Author Center
Editor Work
Peer Review
Editorial Entry
Email Alert
RSS2012 Vol. 31, No. 7
Display Method:
2012, 31(7): 1033-1036.
PDF 702KB
Abstract:
The civil aircraft aisle's width is an important factor which affects the emergency evacuation time and the cabin layout. In this paper, the effects of various aisles' width on the time of emergency evacuation in civil aircrafts are studied. A test platform used to simulate a part of the civil aircraft cabin is built. By doing a series of basic ex-periments on the platform, emergency evacuation time of different passenger groups in different aisle width cabin is obtained. Using statistical and mathematical methods of variance analysis, the experimental data is dealt with. And based on the analysis, a conclusion is drawn that the impact on the emergency evacuation time is not significant as the civil aircraft aisle's width is varied within a certain range.
The civil aircraft aisle's width is an important factor which affects the emergency evacuation time and the cabin layout. In this paper, the effects of various aisles' width on the time of emergency evacuation in civil aircrafts are studied. A test platform used to simulate a part of the civil aircraft cabin is built. By doing a series of basic ex-periments on the platform, emergency evacuation time of different passenger groups in different aisle width cabin is obtained. Using statistical and mathematical methods of variance analysis, the experimental data is dealt with. And based on the analysis, a conclusion is drawn that the impact on the emergency evacuation time is not significant as the civil aircraft aisle's width is varied within a certain range.
2012, 31(7): 1037-1041.
Abstract:
Due to the wind loss of flywheel in disc motor type flywheel energy storage devices, the paper focused on using self-pumping vacuum flywheel energy storage devices to reduce the wind loss, an interior molecular pump of flywheel energy storage devices is designed, and viscous gas flow and slip flow in the rotor spiral groove of the inte-rior molecular pump is simulated by computational fluid dynamics method to analyze its vacuuming performance. The vacuum-pumping time of flywheel energy storage devices in self-pumping style is compared with that in common external vacuum system. The results demonstrate that there always exists pressure difference between the entrance and the exit of the rotor spiral groove of the interior molecular pump of self-pumping style. Within the scope of 12 000 r/min -60 000 r/min, vacuuming performance is good, and it only takes 1/20 of the time when the common external vacuum system needs to reach 0.01 Pa.
Due to the wind loss of flywheel in disc motor type flywheel energy storage devices, the paper focused on using self-pumping vacuum flywheel energy storage devices to reduce the wind loss, an interior molecular pump of flywheel energy storage devices is designed, and viscous gas flow and slip flow in the rotor spiral groove of the inte-rior molecular pump is simulated by computational fluid dynamics method to analyze its vacuuming performance. The vacuum-pumping time of flywheel energy storage devices in self-pumping style is compared with that in common external vacuum system. The results demonstrate that there always exists pressure difference between the entrance and the exit of the rotor spiral groove of the interior molecular pump of self-pumping style. Within the scope of 12 000 r/min -60 000 r/min, vacuuming performance is good, and it only takes 1/20 of the time when the common external vacuum system needs to reach 0.01 Pa.
2012, 31(7): 1042-1045.
Abstract:
A new three degrees of freedoms completely deeoupled parallel mechanism is presented, whose moving platform has a one-dimensional translation and two-dimensional rotations. Firstly the degrees of freedom are calcu-lated and the active joints are chosen. Then the position equation of the mechanism is presented and its direct and inverse analytical solutions are derived. Ditect and inverse Jacobian matrix and the velocity are obtained through the first derivative for the position equations. By using influence coefficient method, the second-order influence coeffi-cient and the acceleration are derived. In addition, as the global Jacobian matrix is lower tion of the mechanism is tion example is given for completely decoupled, which the kinematics curve by using triangular matrix, the mo-simplify dynamic analysis and control. At last, an applica-Matlab.
A new three degrees of freedoms completely deeoupled parallel mechanism is presented, whose moving platform has a one-dimensional translation and two-dimensional rotations. Firstly the degrees of freedom are calcu-lated and the active joints are chosen. Then the position equation of the mechanism is presented and its direct and inverse analytical solutions are derived. Ditect and inverse Jacobian matrix and the velocity are obtained through the first derivative for the position equations. By using influence coefficient method, the second-order influence coeffi-cient and the acceleration are derived. In addition, as the global Jacobian matrix is lower tion of the mechanism is tion example is given for completely decoupled, which the kinematics curve by using triangular matrix, the mo-simplify dynamic analysis and control. At last, an applica-Matlab.
2012, 31(7): 1046-1049.
Abstract:
The basic theory of hybrid FE-SEA method was reviewed and the FE-SEA model of the complex cylindri-cal structure was built in this study. The coupling loss factor of the model was modified by utilizing the FEM-BEM method. Moreover, the sound radiation characteristics of such structures under the white noise excitation were pre-dicted. The sound pressure level in the sound cavity of complex cylindrical structure was measured in the anechoic room under the acoustic excitation. Meanwhile, the model was simulated and the results show well agreement with the experimental data. This method, which modifies the coupling loss factor using FEM-BEM, improves the predic-tion precision and reduces the absolute error to less than 5 dB within intermediate frequency region.
The basic theory of hybrid FE-SEA method was reviewed and the FE-SEA model of the complex cylindri-cal structure was built in this study. The coupling loss factor of the model was modified by utilizing the FEM-BEM method. Moreover, the sound radiation characteristics of such structures under the white noise excitation were pre-dicted. The sound pressure level in the sound cavity of complex cylindrical structure was measured in the anechoic room under the acoustic excitation. Meanwhile, the model was simulated and the results show well agreement with the experimental data. This method, which modifies the coupling loss factor using FEM-BEM, improves the predic-tion precision and reduces the absolute error to less than 5 dB within intermediate frequency region.
2012, 31(7): 1050-1054.
Abstract:
A one-stage symmetrical micro-displacement amplifier that uses flexure hinges is designed to amplify the micro-displacement output of a giant magnetostrictive actuator. Its structural form, geometrical parameters and ri-gidity are analyzed to improve its micro-displacement amplification efficiency. We also do the analysis of its static displacement output characteristics and calculate its stiffness. The finite element method is used to simulate its per-formance, and experiments are done to verify its static displacement output and rigidity. The experimental results show that the micro-displacement amplifier we designed has small micro-displacement loss and good micro-displace-ment amplification capability and efficiency.
