Finally, it uses Matlab/Simulink to simulate and it verifies that Fuzzy vector control system response faster has better stability and stronger robust performance compared to the traditional vector control. Key words: induction motor; vector control; fuzzy control

Based on the analysis on the control requirements of artificial grass tufting machine, this thesis proposes an overall plan on control of CANopen bus. In the control system, on the basis of CoDeSys softPLC technology of fieldbus control system, LMC20 enables the communication by making CANopen bus connect with ATV71, OTB module and these underlying slave stations. The humanized operation interface realized by touch screens and user-friendly application which is developed through CoDeSys have been put into operation in factory. All of those implement the functions of signal acquisition and display, protection, control, etc.

In this paper the electric-hydraulic servo system for excavating robot is analysed. The kinematic and the dynamic model of working equipment are established. Aim at the electric-hydraulic servo system of the feature with many variables, strong coupling and non-linear, the CMAC neural network was presented combined with popular PD algorithm, which could realize intelligent control for the working equipment of excavating robot. The result of simulation show that control strategy features higher precision and robustness.

The uranium ore sample is dissolve with H2SO4, HF and H2O2.Uranium (VI) is reduced to uranium (IV) by titanous. The excess titanous is oxidized with sodium nitrite and excess sodium nitrite is destroyed with urea. Uranium can be determined by ammonium vanadate volumetry in the medium of 6 mol/L sulfuric acid taking o-phenanthroline ferrous sulfate as indicators. The determination limit is 0.03%, the RSD is better than 3%, the recovery is 95~105%. The error is less than 2% compared with the standard sample of uranium ore.

Its hard to define base coordinate of industrial robot because base coordinate of robot in its inner. This article used Laser tracker system (LTS) to test its distance accuracy. Simultaneously, it is hard to must modify the controller of the robot, even though the robot kinematic compensation is high precision. Therefore, it used inverse kinematic compensation to compensate robot error by optimal method. Experiment results demonstrate that it can improve the robot accuracy in the working space, only modifies joint angle.

The preparation of uranium ore gritstone standard substance have been introduced and the contents of U, Th, Ra, K2O, SiO2, Fe, A12O3, CaO, MnO, TiO2, Na2O, P2O5, MoO3, V ,S and C in it have been determined in this paper. The uranium ore sandstone standard substance was authorized as the first national grade standard substance.

A Load-type Commercial Motor-vehicle of Passenger Transport was studied as the research subject in researching front crash safety evaluation technology of front structure by the real car crash test methods, which is to explore the front crash safety evaluation technology suitable for china's National conditions. The results show that the Testing procedure and Evaluation will not only conducive to the carrying out of Commercial Motor-vehicles of Passenger Transport access about structural safety detection, but also played an important role in promoting the safety of the domestic bus, road transport safety, and social harmony.

For tractor-semitrailer, load transfer during cornering braking caused big difference of the vertical load between coaxial wheels. As a result, braking efficiency and directional stability were affected seriously, the traditional design of braking force distribution between axles couldnt meet the requirements. In this paper, a dynamic model of tractor-semitrailer was established according to the motion and force during cornering braking. The rule of vertical load changing of each wheel with longitudinal acceleration and lateral acceleration was obtained. Combining with the tire and road adhesion conditions, the ideal brake force distribution was achieved. The research could provide theoretical reference to better control strategy of tractor-semitrailer braking control system.

This paper introduced an approach of using diphenylthiocarbazone-chloroform benzene mixed solvent to determine silver content in the ore by extraction colorimetric method. Ammonium chloride-sodium chloride was used for sample melting, and hydrochloric acidic water was adopted to digestion. Then, some parts of the interference elements were separated from it. Silver was dissolved quantitatively out of the ore, and formed complex negative ion of [AgCl-in the liquor. Chloroform-benzene mixed solvent as extraction solvent of diphenylthiocarbazone could improve the stability of diphenylthiocarbazone and silver complex, thus it could raise the accuracy and precision, simplify the operate procedure, and also avoid that phosgene pollute to the environment.

