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RSS2023 Vol. 42, No. 5
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2023, 42(5): 657-664.
doi: 10.13433/j.cnki.1003-8728.20200632
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Abstract:
To study the energy absorption characteristics of the cellular anti-climbing device of a subway vehicle, the structure of the energy absorption area was designed reasonably according to the crashworthiness standard of the railway vehicle, and then the energy absorption characteristics of the cellular anti-climbing device under different thin-walled shell thickness and honeycomb thickness were studied. The quaternary polynomial response surface proxy model was used to establish the compressive force efficiency, and the multi-island genetic algorithm was used to optimize the maximum compressive force efficiency. The results show that the specific energy absorption and compression force efficiency of multi-stage honeycomb anti-creeper are obviously better than those of single-stage honeycomb anti-creeper and tubular anti-creeper with the same mass. The effect of the thin-walled shell wall thickness on the impact force of multistage honeycomb is more significant than that of aluminum honeycomb wall thickness. The quaternary polynomial response surface method and multi-island genetic algorithm were used to find the optimal combination of wall thickness in the design space, and the compression force efficiency was increased by 6.03% comparing with that before optimization, and 60.96% comparing with that of the circular tube anti-creep. The anti-climbing device has obvious advantages in compression force efficiency and specific energy absorption, and it will play an important role in energy absorption and anti-climbing of subway vehicles.
To study the energy absorption characteristics of the cellular anti-climbing device of a subway vehicle, the structure of the energy absorption area was designed reasonably according to the crashworthiness standard of the railway vehicle, and then the energy absorption characteristics of the cellular anti-climbing device under different thin-walled shell thickness and honeycomb thickness were studied. The quaternary polynomial response surface proxy model was used to establish the compressive force efficiency, and the multi-island genetic algorithm was used to optimize the maximum compressive force efficiency. The results show that the specific energy absorption and compression force efficiency of multi-stage honeycomb anti-creeper are obviously better than those of single-stage honeycomb anti-creeper and tubular anti-creeper with the same mass. The effect of the thin-walled shell wall thickness on the impact force of multistage honeycomb is more significant than that of aluminum honeycomb wall thickness. The quaternary polynomial response surface method and multi-island genetic algorithm were used to find the optimal combination of wall thickness in the design space, and the compression force efficiency was increased by 6.03% comparing with that before optimization, and 60.96% comparing with that of the circular tube anti-creep. The anti-climbing device has obvious advantages in compression force efficiency and specific energy absorption, and it will play an important role in energy absorption and anti-climbing of subway vehicles.
2023, 42(5): 665-672.
doi: 10.13433/j.cnki.1003-8728.20220008
Abstract:
There are more and more accidents of the long-distance belt conveyors caused by idler failure, however, the traditional manual inspection cannot meet the demand, and a great number of sensors are demanded in the existing contact measuring method which has a difficulty of data collection, so it is necessary to carry out non-contact inspection by using an intelligent inspection robot equipped with a sound picker. In order to eliminate the noise in the test signal, the single channel blind source separation (SCBSS) denoising method based on the complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN), the principal component analysis (PCA) and the robust independent component analysis (RobustICA) is proposed. Since the idler signal has the characteristics of non-smooth and nonlinear, and the Mel-frequency cepstral coefficient (MFCC) alone cannot perfectly depict the signal feature, the adaptive feature parameters extraction method based on CEEMDAN, PCA, MFCC, MFCC' first order difference coefficients and Delta value is proposed. Finally, the fault identification is carried out by supporting vector machine as classifier and its recognition rate reaches up to 97.2%.
There are more and more accidents of the long-distance belt conveyors caused by idler failure, however, the traditional manual inspection cannot meet the demand, and a great number of sensors are demanded in the existing contact measuring method which has a difficulty of data collection, so it is necessary to carry out non-contact inspection by using an intelligent inspection robot equipped with a sound picker. In order to eliminate the noise in the test signal, the single channel blind source separation (SCBSS) denoising method based on the complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN), the principal component analysis (PCA) and the robust independent component analysis (RobustICA) is proposed. Since the idler signal has the characteristics of non-smooth and nonlinear, and the Mel-frequency cepstral coefficient (MFCC) alone cannot perfectly depict the signal feature, the adaptive feature parameters extraction method based on CEEMDAN, PCA, MFCC, MFCC' first order difference coefficients and Delta value is proposed. Finally, the fault identification is carried out by supporting vector machine as classifier and its recognition rate reaches up to 97.2%.
2023, 42(5): 673-678.
doi: 10.13433/j.cnki.1003-8728.20220031
Abstract:
In order to accurately predict the fatigue life of the electric commercial vehicle frame, the finite element model for frame was established and the strength simulation was carried out to determine the dangerous position of fatigue failure. Collecting the load spectrum of the fatigue risk position of the frame, and analyzing the fatigue damage value. The time domain signal of stress spectrum was transformed into rain flow matrix by rain flow counting method and Miner theory. The equivalent conversion relationship between the bench test and the road test of the fatigue life of the frame was established. Designing the experimental bench and method, the comparison between the road fatigue test and the bench fatigue test results shows that the equivalent conversion relation is valid, and the test method can improve the accuracy and reliability of the fatigue life prediction of the frame, shorten the time of the road fatigue test.