A one-stage symmetrical micro-displacement amplifier that uses flexure hinges is designed to amplify the micro-displacement output of a giant magnetostrictive actuator. Its structural form, geometrical parameters and ri-gidity are analyzed to improve its micro-displacement amplification efficiency. We also do the analysis of its static displacement output characteristics and calculate its stiffness. The finite element method is used to simulate its per-formance, and experiments are done to verify its static displacement output and rigidity. The experimental results show that the micro-displacement amplifier we designed has small micro-displacement loss and good micro-displace-ment amplification capability and efficiency.
2012, 31(7): 1055-1061.
Abstract:
We minimize the utility work time by considering both task assignment and product sequence. We build the mathematical model and design a hybrid strategy that uses the immune clone selection algorithm. The algorithm considers independently the balancing of the mixed-mode assembly line in order to obtain the initial solution of the task assignment and then applies the local search algorithm to adjust the initial solution and obtain the optimal task assignment for a certain product sequence. Compared with other algorithms, our algorithm is more effective. The simulation results with eM-PLANT show that the simultaneous balancing and scheduling of the mixed-mode assem-bly line can reduce its utility work time.
We minimize the utility work time by considering both task assignment and product sequence. We build the mathematical model and design a hybrid strategy that uses the immune clone selection algorithm. The algorithm considers independently the balancing of the mixed-mode assembly line in order to obtain the initial solution of the task assignment and then applies the local search algorithm to adjust the initial solution and obtain the optimal task assignment for a certain product sequence. Compared with other algorithms, our algorithm is more effective. The simulation results with eM-PLANT show that the simultaneous balancing and scheduling of the mixed-mode assem-bly line can reduce its utility work time.
2012, 31(7): 1062-1065.
Abstract:
We build the bond graph model of the steering system of the mobile robot CyCab and obtain the modeling equations for its motor and belt. In order to accurately identify the unknown parameters in the model, we propose a method that combines the least squares method with the BP (back propagation) neural network. We utilize the identification results obtained with the least square method as the initial weighing values of the BP neural network training. We also introduce weighing factors to improve the convergence of the training process. Finally we use the least squares method and the improved BP neural network to identify the unknown parameters in the model. The ex-perimental results show that our improved BP neural network identification algorithm has higher precision for identif-ying the unknown parameters.
We build the bond graph model of the steering system of the mobile robot CyCab and obtain the modeling equations for its motor and belt. In order to accurately identify the unknown parameters in the model, we propose a method that combines the least squares method with the BP (back propagation) neural network. We utilize the identification results obtained with the least square method as the initial weighing values of the BP neural network training. We also introduce weighing factors to improve the convergence of the training process. Finally we use the least squares method and the improved BP neural network to identify the unknown parameters in the model. The ex-perimental results show that our improved BP neural network identification algorithm has higher precision for identif-ying the unknown parameters.
2012, 31(7): 1066-1070.
Abstract:
We design a novel structure of the giant magnetostrictive actuator (GMA) for high-frequency servo-valve and then use the FEM to perform the numerical simulation of the magnetic field distribution of the GMA we de-signed. We analyze the effects of drive and bias currents, the size of giant magnetostrictive rod, the structural form of permanent magnet and its output rod on the magnetic field distribution. Finally, we use the numerical simulation results to optimize the structural form and design parameters of the GMA. The simulation results are in agreement with optimization results and experimental curves, thus providing a theoretical basis for designing a high-perform-ance GMA.
We design a novel structure of the giant magnetostrictive actuator (GMA) for high-frequency servo-valve and then use the FEM to perform the numerical simulation of the magnetic field distribution of the GMA we de-signed. We analyze the effects of drive and bias currents, the size of giant magnetostrictive rod, the structural form of permanent magnet and its output rod on the magnetic field distribution. Finally, we use the numerical simulation results to optimize the structural form and design parameters of the GMA. The simulation results are in agreement with optimization results and experimental curves, thus providing a theoretical basis for designing a high-perform-ance GMA.
2012, 31(7): 1071-1074.
Abstract:
Underwater plasma sound source acting as a high-power controllable sound source has many advantages, and been more and more widely applied to exploit resource under the sea and potential in military realm. Its acoustic efficiency is one of the focuses of the issues. This paper presents the techniques of high-power underwater shockwave generation, microcosmic mechanism of underwater plasma, and directional radiation of underwater sound pulse. The design principle of each part of underwater plasma discharge system and the configure scheme of system parameters were particular researched. Some key components of these test devices are designed in detail. Finally, the application of underwater plasma sound source is discussed. The research in this paper accumulates lots of ex-perience about underwater plasma sound source design.
Underwater plasma sound source acting as a high-power controllable sound source has many advantages, and been more and more widely applied to exploit resource under the sea and potential in military realm. Its acoustic efficiency is one of the focuses of the issues. This paper presents the techniques of high-power underwater shockwave generation, microcosmic mechanism of underwater plasma, and directional radiation of underwater sound pulse. The design principle of each part of underwater plasma discharge system and the configure scheme of system parameters were particular researched. Some key components of these test devices are designed in detail. Finally, the application of underwater plasma sound source is discussed. The research in this paper accumulates lots of ex-perience about underwater plasma sound source design.
2012, 31(7): 1075-1078.
Abstract:
Based on the theory of multi-body dynamics, the virtual prototype model of four-link type dependent air suspension for a certain truck is established with the software ADAMS/View. We analyze the riding smoothness of the air suspension by using the total weighed mean square root value of the response acceleration at the frame mass center as the smoothness evaluation indicator. Then, its optimal design model is established by using the minimum weighted mean square root value of vertical acceleration at the frame mass center as the objective function. After ex-periments, design and analysis, we choose the length of the bar of the four-link guiding mechanism and the rigidity and damping of rubber bushing as design variables to optimize the air suspension with the sequential quadratic pro-gramming algorithm. The optimization results show that the selection of suitable parameters of the guiding mecha-nism and rubber bushing to match the air spring of the suspension can enhance its riding smoothness effectively.