Energy absorbing characteristics of the non-stiffened and stiffened single hat sections subjected to quasi-static axial crushing were experimentally investigated. First non-stiffened hat sections were axially crushed, then structures with different stiffened methods (stiffened in hat and stiffened in the plate) were tested, finally energy absorption capacities of these structures were compared. Test results showed that, for the appropriate designed stiffened tube, the mean crush force and mass specific energy absorption were increased significantly compared to the non-stiffened. Stiffened in hat section showed a little more energy absorption capacity than that stiffened in the plate, but the structure may sustain a global bending.

We designed the binary programmable resistor, using search method found near the nominal resistance value closest to the actual resistance. This method is effective to overcome the contact resistance, temperature drift effects, To achieve a low-cost high-precision.

The determination method of ScSe and Re in uranium ore with ICP-AES has been developed. The determination limits of ScSe and Re are 0.03μg/ml0. 03μg/ml0.016μg/ml respectively. The RSD is less than 8% , and the recoveries are 96% ~106%.

To determine the ultimate load capacity of drilled shaft socketed into rock under axial compression loading, it is necessary to predict both the ultimate side shear resistance and the base resistance based on field load test or/ and laboratory tests. In geotechnical engineering there are several methods proposed the relationship between rock properties (the unconfined compressive strength) and the ultimate side shears resistance and base resistance. This paper presents the review of design methods of ultimate side shear and base resistance for rock-socketed pile. These empirical functions depend on the socket type and the range of the unconfined compressive strength of rock.

In order to find a solution to the control of low frequency noise in the cabin of turboprop driven aircraft, an experimental active noise control (ANC) system is introduced in the paper, which consists of vibroacoustic field analogue subsystem, acoustic field measurement subsystem and acoustic barrier exciter subsystem. Effects of both different spaces between the primary sound source and secondary sound source of the ANC system and different frequency noises on noise-reduction result are investigated based on the experimental platform. Results of the experiment show a significant potential of the ANC method for the control of low frequency noise in the cabin of turboprop driven aircraft.

Due to its excellent performances, the combined diesel and diesel (CODAD) propulsion plant is widely applied in modern medium-sized marine vessels. An experimental test rig of marine CODAD propulsion plant is built in the laboratory so that characteristics of the CODAD propulsion plant can be investigated in detail. Modeling of the CODAD test rig is presented at first in the paper. Validity of the model is proved with the experimental data. In order that an optimized merging process of the test rig can be accessed, a simulation analysis based on the model is carried out to choose rational engaging parameters of the clutches.

In order to meet the market demand for carpet sampling, designed a NC control system by analyzing the working principle of Axminster loom, the upper computer program could extract, analyze and process the pixel information from image and to communicate with the lower system instantaneity via Ethernet and send the information of the picture to the lower system. The lower system combines with the Servo control and motion control program, making each part of the system move precisely and coordinately. The system can make carpet sample more efficiently with high quality. The result showed that this control system has practical application value.

A new type of cooling device used for server is designed in this paper. A small type of server is taken as a research object to compare the effect of air cooling and evaporative cooling under different CPU power consumption. The effects of this research are discussed on evaporative cooling for the stability of the CPU heat dissipation and the cooler on other components. The results show that the temperature distribution of the server’s case is more uniform and the temperature test of the CPU is more stable when it is cooled by evaporative cooling.

The performance tests of an electronically controlled high pressure common rail diesel engine and of the car mounted with an engine of this type fuelled by biodiesel–diesel mixed fuel with different mixing ratios are conducted, and its power outputs, fuel economies and emissions are measured and compared with the one of diesel operation. The results indicate that: when the load is 2200 r/min, the effective specific energy consumption decreases, NOx emission increases; smoke emission decreases at high load and keeps almost no change at low and middle loads; HC emission decreases at low and middle loads and keeps the same at high loads, and CO emission maintains the same; at full load characteristics, the power output increases slightly, HC and smoke emissions decrease, CO and NOx emissions increase.

An experimental study is made on the emission of a single-cylinder direct injection diesel engine with different proportions of GDE and diesel. The study shows the mechanism when GDE is added to diesel to reduce diesel emission. And an analysis of pollutant emission is made on the regularities of variation with engine load changes. The results show that the addition of diesel oil in the volume fraction of 10% to 20% of GDE can significantly increase the thermal efficiency, shorten the duration of diesel combustion, substantially decrease carbon smoke and CO in emission under the high-load conditions and slightly lessen the NOx emission, but HC emission still remain basically unchanged.

