The predictive model of Dimension Reduction-Support Vector Regression (DR-SVR) method to evaluating sound quality of car interior with small samples was proposed.The interior stable sound samples were selected as the object to analyze and its physical parameters and psychoacoustics parameters were calculated.Subjective testing was carried out via the paired comparison method,indicating that it is available to justice the merits of such samples preliminary with Psychoacoustic Annoyance (PA).Dimension reduction was achieved through factor analysis,cluster analysis and correlation analysis,then the predict model was established base on SVR method,and the correlation coefficient between predictive value and evaluated value of DR-SVR model was higher than the model without dimension reduction,verifying the method to predict subjective preferences of car interior sound with DR-SVR was effective.

In order to simulate the design thinking and quantify the image cognition,puts forward the concept of the principal and the associate image according to the characteristics of the product image cognition,and constructs the product image cobweb model based on the spider web structure and character of external force of single point with multi-line linkage in nature,to form the product image evolution algorithm on this basis.This algorithm,combined with genetic evolution algorithm,can simulate the change of design thinking in the process of product evolution to a certain extent,and transform the cognitive network into the actual product image network.Finally,some examples are given to demonstrate the feasibility of the algorithm.

The study established the dynamic model of rotor system of vertical axis magnetic levitation wind turbine based on the rotor dynamics theory.The finite element model of the bearing-spindle-thrust plate of vertical axis magnetic levitation wind turbine system was established built by ANSYS Workbench finite element analysis software.To study the influence of the position of the auxiliary bearing on the critical speed of the vertical axis rotor system through modal analysis method and drew a conclusion that the change of the auxiliary bearing position and the critical speed of the vertical axis rotor system.The research results provide a theoretical basis for the structural design,installation and as maintenance of the vertical axis magnetic levitation auxiliary supporting device.

Aiming at the problems of high production cost,long delivery cycle and low qualified rate in the process of power battery production in A company,based on the analysis of characteristics of the value stream and the six Sigma,the improved scheme of integrating the value stream with six Sigma is put forward.The integrated DMAIC process has been used in the improvement of power battery production by integrating the methods of value stream into the mature technical route of six Sigma.The results show that the improved battery delivery cycle is just 6 days,which is the one-fourth of the original delivery period,and the number of operators is half the original,and the production line balance rate has increased from 50.42 % to 87 %,while laser spot welding qualified rate has increased from 78 % to 95 %.The DMAIC method after the integration can not only reduce the work-in-process quantity,cost and production time to quickly responds to customer needs,but also reduce the variability of business process to improve process capability and product stability.

The unified management of the field production data is the important foundation of the construction of digital workshop, production status and business process of the machining A workshop,on the existing production data management system, an integrated optimization schema of the NC program and edition、three dimensional model of working procedure and process requirements is proposed, to improve the processing capacity of the workshop and to improve the digital management level.

During the construction of a super high-rise construction,to meet the requirements of office space and stack materials,it is necessary to design steel platform.This platform is built on the edge of the pit 36 meters deep,so the security of the platform is very important.To ensure the safety of the platform,according to the requirements of site construction plan,established an accurate computational model.Proposed construction loads according to the actual situation,used finite element analysis software,accurately simulate the steel platform mechanical properties of the most unfavorable operating condition in the actual construction process,analysis and simulation of the steel platform actual putting into use situation,finally,through the comparison of the on-site monitoring data and the model data,comprehensive analysis of the results,the results show that the design of the platform is reasonable safe and reliable,and it has the promotion significance in the design of similar large steel platform.d model data,a and draw with the promotion of significance in the design of similar large steel platform.

Python scripting language was used in pre-processing module of ABAQUS for secondary development,through loading the force on the milling region,the data of machining deformation cause by milling error were obtained.Based on the mechanical model,accurate modeling of R cutter milling force was established on the basis of considering the shear effect of the rake face and the ploughing effect of the flank face.The simulation results were in accord with the milling error of actual processing,the milling force model and the simulation method were proved applicable for the milling error predict of the casing,the research results provided theoretical guidance for tooling design of such parts.

In view of the large holes on the scattered point cloud model software reverse engineering repair effect is poor and using of the traditional BP neural network algorithm and improved BP feedforward neural network effciency is low,putted forward a algorithm that based on Extreme Learning Machine feedforward neural network repair hole.Taking toy car body point cloud model for example,the artifical hole data is divided into training data and predicted data,adopting ELM to training the traning data,establish regression model and compared with the BP model,PSO-BP model,proved the ELM neural network own the higher rapidity and accurancy.The excavator bucket teeth natural hole as experimental object achieved very good repair effect.There are very good practicability and reference value.

