一种异类系统中多种故障检测与隔离的空间几何方法研究

针对量测干扰下一种异类过驱动系统中残差与干扰存在耦合关系的问题,提出一种运用空间几何方法实现残差对干扰解耦的新算法.通过设计残差生成器并实现残差对系统输入和量测干扰的解耦,由残差值反馈故障检测情况,根据不可观测子空间中的空间分割建立结构化残差集,使得残差集与故障集满足完全对应关系,完成故障的隔离.最后通过提出对比仿真算例验证了我们所提算法的可行性和有效性.

A shaped annular beam tri-heterodyne confocal microscope with good anti-environmental interference capability

annular beam tri-heterodyne confocal microscope has been proposed to improve the anti-environmental interference capability and the resolution of a eonfoeal microscope. It simultaneously detects far-, on-, and near-focus signals with given phase differences by dividing the measured light path of the eonfoeal microscope into three sub-paths （signals）. Pair-wise real-time heterodyne subtraction of the three signals is used to improve the anti-environmental interference capability, axial resolution, and linearity; and a shaped annular beam super-resolution technique is used to improve lateral resolution. Theoretical analyses and preliminary experiments indicate that an axial resolution of about 1 nm can be achieved with a shaped annular beam tri-heterodyne confoeal microscope and its lateral resolution can be better than 0.2 um for A = 632.8 nm, the numerical aperture of the lens of the microscope is NA = 0.85, and the normalized radius e = 0.5.

Method for Measuring Self-noise of Vector Hydrophones

The Vector Hydrophone(VH) is widely used to remotely detect underwater targets. Accurately measuring the self-noise of the VH provides an important basis for evaluating the performance of the detection system in which it is utilized, since the ability to acquire weak signals is determined by the VH self-noise level. To accurately measure the VH self-noise level in actual working conditions, the Dual-channel Transfer Function Method(DTFM) is proposed to reduce ambient background noise interference. In this paper, the underlying principles of DTFM in reducing ambient background noise is analyzed. The numerical simulations to determine the influence of ambient background noise, and the sensitivity difference of the two VHs on the measurement results are studied. The results of measuring the VH self-noise level in a small laboratory water tank by using DTMF indicate that ambient background noise interference can be reduced effectively by employing DTMF, more accurate self-noise level can be obtained as well. The DTMF provides an effective method for accurately measuring the self-noise level of VHs and also provides technical support for the practical application of the VH in underwater acoustics.

Dynamic Integrity Measurement Model Based on vTPM

With the development of cloud computing, virtualization technology has been widely used in our life. Meanwhile, it became one of the key targets for some attackers. The integrity measurement in virtual machine has become an urgent problem. Some of the existing virtualization platform integrity measurement mechanism introduces the trusted computing technology, according to a trusted chain that the Trusted Platform Module(TPM) established for trusted root to measure the integrity of process in static. But this single chain static measurement cannot ensure the dynamic credible in platform running. To solve the problem that the virtual trusted platform can not guarantee the dynamic credibility, this paper put forward Dynamic Integrity Measurement Model(DIMM) based on virtual Trusted Platform Module(v TPM) which had been implemented with typical virtual machine monitor Xen as an example. DIMM combined with virtual machine introspection and event capture technology to ensure the security of the entire user domain. Based on the framework, this paper put forward Self-modify dynamic measurement strategy which can effectively reduce the measurement frequency and improve the measurement performance. Finally, it is proved that the validity and feasibility of the proposed model with comparison experiments.

02（1△） Yield Measurement by Raman Spectroscopy With Elimination of Chlorine Fluorescence Interference

Deleterious chlorine fluorescence was found to occur at the same frequency as the Raman scattering of 02 （1 A） and 02 （3 E）, seriously affecting the 02 （1 A） yield measurement in the reaction of chlorine with basic hydrogen peroxide by use of the Raman spectroscopy technique. To solve this problem we have taken advantage of the fact that Raman radiation is always strongly polarized while fluorescence is essentially non-polarized in a gaseous medium. When chlorine utilization of a singlet oxygen generator is 88%, 02（1A） yield reaches （42.4±7.4）% with the effect of chlorine fluorescence completely eliminated.

Review of reflective fiber optic sensors for surface topography measurement

Different from the traditional contact surface topography measurement,reflective intensity-modulated fiber optic sensor(RIM-FOS)has the unique advantages of non-contact nondestructive detection.This paper briefly introduces the principle and performance of RIM-FOS for surface topography measurement and compares with several other methods of topography measurement.Based on the review of its development process,this paper summarizes and analyses the hot issues of RIM-FOS in the surface topography measurement,then predicts the future trend for a guidance of the further study.

Investigation of Concrete Distortion with Real-time Holographic Method

In order to find the relationships between the distortion rule ofthe concrete and its surrounding stress field, a real-time opticalholographic setup is used to record the distribution and thevariation of the samples, the waveforms of ultrasonic emissionstimulated by the micro-cracks are recorded by a transient automaticwaveform recorder to determine the time location and intensity of theactions of micro-cracks. The experiment results are worth studying.This method provides a useful experimental approach to study thebrittleness materials.

Evaluation on safety performance of a millimetre wave radar-based autonomous vehicle

This paper presents a method using range deception jamming to evaluate the safety performance of the autonomous vehicle with millimetre wave(MMW)radar.The working principle of this method is described.Combined with a waveform edition software,an experimental platform is developed to generate a deceptive signal that contains false distance information.According to related theories and its principle,the configuration parameters of the experimental setup are calculated and configured.The MMW radar of evaluated vehicle should identify an objective when it receives the deceptive signal from the experimental setup.Even if no obstacle,the evaluated vehicle can immediately brake in order that its braking distance is measured.The experimental results show that the proposed method can meet the requirements of the safety performance evaluation for the autonomous vehicle with MMW radar,and it also overcomes some deficiencies of previous methods.