In order to accurately predict the fatigue life of the electric commercial vehicle frame, the finite element model for frame was established and the strength simulation was carried out to determine the dangerous position of fatigue failure. Collecting the load spectrum of the fatigue risk position of the frame, and analyzing the fatigue damage value. The time domain signal of stress spectrum was transformed into rain flow matrix by rain flow counting method and Miner theory. The equivalent conversion relationship between the bench test and the road test of the fatigue life of the frame was established. Designing the experimental bench and method, the comparison between the road fatigue test and the bench fatigue test results shows that the equivalent conversion relation is valid, and the test method can improve the accuracy and reliability of the fatigue life prediction of the frame, shorten the time of the road fatigue test.
2023, 42(5): 679-686.
doi: 10.13433/j.cnki.1003-8728.20220108
Abstract:
In order to give full play to the advantages of unmanned aerial vehicle cluster operation and complete the UAV cluster launch task quickly and reliably in complex environment and various tasks, a folding wing UAV cluster launch device is designed in this paper. Firstly, by analyzing the main performance indicators of UAV launch process, the principle of group launch and the overall arrangement of the device are studied. Taking the launch technical index as the input, the power matching scheme of the device is determined. Based on the geometry and kinematics relationship, the detailed design of each mechanism is completed. Using the coordination of eccentric block components and intermittent mechanism, the power of the motor is transmitted to the launch mechanism and transmission mechanism in time and section, and the energy storage spring is used to cycle eject the UAV. Finally, LMS Virtual.Lab software is used for multi-body dynamics modeling and simulation, the simulation results show that the motor power, UAV launch speed and launch frequency meet the design requirements, and the design scheme is feasible.
In order to give full play to the advantages of unmanned aerial vehicle cluster operation and complete the UAV cluster launch task quickly and reliably in complex environment and various tasks, a folding wing UAV cluster launch device is designed in this paper. Firstly, by analyzing the main performance indicators of UAV launch process, the principle of group launch and the overall arrangement of the device are studied. Taking the launch technical index as the input, the power matching scheme of the device is determined. Based on the geometry and kinematics relationship, the detailed design of each mechanism is completed. Using the coordination of eccentric block components and intermittent mechanism, the power of the motor is transmitted to the launch mechanism and transmission mechanism in time and section, and the energy storage spring is used to cycle eject the UAV. Finally, LMS Virtual.Lab software is used for multi-body dynamics modeling and simulation, the simulation results show that the motor power, UAV launch speed and launch frequency meet the design requirements, and the design scheme is feasible.
2023, 42(5): 687-693.
doi: 10.13433/j.cnki.1003-8728.20220042
Abstract:
In order to reveal the occurrence and development mechanism of the rotating stall of coal mine contra-rotating fan under distorted inlet condition, based on the detached-eddy simulation and the outlet throttle function, the numerical simulation and analysis of the internal unsteady flow in a coal mine contra-rotating fan under the rotating stall condition are carried out. The results show that stall inception in the two stage impellers are all “spike” inception, stall inception first occurs in the tip area of the two stage impellers, and the rotating stall first forms in the front impeller. The corner area at the root of the rear impeller also undergoes flow separation. However, the separation zone at the root of the blade is generated and developed independently. The propagation of the stall cells in the two stage impellers is realized by the variation of the disturbance intensity of the stall cells along the circumferential direction, which caused by the reverse flow in the adjacent blade passage and the reverse flow of the current blade passage, the propagation speed of the stall inceptions and the stall cells in the front impeller are 60.9% and 35% of the impeller speed, respectively, the two are 55% and 46% of the impeller speed in the rear impeller.
In order to reveal the occurrence and development mechanism of the rotating stall of coal mine contra-rotating fan under distorted inlet condition, based on the detached-eddy simulation and the outlet throttle function, the numerical simulation and analysis of the internal unsteady flow in a coal mine contra-rotating fan under the rotating stall condition are carried out. The results show that stall inception in the two stage impellers are all “spike” inception, stall inception first occurs in the tip area of the two stage impellers, and the rotating stall first forms in the front impeller. The corner area at the root of the rear impeller also undergoes flow separation. However, the separation zone at the root of the blade is generated and developed independently. The propagation of the stall cells in the two stage impellers is realized by the variation of the disturbance intensity of the stall cells along the circumferential direction, which caused by the reverse flow in the adjacent blade passage and the reverse flow of the current blade passage, the propagation speed of the stall inceptions and the stall cells in the front impeller are 60.9% and 35% of the impeller speed, respectively, the two are 55% and 46% of the impeller speed in the rear impeller.