Mowing robot full coverage path planning takes the differential positioning technology as the theoretical basis,utilizes positioning technology,information link technology,serial interface technology,information processing technology and obstacle avoidance algorithm comprehensively.Full cover type mowing robot path planning assignments and obstacle avoidance function platform was set up based on the position precision and environmental factors.Local coverage path planning is proposed to improve the method and completed the test precision of the test platform.

On the basis of analyzing the body structure characteristics and motor function of the tiger beetle,have designed a tiger-beetle-like hexapod robot.According to the structure of the hind legs of the four selected tiger beetles,choose the appropriate size ratio for each leg of the robot.Builds a physical model of the tiger-beetle-like hexapod robot through using Solidworks.The body structure design of the robot is modeled on the body of the tiger beetle,which has slender appearance,and the install location of the six legs on the body of the robot is approximately on a long oval.Each leg is a serial mechanism,which has three degrees of freedom.Also does statics analysis of the key parts of the leg by ANSYS to gain the stress and strain chart,the results indicate that the robot mechanism design is reasonable.

In order to solve the problem that the vibration response of the vehicle-bridge coupling vibration model can not be analyzed completely,through the use of SIMPACK software flexible rail module and the self-made rail *.ftr file,a new method based on SIMPACK and ANSYS is proposed.Then,by using the coupling method to establish the vehicle-floating slab track coupling vibration model,and the displacement response of the rail and the floating slab is analyzed.The analysis results are compared with the existing results,and the results show that the method is correct;Ultimate,a coupled model of train,track,U-girder and pier is established by taking the simply supported U-girder bridge as the research object,and the vibration response of the bridge system is simulated.The results show that the vibration response of the vehicle bridge system can be fully analyzed by the improved method,and the analytic results can provide a reference for the design of the bridge vibration reduction.

Taking the idling noise in car as research object,firstly,the noise anomaly peaks and their frequencies,which causes the excessive idling noise in car,are analyzed through the tests.Secondly,by a series of TroubleShooting tests,lock the air conditioning pipe and the beam for installing the first hanger of exhaust system as the problem points.And then,the method of test adjustment and simulation optimization is used synthetically to rectify the vibration response of the air conditioning pipe and the dynamic characteristics of the beam.Finally,the idling noise in car is improved,and reaches the target value requirements.The above research can provide reference for circumventing technological risks in the NVH performance development of the same type vehicle,meanwhile,it shows that the integrated application of test adjustment and simulation optimization technology is a fast,accurate and effective method to control the idling noise in car.

A robust steering system and suspension model are built.In the model some coordinated movements between vehicle steering system and suspension system are considered.The length of steering trapezoid arm,the angle of trapezoid mechanism,inclination angle,caster,camber and toe are defined as controllable variables,while the using conditions of load,driving force and steering torque are defined as noise factors.The optimization objectives are the minimum wheel movement deviation in some running condition.The robust optimized model is solved based on the response surface method and the robustness is analyzed based on the Monte Carlo method.Results are shown that the variances of objective functions are decreased in the robust optimization method than those results in the genetic optimization method and the robustness wheel tracks under different working condition are improved.

Focusing on the high data redundancy,the single function and the unfriendly user interface of the ordinary standard parts libraries for section bars,the parametric design method of section bars and the mechanical analysis model of the beams are studied.A new standard parts librariy of section bars and a software for beams designing are establish though using Visual Studio 2005,ADK and SQL Server 2008.Three-dimensional CAD software SINOVATION is used as a platform to complete the development.The standardized design of section bars,computer-aided mechanics analysis of beams and output of design report are realized.Finally,a crane’s main girder study case and a lathe spindle study case illustrate the high efficiency and intuition of modeling of the beam design software.

Taking a transfer table structure system as research object,the parametric finite element model is built and analysed by ANSYS.For this transfer table,two optimization mathematical models were built to solve the problem of insufficient stiffness of cantilever which increase the structural support location as optimal design variables besides the girder cross section size parameters.Building the response surface approximation model in Isight,the Multi-Island Genetic Algorithm(MIGA) was used to solve the problem.The results show that the strength and stiffness of the improved structure can meet the requirements.The weight of the structure can be decreased by 33.72 %,and the lightweight effect was obvious.The research results can provide theoretical guidance for design and optimize of transfer table.

