Beijing Institute of Aerospace Control Devices

Beijing, China

Beijing Institute of Aerospace Control Devices

Beijing, China
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Qin Y.,Beijing Institute of Technology | Zhao F.,Beijing Institute of Aerospace Control Devices | Wang Z.,Beijing Institute of Technology | Gu L.,Beijing Institute of Technology | Dong M.,Beijing Institute of Technology
Journal of Vibration and Acoustics, Transactions of the ASME | Year: 2017

This paper presents a comprehensive comparison and analysis for the effect of time delay on the five most representative semi-active suspension control strategies, and refers to four unsolved problems related to semi-active suspension performance and delay mechanism that existed. Dynamic characteristics of a commercially available continuous damping control (CDC) damper were first studied, and a material test system (MTS) load frame was used to depict the velocity-force map for a CDC damper. Both inverse and boundary models were developed to determine dynamic characteristics of the damper. In addition, in order for an improper damper delay of the form t+., to be corrected, a delay mechanism of controllable damper was discussed in detail. Numerical simulation for five control strategies, i.e., modified skyhook control SC, hybrid control (HC), COC, model reference sliding mode control (MRSMC), and integrated error neuro control (IENC), with three different time delays: 5 ms, 10 ms, and 15 ms was performed. Simulation results displayed that by changing control weights/variables, performance of all five control strategies varied from being ride comfort oriented to being road handling oriented. Furthermore, increase in delay time resulted in deterioration of both ride comfort and road handling. Specifically, ride comfort was affected more than road handling. The answers to all four questions were finally provided according to simulation results. © 2017 by ASME.

Liu Z.,Beihang University | Yin Y.,Beihang University | Liu S.,Beijing Institute of Aerospace Control Devices | Chen X.,Beijing Institute of Aerospace Control Devices
Applied Optics | Year: 2016

The on-site calibration of stereo vision sensors plays an important role in the measurement field. Image coordinate extraction of feature points of existing targets is difficult under complex light conditions in outdoor environments, such as strong light and backlight. This paper proposes an on-site calibration method for stereo vision sensors based on a spot laser projector for solving the above-mentioned problem. The proposed method is used to mediate the laser spots on the parallel planes for the purpose of calibrating the coordinate transformation matrix between two cameras. The optimal solution of a coordinate transformation matrix is then solved by nonlinear optimization. Simulation experiments and physical experiments are conducted to validate the performance of the proposed method. Under the condition that the field of view is approximately 400 mm x 300 mm, the proposed method can reach a calibration accuracy of 0.02 mm. This accuracy value is comparable to that of the method using a planar target. © 2016 Optical Society of America.

Liu Z.,Beihang University | Wu Q.,Beihang University | Chen X.,Beijing Institute of Aerospace Control Devices | Yin Y.,Beihang University
Optics Express | Year: 2016

Nonindustrial low-cost cameras have the advantages of cheap and simple structure, but have the disadvantages of low resolution and large image noise. When the existing camera calibration methods are used to calibrate nonindustrial low-cost cameras, high-accuracy calibration cannot be obtained. A high-accuracy calibration method using a high-accuracy planar target is introduced in this study to solve this problem. First, the initial values and the uncertainties of all image feature points are determined by the multiscale image analysis method. Then, the image disturbance factor is added to each target image feature point. In addition, the image projection error is established as the minimum objective function according to the homography matrix between the target plane and the image plane. Thus, the optimal coordinates of all image feature points are obtained by the nonlinear optimization method. Finally, the calibration of the intrinsic and extrinsic parameters of the camera will be achieved by using Zhang's method according to the image feature points obtained from the previous step. Simulative and real experiments have been conducted to evaluate the performance of the proposed method, and results show that the calibration accuracy of the proposed method is at least three times that of Zhang's method. © 2016 Optical Society of America.