Based on the theory of multi-body dynamics, the virtual prototype model of four-link type dependent air suspension for a certain truck is established with the software ADAMS/View. We analyze the riding smoothness of the air suspension by using the total weighed mean square root value of the response acceleration at the frame mass center as the smoothness evaluation indicator. Then, its optimal design model is established by using the minimum weighted mean square root value of vertical acceleration at the frame mass center as the objective function. After ex-periments, design and analysis, we choose the length of the bar of the four-link guiding mechanism and the rigidity and damping of rubber bushing as design variables to optimize the air suspension with the sequential quadratic pro-gramming algorithm. The optimization results show that the selection of suitable parameters of the guiding mecha-nism and rubber bushing to match the air spring of the suspension can enhance its riding smoothness effectively.
2012, 31(7): 1079-1084.
Abstract:
Three-dimensional printing (3DP) as an important solid free from tabrication (3FF) tecnnology he-comes popular due to rapid prototyping, no pollution, and high productivity. Based on the experiment platform of ZP310, in this paper, the influence of print parameters of the location of parts, power thickness and saturation level on the parts surface topography and accuracy were investigated. The full factorial experimental method was used to obtain the rectangular parts which were made with different print parameters. Finally, all parts' surface topography was measured by profiler. The results show that the best surface topography can be obtained at the parametrical set-ting of power thickness 0.1 mm and saturation level 70% as the parts are placed on the left of manufacturing room.
Three-dimensional printing (3DP) as an important solid free from tabrication (3FF) tecnnology he-comes popular due to rapid prototyping, no pollution, and high productivity. Based on the experiment platform of ZP310, in this paper, the influence of print parameters of the location of parts, power thickness and saturation level on the parts surface topography and accuracy were investigated. The full factorial experimental method was used to obtain the rectangular parts which were made with different print parameters. Finally, all parts' surface topography was measured by profiler. The results show that the best surface topography can be obtained at the parametrical set-ting of power thickness 0.1 mm and saturation level 70% as the parts are placed on the left of manufacturing room.
2012, 31(7): 1085-1089.
Abstract:
To solve the problem that the intelligent mobile robot path planning method is easy to fall into local opti-mization, this paper presents an adaptive artificial fish school algorithm with variable step size, variable congestion factor and the variable view domain, for the global path planning of mobile cleaning tank robot. Aiming at the shortcomings of artificial fish school algorithm, the new algorithm uses an adaptive adjustment factor to adjust the artificial fish's visual field, moving step and the congestion factor to improve the periodicity in cleaning tank path planning of mobile robot, and can get the global best optimal path and local search to avoid the traditional local searching AFSA weak shortcomings. Simulation results show that compared with the artificial fish school algorithm, the adaptive artificial fish school algorithm can quickly obtain the global optimal path and improve the convergence speed and accuracy.
To solve the problem that the intelligent mobile robot path planning method is easy to fall into local opti-mization, this paper presents an adaptive artificial fish school algorithm with variable step size, variable congestion factor and the variable view domain, for the global path planning of mobile cleaning tank robot. Aiming at the shortcomings of artificial fish school algorithm, the new algorithm uses an adaptive adjustment factor to adjust the artificial fish's visual field, moving step and the congestion factor to improve the periodicity in cleaning tank path planning of mobile robot, and can get the global best optimal path and local search to avoid the traditional local searching AFSA weak shortcomings. Simulation results show that compared with the artificial fish school algorithm, the adaptive artificial fish school algorithm can quickly obtain the global optimal path and improve the convergence speed and accuracy.
2012, 31(7): 1090-1093.
Abstract:
Starting from the operating principle of interlock device on the ejection seat and the working order of its agencies, we analyzed the reasons why ignition institution worked in advance, and established the finite element analysis model of the key component-lock arm in the interlock device. Through the simulation analysis, we found clearly the maximum deformation site of the lock arm, the risk strength parts of the lock arm, and proposed the modification program of the lock arm in the structure size, and finished the deformation and stress analysis of the modified lock arm. The results showed that the end maximum deformation of the lock arm was reduced, and the stress intensity of the weak parts was significantly lower than before, which verified the effectiveness of the modifi-cation program. The study provides a reference for the optimal design of key components on the interlock device.
Starting from the operating principle of interlock device on the ejection seat and the working order of its agencies, we analyzed the reasons why ignition institution worked in advance, and established the finite element analysis model of the key component-lock arm in the interlock device. Through the simulation analysis, we found clearly the maximum deformation site of the lock arm, the risk strength parts of the lock arm, and proposed the modification program of the lock arm in the structure size, and finished the deformation and stress analysis of the modified lock arm. The results showed that the end maximum deformation of the lock arm was reduced, and the stress intensity of the weak parts was significantly lower than before, which verified the effectiveness of the modifi-cation program. The study provides a reference for the optimal design of key components on the interlock device.
2012, 31(7): 1094-1099.
Abstract:
A novel 3-SPS/CR spatial parallel mechanism that can perform two-dimensional rotations and translationfor Z axis is presented, the SPS-limp and CR-limp are regarded as the driver and driven. The parallel mechanism is synthesized by the configuration evolution and the constraint synthesis theory. The principles for motions are ana-lyzed based on the screw theory, the degree of freedom is calculated, the forward and reverse solutions of position analysis were presented, the Jaeobian matrix and the workspace were analyzed. The optimal objective function is presented about weight eomposite of dexterousness and capacity performance, the structure parameters of the mech-anism are optimized with genetic algorithm and the optimization results are applied to design of mechanism. Lastly this method is verified through real examole and simulation.
A novel 3-SPS/CR spatial parallel mechanism that can perform two-dimensional rotations and translationfor Z axis is presented, the SPS-limp and CR-limp are regarded as the driver and driven. The parallel mechanism is synthesized by the configuration evolution and the constraint synthesis theory. The principles for motions are ana-lyzed based on the screw theory, the degree of freedom is calculated, the forward and reverse solutions of position analysis were presented, the Jaeobian matrix and the workspace were analyzed. The optimal objective function is presented about weight eomposite of dexterousness and capacity performance, the structure parameters of the mech-anism are optimized with genetic algorithm and the optimization results are applied to design of mechanism. Lastly this method is verified through real examole and simulation.
