The practical method for precise penetration rate measurement in a short time and the instrument design have been specially discussed in this paper.Considering the defects of the penetration rate meters available,via ...The practical method for precise penetration rate measurement in a short time and the instrument design have been specially discussed in this paper.Considering the defects of the penetration rate meters available,via the balanced design in consideration of service life,costs,accuracy and reliability,a kind of penetration rate meter has been put forward.The meter consists of a magnetic clutch,a gear box and a raster disk system to pick up the signal.The meter has the following advantages-it might measure a low speed with higher accura-cy,it could disengage automatically without being divorced from the driving device during tripping rods at high speed,it has a circuit of rotary direction discrimination and of repeated counting prevention so as to eU-minate error caused by rod vibration.展开更多
Typical multidisciplinary design optimization（MDO） has gradually been proposed to balance performances of lightweight, noise, vibration and harshness（NVH） and safety for instrument panel（IP） structure in the aut...Typical multidisciplinary design optimization（MDO） has gradually been proposed to balance performances of lightweight, noise, vibration and harshness（NVH） and safety for instrument panel（IP） structure in the automotive development. Nevertheless, plastic constitutive relation of Polypropylene（PP） under different strain rates, has not been taken into consideration in current reliability-based and collaborative IP MDO design. In this paper, based on tensile test under different strain rates, the constitutive relation of Polypropylene material is studied. Impact simulation tests for head and knee bolster are carried out to meet the regulation of FMVSS 201 and FMVSS 208, respectively. NVH analysis is performed to obtain mainly the natural frequencies and corresponding mode shapes, while the crashworthiness analysis is employed to examine the crash behavior of IP structure. With the consideration of lightweight, NVH, head and knee bolster impact performance, design of experiment（DOE）, response surface model（RSM）, and collaborative optimization（CO） are applied to realize the determined and reliability-based optimizations, respectively. Furthermore, based on multi-objective genetic algorithm（MOGA）, the optimal Pareto sets are completed to solve the multi-objective optimization（MOO） problem. The proposed research ensures the smoothness of Pareto set, enhances the ability of engineers to make a comprehensive decision about multi-objectives and choose the optimal design, and improves the quality and efficiency of MDO.展开更多
Tubular hydroforming has attracted increased attention in the vehicle industry recently. This paper covers a complete hydroforming process design for an instrum ent panel frame by finite element simulation using the e...Tubular hydroforming has attracted increased attention in the vehicle industry recently. This paper covers a complete hydroforming process design for an instrum ent panel frame by finite element simulation using the explicit code LS-DYNA. The manufacturing process for the instrument panel frame consists of tube pre-be nding and final hydroforming. To accomplish hydroforming process design successf ully, a thorough investigation of proper combination of process parameters such as internal hydraulic pressure and axial feeding is carried out by finite element simulation to predict the tube wall thickness and shape. An optimized process parameter combination is obtained and verified by the instrument panel frame hyd roforming experiment. The experiment shows that designed process parameters can be used in real production through FEA simulation, but tubular thinned amplitu de by FEA is less than that with the experiment.展开更多
In musical instruments, the geometric design and material features of the instrument are the most important factors that determine the sound characteristics of the instrument. Traditional replication and experiment-ba...In musical instruments, the geometric design and material features of the instrument are the most important factors that determine the sound characteristics of the instrument. Traditional replication and experiment-based handcrafting methods are predominant in the production of Turkish Folk Music wind instruments. The instrument manufacturing and standardization approaches, which include the relevant rules of physics and engineering practices, are limited purely to prototype studies for scientific research purposes. It is almost impossible to find studies on Turkish Folk Music wind instrument design and production involving computer aided design and engineering applications. In this study, an example Turkish woodwind instrument, the Turkish Treble Recorder (dilli kaval) is considered, and the air flow behaviour and acoustic (sound) power magnitudes that occur at different air flow rates are simulated in a computer environment using a Computational Fluid Dynamics (CFD) simulation technique. In the study, numerical and visual outputs related to air behaviour at different air flow rates that may be used in the instrument manufacturing phases were obtained. Acoustic power level was also measured experimentally. Simulation outputs (the acoustic power level) were compared to experimental results in order to validate the simulation results. The comparison revealed that the highest relative difference was calculated as 13.32(%). This value indicated that the simulation results were reasonably consistent with the results of the experimental measurement. Additionally, this study was constructed as a case study that may provide reference for future research studies in this field.展开更多