Hu Q.-F.,Beijing Institute of Aerospace Control Devices | Xing C.-Y.,Beijing Institute of Aerospace Control Devices | Liu G.-W.,Beijing Institute of Aerospace Control Devices
Zhongguo Guanxing Jishu Xuebao/Journal of Chinese Inertial Technology | Year: 2017

The precision of the inertial navigation is highly related with the thermal stability of MEMS inertial sensor devices. The structure-related thermal drift is mainly caused by the mismatch stresses of MEMS material, the fabrication-induced stress, and the packaging stress. This paper focuses on the FEM simulation researches of standard bulk silicon MEMS inertial devices. Based on ANSYS FEM simulation, the FEM models of common beam-mass structures in MEMS inertial devices are built, including cantilever beam, double-clamped beams, L-shaped beams, and diagonal-suspension beams. Based on thermal-mechanical coupling simulation, the distributions of thermal mismatch stresses in these structures and the resulting structural deformation are studied. Based on the coupling simulation of multi-physics fields in full temperature range from -40℃ to 60℃, the packaging-induced stress and the stress-temperature relationship of various chip-bonding methods are evaluated, including single-point chip bonding, multi-points chip bonding, and whole area bonding. In addition, the isolation effects of different substrate thicknesses on the packaging-induced stress are shown by analysis and research. © 2017, Editorial Department of Journal of Chinese Inertial Technology. All right reserved.

Xia D.,Nanjing Southeast University | Hu Y.,Nanjing Southeast University | Wang Y.,Beijing Institute of Aerospace Control Devices
Sensors and Actuators, A: Physical | Year: 2016

To optimize conventional phase locked loop (PLL) performance through enhancement of drive mode stability of frequency and amplitude, enhanced phase locked loop (EPLL) and quadrature phase locked loop (QPLL) algorithms were investigated. First, stable point averaging analysis was applied to verify the stability of the closed-loop and determine the range of the critical parameters. When simulations were conducted to compare PLL, EPLL and QPLL, it was found the use of QPLL resulted in superior control precision and noise suppression. Next, different nonlinear dynamic closed-loops in PLL modules allowed for stable amplitude and constant frequency in the drive mode, and parameter estimates were needed for both EPLL and QPLL algorithms without amplitude demodulation. Then, after the control parameters were optimized, the EPLL and QPLL algorithms were compared at the module level by Field Programmable Gate Array (FPGA) chip, and specified amplitude and frequency startup characteristics were analyzed. Finally, under the same test conditions, system level experiments were implemented to compare some major specifications of the digital gyroscope system. During experiments, the phase noise of the drive mode detection signal was utilized to estimate the frequency control stability. The QPLL based gyroscope yielded better bias instability with 4.34°/h and a noise floor of 0.0229 °·s−1/Hz, while the EPLL system was only 9.33°/h with a noise floor of 0.0711°·s−1/Hz. © 2016 Elsevier B.V.

Han B.,Beihang University | Xu Q.,Beihang University | Yuan Q.,Beijing Institute of Aerospace Control Devices
IEEE Transactions on Industrial Electronics | Year: 2016

The combined radial-axial magnetic bearing (CRAMB) with permanent magnet (PM) providing bias magnetic flux is designed for magnetically suspended high-speed electromotor in the compressor for its compact construction. In this paper, the design principle and the initial model of CRAMB are introduced. To improve the performances of CRAMB and better meet the engineering requirements, the optimization is conducted on the bearing. Considering the incompatible objectives of the optimization model, the method of multiobjective optimization (MOO) on the bearing is proposed, which can balance these objectives compared with single-objective optimization (SOO). The objectives and constraints are provided in the form of analytical expressions by means of equivalent magnetic circuit whose rationality is demonstrated by finite-element method (FEM). To optimize the bearing efficiently, the integrated optimum methodology is adopted. After MOO process, the synthetical performances are improved, which are verified by FEM and experiment. © 1982-2012 IEEE.

Jin H.,Nanjing University | Liu F.M.,Beijing Institute of Aerospace Control Devices | Xu P.,Nanjing University | Xia J.L.,Beijing Institute of Aerospace Control Devices | And 6 more authors.
Physical Review Letters | Year: 2014

A consequent tendency toward high-performance quantum information processing is to develop the fully integrated photonic chip. Here, we report the on-chip generation and manipulation of entangled photons based on reconfigurable lithium-niobate waveguide circuits. By introducing a periodically poled structure into the waveguide circuits, two individual photon-pair sources with a controllable electro-optic phase shift are produced within a Hong-Ou-Mandel interferometer, resulting in a deterministically separated identical photon pair. The state is characterized by 92.9±0.9% visibility Hong-Ou-Mandel interference. The photon flux reaches ∼1.4×107pairsnm-1mW-1. The whole chip is designed to contain nine similar units to produce identical photon pairs spanning the telecom C and L band by the flexible engineering of nonlinearity. Our work presents a scenario for on-chip engineering of different photon sources and paves the way to fully integrated quantum technologies. © 2014 American Physical Society.