2012, 31(7): 1100-1103.
Abstract:
The instantaneous center of velocity between two components must first be located in order to analyze the velocity of the mechanism using the velocity instantaneous center method. For some simple mechanism, the velocity instantaneous center between two components can not be determined by the relations between components in analy-zing mechanism. In order to solve the kind of problem, this paper puts forward the mechanism extension method to determine some indefinite instantaneous center of velocity. The mechanism extension method is the way that the ini-tial mechanism is extended to the mechanism consisting of more components and it increases three component com-binations being used for theorem of three velocity instantaneous centers. Meanwhile, it is ensured that both the ex-tended mechanism and the initial mechanism are equivalent. Thus, some indefinite instantaneous centers of velocity in the initial mechanism can be located with its extended mechanism. The application of the mechanism extension method is demonstrated with examples and the results show that the new method is supplied for the kinetic synthesis of mechanism.
The instantaneous center of velocity between two components must first be located in order to analyze the velocity of the mechanism using the velocity instantaneous center method. For some simple mechanism, the velocity instantaneous center between two components can not be determined by the relations between components in analy-zing mechanism. In order to solve the kind of problem, this paper puts forward the mechanism extension method to determine some indefinite instantaneous center of velocity. The mechanism extension method is the way that the ini-tial mechanism is extended to the mechanism consisting of more components and it increases three component com-binations being used for theorem of three velocity instantaneous centers. Meanwhile, it is ensured that both the ex-tended mechanism and the initial mechanism are equivalent. Thus, some indefinite instantaneous centers of velocity in the initial mechanism can be located with its extended mechanism. The application of the mechanism extension method is demonstrated with examples and the results show that the new method is supplied for the kinetic synthesis of mechanism.
2012, 31(7): 1104-1109.
Abstract:
On the basis road feel concept and human psychological feeling characteristics in vehicle handling, a comprehensive road feel concept, which takes steering wheel torque and angle into account, is proposed. According to Weber-Fischna's law and the corresponding relationship between road feel and vehicle response, a method to cal-culate the desired steering wheel torque is presented in this paper. The desired steering wheel torque in various driving conditions is calculated and the results are compared with the experiment ones of literatures. To improve the calculation accuracy, a revised method to compute the intensity of vehicle response is discussed. The comparisons of results demonstrate the feasibility of the proposed method.
On the basis road feel concept and human psychological feeling characteristics in vehicle handling, a comprehensive road feel concept, which takes steering wheel torque and angle into account, is proposed. According to Weber-Fischna's law and the corresponding relationship between road feel and vehicle response, a method to cal-culate the desired steering wheel torque is presented in this paper. The desired steering wheel torque in various driving conditions is calculated and the results are compared with the experiment ones of literatures. To improve the calculation accuracy, a revised method to compute the intensity of vehicle response is discussed. The comparisons of results demonstrate the feasibility of the proposed method.
2012, 31(7): 1110-1114.
Abstract:
Discrete wavelet transform (DWT) is suggested to analyze the acceleration signals at different testing points, in order to study the characteristic quantity of bolted joints condition and monitor the results of the localized sensor region. The experimental system is built with the NI data acquisition equipment. Based on the qualitative analysis for the loose process of the bolted joints and the spectrum analysis for response signals, an appropriate wavelet function is chosen and the decomposed different measuring points, the contour diagrams levels are determined. According to the amplitude of each level at are drawn, then the maximun, minimun amplitude and range of all levels'detail coefficients and the RMS of detail coefficients at the sensitive level are calculated. The experimental result shows that through the DWT combined with statistical analysis to analyze the response signals at evenly dis-tributed measuring points, the obtained characteristic quantities have significant difference with the preloading changes and can identify the bolted joints condition in a better way.
Discrete wavelet transform (DWT) is suggested to analyze the acceleration signals at different testing points, in order to study the characteristic quantity of bolted joints condition and monitor the results of the localized sensor region. The experimental system is built with the NI data acquisition equipment. Based on the qualitative analysis for the loose process of the bolted joints and the spectrum analysis for response signals, an appropriate wavelet function is chosen and the decomposed different measuring points, the contour diagrams levels are determined. According to the amplitude of each level at are drawn, then the maximun, minimun amplitude and range of all levels'detail coefficients and the RMS of detail coefficients at the sensitive level are calculated. The experimental result shows that through the DWT combined with statistical analysis to analyze the response signals at evenly dis-tributed measuring points, the obtained characteristic quantities have significant difference with the preloading changes and can identify the bolted joints condition in a better way.
2012, 31(7): 1115-1120.
Abstract:
Complete and credible assembly model are imperative in assembly sequence planning. Timed Petri net is an efficient graph-based mathematical tool suitable to optimize and select assembly sequences based on a complete and credible assembly model. An approach for estimating assembly timed Petri net model is proposed. In this ap-proach, all possible assembly operations are analyzed and local geometrically feasibility of subassemblies is esti-mated layer by layer to guarantee the reliability of assembly model. The established assembly timed Petri net model can provide data support for the evaluation, optimization and selection of assembly sequences.
Complete and credible assembly model are imperative in assembly sequence planning. Timed Petri net is an efficient graph-based mathematical tool suitable to optimize and select assembly sequences based on a complete and credible assembly model. An approach for estimating assembly timed Petri net model is proposed. In this ap-proach, all possible assembly operations are analyzed and local geometrically feasibility of subassemblies is esti-mated layer by layer to guarantee the reliability of assembly model. The established assembly timed Petri net model can provide data support for the evaluation, optimization and selection of assembly sequences.
2012, 31(7): 1121-1127.