2023, 42(5): 694-701.
doi: 10.13433/j.cnki.1003-8728.20220021
Abstract:
In order to shorten the time of parachute opening, the ejecting dynamics of the UAV parachute ejection system is studied. By means of high-speed rotation, a traction ball is used to pull the parachute opening to increase the initial area of the opening and accelerate more airflow into the parachute. After building the 3D model of parachute ejection system using Solidworks, it was imported into Adams for kinematics simulation, and the simulation results were analyzed. The results show that the traction ball does oblique throw after ejection and spreads out in four directions. And increasing the motor speed can increase the velocity and displacement of the traction ball in the horizontal direction, and increasing the spring stiffness coefficient can also increase the stiffness and displacement of the traction ball in the vertical direction. Under the ideal condition, the optimal motor speed is 2000 °/s, and the spring stiffness coefficient is 80 N/m. Compared with the previous ejection system, the opening time of the UAV recovery parachute drop system is only 1.4033 s and shortened by at least 0.5 s.
In order to shorten the time of parachute opening, the ejecting dynamics of the UAV parachute ejection system is studied. By means of high-speed rotation, a traction ball is used to pull the parachute opening to increase the initial area of the opening and accelerate more airflow into the parachute. After building the 3D model of parachute ejection system using Solidworks, it was imported into Adams for kinematics simulation, and the simulation results were analyzed. The results show that the traction ball does oblique throw after ejection and spreads out in four directions. And increasing the motor speed can increase the velocity and displacement of the traction ball in the horizontal direction, and increasing the spring stiffness coefficient can also increase the stiffness and displacement of the traction ball in the vertical direction. Under the ideal condition, the optimal motor speed is 2000 °/s, and the spring stiffness coefficient is 80 N/m. Compared with the previous ejection system, the opening time of the UAV recovery parachute drop system is only 1.4033 s and shortened by at least 0.5 s.
2023, 42(5): 702-708.
doi: 10.13433/j.cnki.1003-8728.20200624
Abstract:
Because a redundant manipulator does not satisfy the Pieper criterion and is not able to obtain a closed inverse kinematics solution, we propose an adaptive chaotic sparrow search algorithm (ACSSA). Firstly, the uniform distribution characteristics of the good point set is used to generate the initial population. Secondly, the adaptive dynamic weight is introduced to balance global and local search capabilities, enhance population diversity and local optimization. Finally, the Gaussian mutation is introduced to strengthen the local search capability, and at the same time to generate a Tent chaotic sequence to prevent falling into local optimization. The ACSSA is applied to solving the inverse kinematics of the redundant manipulator. The two working conditions of spatial point-to-point motion and spatial continuous trajectory tracking are simulated, and compared with the chaotic sparrow search algorithm (CSSA) and the sparrow search algorithm (SSA). The results show that, in the first working condition, the ACSSA improves the convergence accuracy by 2 orders of magnitude, and its stability is 2 or 3 orders of magnitude higher than the CSSA and the SSA respectively. In the second working condition, the ACSSA is one order of magnitude higher than the CSSA and 6 orders of magnitude higher than the SSA in terms of the absolute error accuracy and the stability of calculated value and theoretical value. It fully shows that the ACSSA has the characteristics of high accuracy and fast convergence speed.
Because a redundant manipulator does not satisfy the Pieper criterion and is not able to obtain a closed inverse kinematics solution, we propose an adaptive chaotic sparrow search algorithm (ACSSA). Firstly, the uniform distribution characteristics of the good point set is used to generate the initial population. Secondly, the adaptive dynamic weight is introduced to balance global and local search capabilities, enhance population diversity and local optimization. Finally, the Gaussian mutation is introduced to strengthen the local search capability, and at the same time to generate a Tent chaotic sequence to prevent falling into local optimization. The ACSSA is applied to solving the inverse kinematics of the redundant manipulator. The two working conditions of spatial point-to-point motion and spatial continuous trajectory tracking are simulated, and compared with the chaotic sparrow search algorithm (CSSA) and the sparrow search algorithm (SSA). The results show that, in the first working condition, the ACSSA improves the convergence accuracy by 2 orders of magnitude, and its stability is 2 or 3 orders of magnitude higher than the CSSA and the SSA respectively. In the second working condition, the ACSSA is one order of magnitude higher than the CSSA and 6 orders of magnitude higher than the SSA in terms of the absolute error accuracy and the stability of calculated value and theoretical value. It fully shows that the ACSSA has the characteristics of high accuracy and fast convergence speed.
