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Wang Z.,Beijing University of Technology | Yang Y.,Beijing University of Technology | Yang J.,Tsinghua University | Yang J.,Collaborative Innovation Center for Devices and Systems | Yang J.,State Key Laboratory of Precision Measurement Technology and Instruments
Mathematical Problems in Engineering | Year: 2015

Inertial navigation devices include star sensor, GPS, and gyroscope. Optical fiber and laser gyroscopes provide high accuracy, and their manufacturing costs are also high. Magnetic suspension rotor gyroscope improves the accuracy and reduces the production cost of the device because of the influence of thermodynamic coupling. Therefore, the precision of the gyroscope is reduced and drift rate is increased. In this study, the rotor of liquid floated gyroscope, particularly the dished rotor gyroscope, was placed under a thermal field, which improved the measurement accuracy of the gyroscope. A dynamic theory of the rotor of liquid floated gyroscope was proposed, and the thermal field of the rotor was simulated. The maximum stress was in x, 1.4; y, 8.43; min 97.23; and max 154.34. This stress occurred at the border of the dished rotor at a high-speed rotation. The secondary flow reached 5549 r/min, and the generated heat increased. Meanwhile, the high-speed rotation of the rotor was volatile, and the dished rotor movement was unstable. Thus, nanomaterials must be added to reduce the thermal coupling fluctuations in the dished rotor and improve the accuracy of the measurement error and drift rate. © 2015 Wang Zhengjun et al. Source


Li R.,State Key Laboratory of Precision Measurement Technology and Instruments | Qu X.,State Key Laboratory of Precision Measurement Technology and Instruments
Jiqiren/Robot | Year: 2014

A measurement and control technology is presented to compensate the movement angle error for each axis of the robot. The effect significance of various factors on the movement angle error is discussed. The control error model of motor moving and the deformation error model of joint or link are analyzed independently. A measuring scheme based on biaxial orthogonal inertial measurement is proposed. In order to obtain the distribution of the space geometric error, the angle error of each robot axis is measured in the motion range of every axis in advance. Then the orthogonal polynomial fitting is used to establish the position error distribution model of each axis. An error compensation value is calculated using the proposed model before the robot runs, so as to control the robot for position compensation. The distribution law of each axis motion error in the robot and the way of orthogonal polynomial fitting are analyzed. The laser tracker is used to measure the compensation effect of the position accuracy of the robot end. The robot control accuracy can be improved by studying robot performance and its compensation. Source


Zhao J.,State Key Laboratory of Precision Measurement Technology and Instruments | Zhao J.,Tianjin University of Traditional Chinese Medicine | Li Z.,State Key Laboratory of Precision Measurement Technology and Instruments | Li G.,State Key Laboratory of Precision Measurement Technology and Instruments | And 4 more authors.
Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis | Year: 2012

In order to solve the problem that the collected spectrum was influenced seriously by the operation method, improve the instrument sensitivity and enhance the differences between samples, reflectivity normalization method was used for data preprocessing in the present article. First, the reflect spectrum of tongue was collected, then the reflectivity and the normalized reflectivity of the samples were compared, and it was found that reflectivity normalization method can eliminate the impact brought by the collection from different distance. At the same time, the classification results between the reflectivity and the normalization reflectivity of the different samples were compared, and the results showed that the reflectivity normalization method can enhance differences between the samples and enhance model's robustness and prediction ability of subsequent disease screening. Source


Wang Z.,State Key Laboratory of Precision Measurement Technology and Instruments | Wang Z.,Beijing University of Technology | Yang J.,Tsinghua University | Yang J.,State Key Laboratory of Precision Measurement Technology and Instruments | And 2 more authors.
Sensors and Transducers | Year: 2014

In this paper, it is based on the dynamics analysis about the dishing rotor’s gyroscope, and it is under the comsol software, the rotor’s effects that is on the rotor by magnetic field and thermal field, and that are simulated. Meanwhile it is concluded that the rotor is under the effect of Magnetic. The current is 100 mA, 200 mA, 800 mA, through the force of dishing rotor’s border, it is the biggest place that was established a theoretical model in the flow fields. This is related in the comsol software simulation. At the same time for the dishing rotor sphere of heated, the highest temperature: X part of the border, Y, Z: Magnetic flux density norm (T) 384.3, 32.8, 224.4, 1.2 e-10, for the dishing rotor boundary, the minimum thermal stress field is in the X, Y, Z: Value117.6, 24.7, 24.7, 117.6 e-12. © 2014 IFSA Publishing, S. L. Source


Deng Y.,State Key Laboratory of Precision Measurement Technology and Instruments | Zhou B.,State Key Laboratory of Precision Measurement Technology and Instruments | Xing C.,State Key Laboratory of Precision Measurement Technology and Instruments | Zhang R.,State Key Laboratory of Precision Measurement Technology and Instruments
Sensors (Switzerland) | Year: 2014

A novel multifrequency excitation (MFE) method is proposed to realize rapid and accurate dynamic testing of micromachined gyroscope chips. Compared with the traditional sweep-frequency excitation (SFE) method, the computational time for testing one chip under four modes at a 1-Hz frequency resolution and 600-Hz bandwidth was dramatically reduced from 10 min to 6 s. A multifrequency signal with an equal amplitude and initial linear-phase-difference distribution was generated to ensure test repeatability and accuracy. The current test system based on LabVIEW using the SFE method was modified to use the MFE method without any hardware changes. The experimental results verified that the MFE method can be an ideal solution for large-scale dynamic testing of gyroscope chips and gyroscopes. © 2014 by the authors; licensee MDPI, Basel, Switzerland. Source

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