Abstract:
The automation adjustment positioner of position and pose is designed for fuselage. Cubic polynomial traj-ectory planning algorithm is proposed for fuselage considering the adjustment kinematic characteristics of fuselage po-sition and pose. Fuselage position and pose accuracy tracking measurement method is presented based on reference points which position and pose are tracked by using a laser tracker. Fuselage position and pose adjustment is divided into four stages： roll adjustment, pitch adjustment, yaw adjustment and position adjustment. The state equation of each stage and the observation equation are established; ative algorithm are presented for reference points. Using are obtained, and the real-time position and pose of racy automation adjustment method of fuselage moreover, the unscented Kalman filter and extrapolation iter-the algorithm, the measurement coordinate optimal estimates fuselage are calculated. Based on the above research, the accu-position and pose is presented. Simulation experiments show there are small derivation variations due to the real-time correction of fuselage position and pose, but the whole adjustment can keep stable and is easily realized and high tracking precisions of position and pose are achieved.
The automation adjustment positioner of position and pose is designed for fuselage. Cubic polynomial traj-ectory planning algorithm is proposed for fuselage considering the adjustment kinematic characteristics of fuselage po-sition and pose. Fuselage position and pose accuracy tracking measurement method is presented based on reference points which position and pose are tracked by using a laser tracker. Fuselage position and pose adjustment is divided into four stages： roll adjustment, pitch adjustment, yaw adjustment and position adjustment. The state equation of each stage and the observation equation are established; ative algorithm are presented for reference points. Using are obtained, and the real-time position and pose of racy automation adjustment method of fuselage moreover, the unscented Kalman filter and extrapolation iter-the algorithm, the measurement coordinate optimal estimates fuselage are calculated. Based on the above research, the accu-position and pose is presented. Simulation experiments show there are small derivation variations due to the real-time correction of fuselage position and pose, but the whole adjustment can keep stable and is easily realized and high tracking precisions of position and pose are achieved.
2012, 31(7): 1128-1131.
Abstract:
This paper inv Firstly, the mode shapes estigated the characteristics of structure dynamic response under thermal-acoustic loading. and modal frequencies before and after thermal buckled were analyzed. Then the thin-wall structure out-of-plane displacement response was evaluated, by analyzing displacement probability distribution func-tion(PDF), it showed that thin wall panel vibrated around two different equilibrium configuration, that is snap-through motion, and also showed that snap-through frequencies increases with the increasing of sound pressure level (SPL). Lastly, the displacement power spectrum density (PSD) is calculated to investigate the effect of geometric nonlinearity on structure stiffness. It shows that the resonant frequency and corresponding displacement PSD change with different thermal-acoustic contributions tO structure dynamic response.
This paper inv Firstly, the mode shapes estigated the characteristics of structure dynamic response under thermal-acoustic loading. and modal frequencies before and after thermal buckled were analyzed. Then the thin-wall structure out-of-plane displacement response was evaluated, by analyzing displacement probability distribution func-tion(PDF), it showed that thin wall panel vibrated around two different equilibrium configuration, that is snap-through motion, and also showed that snap-through frequencies increases with the increasing of sound pressure level (SPL). Lastly, the displacement power spectrum density (PSD) is calculated to investigate the effect of geometric nonlinearity on structure stiffness. It shows that the resonant frequency and corresponding displacement PSD change with different thermal-acoustic contributions tO structure dynamic response.
2012, 31(7): 1132-1135.
Abstract:
A data analysis method of the cam profile correction in reverse design of rotary paper-transferring mecha-nism is presented. The profile curve can be deduced from the measurement data of the cam profile according to the cam design theory. Using numerical analysis method the angular displacement and quasi-acceleration of the cam follo-wer are calculated. Compared with the expected quasi-acceleration, the quasi-acceleration error and the angular dis-placement error can be obtained. The cam profile can be deduced from the profile curve by removing angular dis-placement error. Results show that the cam profile is closer to original design data after the error correction.
A data analysis method of the cam profile correction in reverse design of rotary paper-transferring mecha-nism is presented. The profile curve can be deduced from the measurement data of the cam profile according to the cam design theory. Using numerical analysis method the angular displacement and quasi-acceleration of the cam follo-wer are calculated. Compared with the expected quasi-acceleration, the quasi-acceleration error and the angular dis-placement error can be obtained. The cam profile can be deduced from the profile curve by removing angular dis-placement error. Results show that the cam profile is closer to original design data after the error correction.
2012, 31(7): 1136-1139.
Abstract:
Field data missing account for mini-repairs in components reliability estimation is usually severe. Aimed to this situation, the mixture-Gamma distribution model is adopted to establish the lifetime distribution model of component, and the parameters are estimated using improved MLE method and Chi-square test. The distribution characteristics are statistically deduced and then a reasonable lifetime distribution is obtained with the analysis of physical failure mechanism of the component.
Field data missing account for mini-repairs in components reliability estimation is usually severe. Aimed to this situation, the mixture-Gamma distribution model is adopted to establish the lifetime distribution model of component, and the parameters are estimated using improved MLE method and Chi-square test. The distribution characteristics are statistically deduced and then a reasonable lifetime distribution is obtained with the analysis of physical failure mechanism of the component.
2012, 31(7): 1140-1144.
Abstract:
A coupling analytical model of vibration fatigue for the cracked plate was derived for the prediction of vibra-tion fatigue life. Firstly, the crack was replaced by an additional external force and the vibration equation of the cracked plate was derived based on Newton's second law. Then, the crack terms were obtained by using stress relational expres-sion introduced by Rice and Levy, and the vibration equation of the bilateral cantilevered cracked plate was simplified into a single-degree-of-freedom system using Galerkin method and nonlinearity terms of the equation were obtained by the formulation of middle plane strain. Vibration equation was solved by the method of multiple scales. Results indicate that the proposed coupling analytical model can be used in the coupling analysis for the cracked plate.
A coupling analytical model of vibration fatigue for the cracked plate was derived for the prediction of vibra-tion fatigue life. Firstly, the crack was replaced by an additional external force and the vibration equation of the cracked plate was derived based on Newton's second law. Then, the crack terms were obtained by using stress relational expres-sion introduced by Rice and Levy, and the vibration equation of the bilateral cantilevered cracked plate was simplified into a single-degree-of-freedom system using Galerkin method and nonlinearity terms of the equation were obtained by the formulation of middle plane strain. Vibration equation was solved by the method of multiple scales. Results indicate that the proposed coupling analytical model can be used in the coupling analysis for the cracked plate.
