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Noise Control of a Two Stroke Engine Car
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作者 葛蕴珊 吴思进 +2 位作者 刘福水 张付军 黄英 《Journal of Beijing Institute of Technology》 EI CAS 1998年第2期203-209,共7页
Aim To control the noise of two stroke engine Methods On the basis of noise identification,a new muffler and acoustic shield were designed,Results the car's pass-by noise below the national limit Conclusion throug... Aim To control the noise of two stroke engine Methods On the basis of noise identification,a new muffler and acoustic shield were designed,Results the car's pass-by noise below the national limit Conclusion through proper noise controlling measures,the pass-by noise of two stroke engines could be reduced under national permitting limit. 展开更多
关键词 noise control two stroke engine VEHICLE
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Structural Intensity Characterization of Composite Laminates Subjected to Impact Load 被引量:4
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作者 王东方 贺鹏飞 刘子顺 《Journal of Shanghai Jiaotong university(Science)》 EI 2008年第3期375-380,共6页
Structural intensity (SI) characterization of composite laminates subjected to impact load was dis-cussed. The SI pattern of the laminates which have different fiber orientations and boundary conditions was analyzed. ... Structural intensity (SI) characterization of composite laminates subjected to impact load was dis-cussed. The SI pattern of the laminates which have different fiber orientations and boundary conditions was analyzed. The resultant forces and velocities of the laminates were calculated, and the structural intensity was evaluated. The SI streamlines of carbon fiber reinforced epoxy composite laminates and the steel plates were discussed. The results show that the SI streamlines of the graphite/epoxy laminates are different from that of the steel plates, and the SI streamlines are influenced by the boundaries, the stacking sequence of the composite laminates. The change of the historical central displacement of the graphite/epoxy laminates is fasten than that of the steel plates. 展开更多
关键词 structural intensity structural noise vibration control power flow
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Sliding mode control of chaos in the noise-perturbed permanent magnet synchronous motor with non-smooth air-gap 被引量:6
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作者 Ma Caoyuan Wang Longshun +2 位作者 Yin Zhe Liu Jianfeng Chen Diyi 《Mining Science and Technology》 EI CAS 2011年第6期835-838,共4页
Permanent magnet synchronous motor (PMSM) is widely used in mining, and there exists chaotic behav- ior when it runs. In order to dispel its adverse effect on security in mining, the chaotic system of PMSM was analyze... Permanent magnet synchronous motor (PMSM) is widely used in mining, and there exists chaotic behav- ior when it runs. In order to dispel its adverse effect on security in mining, the chaotic system of PMSM was analyzed. With noise disturbances, the complex dynamic characteristics of chaos were also analyzed, and proved the objective existence of chaos. As we all know, it is very difficult for conventional PMSM control to meet the design requirements, therefore, in order to ensure the robustness of the system, the chaotic orbits were stabilized to arbitrary chosen fixed points and periodic orbits by means of sliding mode method. Finally MATLAB simulations were presented to confirm the validity of the controller. The results show that the PMSM with the sliding mode control has a good dynamic performance and steady state accuracy. 展开更多
关键词 PMSM Chaos Sliding mode control Noise disturbance
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Analysis and active control of low frequency booming noise in car 被引量:2
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作者 曹友强 Deng Zhaoxiang +1 位作者 Zhang Yu Chen Dexin 《High Technology Letters》 EI CAS 2015年第4期414-421,共8页
For Lightweight body,sound radiation and sound insulation performance have negative effects on interior noise by the deterioration of local stiffness and modality.So the research on the active control of vibration and... For Lightweight body,sound radiation and sound insulation performance have negative effects on interior noise by the deterioration of local stiffness and modality.So the research on the active control of vibration and noise for car body panels is useful for engineering.Analysis and active control of booming noise in car is researched by using a new active damping vibration reduction technology named smart constrained layer damping(SCLD).According to the vibration characters of body roof,an optimal placement of actuators is distributed.Based on dSPACE hardware in loop environment,an adaptive active control system is designed.Selecting vibration signals of engine mounting point as the reference input of adaptive controller,an active control experiment of booming noise for mini-car is carried out.Experimental results show that,when the engine speed is at 3700 RPM and4250RPM,the interior booming noise decreases 4.2dB(A),and 3.5dB(A) separately.It proposes new methods and techniques for intelligent control of car body NVH in the future. 展开更多
关键词 interior booming noise smart constrained layer damping SCLD) adaptive active control system active control
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广播与电视
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《电子科技文摘》 1999年第12期80-81,共2页
本文集收录10篇论文。内容主要涉及:利用 M系列 PRK 波段进行的音响式汽体温度测量,太平洋海豚的超声波接收特性,基于自适应算法的频率分析法及其应用,能动噪声控制中的返还控制滤波器系数更新法,将音响信号变成假程序的大容量深层密码... 本文集收录10篇论文。内容主要涉及:利用 M系列 PRK 波段进行的音响式汽体温度测量,太平洋海豚的超声波接收特性,基于自适应算法的频率分析法及其应用,能动噪声控制中的返还控制滤波器系数更新法,将音响信号变成假程序的大容量深层密码化法。 展开更多
关键词 自适应算法 温度测量 动噪声控制 频率分析法 三维立体声 超声波 接收特性 滤波器系数 音响信号 传声器阵列
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Prediction and control of trailing edge noise based on bionic airfoil 被引量:6