Yang W.,University of Science and Technology Beijing | Zhu R.,Tsinghua University | Ma B.,Beijing Institute of Aerospace Control Devices
IEEE Transactions on Plasma Science | Year: 2016

There has been considerable interest in nonthermal atmospheric pressure discharges due to their widely used industrial applications. A repetitively pulsed (RP) discharge ignited in microchannels between two nonequally broad planar electrodes is studied in this paper. The discharge current attains several 10-5 A orders of magnitude, and the ion concentration produced in interelectrode space by RP discharge is estimated to be about 1017/m3. The duration of each time of RP discharge is several 10-8 s and the repetition frequency exceeds a few tenths of kilohertz. The repetition frequency of RP discharge depends on the RC product, applied voltage, and the environmental humidity. The experiments of charging aerosol particles by RP discharges have shown that for particles with diameters of 34.8 and 103 nm, the charging efficiency can attain 14.8% and 35%, respectively. © 2015 IEEE.

Yang T.,Beijing Institute of Aerospace Control Devices | Zhou L.-B.,Huazhong University of Science and Technology
Dianji yu Kongzhi Xuebao/Electric Machines and Control | Year: 2014

To investigate the influence of the longitudinal dynamic end effect(LDEE) on the magnetic field and performance of the long primary double-sided linear induction motor(LP-DSLIM), the airgap magnetic field for LP-DSLIM was analyzed, in part 1, by using the analytical method. According to the derived analytical expressions of the airgap magnetic flux density, the analytical calculations, when taking into account LDEE, were extended to the prediction of the motor performances, which include electromagnetic thrust, active and reactive power, power factor and efficiency, etc in this part. The analytical results were compared and validated by the predictions from two-dimensioanl finite element analysis. The fact that thrust due to the entry-end effect comes into being as the braking force at high speed, and its influence on the resultant thrust-speed characteristics were investigated by the phasor diagram of the airgap magnetic flux density. The effects of the motor design parameters, including the goodness factor and the pole numbers, on the improving the high speed thrust-speed characteristics for LP-DSLIM were also analyzed. The analysis result show that LDEE makes the rated operating speed in the thrust-speed characteristics be far away from the synchronous speed, thereby resulting in the higher secondary copper losses and lower efficiency. Adjusting the goodness factor has little influence on the thrust improvement, while increasing the pole numbers could effectively alleviate LDEE.

Yang T.,Beijing Institute of Aerospace Control Devices | Zhou L.-B.,Huazhong University of Science and Technology
Dianji yu Kongzhi Xuebao/Electric Machines and Control | Year: 2014

To investigate the influence of the longitudinal dynamic end effect (LDEE) on the magnetic field and performance of the long primary double-sided linear induction motor (LP-DSLIM), the one-dimensional time-harmonic magnetic field equations in the airgap region of LP-DSLIM, accounting for LDEE, were developed and solved. The analytical solutions of the fundamental airgap fields and the component fields due to entry-and exit-end are derived. The characteristics of the amplitude, phase and waveform of each three components of the traveling wave, as well as the LDEE wave's influence on the airgap magnetic field distribution were both analyzed. The analytical results were compared and validated by the predictions from corresponding two-dimensional finite element analyses. The variations of LDEE-related characteristic parameters, such as attenuating constant, half-wave length and wave velocity, with the goodness factor were given. The analysis results show that LP-DSLIM and its short primary counterpart exhibit are quite different on the airgap magnetic field distribution, especially operating at high-speed conditions. By adjusting the motor design parameters, the measures to reduce the goodness factor may effectively alleviate LDEE, whilst these effects also degrade the LP-DSLIM fundamental performance. Therefore, the compromised measures should be taken during the design procedures for LP-DSLIM.

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