Needle valve flow coefficient and spray hole surface quality have important influences on engine fuel power performance and emission.Researches the extrude honing parameters on the nozzle surface quality and the influence law of flow characteristics.The effect of abrasive grain material,particle size and concentration on the processing effect was studied.Then the design experiment was carried out to study the effect of extrusion grinding pressure and time parameters on the processing effect.The results show that increasing the pressure and time within a certain range can improve the surface mass and the flow rate increase rate.

When the bend of titanium alloy tube is bent,the inner surface will produce a surface micro defect that influence the normal use.Magnetic particle grinding with auxiliary pole can solve this problem well.Orthogonal test method was used to optimize the three technological parameters of magnetic pole speed,magnetic abrasive particle size and grinding fluid type,and the test parameters were analyzed by range and variance.Analysis shows that when the magnetic pole is used to assist the grinding of the inner surface of the elbow pipe,the speed of 600 r/min,the honing oil and magnetic abrasive particles with a particle size of 150 μm are selected,the average surface roughness decreased from Ra1.33 μm to Ra0.12 μm,surface quality has been improved very well after grinding.By means of a single variable test of significant factors can show that the combination of roughing and finishing can guarantee the machining quality and improve the machining efficiency.

Using long-span linear motion mechanism driven by synchronous belt as the linear motion mechanism for a novel three-degree-of-freedom optical testing target to meet the accuracy requirements in the large stroke and high speed conditions.The linear synchronous belt drive virtual prototype model is created using UG and RecurDyn software,and the multi-body dynamics simulation was carried out.The main factors leading to the linear motion error of the load during the linear motion and the influence of initial tension,load acceleration and mass on the linear motion error were analyzed.The results show that the motion error of the load decreases with the increase of the initial tension force,and increases with the increase of the acceleration and the mass of the load.It provides a reference for the application of the linear drive mechanism of the synchronous belt in the long distance linear motion precision machinery.

On the basis of analyzing 2×2 symmetrical capillary throttle air bearing table model,the Fluent software was used to obtain the pressure and velocity distribution of the gas membrane flow field,mass flow rate and bearing capacity were also obtained,and analyzed the effects of capillary throttle spacing,the structural parameters of capillary throttle and gas supply pressure on the static characteristics of air bearing table.The results show that:the influence of the spacing of restrictors on the mass flow rate is not significant,bearing capacity increases with the increase of the restrictors’ spacing;the changing of restrictors’ angle has little effect on mass flow rate,bearing capacity and static stiffness;mass flow rate and bearing capacity increase with the increase of gas supply pressure.The results provide a simulation data reference for the design of air bearing table and the actual engineering needs.

Thermal error seriously affects the machining accuracy of the machine,and it is a very effective way to improve the precision of the machine by thermal error compensation.The selection and optimization of temperature measurement points are the difficulties in the study of thermal error compensation technology.In order to reduce the number of temperature measurement points reasonably,the temperature distribution of the parts in the feed system under different working conditions is tested.The fuzzy clustering analysis method is used to classify the temperature variation of the measuring point.Through the analysis of the distribution of the spindle temperature field and the method of correlation analysis,five temperature characteristic points were selected from 24 temperature measuring points to compensate the thermal error of the machining center,which greatly improved the efficiency of the thermal error model.The method optimizes the position of the temperature sensor measuring point,achieves the simplified temperature measuring point and improves the accuracy of the thermal error compensation.

Reliability evaluation is the primary task of reliability work,in order to avoid the subjectivity in the process of reliability modeling and replace the cumbersome calculation process,firstly,the Inter-Quartile Range(IQR) method is used to determine the outliers of the fault data,and then the MINITAB software is used to optimize the reliability model of the effective data,finally,the linear correlation and K-S test are put forward to verify the accuracy of the method.Meanwhile,in order to improve the reliability level of CNC grinder,the Failure Mode and Effects Analysis(FMEA) and Fault Tree Analysis(FTA) methods are used to analyze the reliability of the machine tools,and effective reliability improvement measures for key failure factors are put forward.The above methods are effectively applied in the project,which play important roles in improving the reliability level of the machine tool and improving the reliability design in the future.