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作者 GE ChangJiang ZHANG ZhiHui +2 位作者 LIANG Ping ZHANG ChengChun REN LuQuan 《Science China(Technological Sciences)》 SCIE EI CAS 2014年第7期1462-1470,共9页
As a promising means,the passive porosity technology is used for the trailing-edge noise reduction of a bionic airfoil.The detailed two-dimensional Large Eddy Simulation is achieved to gain a better understanding of t... As a promising means,the passive porosity technology is used for the trailing-edge noise reduction of a bionic airfoil.The detailed two-dimensional Large Eddy Simulation is achieved to gain a better understanding of the prediction and passive control of trailing-edge noise source with the non-porous and porous treatment,respectively.The flow fields around the bionic airfoil indicate that the leading-edge separation causes both the noise contributors,i.e.,the turbulent boundary layer and the vortex shedding.In addition,the effect of the porous trailing edge is substantiated in the distribution of the static pressure.The relevant noise also suggests a pronounced noise reduction potential in excess of 10 dB,but it has dependence on the flow resistivities.The two trailing-edge noise reduction mechanisms are characterized:(1)the suppression of the tonal vortex shedding noise;(2)the reduction of broadband turbulent boundary layer scattering noise.The findings may be used as reference in the design of silent aircraft. 展开更多
关键词 bionic airfoil POROSITY trailing-edge noise reduction vortex shedding turbulent boundary layer
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Counter Rotating Fans- An Aircraft Propulsion for the Future? 被引量:5
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作者 Peter Schimming 《Journal of Thermal Science》 SCIE EI CAS CSCD 2003年第2期97-103,共7页
In the mid seventies a new propulsor for aircraft was designed and investigated - the so-called PROPFAN. With regard to the total pressure increase, it ranges between a conventional propeller and a turbofan with very ... In the mid seventies a new propulsor for aircraft was designed and investigated - the so-called PROPFAN. With regard to the total pressure increase, it ranges between a conventional propeller and a turbofan with very high bypass ratio. This new propulsion system promised a reduction in fuel consumption of 15 to 25% compared to engines at that time.A lot of propfans (Hamilton Standard, USA) with different numbers of blades and blade shapes have been designed and tested in wind tunnels in order to find an optimum in efficiency, Fig.1. Parallel to this development GE, USA, made a design of a counter rotating unducted propfan, the so-called UDF, Fig.2. A prototype engine was manufactured and investigated on an in-flight test bed mounted at the MD82 and the B727. Since that time there has not been any further development of propfans (except AN 70 with NK 90-engine, Ukraine, which is more or less a propeller design) due to relatively low fuel prices and technical obstacles. Only technical programs in different countries are still going on in order to prepare a data base for designing counter rotating fans in terms of aeroacoustics, aerodynamics and aeroelasticities. In DLR, Germany, a lot of experimental and numerical work has been undertaken to understand the physical behaviour of the unsteady flow in a counter rotating fan. 展开更多
关键词 propfan counter rotation unsteady aerodynamics active noise control aeroelasticities.
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A Robust Adaptive Dynamic Programming Principle for Sensorimotor Control with Signal-Dependent Noise 被引量:2
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作者 JIANG Yu JIANG Zhong-Ping 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2015年第2期261-288,共28页
As human beings,people coordinate movements and interact with the environment through sensory information and motor adaptation in the daily lives.Many characteristics of these interactions can be studied using optimiz... As human beings,people coordinate movements and interact with the environment through sensory information and motor adaptation in the daily lives.Many characteristics of these interactions can be studied using optimization-based models,which assume that the precise knowledge of both the sensorimotor system and its interactive environment is available for the central nervous system(CNS).However,both static and dynamic uncertainties occur inevitably in the daily movements.When these uncertainties are taken into consideration,the previously developed models based on optimization theory may fail to explain how the CNS can still coordinate human movements which are also robust with respect to the uncertainties.In order to address this problem,this paper presents a novel computational mechanism for sensorimotor control from a perspective of robust adaptive dynamic programming(RADP).Sharing some essential features of reinforcement learning,which was originally observed from mammals,the RADP model for sensorimotor control suggests that,instead of identifying the system dynamics of both the motor system and the environment,the CNS computes iteratively a robust optimal control policy using the real-time sensory data.An online learning algorithm is provided in this paper,with rigorous convergence and stability analysis.Then,it is applied to simulate several experiments reported from the past literature.By comparing the proposed numerical results with these experimentally observed data,the authors show that the proposed model can reproduce movement trajectories which are consistent with experimental observations.In addition,the RADP theory provides a unified framework that connects optimality and robustness properties in the sensorimotor system. 展开更多
关键词 Adaptive dynamic programming human motor adaptation robust optimal control.
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