随着手机镜头成像距离范围的拓展,成像质量的测试范围也需要同步拓展。传统测试方法需频繁移动图卡,效率和精度受限。为了满足高精度调制传递函数(Modulation Transfer Function,MTF)测量的需求,设计并实现了一款可变模拟物距的平行光...随着手机镜头成像距离范围的拓展,成像质量的测试范围也需要同步拓展。传统测试方法需频繁移动图卡,效率和精度受限。为了满足高精度调制传递函数(Modulation Transfer Function,MTF)测量的需求,设计并实现了一款可变模拟物距的平行光管系统,可实现从150?mm至无穷远的物距模拟,具备16?mm的出瞳直径和75?mm的工作距离,适用于多数光学测试场景。使用ZEMAX对系统进行了多波长、多模拟物距条件下的优化,结果表明该光学系统在各项指标上均接近衍射极限。对系统的公差分析表明其具备良好的可加工性。镜头加工完成后,采用Trioptics公司的ImageMaster Universal进行MTF测试,并通过分辨率测试板对系统分辨率进行评估。实测结果表明,系统在各模拟物距下均能保持良好的成像质量,验证了该设计的工程应用价值。展开更多
Design patterns are micro architectures that have proved to be reliable, robust and easy to implement. Detecting design pattern from source code of object-oriented system can help a designer, a developer or a maintain...Design patterns are micro architectures that have proved to be reliable, robust and easy to implement. Detecting design pattern from source code of object-oriented system can help a designer, a developer or a maintainer to understand the software system. In this paper, a new method is provided which can detect design patterns from source code combining both static and dynamic analysis. To acquire the run-time dynamic information of software systems, a code instrumentation method is adopted. At the same time, all static and dynamic information is presented in UML diagrams format. The pattern detection process and its detection results are visual and interactive. This method is tested on a call center and a traffic simulation system. Experimental results prove that the method is effective in design patterns detection.展开更多
In order to improve the flexibility of the surgical instruments, a wire-driven wrist-like structure is proposed in this paper. The instrument has three degrees of freedom (DOFs) of rotation, yaw, opening and closing. ...In order to improve the flexibility of the surgical instruments, a wire-driven wrist-like structure is proposed in this paper. The instrument has three degrees of freedom (DOFs) of rotation, yaw, opening and closing. Furthermore, we also acknowledge no coupling motion for each DOF. Moreover, the self-locking motion contributes to sustaining joint posture under external force. A static analysis for the end effector was conducted using the ANSYS software. At the end of this paper, a series of experiments for the prototype was performed. The results revealed that for the same surgical task, the proposed instrument had higher flexibility and the completion time of the operation tasks was obviously less than that of the traditional instrument. The results of the self-locking and operating force test showed that the surgical instruments perform well in maintaining joint posture under the force of 8.2N. The proposed surgical instrument meets the requirements of minimally invasive surgery (MIS).展开更多
Virtual Instruments, which have the most brilliant prospect in the domain of instruments, are the combination of the computers and traditional instruments. According to the constructions and the characters of the Teac...Virtual Instruments, which have the most brilliant prospect in the domain of instruments, are the combination of the computers and traditional instruments. According to the constructions and the characters of the Teaching Lab Instruments, the paper introduces the principle and design of Virtual Instrument System. Meanwhile, a practical application is indicated.展开更多
文摘The practical method for precise penetration rate measurement in a short time and the instrument design have been specially discussed in this paper.Considering the defects of the penetration rate meters available,via the balanced design in consideration of service life,costs,accuracy and reliability,a kind of penetration rate meter has been put forward.The meter consists of a magnetic clutch,a gear box and a raster disk system to pick up the signal.The meter has the following advantages-it might measure a low speed with higher accura-cy,it could disengage automatically without being divorced from the driving device during tripping rods at high speed,it has a circuit of rotary direction discrimination and of repeated counting prevention so as to eU-minate error caused by rod vibration.
基金supported by National Hi-tech Research and Development Program of China(863 Program, Grant No. 2007AA04Z132)National Natural Science Foundation of China(Grant No. 51175379)
文摘Typical multidisciplinary design optimization（MDO） has gradually been proposed to balance performances of lightweight, noise, vibration and harshness（NVH） and safety for instrument panel（IP） structure in the automotive development. Nevertheless, plastic constitutive relation of Polypropylene（PP） under different strain rates, has not been taken into consideration in current reliability-based and collaborative IP MDO design. In this paper, based on tensile test under different strain rates, the constitutive relation of Polypropylene material is studied. Impact simulation tests for head and knee bolster are carried out to meet the regulation of FMVSS 201 and FMVSS 208, respectively. NVH analysis is performed to obtain mainly the natural frequencies and corresponding mode shapes, while the crashworthiness analysis is employed to examine the crash behavior of IP structure. With the consideration of lightweight, NVH, head and knee bolster impact performance, design of experiment（DOE）, response surface model（RSM）, and collaborative optimization（CO） are applied to realize the determined and reliability-based optimizations, respectively. Furthermore, based on multi-objective genetic algorithm（MOGA）, the optimal Pareto sets are completed to solve the multi-objective optimization（MOO） problem. The proposed research ensures the smoothness of Pareto set, enhances the ability of engineers to make a comprehensive decision about multi-objectives and choose the optimal design, and improves the quality and efficiency of MDO.