2023, 42(5): 709-714.
doi: 10.13433/j.cnki.1003-8728.20220013
Abstract:
In this paper, the quarter car model is taken as the research object, and a feasible nonlinear suspension system construction method is proposed based on the nonlinear Duffing oscillator constructed by linear damping spring. The dynamic model of nonlinear suspension system is solved by the increased dimensional fine integral method. The optimization model of the nonlinear suspension system was established, in which the optimization objective is to minimize the root mean square value of the total weighted acceleration of the vehicle body, and the constraint condition is the value of vehicle offset frequency. Genetic algorithm is introduced to determine the optimal spring stiffness and damping coefficient of nonlinear suspension system. The Simulink simulation result proves that the nonlinear suspension system has better feasibility and superiority than the traditional linear suspension system. This study provides a new method for the design and optimization of nonlinear suspension system.
In this paper, the quarter car model is taken as the research object, and a feasible nonlinear suspension system construction method is proposed based on the nonlinear Duffing oscillator constructed by linear damping spring. The dynamic model of nonlinear suspension system is solved by the increased dimensional fine integral method. The optimization model of the nonlinear suspension system was established, in which the optimization objective is to minimize the root mean square value of the total weighted acceleration of the vehicle body, and the constraint condition is the value of vehicle offset frequency. Genetic algorithm is introduced to determine the optimal spring stiffness and damping coefficient of nonlinear suspension system. The Simulink simulation result proves that the nonlinear suspension system has better feasibility and superiority than the traditional linear suspension system. This study provides a new method for the design and optimization of nonlinear suspension system.
2023, 42(5): 715-723.
doi: 10.13433/j.cnki.1003-8728.20220028
Abstract:
Because it is difficult to diagnosecomplex hydraulic signals, the multi-scale one-dimensional convolutional neural network and multi-sensor information fusion (MS1D-CNN-MSIF) deep neural network model is proposed to diagnose the fault of hydraulic pump and accumulator. Under the proposed method, the convolution check signals of different sizes are used to extract multi-scale features. The multi-sensor information fusion strategy is used to fuse the characteristic signals of multiple sensors, which are thenclassified and recognized with the Softmax software. The experimental results on diagnosing the accumulator pressure state and hydraulic pump leakage state show that, compared with the support vector machine, stack self coding and deep confidence network, the proposed method has a better fault diagnosis performance and that the method’s recognition accuracy of the accumulator and hydraulic pump reaches 99.50% and 99.73% respectively.
Because it is difficult to diagnosecomplex hydraulic signals, the multi-scale one-dimensional convolutional neural network and multi-sensor information fusion (MS1D-CNN-MSIF) deep neural network model is proposed to diagnose the fault of hydraulic pump and accumulator. Under the proposed method, the convolution check signals of different sizes are used to extract multi-scale features. The multi-sensor information fusion strategy is used to fuse the characteristic signals of multiple sensors, which are thenclassified and recognized with the Softmax software. The experimental results on diagnosing the accumulator pressure state and hydraulic pump leakage state show that, compared with the support vector machine, stack self coding and deep confidence network, the proposed method has a better fault diagnosis performance and that the method’s recognition accuracy of the accumulator and hydraulic pump reaches 99.50% and 99.73% respectively.
2023, 42(5): 724-729.
doi: 10.13433/j.cnki.1003-8728.20220023
Abstract:
To remove polishing pressure fluctuation during robot bonnet polishing, the factors affecting the stability of polishing pressure were analyzed. The error compensation method was proposed to reduce the influence of polishing pressure fluctuation on the machining surface. Firstly, according to the motion model of bonnet polishing, the motion process was analyzed, and the material removal function model was established according to the Preston equation. The removal function was simulated and analyzed with the MATLAB. Then, in view of the system error caused by the end position fluctuation of the robot and according to the error data model, the machining point position is corrected immediately so as to reduce the polishing pressure fluctuation error introduced by the robot. The experimental results show that the error values in X and Y directions of the end position of the robot after compensation decrease by 86.2 % and 67.6 % respectively. The accuracy of the robot′s end position is significantly improved, and the RMS of final machining surface accuracy is 0.118λ. It is proved that the error compensation method can effectively reduce the fluctuation of polishing pressure and improve the quality of the machining surface.
To remove polishing pressure fluctuation during robot bonnet polishing, the factors affecting the stability of polishing pressure were analyzed. The error compensation method was proposed to reduce the influence of polishing pressure fluctuation on the machining surface. Firstly, according to the motion model of bonnet polishing, the motion process was analyzed, and the material removal function model was established according to the Preston equation. The removal function was simulated and analyzed with the MATLAB. Then, in view of the system error caused by the end position fluctuation of the robot and according to the error data model, the machining point position is corrected immediately so as to reduce the polishing pressure fluctuation error introduced by the robot. The experimental results show that the error values in X and Y directions of the end position of the robot after compensation decrease by 86.2 % and 67.6 % respectively. The accuracy of the robot′s end position is significantly improved, and the RMS of final machining surface accuracy is 0.118λ. It is proved that the error compensation method can effectively reduce the fluctuation of polishing pressure and improve the quality of the machining surface.