2012, 31(7): 1145-1149.
Abstract:
The "N-2-1" locating principle is widely used in the locator's layout for the flexible sheet metal work-piece, in which N, the number of locators on primary datum, is a key to sheet metal fixture design. At present, lo-cator's layout is frequently decided by experience, which often leads to unsatisfactory locating precision in sheet stamping and assembly. In this paper, a genetic algorithm, which is programmed using APDL (ANSYS Parametric Design Language) , was proposed to lay out the N locators for the flexible sheet metal workpiece. The present meth-od was successfully applied to study the locators' layout of flat and curved surface workpiece, analyze the phenome-non of deviation amplification on observing point in curved surface work pieces and consummate the method of loca-tors' layout which considers deviation of workpiece. The present results have a guiding significance to consummate optimization method of locators' layout of flexible sheet workpiece.
The "N-2-1" locating principle is widely used in the locator's layout for the flexible sheet metal work-piece, in which N, the number of locators on primary datum, is a key to sheet metal fixture design. At present, lo-cator's layout is frequently decided by experience, which often leads to unsatisfactory locating precision in sheet stamping and assembly. In this paper, a genetic algorithm, which is programmed using APDL (ANSYS Parametric Design Language) , was proposed to lay out the N locators for the flexible sheet metal workpiece. The present meth-od was successfully applied to study the locators' layout of flat and curved surface workpiece, analyze the phenome-non of deviation amplification on observing point in curved surface work pieces and consummate the method of loca-tors' layout which considers deviation of workpiece. The present results have a guiding significance to consummate optimization method of locators' layout of flexible sheet workpiece.
2012, 31(7): 1150-1155.
Abstract:
Hydro-pneumatic suspension system and multi-axle electro-hydraulic steering system in all-terrain crane's chassis consist of mechanics system, hydraulic transmission and electric-control sub-systems. The development of the complex mechatronic system, which is involved with mechanics, control, electrics, hydraulics, aerodynamic and software development, is a cross domain systematic process and need multi-domain modeling and simulation. Aiming at the problem, the platform is redeveloped based on software AMESim, Matlab/Simulink and Adams to es-tablish the multi-domain co-simulation analysis platform for suspension system and multi-axle steering system. The comparison between the analysis and testing results verifies the platform efficiently.
Hydro-pneumatic suspension system and multi-axle electro-hydraulic steering system in all-terrain crane's chassis consist of mechanics system, hydraulic transmission and electric-control sub-systems. The development of the complex mechatronic system, which is involved with mechanics, control, electrics, hydraulics, aerodynamic and software development, is a cross domain systematic process and need multi-domain modeling and simulation. Aiming at the problem, the platform is redeveloped based on software AMESim, Matlab/Simulink and Adams to es-tablish the multi-domain co-simulation analysis platform for suspension system and multi-axle steering system. The comparison between the analysis and testing results verifies the platform efficiently.
2012, 31(7): 1156-1160.
Abstract:
Correctly predicting the squeeze film damping is of utmost importance for designing a micro-electro-me-chanical system(MEMS). We use the Wavelet-Galerkin method to calculate the squeeze film damping of its mico-mechanical resonator device. We set up its squeeze film damping model and work out its differential equations and boundary conditions. Then we carry out some necessary simplification of the equations. We use the Daubechies wavelet to expand the fluid pressure response of the MEMS, assuming that one input is known. Finally, we calcu-late the expansion coefficient with the Wavelet-Galerkin method so as to obtain the approximate solutions of the equations. In view of the fact that the Daubechies wavelet has no analytical expression and has strong oscillation, we also calculate the correlation coefficient, which is the derivation and integral of the wavelet involved in the Wavelet-Galerkin method. We use our method to calculate the model with given parameters and compare the calcu-lated results with those obtained with the traditional methods. The comparison results show that our method is effec-tive for analyzing squeeze film damping and has a simple calculation process and fast calculation sneed.
Correctly predicting the squeeze film damping is of utmost importance for designing a micro-electro-me-chanical system(MEMS). We use the Wavelet-Galerkin method to calculate the squeeze film damping of its mico-mechanical resonator device. We set up its squeeze film damping model and work out its differential equations and boundary conditions. Then we carry out some necessary simplification of the equations. We use the Daubechies wavelet to expand the fluid pressure response of the MEMS, assuming that one input is known. Finally, we calcu-late the expansion coefficient with the Wavelet-Galerkin method so as to obtain the approximate solutions of the equations. In view of the fact that the Daubechies wavelet has no analytical expression and has strong oscillation, we also calculate the correlation coefficient, which is the derivation and integral of the wavelet involved in the Wavelet-Galerkin method. We use our method to calculate the model with given parameters and compare the calcu-lated results with those obtained with the traditional methods. The comparison results show that our method is effec-tive for analyzing squeeze film damping and has a simple calculation process and fast calculation sneed.
2012, 31(7): 1161-1165.
Abstract:
The methods of parameterized modeling and curved edge angle quick tagging based on the further devel-opment of CATIA (computer aided tri-dimensional interface application) are proposed to solve the design of manu-facturing data sets, such as the low efficiency and high error rate for 3 D modeling in manufacturing data sets and engineering drawings informations' labeling of sheet metal parts. The geometric model for process lug is established through constraining the coordinates sizes of key points on the contours of the process lugs; the angles of the sheet metal part's curved edge which will be tagged on the curved edge by invoking CAA (component application archi-tecture) functions, are calculated through the methods of cut plane; in 2D data sets design 3D process information are obtained in the structure tree and marked in the engineering drawing. The software of the quick design for man-ufacturing data sets of sheet metal was completed, which has been integrated into the environment of CATIA and it has been successfully applied in the number of aviation enterprise.
