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Vision-aided inertial navigation for low altitude aircraft with a downward-viewing camera
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作者 ZHOU Ruihu TONG Mengqi GAO Yongxin 《Journal of Systems Engineering and Electronics》 2025年第3期825-834,共10页
Visual inertial odometry(VIO)problems have been extensively investigated in recent years.Existing VIO methods usually consider the localization or navigation issues of robots or autonomous vehicles in relatively small... Visual inertial odometry(VIO)problems have been extensively investigated in recent years.Existing VIO methods usually consider the localization or navigation issues of robots or autonomous vehicles in relatively small areas.This paper considers the problem of vision-aided inertial navigation(VIN)for aircrafts equipped with a strapdown inertial navigation system(SINS)and a downward-viewing camera.This is different from the traditional VIO problems in a larger working area with more precise inertial sensors.The goal is to utilize visual information to aid SINS to improve the navigation performance.In the multistate constraint Kalman filter(MSCKF)framework,we introduce an anchor frame to construct necessary models and derive corresponding Jacobians to implement a VIN filter to directly update the position in the Earth-centered Earth-fixed(ECEF)frame and the velocity and attitude in the local level frame by feature measurements.Due to its filtering-based property,the proposed method is naturally low computational demanding and is suitable for applications with high real-time requirements.Simulation and real-world data experiments demonstrate that the proposed method can considerably improve the navigation performance relative to the SINS. 展开更多
关键词 visual inertial odometry(VIO) strapdown inertial navigation system(SINS) multi-state constraint Kalman filter(MSCKF)
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Design and implementation of disturbance sliding mode observer for enhancing the dynamic control precision of inertial stabilization platform
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作者 ZHANG Zhidong YANG Gongliu +2 位作者 CAI Qingzhong FAN Jing LI Tao 《Journal of Systems Engineering and Electronics》 2025年第3期791-802,共12页
In order to enhance the dynamic control precision of inertial stabilization platform(ISP),a disturbance sliding mode observer(DSMO)is proposed in this paper suppressing disturbance torques inherent within the system.T... In order to enhance the dynamic control precision of inertial stabilization platform(ISP),a disturbance sliding mode observer(DSMO)is proposed in this paper suppressing disturbance torques inherent within the system.The control accuracy of ISP is fundamentally circumscribed by various disturbance torques in rotating shaft.Therefore,a dynamic model of ISP incorporating composite perturbations is established with regard to the stabilization of axis in the inertial reference frame.Subsequently,an online estimator for control loop uncertainties based on the sliding mode control algorithm is designed to estimate the aggregate disturbances of various parameters uncertainties and other unmodeled disturbances that cannot be accurately calibrated.Finally,the proposed DSMO is integrated into a classical proportional-integral-derivative(PID)control scheme,utilizing feedforward approach to compensate the composite disturbance in the control loop online.The effectiveness of the proposed disturbance observer is validated through simulation and hardware experimentation,demonstrating a significant improvement in the dynamic control performance and robustness of the classical PID controller extensively utilized in the field of engineering. 展开更多
关键词 inertial stabilization platform disturbance suppression sliding mode observer robust control
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Hybrid pedestrian positioning system using wearable inertial sensors and ultrasonic ranging 被引量:1
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作者 Lin Qi Yu Liu +2 位作者 Chuanshun Gao Tao Feng Yue Yu 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期327-338,共12页
Pedestrian positioning system(PPS)using wearable inertial sensors has wide applications towards various emerging fields such as smart healthcare,emergency rescue,soldier positioning,etc.The performance of traditional ... Pedestrian positioning system(PPS)using wearable inertial sensors has wide applications towards various emerging fields such as smart healthcare,emergency rescue,soldier positioning,etc.The performance of traditional PPS is limited by the cumulative error of inertial sensors,complex motion modes of pedestrians,and the low robustness of the multi-sensor collaboration structure.This paper presents a hybrid pedestrian positioning system using the combination of wearable inertial sensors and ultrasonic ranging(H-PPS).A robust two nodes integration structure is developed to adaptively combine the motion data acquired from the single waist-mounted and foot-mounted node,and enhanced by a novel ellipsoid constraint model.In addition,a deep-learning-based walking speed estimator is proposed by considering all the motion features provided by different nodes,which effectively reduces the cumulative error originating from inertial sensors.Finally,a comprehensive data and model dual-driven model is presented to effectively combine the motion data provided by different sensor nodes and walking speed estimator,and multi-level constraints are extracted to further improve the performance of the overall system.Experimental results indicate that the proposed H-PPS significantly improves the performance of the single PPS and outperforms existing algorithms in accuracy index under complex indoor scenarios. 展开更多