2023, 42(5): 730-735.
doi: 10.13433/j.cnki.1003-8728.20220036
Abstract:
Aiming at the problems that it is difficult to determine the penalty parameter and kernel function parameter , and different parameters have a great influence on the prediction effect with the support vector regression to predict the milling cutter’s life, the adaptive mutation particle swarm optimizationalgorithm was proposed. On the basis of the support vector regression algorithm, AMPSO (Adaptive Mutation Particle Swarm Optimization) was used to optimize the SVR (Support Vector Regression) parameters, and a life prediction model for milling cutter combining AMPSO with SVR was established. The results show that the average relative prediction error of the AMPSO-SVR algorithm in the test sample set is as low as 0.72%, which is smaller than that of the grid search method and the neural network algorithm. It can accurately predict the milling cutter’s life, which can provide a basis for tool change decisions during the machining process.
Aiming at the problems that it is difficult to determine the penalty parameter and kernel function parameter , and different parameters have a great influence on the prediction effect with the support vector regression to predict the milling cutter’s life, the adaptive mutation particle swarm optimizationalgorithm was proposed. On the basis of the support vector regression algorithm, AMPSO (Adaptive Mutation Particle Swarm Optimization) was used to optimize the SVR (Support Vector Regression) parameters, and a life prediction model for milling cutter combining AMPSO with SVR was established. The results show that the average relative prediction error of the AMPSO-SVR algorithm in the test sample set is as low as 0.72%, which is smaller than that of the grid search method and the neural network algorithm. It can accurately predict the milling cutter’s life, which can provide a basis for tool change decisions during the machining process.
2023, 42(5): 736-746.
doi: 10.13433/j.cnki.1003-8728.20220018
Abstract:
In order to improve the machining accuracy of complex curved components, the tool path generation of slow tool servo turning was carried out, and the tool radius compensation algorithm was studied. In this paper, a tool compensation algorithm based on chord length vertical is proposed by analyzing the shortcomings of the direction compensation algorithm and the Z-direction compensation algorithm, and the feasibility of the algorithm is verified with the simulation and turning of the torus surface. The simulation results show that the tool compensation algorithm of chord length vertical line has high precision in solving the CLPs, and the uniform motion of X axis is realized. The experimental results show that the tool compensation algorithm for chord length vertical line is better than the normal compensation algorithm and the Z-direction compensation algorithm, and the surface roughness is less affected by the tool compensation algorithm.
In order to improve the machining accuracy of complex curved components, the tool path generation of slow tool servo turning was carried out, and the tool radius compensation algorithm was studied. In this paper, a tool compensation algorithm based on chord length vertical is proposed by analyzing the shortcomings of the direction compensation algorithm and the Z-direction compensation algorithm, and the feasibility of the algorithm is verified with the simulation and turning of the torus surface. The simulation results show that the tool compensation algorithm of chord length vertical line has high precision in solving the CLPs, and the uniform motion of X axis is realized. The experimental results show that the tool compensation algorithm for chord length vertical line is better than the normal compensation algorithm and the Z-direction compensation algorithm, and the surface roughness is less affected by the tool compensation algorithm.
2023, 42(5): 747-754.
doi: 10.13433/j.cnki.1003-8728.20220024
Abstract:
In order to accurately obtain users' color perceptual needs and improve the success rate and efficiency of automotive interior design, EEG technology is introduced to analyze users' implicit perceptual information. Firstly, collect adjective vocabulary related to automotive interior design, and obtain representative image vocabulary through cluster analysis. The representative hues and spatial layout of the interior are summarized from the pictures of the interior of the automobile. Secondly, two sets of new interior color samples are synthesized and the representative vocabulary establishes an EEG-based perceptual cognitive experiment. Then, the collected original EEG data and behavioral data are processed to eliminate outliers and forward normalization to obtain standardized data. Finally, based on the standardized data, the entropy weight TOPSIS (Technique for order preference by similarity to an ideal solution) method is applied to weight different indicators, and the relative closeness between the sample and the image is calculated, and the best color sample ranking under the disagreement is obtained. The result was discussed by the expert group and proved that the scheme selected by the objective index is effective, which can be used as a design reference for the color design of automotive interiors.
In order to accurately obtain users' color perceptual needs and improve the success rate and efficiency of automotive interior design, EEG technology is introduced to analyze users' implicit perceptual information. Firstly, collect adjective vocabulary related to automotive interior design, and obtain representative image vocabulary through cluster analysis. The representative hues and spatial layout of the interior are summarized from the pictures of the interior of the automobile. Secondly, two sets of new interior color samples are synthesized and the representative vocabulary establishes an EEG-based perceptual cognitive experiment. Then, the collected original EEG data and behavioral data are processed to eliminate outliers and forward normalization to obtain standardized data. Finally, based on the standardized data, the entropy weight TOPSIS (Technique for order preference by similarity to an ideal solution) method is applied to weight different indicators, and the relative closeness between the sample and the image is calculated, and the best color sample ranking under the disagreement is obtained. The result was discussed by the expert group and proved that the scheme selected by the objective index is effective, which can be used as a design reference for the color design of automotive interiors.