The methods of parameterized modeling and curved edge angle quick tagging based on the further devel-opment of CATIA (computer aided tri-dimensional interface application) are proposed to solve the design of manu-facturing data sets, such as the low efficiency and high error rate for 3 D modeling in manufacturing data sets and engineering drawings informations' labeling of sheet metal parts. The geometric model for process lug is established through constraining the coordinates sizes of key points on the contours of the process lugs; the angles of the sheet metal part's curved edge which will be tagged on the curved edge by invoking CAA (component application archi-tecture) functions, are calculated through the methods of cut plane; in 2D data sets design 3D process information are obtained in the structure tree and marked in the engineering drawing. The software of the quick design for man-ufacturing data sets of sheet metal was completed, which has been integrated into the environment of CATIA and it has been successfully applied in the number of aviation enterprise.
2012, 31(7): 1166-1169.
Abstract:
There is strong relationship between the acoustic emission and the states of the wheel and grinding. The Bayesian networks were used to separate and identify the acoustic emission signal for the better intelligent monito-ring of grinding. The grinder intelligent monitoring system based on Bayesian networks was established and grinding experiments were performed. The results show that thesyatem can predict the surface roughness of grinding work-pieces, blunt level and the contact states of grinding wheel.
There is strong relationship between the acoustic emission and the states of the wheel and grinding. The Bayesian networks were used to separate and identify the acoustic emission signal for the better intelligent monito-ring of grinding. The grinder intelligent monitoring system based on Bayesian networks was established and grinding experiments were performed. The results show that thesyatem can predict the surface roughness of grinding work-pieces, blunt level and the contact states of grinding wheel.
2012, 31(7): 1170-1173,1179.
Abstract:
This article has proposed a new structure of lateral tensile piezoelectric driving feeder, which is based on the research on advanced technology of foreign piezoelectric feeders. The installing angles of the feeder's driving source are 60 degrees with the horizontal and 12 degrees with the vertical, that has produced driving forces in two degrees of freedom-circumferential and vertical directions, and that improved the feeding performance of the feeder. After analyzing the driving structure and parts' movement performance, the finite element software Ansys is applied to analyze the whole machine, that, as a result, optimizing the driving structure and getting the whole machine's resonance frequency. According to the experimental study, we analyzed the relationships between the driving fre-quency and feeding speed, the driving voltage and feeding speed, and the driving output frequency and output cur-rent. Compared with the electromagnetic vibration feeders, the piezoelectric vibration feeders have improved the feeding performance greatly and their energy-saving effect is remarkable.
This article has proposed a new structure of lateral tensile piezoelectric driving feeder, which is based on the research on advanced technology of foreign piezoelectric feeders. The installing angles of the feeder's driving source are 60 degrees with the horizontal and 12 degrees with the vertical, that has produced driving forces in two degrees of freedom-circumferential and vertical directions, and that improved the feeding performance of the feeder. After analyzing the driving structure and parts' movement performance, the finite element software Ansys is applied to analyze the whole machine, that, as a result, optimizing the driving structure and getting the whole machine's resonance frequency. According to the experimental study, we analyzed the relationships between the driving fre-quency and feeding speed, the driving voltage and feeding speed, and the driving output frequency and output cur-rent. Compared with the electromagnetic vibration feeders, the piezoelectric vibration feeders have improved the feeding performance greatly and their energy-saving effect is remarkable.
2012, 31(7): 1174-1179.
Abstract:
By using lumped-mass method, the dynamic model of planetary gear transmission with floating sun-gear was established; the time-variant stiffness and meshing error were considered in the model. The motion differential equation of the model was presented and solved by Runge-Kutta numerical integration method with variable steps. Dynamic time-domain responses, dynamic loads and load sharing characteristics of the high contact ratio planetary gear transmission and general planetary gear transmission were both investigated for comparison. The results indica-ted that the high contact ratio planetary gear transmission had lower vibration amplitude, smaller dynamic load and dynamic load-sharing coefficient. So the high contact ratio planetary gear drive had better performance with smoot-her transmission, lower noise, and its load distribution is more uniform.
By using lumped-mass method, the dynamic model of planetary gear transmission with floating sun-gear was established; the time-variant stiffness and meshing error were considered in the model. The motion differential equation of the model was presented and solved by Runge-Kutta numerical integration method with variable steps. Dynamic time-domain responses, dynamic loads and load sharing characteristics of the high contact ratio planetary gear transmission and general planetary gear transmission were both investigated for comparison. The results indica-ted that the high contact ratio planetary gear transmission had lower vibration amplitude, smaller dynamic load and dynamic load-sharing coefficient. So the high contact ratio planetary gear drive had better performance with smoot-her transmission, lower noise, and its load distribution is more uniform.
2012, 31(7): 1180-1183,1188.
Abstract:
Based on the function requirement analysis of virtual assembly system of vehicle transmission, the archi-tecture of virtual assembly is established. Function modules of the system are analyzed. Virtual assembly model in-formation technology, virtual assembly sequence planning, interference checking of running state of transmission and real-time collision detection have been studied. According to the characteristics of transmission, the assembly information model of vehicle transmission has been established. Based on the analysis of system, a virtual assembly sequence planning method has been developed. Interference checking of running state has also implemented. Based on the analysis of the collision detection algorithms, the real-time collision detection method has been worked out to meet the transmission. Based on analyses of function modules and system key technologies, VASVT(virtual assem-bly system of vehicle transmission) software system based on virtual reality system has been developed.
Based on the function requirement analysis of virtual assembly system of vehicle transmission, the archi-tecture of virtual assembly is established. Function modules of the system are analyzed. Virtual assembly model in-formation technology, virtual assembly sequence planning, interference checking of running state of transmission and real-time collision detection have been studied. According to the characteristics of transmission, the assembly information model of vehicle transmission has been established. Based on the analysis of system, a virtual assembly sequence planning method has been developed. Interference checking of running state has also implemented. Based on the analysis of the collision detection algorithms, the real-time collision detection method has been worked out to meet the transmission. Based on analyses of function modules and system key technologies, VASVT(virtual assem-bly system of vehicle transmission) software system based on virtual reality system has been developed.
2012, 31(7): 1184-1188.