关键词 Pedestrian positioning system Wearable inertial sensors Ultrasonic ranging Deep-learning Data and model dual-driven
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Free-walking:Pedestrian inertial navigation based on dual foot-mounted IMU 被引量:2
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作者 Qu Wang Meixia Fu +6 位作者 Jianquan Wang Lei Sun Rong Huang Xianda Li Zhuqing Jiang Yan Huang Changhui Jiang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期573-587,共15页
The inertial navigation system(INS),which is frequently used in emergency rescue operations and other situations,has the benefits of not relying on infrastructure,high positioning frequency,and strong real-time perfor... The inertial navigation system(INS),which is frequently used in emergency rescue operations and other situations,has the benefits of not relying on infrastructure,high positioning frequency,and strong real-time performance.However,the intricate and unpredictable pedestrian motion patterns lead the INS localization error to significantly diverge with time.This paper aims to enhance the accuracy of zero-velocity interval(ZVI)detection and reduce the heading and altitude drift of foot-mounted INS via deep learning and equation constraint of dual feet.Aiming at the observational noise problem of low-cost inertial sensors,we utilize a denoising autoencoder to automatically eliminate the inherent noise.Aiming at the problem that inaccurate detection of the ZVI detection results in obvious displacement error,we propose a sample-level ZVI detection algorithm based on the U-Net neural network,which effectively solves the problem of mislabeling caused by sliding windows.Aiming at the problem that Zero-Velocity Update(ZUPT)cannot suppress heading and altitude error,we propose a bipedal INS method based on the equation constraint and ellipsoid constraint,which uses foot-to-foot distance as a new observation to correct heading and altitude error.We conduct extensive and well-designed experiments to evaluate the performance of the proposed method.The experimental results indicate that the position error of our proposed method did not exceed 0.83% of the total traveled distance. 展开更多
关键词 Indoor positioning inertial navigation system(INS) Zero-velocity update(ZUPT) Internet of things(IoTs) Location-based service(LBS)
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基于多解分离的GNSS/Inertial组合系统完好性监测 被引量:13
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作者 刘海颖 岳亚洲 +1 位作者 杨毅钧 蒋德杰 《中国惯性技术学报》 EI CSCD 北大核心 2012年第1期63-68,共6页
在卫星导航系统的完好性监测中,通常的接收机自主完好性监测过分依赖于可见星的几何分布,并且不能提供足够的可用性。针对该问题,给出了一种基于多解分离的惯性辅助卫星导航完好性监测方法。在对基于奇偶矢量的接收机自主完好性监测法... 在卫星导航系统的完好性监测中,通常的接收机自主完好性监测过分依赖于可见星的几何分布,并且不能提供足够的可用性。针对该问题,给出了一种基于多解分离的惯性辅助卫星导航完好性监测方法。在对基于奇偶矢量的接收机自主完好性监测法及其可用性分析基础上,设计了基于多解分离的卫星导航/惯性组合导航紧耦合滤波器,推导了其完好性监测以及可用性计算方法。通过仿真实验,从可用性、阶跃故障和斜坡故障的完好性监测效果等方面,对两种方法进行了对比分析。结果表明,多解分离法在5颗星时仍能定位故障,水平保护限值可以降低50 m,对于1 m/s的斜坡故障检测时间可以缩短71 s,显著提高了完好性监测性能。 展开更多
关键词 卫星导航 惯性导航 完好性监测 多解分离法 奇偶矢量法
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Transfer alignment of shipborne inertial-guided weapon systems 被引量:4
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作者 Sun Changyue Deng Zhenglong 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第2期348-353,共6页
The transfer alignment problem of the shipborne weapon inertial navigation system (INS) is addressed. Specifically, two transfer alignment algorithms subjected to the ship motions induced by the waves are discussed.... The transfer alignment problem of the shipborne weapon inertial navigation system (INS) is addressed. Specifically, two transfer alignment algorithms subjected to the ship motions induced by the waves are discussed. To consider the limited maneuver level performed by the ship, a new filter algorithm for transfer alignment methods using velocity and angular rate matching is first derived. And then an improved method using integrated velocity and integrated angular rate matching is introduced to reduce the effect of the ship body flexure. The simulation results show the feasibility and validity of the proposed transfer alignment algorithms. 展开更多
关键词 transfer alignment inertial navigation system Kalman filtering ship flexure
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Error model identification of inertial navigation platform based on errors-in-variables model 被引量:6
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作者 Liu Ming Liu Yu Su Baoku 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第2期388-393,共6页