文摘Tubular hydroforming has attracted increased attention in the vehicle industry recently. This paper covers a complete hydroforming process design for an instrum ent panel frame by finite element simulation using the explicit code LS-DYNA. The manufacturing process for the instrument panel frame consists of tube pre-be nding and final hydroforming. To accomplish hydroforming process design successf ully, a thorough investigation of proper combination of process parameters such as internal hydraulic pressure and axial feeding is carried out by finite element simulation to predict the tube wall thickness and shape. An optimized process parameter combination is obtained and verified by the instrument panel frame hyd roforming experiment. The experiment shows that designed process parameters can be used in real production through FEA simulation, but tubular thinned amplitu de by FEA is less than that with the experiment.
文摘In musical instruments, the geometric design and material features of the instrument are the most important factors that determine the sound characteristics of the instrument. Traditional replication and experiment-based handcrafting methods are predominant in the production of Turkish Folk Music wind instruments. The instrument manufacturing and standardization approaches, which include the relevant rules of physics and engineering practices, are limited purely to prototype studies for scientific research purposes. It is almost impossible to find studies on Turkish Folk Music wind instrument design and production involving computer aided design and engineering applications. In this study, an example Turkish woodwind instrument, the Turkish Treble Recorder (dilli kaval) is considered, and the air flow behaviour and acoustic (sound) power magnitudes that occur at different air flow rates are simulated in a computer environment using a Computational Fluid Dynamics (CFD) simulation technique. In the study, numerical and visual outputs related to air behaviour at different air flow rates that may be used in the instrument manufacturing phases were obtained. Acoustic power level was also measured experimentally. Simulation outputs (the acoustic power level) were compared to experimental results in order to validate the simulation results. The comparison revealed that the highest relative difference was calculated as 13.32(%). This value indicated that the simulation results were reasonably consistent with the results of the experimental measurement. Additionally, this study was constructed as a case study that may provide reference for future research studies in this field.
文摘随着手机镜头成像距离范围的拓展,成像质量的测试范围也需要同步拓展。传统测试方法需频繁移动图卡,效率和精度受限。为了满足高精度调制传递函数(Modulation Transfer Function,MTF)测量的需求,设计并实现了一款可变模拟物距的平行光管系统,可实现从150?mm至无穷远的物距模拟,具备16?mm的出瞳直径和75?mm的工作距离,适用于多数光学测试场景。使用ZEMAX对系统进行了多波长、多模拟物距条件下的优化,结果表明该光学系统在各项指标上均接近衍射极限。对系统的公差分析表明其具备良好的可加工性。镜头加工完成后,采用Trioptics公司的ImageMaster Universal进行MTF测试,并通过分辨率测试板对系统分辨率进行评估。实测结果表明,系统在各模拟物距下均能保持良好的成像质量,验证了该设计的工程应用价值。
基金Project supported by the National Natural Science Foundation of China（Grant No.60473063）
文摘Design patterns are micro architectures that have proved to be reliable, robust and easy to implement. Detecting design pattern from source code of object-oriented system can help a designer, a developer or a maintainer to understand the software system. In this paper, a new method is provided which can detect design patterns from source code combining both static and dynamic analysis. To acquire the run-time dynamic information of software systems, a code instrumentation method is adopted. At the same time, all static and dynamic information is presented in UML diagrams format. The pattern detection process and its detection results are visual and interactive. This method is tested on a call center and a traffic simulation system. Experimental results prove that the method is effective in design patterns detection.
基金Supported by the National Natural Science Foundation of China(61305102)the Foundation for Outstanding Young Scholars of Jilin Province(20170520106JH)
文摘In order to improve the flexibility of the surgical instruments, a wire-driven wrist-like structure is proposed in this paper. The instrument has three degrees of freedom (DOFs) of rotation, yaw, opening and closing. Furthermore, we also acknowledge no coupling motion for each DOF. Moreover, the self-locking motion contributes to sustaining joint posture under external force. A static analysis for the end effector was conducted using the ANSYS software. At the end of this paper, a series of experiments for the prototype was performed. The results revealed that for the same surgical task, the proposed instrument had higher flexibility and the completion time of the operation tasks was obviously less than that of the traditional instrument. The results of the self-locking and operating force test showed that the surgical instruments perform well in maintaining joint posture under the force of 8.2N. The proposed surgical instrument meets the requirements of minimally invasive surgery (MIS).
文摘Virtual Instruments, which have the most brilliant prospect in the domain of instruments, are the combination of the computers and traditional instruments. According to the constructions and the characters of the Teaching Lab Instruments, the paper introduces the principle and design of Virtual Instrument System. Meanwhile, a practical application is indicated.