Abstract:
The topology optimization of microstructure for composite material is studied. Based on the finite element method, the mode is established by using the density of micro-unit as the design variable, the volume fraction as the optimization constraints, the mechanical properties as the optimization objective. The solid isotropic material with penalization is adopted to describe the model, with the optimization criterion method as the solution algorithm. And the topology optimization of mierostructure is realized by using Maflab language. Therefore, the optimal effec-tive properties are obtained. Different filter radius, mesh sizes and penalization factors are discussed to obtain the optimal parameters. The optimization model is used on the design of porous plate, and the implementation of the components with light weight and high strength is done.
The topology optimization of microstructure for composite material is studied. Based on the finite element method, the mode is established by using the density of micro-unit as the design variable, the volume fraction as the optimization constraints, the mechanical properties as the optimization objective. The solid isotropic material with penalization is adopted to describe the model, with the optimization criterion method as the solution algorithm. And the topology optimization of mierostructure is realized by using Maflab language. Therefore, the optimal effec-tive properties are obtained. Different filter radius, mesh sizes and penalization factors are discussed to obtain the optimal parameters. The optimization model is used on the design of porous plate, and the implementation of the components with light weight and high strength is done.
2012, 31(7): 1189-1191,1195.
Abstract:
After the working principle and working characters of the straight track flap movement mechanism being illustrated, a reliability analysis model was established, in which the randomness of rod length and angle is taken into consideration. Then a following reliability analysis method was proposed. Taking a certain type of straight track flap movement mechanism as an example, the reliability analysis results under different standard deviations of input angle and rod length are obtained. Such analysis results show that the reliability of straight track flap movement mechanism is highly sensitive to the standard deviation of input angle, but not sensitive to the standard deviation of each rod length. The analysis results could provide helpful reference for designing the straight track flap movement mechanism.
After the working principle and working characters of the straight track flap movement mechanism being illustrated, a reliability analysis model was established, in which the randomness of rod length and angle is taken into consideration. Then a following reliability analysis method was proposed. Taking a certain type of straight track flap movement mechanism as an example, the reliability analysis results under different standard deviations of input angle and rod length are obtained. Such analysis results show that the reliability of straight track flap movement mechanism is highly sensitive to the standard deviation of input angle, but not sensitive to the standard deviation of each rod length. The analysis results could provide helpful reference for designing the straight track flap movement mechanism.
2012, 31(7): 1192-1195.
Abstract:
The fiat spiral spring is the key component of wind power mechanical energy storage sector, the perform-ance of it is directly related to the geometric size of the spring and other paramenters. In order to improve the effi-ciency of wind power mechanical energy storage, it demands that the spring should meet the requirement of the me-chanical properties, and achieve the design goal of the small size and light weight. In this paper, genetic algorithm is adopted for its advantage of automatic optimization to build the optimization design model of the mechanical ener-gy storage spiral spring in which the smallest volume is used as the design goal. Design example shows that using this optimization model, the performance of the present designed spiral springs has been improved compared with that of traditional designed ones.
The fiat spiral spring is the key component of wind power mechanical energy storage sector, the perform-ance of it is directly related to the geometric size of the spring and other paramenters. In order to improve the effi-ciency of wind power mechanical energy storage, it demands that the spring should meet the requirement of the me-chanical properties, and achieve the design goal of the small size and light weight. In this paper, genetic algorithm is adopted for its advantage of automatic optimization to build the optimization design model of the mechanical ener-gy storage spiral spring in which the smallest volume is used as the design goal. Design example shows that using this optimization model, the performance of the present designed spiral springs has been improved compared with that of traditional designed ones.
2012, 31(7): 1196-1200,1204.
Abstract:
We carry out the numerical analysis of the thermal-flow-structural coupling of the float-wall of a combus-tor chamber. We use the heat-flow coupling method to 6alculate the float-wall's temperature distribution and the thermal-structural indirect coupling finite element method to calculate its structural strength. The analysis results show that: the stress and deformation of the float-wall are mostly caused by the temperature load; the mechanical load exercises a great influence on the deformation and the minimum stress of the float wall; therefore the analysis of its structure needs to consider both its temperature load and pressure load; our numerical analysis method is feasible and applicable.
We carry out the numerical analysis of the thermal-flow-structural coupling of the float-wall of a combus-tor chamber. We use the heat-flow coupling method to 6alculate the float-wall's temperature distribution and the thermal-structural indirect coupling finite element method to calculate its structural strength. The analysis results show that: the stress and deformation of the float-wall are mostly caused by the temperature load; the mechanical load exercises a great influence on the deformation and the minimum stress of the float wall; therefore the analysis of its structure needs to consider both its temperature load and pressure load; our numerical analysis method is feasible and applicable.
2012, 31(7): 1201-1204.
Abstract:
The support vector data description (SVDD) is a kind of single-value classification method, by which a single-value classifier can be built by using its normal state data samples even if the fault samples are lacking, thus revealing its normal operation. The orthogonal wavelet transform (OWT) has good performance for extracting the shock elements of a non-stable signal. We propose a new state evaluation method that uses the SVDD and the OWT and use the OWT to extract the peak-peak values of various detail signals, which are in turn used as input parame-ters of the classifier. We build the classification model of the classifier with the SVDD method to carry out the quan-titive evaluation of the state of the machine. We also use our method to do experimental analysis of the pitting faults on the inner ring of a rolling bearing and establish the quantitive indicators for evaluating its worsening perform-ance; the experimental results show that our method is effective.
The support vector data description (SVDD) is a kind of single-value classification method, by which a single-value classifier can be built by using its normal state data samples even if the fault samples are lacking, thus revealing its normal operation. The orthogonal wavelet transform (OWT) has good performance for extracting the shock elements of a non-stable signal. We propose a new state evaluation method that uses the SVDD and the OWT and use the OWT to extract the peak-peak values of various detail signals, which are in turn used as input parame-ters of the classifier. We build the classification model of the classifier with the SVDD method to carry out the quan-titive evaluation of the state of the machine. We also use our method to do experimental analysis of the pitting faults on the inner ring of a rolling bearing and establish the quantitive indicators for evaluating its worsening perform-ance; the experimental results show that our method is effective.