2023, 42(5): 755-764.
doi: 10.13433/j.cnki.1003-8728.20230113
Abstract:
The traditional house of quality (HoQ) has poor ability to deal with the asymmetry of autocorrelation matrix and the autocorrelation between technical characteristics while transforming user requirements into technical characteristics. In order to address these problems, a new method that based on an improved HoQ model for product-service system (PSS) technical characteristics analysis was proposed. Firstly, the interaction graph model for functions and characteristics was used to identify the PSS technical characteristics, and then the triangle structure of traditional HoQ autocorrelation matrix was changed to rectangular structure to solve the asymmetry problem of technical characteristics. Secondly, the multi-granularity mixed language variables were introduced to establish the HoQ matrix to evaluate the correlation of different technical characteristics comprehensively. Finally, a case was used to illustrate the feasibility of the present model and method. The results show that the present method can effectively solve the technical characteristics conflict without losing the decision information, and also make the calculation of the HoQbe more convenient.
The traditional house of quality (HoQ) has poor ability to deal with the asymmetry of autocorrelation matrix and the autocorrelation between technical characteristics while transforming user requirements into technical characteristics. In order to address these problems, a new method that based on an improved HoQ model for product-service system (PSS) technical characteristics analysis was proposed. Firstly, the interaction graph model for functions and characteristics was used to identify the PSS technical characteristics, and then the triangle structure of traditional HoQ autocorrelation matrix was changed to rectangular structure to solve the asymmetry problem of technical characteristics. Secondly, the multi-granularity mixed language variables were introduced to establish the HoQ matrix to evaluate the correlation of different technical characteristics comprehensively. Finally, a case was used to illustrate the feasibility of the present model and method. The results show that the present method can effectively solve the technical characteristics conflict without losing the decision information, and also make the calculation of the HoQbe more convenient.
2023, 42(5): 765-771.
doi: 10.13433/j.cnki.1003-8728.20220022
Abstract:
The single pass and multi-layer stress field of arc additive in tungsten inert gas (TIG) shielded welding of Superalloy GH4169 was numerically simulated with the life and death element method with the finite element analysis software Simulact welding. The blind hole method is used to test the residual stress at each point on the selected substrate perpendicular to the vertical line of the weld, and the error between the measured value and the simulated is within 10 MPa, and the error percentage is about 2.8%. Deformation analysis of the additive workpiece shows that the repeated thermal cycle action causes the internal stress of the formed part to rise and fall continuously, and the peak stress decreases gradually. After forming and unloading, the residual stress is mainly concentrated on the bottom end of the arc starting and extinguishing part of the forming part. The total deformation of the formed part is symmetrically distributed after cooling to room temperature, and the degree of warping in the transverse direction is the largest, and the total deformation reaches 1.82 mm.
The single pass and multi-layer stress field of arc additive in tungsten inert gas (TIG) shielded welding of Superalloy GH4169 was numerically simulated with the life and death element method with the finite element analysis software Simulact welding. The blind hole method is used to test the residual stress at each point on the selected substrate perpendicular to the vertical line of the weld, and the error between the measured value and the simulated is within 10 MPa, and the error percentage is about 2.8%. Deformation analysis of the additive workpiece shows that the repeated thermal cycle action causes the internal stress of the formed part to rise and fall continuously, and the peak stress decreases gradually. After forming and unloading, the residual stress is mainly concentrated on the bottom end of the arc starting and extinguishing part of the forming part. The total deformation of the formed part is symmetrically distributed after cooling to room temperature, and the degree of warping in the transverse direction is the largest, and the total deformation reaches 1.82 mm.
Modeling and Simulation of Grinding Surface Microtopography Considering Grinding Thermal Deformation
2023, 42(5): 772-778.
doi: 10.13433/j.cnki.1003-8728.20220019
Abstract:
A modeling method of grinding surface micro-topography considering the influence of the grinding thermal deformation is proposed to solve the influence of the grinding heat on the surface grinding morphology of workpieces.Assuming that the abrasive grains are regular tetrahedrons; establish a three-dimensional cutting trajectory of a single abrasive grain by considering the effect of the grinding thermal deformation; establish a prediction model for the grinding surface micro-morphology. The results of grinding experiments show that the minimum error of the model is only 0.135%, and the maximum error is 13.31%, which verifies the accuracy of the simulation results under the influence of the grinding thermal deformation effects.
A modeling method of grinding surface micro-topography considering the influence of the grinding thermal deformation is proposed to solve the influence of the grinding heat on the surface grinding morphology of workpieces.Assuming that the abrasive grains are regular tetrahedrons; establish a three-dimensional cutting trajectory of a single abrasive grain by considering the effect of the grinding thermal deformation; establish a prediction model for the grinding surface micro-morphology. The results of grinding experiments show that the minimum error of the model is only 0.135%, and the maximum error is 13.31%, which verifies the accuracy of the simulation results under the influence of the grinding thermal deformation effects.