Because the real input acceleration cannot be obtained during the error model identification of inertial navigation platform, both the input and output data contain noises. In this case, the conventional regression mo... Because the real input acceleration cannot be obtained during the error model identification of inertial navigation platform, both the input and output data contain noises. In this case, the conventional regression model and the least squares (LS) method will result in bias. Based on the models of inertial navigation platform error and observation error, the errors-in-variables (EV) model and the total least squares (TLS) method axe proposed to identify the error model of the inertial navigation platform. The estimation precision is improved and the result is better than the conventional regression model based LS method. The simulation results illustrate the effectiveness of the proposed method. 展开更多
关键词 errors-in-variables model total least squares method inertial navigation platform error model identification
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Inertial projection algorithms for convex feasibility problem 被引量:2
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作者 Yazheng Dang Yan Gao Lihua Li 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2012年第5期734-740,共7页
The purpose of this paper is to apply inertial technique to string averaging projection method and block-iterative projection method in order to get two accelerated projection algorithms for solving convex feasibility... The purpose of this paper is to apply inertial technique to string averaging projection method and block-iterative projection method in order to get two accelerated projection algorithms for solving convex feasibility problem.Compared with the existing accelerated methods for solving the problem,the inertial technique employs a parameter sequence and two previous iterations to get the next iteration and hence improves the flexibility of the algorithm.Theoretical asymptotic convergence results are presented under some suitable conditions.Numerical simulations illustrate that the new methods have better convergence than the general projection methods.The presented algorithms are inspired by the inertial proximal point algorithm for finding zeros of a maximal monotone operator. 展开更多
关键词 convex feasibility problem inertial technique string averaging block iteration asymptotic convergence
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Suppression of the G-sensitive drift of laser gyro in dual-axis rotational inertial navigation system 被引量:3
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作者 YU Xudong WANG Zichao +2 位作者 FAN Huiying WEI Guo WANG Lin 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2021年第4期822-830,共9页
The dual-axis rotational inertial navigation system(INS)with dithered ring laser gyro(DRLG)is widely used in high precision navigation.The major inertial sensor errors such as drift errors of gyro and accelerometer ca... The dual-axis rotational inertial navigation system(INS)with dithered ring laser gyro(DRLG)is widely used in high precision navigation.The major inertial sensor errors such as drift errors of gyro and accelerometer can be averaged out,but the G-sensitive drifts of laser gyro cannot be averaged out by indexing.A 16-position rotational simulation experiment proves the G-sensitive drift will affect the long-term navigation error for the rotational INS quantitatively.The vibration coupling and asymmetric structure of the DRLG are the main errors.A new dithered mechanism and optimized DRLG is designed.The validity and efficiency of the optimized design are conformed by 1 g sinusoidal vibration experiments.An optimized inertial measurement unit(IMU)is formulated and measured experimentally.Laboratory and vehicle experimental results show that the divergence speed of longitude errors can be effectively slowed down in the optimized IMU.In long term independent navigation,the position accuracy of dual-axis rotational INS is improved close to 50%,and the G-sensitive drifts of laser gyro in the optimized IMU are less than 0.0002°/h.These results have important theoretical significance and practical value for improving the structural dynamic characteristics of DRLG INS,especially the highprecision inertial system. 展开更多
关键词 inertial navigation rotational inertial navigation system(INS) laser gyro G-sensitive drift
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An improved computation scheme of strapdown inertial navigation system using rotation technique 被引量:8
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作者 张伦东 练军想 +1 位作者 吴美平 胡小平 《Journal of Central South University》 SCIE EI CAS 2012年第5期1258-1266,共9页