A pressure control system based on PI algorithm is proposed.In order to make the pressure of the micro-pressure and oxygen-rich cabin stable and controllable at the lifting stage and maintain the pressure at a steady pressure.Control the rate of pressure change by tracking the slope of the target curve and track the value of the curve control pressure.Establish the mathematical model of the pressure in the cabin;use Matlab/Simulink to establish the simulation model of the control system;and set the PI parameters of each stage.The simulation results show that the ascending and descending speed can reach steady state quickly,less error,the overshoot is small and the pressure rise and fall can effectively follow the target curve.At the same time,the experiment is carried out.The experimental results show that the pressure model of micro-pressure and oxygen-rich cabin is correct and the control method is feasible.

In order to solve the problems of inefficiency,instability,inaccurate and low degree of automation,the roll position automatic adjustment system is designed for the one time forming of cold-formed steel unit.The automatic control technology,sensor technology,communication technology and Human Machine Interface(HMI) configuration technology are applied to this system and with the high performance PLC controller as control core.Triple-phase asynchronous motor controlled by PLC(S7-1500) driving gear connected with reducer and coupling,so as to drive rolls connected with the upper and lower horizontal axis to move;the osiswitch is used to calibration zero position and the closed-loop control system is constructed by analyzing and feedback the signal of the sensor,and in this way can improve the roll position adjustment accuracy.The practical applications show that the whole system is simple,stable and efficient,the maximum detection error of roller displacement is only±2 mm.The system can automatically call the corresponding roll position data according to the specification of the steel pipe.The system not only improve the change speed and accuracy,but also avoids the waste of manpower,so that make the enterprise production efficiency has been greatly improved.Meanwhile,in order to predict the roller parameters and carry out efficient management of the unit,the unit health management system was used to analyze and monitor the status of the unit in real time.

In order to effectively solve the problems of high system control complexity and volumetric flow rate dynamics caused by the application of hydraulic transmission system,design a highly efficient and stable servo hydraulic PID control system based the least squares hydraulic control model.Firstly,aiming at the valve control loss and volume instability under high power load,combined with the least squares fitting of the sensor control vector,a hydraulic control model based on the least squares method is proposed;then,throught the cross-cylinder is used to push the module in combination with the mixing crankshaft and the hydraulic pressure sensor, design the servo group hydraulic pressure PID control system transmission group,and established the servo hydraulic pressure PID control system.Finally,throught the field test and experimental analysis show that the designed servo-hydraulic PID control system has good performance in reducing the valve displacement,the output hydraulic pressure jitter,the number of sensor failures,and improving the volumetric efficiency of the hydraulic pump.

Presenting a fault diagnosis method in complex machine based on the shearer virtual prototyp experiment.The method is building a series of fault virtual prototyp experiment for its weight of testpoint,and then acquiring the fault-expression-vector corresponds to weight information by wavelet decomposition and neural network analysis.Through the analysis of neural network,building a classification system to diagnose the fault of machine.The fault virtual prototyp was applied to whole machine,and various testpoint was set.At length,the method was verified by simulation signals and engineering examples of mechanical fault diagnosis effectively.

With the continuous improvement of the operating speed of high-speed trains,the service environment and failure of high speed train gearbox are becoming ever more serious.At present,the domestic and foreign high-speed train gearbox has the fault phenomenon,which has seriously threatened the safety of high-speed train operation.Depending on this,some scholars at home and abroad have done some research on the causes of the failure of high-speed train gearbox.The technical methods and the results of the study on the vibration characteristics of high speed trains are summarized based on four aspects:the external excitation of the gear box,the internal excitation,the internal and external coupling excitation and the frequency characteristic.It is expected to provide technical support and reference for further study on the causes of gearbox failure.

In the recent two decades,especially in the last ten years,the theory and application of sparse decomposition have made great progress,and a great deal of literature has also been published in the field of fault diagnosis.Based on the published literature,the development of sparse decomposition is reviewed.Based on the brief introduction of sparse decomposition method,the existing improved algorithms are summarized according to the existing problems,including improving the atomic library and improving the computing speed.The fast algorithm mainly introduces the intelligent sparse decomposition method.The application of sparse decomposition in rotating machinery fault diagnosis is summarized.Some new research trends are also discussed,including artificial intelligence sparse decomposition,sparse decomposition for specific signal and compound fault sparse decomposition method which is helpful to the development of fault diagnosis technology.It is concluded that the sparse decomposition method has a broad prospect in the development of rotating machinery fault diagnosis.In the future,a large number of new algorithms combining artificial intelligence will appear.