2023, 42(5): 779-784.
doi: 10.13433/j.cnki.1003-8728.20220029
Abstract:
The reliability of embedded CNC (Computer Numerical Control) software is an important issue. Because it contains many modules such as motor drive and interpolation interruption, the programs′ operation logic is complicated, and the execution sequence of the software modules is random, so the reliability evaluation of the software system is difficult. We adopted the Markov chain model to carry out the reliability evaluation of embedded CNC software, proposed a method of time sequence traceability, re-traced the program running sequence diagram, constructed the running profile and quantified the transition probability; Then we adopted a time-compensated program operation logic recovery method to eliminate the impact of key point data monitoring and output on the real-time performance of the system, and restore the logical sequence of the CPU on the time axis. Finally, an example is used to verify the feasibility of the method.
The reliability of embedded CNC (Computer Numerical Control) software is an important issue. Because it contains many modules such as motor drive and interpolation interruption, the programs′ operation logic is complicated, and the execution sequence of the software modules is random, so the reliability evaluation of the software system is difficult. We adopted the Markov chain model to carry out the reliability evaluation of embedded CNC software, proposed a method of time sequence traceability, re-traced the program running sequence diagram, constructed the running profile and quantified the transition probability; Then we adopted a time-compensated program operation logic recovery method to eliminate the impact of key point data monitoring and output on the real-time performance of the system, and restore the logical sequence of the CPU on the time axis. Finally, an example is used to verify the feasibility of the method.
2023, 42(5): 785-792.
doi: 10.13433/j.cnki.1003-8728.20230143
Abstract:
In order to solve the problem that the surface defects for steel strip are difficult to identify effectively, based on mixed domain feature set and multi-kernel support vector machine (MK-SVM), a classification and identification method for surface defects of steel strip was proposed. Firstly, the image feature indexes of surface defects for steel strip were calculated based on gray level features and texture features, and the mixed domain feature set was constructed, and then the mixed domain feature set was input to multi-kernel support vector machine to achieve the classification and identification of surface defects for steel strip. The experimental results show that the method can effectively extract the low dimensional sensitive features of surface defects for steel strip, with high identification accuracy and strong generalization ability, and can be applied to the classification and identification of surface defects steel strip in engineering.
In order to solve the problem that the surface defects for steel strip are difficult to identify effectively, based on mixed domain feature set and multi-kernel support vector machine (MK-SVM), a classification and identification method for surface defects of steel strip was proposed. Firstly, the image feature indexes of surface defects for steel strip were calculated based on gray level features and texture features, and the mixed domain feature set was constructed, and then the mixed domain feature set was input to multi-kernel support vector machine to achieve the classification and identification of surface defects for steel strip. The experimental results show that the method can effectively extract the low dimensional sensitive features of surface defects for steel strip, with high identification accuracy and strong generalization ability, and can be applied to the classification and identification of surface defects steel strip in engineering.
2023, 42(5): 793-801.
doi: 10.13433/j.cnki.1003-8728.20220015
Abstract:
Taking into account the roll stability and ride comfort under different working conditions as well as differences of drivers' driving habits, this paper proposes the fuzzy control strategy of an electric active anti-roll stabilizer (EAAS) with multiple operating modes. Firstly, a nine-degree-of-freedom vehicle dynamic model of the EAAS is established by using the MATLAB/Simulink and Vehicle Network Toolbox. Then, the Mamdani fuzzy control method is used to construct the fuzzy control strategy of the EAAS with multiple operating modes. Its off-line simulation is carried out under the angle step condition and fishhook condition. Finally, the electronic control unit and HIL test-bed of the EAAS are designed respectively. The effectiveness of the fuzzy control strategy is further verified with the HIL simulation. The simulation results show that the fuzzy control strategy of the EAAS with multiple operating modes can effectively improve the vehicle's roll stability.
Taking into account the roll stability and ride comfort under different working conditions as well as differences of drivers' driving habits, this paper proposes the fuzzy control strategy of an electric active anti-roll stabilizer (EAAS) with multiple operating modes. Firstly, a nine-degree-of-freedom vehicle dynamic model of the EAAS is established by using the MATLAB/Simulink and Vehicle Network Toolbox. Then, the Mamdani fuzzy control method is used to construct the fuzzy control strategy of the EAAS with multiple operating modes. Its off-line simulation is carried out under the angle step condition and fishhook condition. Finally, the electronic control unit and HIL test-bed of the EAAS are designed respectively. The effectiveness of the fuzzy control strategy is further verified with the HIL simulation. The simulation results show that the fuzzy control strategy of the EAAS with multiple operating modes can effectively improve the vehicle's roll stability.