To improve the accuracy of strapdown inertial navigation system(SINS) for long term applications,the rotation technique is employed to modulate the errors of the inertial sensors into periodically varied signals,and,a... To improve the accuracy of strapdown inertial navigation system(SINS) for long term applications,the rotation technique is employed to modulate the errors of the inertial sensors into periodically varied signals,and,as a result,to suppress the divergence of SINS errors.However,the errors of rotation platform will be introduced into SINS and might affect the final navigation accuracy.Considering the disadvantages of the conventional navigation computation scheme,an improved computation scheme of the SINS using rotation technique is proposed which can reduce the effects of the rotation platform errors.And,the error characteristics of the SINS with this navigation computation scheme are analyzed.Theoretical analysis,simulations and real test results show that the proposed navigation computation scheme outperforms the conventional navigation computation scheme,meanwhile reduces the requirement to the measurement accuracy of rotation angles. 展开更多
关键词 strapdown inertial navigation system rotation technique navigation computation scheme error characteristic
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Time-asynchrony identification between inertial sensors in SIMU 被引量:1
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作者 Gongmin Yan Xi Sun +2 位作者 Jun Weng Qi Zhou Yongyuan Qin 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2015年第2期346-352,共7页
Traditional strapdown inertial navigation system (SINS) algorithm studies are based on ideal measurements from gy- ros and accelerometers, while in the actual strapdown inertial measurement unit (SIMU), time-async... Traditional strapdown inertial navigation system (SINS) algorithm studies are based on ideal measurements from gy- ros and accelerometers, while in the actual strapdown inertial measurement unit (SIMU), time-asynchrony between each iner- tial sensor is inevitable. Testing principles and methods for time- asynchrony parameter identification are studied. Under the single- axis swaying environment, the relationships between the SINS platform drift rate and the gyro time-asynchrony are derived using the SINS attitude error equation. It is found that the gyro time- asynchrony error can be considered as a kind of pseudo-coning motion error caused by data processing. After gyro testing and synchronization, the single-axis tumble test method is introduced for the testing of each accelerometer time-asynchrony with respect to the ideal gyro triad. Accelerometer time-asynchrony parame- ter identification models are established using SINS specific force equation. Finally, all of the relative time-asynchrony parameters between inertial sensors are well identified by using fiber optic gyro SIMU as experimental verification. 展开更多
关键词 strapdown inertial navigation system(SINS) time-asynchrony pseudo-coning error velocity error
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Robust control with compensation of adaptive model for dual-stage inertially stabilized platform 被引量:3
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作者 SONG Jiang-peng ZHOU Di +1 位作者 SUN Guang-li QI Zhi-hui 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第11期2615-2625,共11页
To achieve excellent tracking accuracy,a coarse-fine dual-stage control system is chosen for inertially stabilized platform.The coarse stage is a conventional inertially stabilized platform,and the fine stage is a sec... To achieve excellent tracking accuracy,a coarse-fine dual-stage control system is chosen for inertially stabilized platform.The coarse stage is a conventional inertially stabilized platform,and the fine stage is a secondary servo mechanism to control lens motion in the imaging optical path.Firstly,the dual-stage dynamics is mathematically modeled as a coupling multi-input multi-output(MIMO)control system.Then,by incorporating compensation of adaptive model to deal with parameter variations and nonlinearity,a systematic robust H∞control scheme is designed,which can achieve good tracking performance,as well as improve system robustness against model uncertainties.Lyapunov stability analysis confirmed the stability of the overall control system.Finally,simulation and experiment results are provided to demonstrate the feasibility and effectiveness of the proposed control design method. 展开更多
关键词 dual-stage control inertially stabilized platform robust H∞control adaptive model
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Special epoxy silicone adhesive for inertial confinement fusion experiment 被引量:3
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作者 李芝华 李波 郑子樵 《Journal of Central South University of Technology》 EI 2007年第2期153-156,共4页
The effects of toughener and coupling agent on special epoxy silicone adhesive were discussed by researching the surface morphology characters, thermal properties and shear strength of the adhesive. The results indica... The effects of toughener and coupling agent on special epoxy silicone adhesive were discussed by researching the surface morphology characters, thermal properties and shear strength of the adhesive. The results indicate that silicone coupling agent (KH-550) can improve the shear strength of the epoxy silicone adhesive effectively. The mass fraction of the toughener in the epoxy silicone adhesive plays an important role in its properties. When the mass fraction of the toughener is less than 14%, the shear strength of the adhesive is low. When the mass fraction of the toughener is over 33%, thermal properties and shear strength of the adhesive decrease with the increasing of the toughener. The mass fraction of toughener of 25% results in good integral properties of the epoxy silicone adhesive. The morphologic analysis indicates that the micro-phase separation exists in the epoxy molecular chain and the silicone molecular chain of the epoxy silicone adhesive. 展开更多