Distributed Fabry-Perot Measurement System

The theoretic analysis indicates that if the lengths of the cascaded and paralleled Fabry-Perot sensors are properly selected, the crosstalk can be well restricted.And the experiment simulation results agree with that of the theoretic analysis.

Sensor fusion for heading angle estimation based on random forest algorithm

To improve the accuracy of the calculation of a heading angle under magnetic interference,magnetometers and inertial measurement units(IMUs)were fused.The observation value of the heading angle was deduced on the basis of the modeling of the magnetometer error and the analysis of the relation of the magnetometer triaxial output and the distribution characteristics of the magnetic field at two adjacent time periods.Meanwhile,the gyro state and angular velocity increment were used as the basis of the IMU to calculate the prediction value of the heading angle.With the changes in the heading angle and environmental interference,a random forest(RF)algorithm was used to iteratively calculate the weights to fuse the observation value of the heading angle based on the magnetometer and the prediction value of the heading angle based on the IMU.The results show that relative to the common sensor fusion method,the proposed sensor fusion method based on the RF algorithm achieved an approximate 60%improvement in heading angle accuracy.Hence,the proposed method can effectively improve the accuracy of the heading angle under magnetic interference by using an RF algorithm to calculate the output weights of the magnetometer and IMU.

Evaluation of Cloud Feedback at Local Scale： Warming or Cooling？

Clouds affect the climate by positive and negative feedback. To study these effects at local scale, a radiation station was set up, which used two CM21 Kipp ＆ Zonen pyranometers （one inverted）, and two CG1 Kipp ＆ Zonen pyrgeometers （one inverted） in Logan, Utah, USA. The pyranometers and pyrgeometers were ventilated using four CV2 Kipp ＆ Zonen ventilation systems. Ventilation of pyranometers and pyrgeometers prevent dew, frost and snow accumulation, which otherwise would disturb the measurement. Knowing that available energy （Rn） as Rn = Rsi - Rso ＋ Rli - Rio where Rsi and Rso are downward and upward solar radiation, respectively, and Rli and Rio as atmospheric and terrestrial, respectively, the effects of cloudiness were evaluated on a daily and annual basis. The results indicate that for the partly cloudy days of 4 and 5 September, 2007, cloudiness caused less available energy （Rn） in the amounts of-1.83 MJ·m^-2·d^-1 and -3.83 MJ·m^-2·d^-1 on these days, respectively. As shown, due to cloudiness at the experimental site, the net radiation loss was 2,804 - 4,055 = -1,251 MJ·m^-2·d^-1, which indicates a negative feedback due to cloudiness.

Differentiation of the Atmospheric Moisture Collected by Dew and Fog

Dew and fog play major roles in providing the atmospheric moisture for plants and arthropods living in arid regions all over the world. Studies are needed to discriminate between dew and fog. A radiation system was developed for measuring the incoming and outgoing solar （shortwave） radiation using two CM21 Kipp ＆ Zonen pyranometers （one inverted）, and the incoming （atmospheric） and outgoing （terrestrial） longwave radiation using two CG1 pyrgeometers in Logan （41047＇ N, 111~51＇ W, 1,460 m above mean sea level）, Utah, USA, continuously since 1995. These instruments are ventilated with heated air to prevent precipitation of dew and frost on the sensors, which otherwise would disturb the measurements. Based upon these measurements and an algorithm, the cloud base height, the cloud base temperature and percent of cloudiness can be parameterized at local scale. A cloud base height around zero would indicate fog at the local scale. In 1999, Bowen ratio system was added to measure the evapotranspiration, dew and frost continuously throughout the year at the same location close to the radiation system. Combining these two systems （radiation and Bowen ratio） has yielded a reasonable approach to differentiate between the atmospheric moistures collected by dew and fog.

Suppression of Pulse Interference in Partial Discharge Measurement Based on Phase Correlation and Waveform Characteristics

Partial discharge measurement is one of the most effective methods to find insulation defects and early failure of high voltage power equipments. The accuracy is significantly reduced by the interference in the partial discharge on-site detection or on-line monitoring, especially by the pulse interference. This paper studies the phase correlation of some types of typical partial discharge pulses and their characteristics in time domain and frequency domain. By collecting enough partial discharge pulse data, the correlation coefficient can be calculated based on both phase correlation and waveform similarity. The type of pulse will be determined by the scope of the calculated correlation coefficient. The pulses with very strong correlation will be identified as periodic pulse interference. The pulses with very weak correlation will be identified as random pulse interference. Only the pulses whose correlation coefficients fall into a specific range will be identified as partial discharge signals. In laboratory, simulated pulse interference is injected into measurement circuit, and typical partial discharge pulses are sampled by a high-speed acquisition system. The pulse interference can be effectively separated from partial discharge signals by correlation coefficient.

卡尔曼滤波器在数控非圆车削系统中的应用与仿真

在实际加工中,数控非圆车削系统会受到各种干扰的影响,其中包括控制系统所受到的干扰和传感器测量所受到的干扰。应用卡尔曼滤波器可以有效补偿这些干扰的影响,本文利用仿真实验进行了证明。

Measurement-Based Interference in Quantum Computation

The interference has been measured by the visibility in two-level systems, which, however, does not work for multi-level systems. We generalize a measure of the interference based on decoherence process, consistent with the visibility in qubit systems. By taking duster states as examples, we show in the one-way quantum computation that the gate fidelity is proportional to the interference of the measured qubit and is inversely proportional to the interference of all register qubits. We also find that the interference increases with the number of the computing steps. So we conjecture that the interference may be the source of the speedup of the one-way quantum computation.