This paper analyzes the basic combustion characteristics of dual-fuel engine with diesel-natural gas, including the engine’s running characteristics, the external characteristics and the low-load performance. Taking the development and application of natural gas for consideration, this paper also makes studies on how to improve the dynamic performance of the dual-fuel engine CA6110ZLA5N2.

Indoor model experiments were made to study drag loads on two piles of side-by-side arrangements in the uniform flow. Take three different velocities of the flow, three different diameters of piles and five different distances of two piles in the experiments to get the variations of loads. Drag forces were measured by a two-component balance. Analysis on experiment results shows that drag forces increase with the increase of the pile diameter, the increase of the flow velocity and the decrease of the distance of two piles. The drag coefficient CDunder different Reynolds numbers shows the same change law. The drag coefficient CDdecreases with the increase of the distance of two piles and has good coherence to the ratio of the distance of two piles to the pile diameter.

Indoor model experiments were made to study loads on single pile under the wave-current flow. Take three different velocities of the current and three different diameters of piles in the experiments to get the variations of loads. Drag and lift forces were measured by a two-component balance. Analysis on experiment results shows that, both drag force and lift force increase with the increase of the pile diameter and the current velocity. The drag coefficient Cd increases with the increase of Kc number until Kc researches 12, when Kc is more than 12, Cd decreases with the increase of Kc; while the inertia force coefficient Cm decreases with the increase of Kc, when Kc is more than 12, Cmchanges little. And the lift coefficient shows no correlation with the Kc number.

Hydraulic excavator energy saving is one of the dominating problem that trouble construction machinery industry. Hybrid technology brings forward a new solution for this puzzle. In the research of hybrid hydraulic excavator, we set up a parallel hybrid excavator test bench based on modular-design method, this fills a domestic technology gap. Power-train performance test is undertaken on this bench and the power assist control strategy is proved to be significant energy saving.

Draw rod is one of the main mechanical parts of vehicle steering system，which is required extremely high quality. At present the way to produce the draw rod is machining after common open-die forging. This technology will produce big flashings，damage the metal’s fibrous structure and reduce the material utilization. In this essay, we will use the technology of closed multiple-ram forging to produce it. We will utilize numerical simulation on several blanks through numerical simulation combined with experiments. In this way, the defects that some parts of the blank are folded and cannot fill well during forming process can be effectively avoided. Besides, there will be free of flashing and the draw rod forgings do not need to be cut. The weight of the original blank will be about 3.5 kg after being optimized, down by 36.4 percent compared with that of original material about 5.5 kg. And we will make different settings for the loading way of the plunger chips during the forming process, then compare with the simulation results and ultimately find out the best loading way. At last, we will verify the feasibility of such an optimal technology through experiments on the material-lead.

After analyzing the loader duty cycle with hybrid drive theory and gaining the characteristics of loader duty cycle, an integrated started generator-ISG based coaxial parallel hybrid loader is designed. Two simulation models are built with the simulation software Cruise, one is tradition loader another is hybrid loader. The simulation result of tradition loader model compare with the test data to amend the model. To gain same accuracy, the hybrid loader model is rebuilt based on the tradition loader model. According to the “I” type duty cycle, comparing the simulation result of tradition and hybrid loader, the result shows that hybrid loader can save fuel 10.4%.

The theory of the excavator’s hydraulic system was elaborated in the paper taking a 20t hybrid hydraulic excavator produced by a domestic company for example. The rotary movement of the hybrid hydraulic excavator was achieved by a newly developed electric motor, fuel consumption could be reduced as the result of the speed inhibition when the excavator standby. The modeling of excavator’s hydraulic system, front-end attachments and revolving frame were built on the AMESim platform according to the installation and actual sizes of the hydraulic components. By setting the parameters of every component in the model, mechanical- electronic- hydraulic integrated simulation was achieved. The paper focused on the solutions of hydraulic system’s pressure fluctuation and poor simulation results of front-end attachments. As a conclusion, appropriate solutions and simulation results were proposed to improve the precision.