关键词 inertial confinement fusion experiment epoxy silicone toughener coupling agent micro-phase separation
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Parameter identification of inertially stabilized platforms using current command design 被引量:2
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作者 黎志强 张智永 +1 位作者 周擎坤 范大鹏 《Journal of Central South University》 SCIE EI CAS 2013年第2期342-353,共12页
Accurate parameter identification is essential when designing controllers for inertially stabilized platforms (lSPs). But traditional identification methods suffer from observation measurement noise and operating re... Accurate parameter identification is essential when designing controllers for inertially stabilized platforms (lSPs). But traditional identification methods suffer from observation measurement noise and operating restrictions of ISPs. To address this issue, a novel identification method based on current command design and multilevel coordinate search (MCS) algorithm without any higher order measurement differentiations was proposed. The designed current commands were adopted to obtain parameter decoupled models with the platform operating under allowable conditions. MCS algorithm was employed to estimate the parameters based on parameter decoupled models. A comparison experiment between the proposed method and non-linear least square method was carried out and most of the relative errors of identified parameters obtained by the proposed method were below 10%. Simulation and experiment based on identified parameters were conducted. A velocity control structure was also developed with disturbance observer (DOB) for application in disturbance compensation control system of an ISR Experimental results show that the control scheme based on the identified parameters with DOB has the best disturbance rejection performance. It reduces the peak to peak value (PPV) of velocity error integral to 0.8 mrad which is much smaller than the value (10 mrad) obtained by the single velocity controller without DOB. Compared with the control scheme based on sweep model with DOB compensation, the proposed control scheme improves the PPV of velocity error integral by 1.625 times. 展开更多
关键词 parameter identification current command design multilevel coordinate search inertially stabilized platforms
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Study on Inertial Response Performance of A Micro Electrical Switch for Fuze 被引量:11
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作者 Wei-rong NIE Zhan-wen XI +1 位作者 Wei-qing XUE Zhi-jian ZHOU 《Defence Technology(防务技术)》 SCIE EI CAS 2013年第4期187-192,共6页
The design,modeling,and simulation of a micro electrical switch for fuze are presented.It consists of springemass system with zigzag slot in mass,latching and electrical connection mechanism and movement-limit mechani... The design,modeling,and simulation of a micro electrical switch for fuze are presented.It consists of springemass system with zigzag slot in mass,latching and electrical connection mechanism and movement-limit mechanism.The switch keeps off-state until it is subjected to an acceleration when fuze is launched normally.The acceleration is simulated as half-sine pulse with specific amplitude and duration.The dynamics model of the switch is studied.Based on zigzag slot in mass,the methods used for recognizing acceleration load are established and analyzed according to the dynamics theory.Two typical half-sine accelerations are loaded on the switch in simulation.The simulation results are in accordance with those of theoretical analysis.The inertial response characteristics of the switch can ensure that the fuze power supply and circuit are connected safely and reliably. 展开更多
关键词 引信电源 响应性能 电开关 惯性 弹簧质量系统 模拟交换机 微机 动力学模型
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Effects of Squeeze-film Air Damping on Properties of MEMS Inertial Switch in Fuse
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作者 牛兰杰 李晓杰 翟蓉 《Defence Technology(防务技术)》 SCIE EI CAS 2010年第1期20-24,共5页
The squeeze-film air damping exists in a lot of micro-electronic-mechanical system (MEMS) devices unavoidably. The effects of air damping in traditional inertial switch with spring-mass system can be ignored for its l... The squeeze-film air damping exists in a lot of micro-electronic-mechanical system (MEMS) devices unavoidably. The effects of air damping in traditional inertial switch with spring-mass system can be ignored for its large volume and mass. But, many properties of MEMS switch, such as sensitivity, resolution and contact time, are affected by the air damping caused from the squeezed air film between two parallel plates moving relatively. Based on the conservation laws for mass and flux and the nonlinear Reynolds equation, the coefficient of squeeze-film damping was derived. The dynamic responses of the inertial switch with and without squeeze-film damping were simulated by using software ANSYS. The simulated results show that the sensitivity and contact time of the switch descend by about 5% and 15%, respectively, when the effects of squeeze-film damping are considered. 展开更多