2023, 42(5): 802-807.
doi: 10.13433/j.cnki.1003-8728.20200628
Abstract:
Life evaluation and prediction methods for lubrication and sealing materials is a bottleneck that needs to be broken. In order to improve the efficiency of accelerated life assessment while ensuring the accuracy of accelerated life assessment, on the basis of traditional accelerated life assessment methods, an accelerated life assessment method based on time scale optimization is proposed. Firstly, a unified model for performance decay trajectory with time scaleis established, and the mean square error minimization as the optimization goal to obtain the optimal time scale coefficientis taken consideration. Secondly, the parameters of the trajectory model through the nonlinear least squares method isidentified, and then the decay rateis established. The acceleration model is used to extrapolate the decay rate at room temperature from accelerated high temperatures. Finally, a three-dimensional model for aging time-temperature-performance decay is established, with which the accuracy of the model is verified by comparing the measured data.
Life evaluation and prediction methods for lubrication and sealing materials is a bottleneck that needs to be broken. In order to improve the efficiency of accelerated life assessment while ensuring the accuracy of accelerated life assessment, on the basis of traditional accelerated life assessment methods, an accelerated life assessment method based on time scale optimization is proposed. Firstly, a unified model for performance decay trajectory with time scaleis established, and the mean square error minimization as the optimization goal to obtain the optimal time scale coefficientis taken consideration. Secondly, the parameters of the trajectory model through the nonlinear least squares method isidentified, and then the decay rateis established. The acceleration model is used to extrapolate the decay rate at room temperature from accelerated high temperatures. Finally, a three-dimensional model for aging time-temperature-performance decay is established, with which the accuracy of the model is verified by comparing the measured data.
2023, 42(5): 808-813.
doi: 10.13433/j.cnki.1003-8728.20200622
Abstract:
In order to study the failure mode of the fan blade coating under random sand erosion, numerical simulation is carried out for the blade erosion by random sand erosion. Taking Inner Mongolia as an example, Weibull distribution model for random wind speed is established, and by coupling Fluent with EDEM sand erosion simulation and analysis of fluid-solid coupling surface forms the time course of the FSI dynamic pressure data and the grains of sand shock impact load of blade coating, finally the random load obtained by using finite element method applied to the blade model is analyzed. The results show that the dynamic pressure of FSI on the fluid-solid coupling surface is between 20-140 Pa, and the impact load of sand particles is between 0.4-7.9 N, both of which have significant randomness. The maximum stress response of the blade coating is 2.79 MPa, located near the leading edge of the blade tip and its side.
In order to study the failure mode of the fan blade coating under random sand erosion, numerical simulation is carried out for the blade erosion by random sand erosion. Taking Inner Mongolia as an example, Weibull distribution model for random wind speed is established, and by coupling Fluent with EDEM sand erosion simulation and analysis of fluid-solid coupling surface forms the time course of the FSI dynamic pressure data and the grains of sand shock impact load of blade coating, finally the random load obtained by using finite element method applied to the blade model is analyzed. The results show that the dynamic pressure of FSI on the fluid-solid coupling surface is between 20-140 Pa, and the impact load of sand particles is between 0.4-7.9 N, both of which have significant randomness. The maximum stress response of the blade coating is 2.79 MPa, located near the leading edge of the blade tip and its side.
2023, 42(5): 814-820.
doi: 10.13433/j.cnki.1003-8728.20220027
Abstract:
The structure of aircraft turbofan engine is extremely precise and complex, and the health of the engine's starting system has a particularly important impact on the engine. Therefore, the reliability evaluation of the engine's starting system plays a vital role in the safety and stability of air flight. In order to improve the accuracy of system reliability analysis, trapezoidal fuzzy method is used to process the original fault data. Based on experts′ experience, two kinds of importance and the posterior probability are calculated, which complete the modeling of reliability assessment of turbofan engine starting system. By means of example verification, the reliability evaluation of the starting system of a certain type of aero-turbofan engine is carried out, the influence of different states of each component on the starting system and its importance degree are calculated. So we can find the weak links of the starting system that are easy to fail, which can supply us ideas and methods to improve the safety and reliability of the whole engine system.
The structure of aircraft turbofan engine is extremely precise and complex, and the health of the engine's starting system has a particularly important impact on the engine. Therefore, the reliability evaluation of the engine's starting system plays a vital role in the safety and stability of air flight. In order to improve the accuracy of system reliability analysis, trapezoidal fuzzy method is used to process the original fault data. Based on experts′ experience, two kinds of importance and the posterior probability are calculated, which complete the modeling of reliability assessment of turbofan engine starting system. By means of example verification, the reliability evaluation of the starting system of a certain type of aero-turbofan engine is carried out, the influence of different states of each component on the starting system and its importance degree are calculated. So we can find the weak links of the starting system that are easy to fail, which can supply us ideas and methods to improve the safety and reliability of the whole engine system.