关键词 engineering mechanics FUSE MEMS inertial switch squeeze-film air damping
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THE DETERMINATION OF THE DEFLECTION OF VERTICAL USING INERTIAL SURVEYI 被引量:1
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作者 Wang Wei(Department of Automatic Control,NUDT,Changsha, 410073) 《国防科技大学学报》 EI CAS CSCD 北大核心 1995年第3期126-130,共5页
THEDETERMINATIONOFTHEDEFLECTIONOFVERTICALUSINGINERTIALSURVEYINGSYSTEMWangWei(DepartmentofAutomaticControl,NU... THEDETERMINATIONOFTHEDEFLECTIONOFVERTICALUSINGINERTIALSURVEYINGSYSTEMWangWei(DepartmentofAutomaticControl,NUDT,Changsha,41007... 展开更多
关键词 垂线偏差 惯性测量 ZUPT
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Classical Theory of Advance of Perihelion of Mercury with Velocity Dependent Inertial and Gravitational Masses
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作者 Erich R. Bagge (Institute for Pure and Applied Nuclear Physics, Christian Albrechts University, Kiel,Germany) 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1995年第4期87-98,共12页
It is shown that Mercury's motion of the perihelion around the Sun, which is believed to be explicable quantitatively only by general relativity, can be fully understood within the frame of the dynamics of special... It is shown that Mercury's motion of the perihelion around the Sun, which is believed to be explicable quantitatively only by general relativity, can be fully understood within the frame of the dynamics of special relativity. It is only necessary to take into consideration the relativistic dependence of the planet's inertial and gravitational masses on its velocity (relative to the Sun) in the conservation equations for energy, and linear and angular momenta in the gravitational field. The physical Problem is reduced to a singular, nonlinear differential equation, which is solved numerically for the planet Mercury. The advance of the perihelion of Mercury is shown to be = 42.087' for a period of 100 years, which is in agreement with the as- tronomical observations and the result (by analytical approximations) of general relativity. 展开更多
关键词 Planet mercury Advance of perihelion Classical theory Velocity dependent inertial and gravitational masses Agreement with observations.
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Impact of Shaft Stiffness on Inertial Response of Fixed Speed Wind Turbines 被引量:1
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作者 Francisco GONZLEZ-LONGATT 《电力系统自动化》 EI CSCD 北大核心 2012年第8期191-197,共7页
Future power system faces several challenges,one of them is the high penetration level of intermittent wind power generation,providing small or even no inertial response and being not contributing to the frequency sta... Future power system faces several challenges,one of them is the high penetration level of intermittent wind power generation,providing small or even no inertial response and being not contributing to the frequency stability.The effect of shaft stiffness on inertial response of fixed speed wind turbines is presented.Four different drive-train models based on the multi-body system are developed.The small-signal analysis demonstrates no significant differences between models in terms of electro-mechanical eigen-values for increasing shaft stiffness.The natural resonance frequency of drive-train torsion modes shows slightly different values between damped and undamped models,but no significant differences are found in the number-mass models.Time-domain simulations show the changes in the active power contribution of a wind farm based on a fixed speed wind turbine during the system frequency disturbance.The changes in the kinetic energy during the dynamic process are calculated and their contribution to the inertia constant is small and effective.The largest contribution of the kinetic energy is provided at the beginning of the system frequency disturbance to reduce the rate of the frequency change,it is positive for the frequency stability. 展开更多
关键词 风力发电机 刚度模型 惯性 风力涡轮机 频率稳定性 定速 传动系统
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Approximate Inertial Manifold Method andMultilevel Finite Element Approximationfor the Navier-Stokes Equations 被引量:1
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作者 李开泰 黄艾香 《工程数学学报》 CSCD 1990年第2期1-41,共41页
This paper presents the Approximate Incrtial Manifold ∑ and its successive approximate incrtial manifold ∑i and ∑ij . We give the estimates of thickness of neighborhood of ∑, ∑j, Ejt respectively in which the eve... This paper presents the Approximate Incrtial Manifold ∑ and its successive approximate incrtial manifold ∑i and ∑ij . We give the estimates of thickness of neighborhood of ∑, ∑j, Ejt respectively in which the every solution of Navier-Stokcs equation enters.Another part of this paper presents construction method for A.I.M. by multilevel finite clement method and give error estimates of the approximate solution of incrtial form. 展开更多
关键词 惯性流形逼近 多级有限元逼近 Navier-Stakes方程
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