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Wang X.,CAS Institute of Electronics | Wang X.,China South Industries Research Academy | Yang H.,CAS Institute of Electronics | Li F.,CAS Institute of Electronics | And 5 more authors.
Analog Integrated Circuits and Signal Processing | Year: 2014

An analog hearing aid with the function of frequency compensation is proposed and implemented considering the human factors. Introducing the current-mode technique, a filter designed by the state space methodology is integrated in the hearing aid to offer the function which only appears in the DSP unit of digital hearing aid. Combined with the filter embedded in the driver circuit adopting the minimum current selecting technique, the enhance frequency compensation can well match to the common low-frequency hearing loss with a stopband attenuation of 80 dB/dec. Moreover, a low-noise automatic gain control (AGC) is presented to improve the programmability with discreet gains, knee points and compression ratios. To enhance the comfortable level, the attack time and release time is set 20 and 100 ms with a peak detector. The input-referred noise is below 5 μVrms. The hearing aid can drive a 16 receiver at the supply voltage of 1 V. The die area is 2.3 × 1.5 mm2 (AGC) and 0.93 × 0.86 mm2 (driver) in a 0.13 μm standard CMOS process and 1 × 1 mm2 (filter) in a 0.35 μm standard CMOS process. © 2014 Springer Science+Business Media New York.


Nan Y.-X.,Beijing Institute of Technology | Jiang J.-W.,Beijing Institute of Technology | Wang S.-Y.,Beijing Institute of Technology | Fang Y.-J.,China South Industries Research Academy
Zhendong yu Chongji/Journal of Vibration and Shock | Year: 2013

Using LS-DYNA software, impact response of submunitions drop on concrete was simulated and tested, with different drop angles and attack ones. The drop law of the maximum overload and the impact action time were obtained in the ranges of 60°~90° drop angles and less than 5° attack ones. The numerical simulation results agreed well with those of test. The study results were useful for establishing an impact response theoretical model of submunitions drop.


Li D.,Beijing Institute of Technology | Xu P.,China South Industries Research Academy | Qin G.,China Aerospace Science and Technology Corporation | Yang D.,Beijing Institute of Technology
Proceedings of 2014 International Conference on Modelling, Identification and Control, ICMIC 2014 | Year: 2015

Moving objects detection in a complicated surrounding is one of the most significant issues to be solved in the infrared target recognition because of the time-varying background. Biomimetic approach is a promising solution for tackling this problem. Visual detection and processing of motion in flies is thought to occur based on an elementary delay-and-correlate operation at an early stage in the visual pathway, which is the so-called 'Reichardt detector'. However, the original Reichardt detector is a coarse description of the visual system of the fly. In this paper, we studied moving target detection method in a complicated background using a two-dimensional 2 quadrant motion detector network consisting of a grid of modified double channel motion detectors. At first, the scheme of modified double channel motion detector is analyzed and general properties of the modified double channel motion detectors are presented in detail. Then, the modified double channel motion detectors are interconnected in a grid to form a two-dimensional detectors network that can be used to model motion in two-dimensional scenes. The infrared image sequences including moving vehicle objects in the complicated background are used to confirm the proposed method in the experiment. The experimental results illustrate that, the proposed method achieves much better detection performance in infrared frames than the original Reichardt's model. Moving object could be detected in infrared frames without the interference of background. © 2014 Swinburne University of Technology, Australia.


Zhang R.,University of Chinese Academy of Sciences | Zhang R.,CAS Academy of Opto Electronics | Xue Y.,China South Industries Research Academy | Zhang H.,China South Industries Research Academy | And 3 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2014

We have demonstrated a 1018 nm continuous wave fiber oscillator pumped by LDs operating at 976 nm. Three kinds of Ytterbium-doped dual-clad fibers, 15/130 μm fiber, 25/250 μm fiber and 30/250 μm fiber, are employed separately in the experiments. We achieve 67 W total output power with the 15/130 μm fiber for 100 W of pump power with a slope efficiency of 67%. And with the 25/250 μm fiber, 276 W total output power is generated for 372 W of pump power with a slope efficiency of 74%. In the end, 300 W output power with the slope efficiency of 81% is successfully achieved with the 30/250 μm fiber for 372 W of pump power. To the best of our knowledge, this is the highest output ever reached by a dual-clad fiber oscillator at this wavelength that ever reported in open detail. © 2014 SPIE.


Yu J.,North China Institute of Science and Technology | Xu X.,China South Industries Research Academy
Xitong Fangzhen Xuebao / Journal of System Simulation | Year: 2015

According to the characteristic of multibeam bathymetry in which measurement depth is influenced by terrain, revision algorithm was proposed based on average slope along the horizontal and vertical terrain. Five depth revision factors were obtained, and a depth smooth template was designed. The initial scan depth data were revised by the 5 revision factors, and then the revised depth data were filtered by the template. Simulation results show that, the depth of measurement error can be reduced greatly after revision, the designed template relative to the conventional Gauss template has higher smooth precision, more adapted to the water depth data filtering. Through two ways, the measurement accuracy has been improved obviously, and seabed terrain accuracy and smoothness both have been better modified. ©, 2015, Editorial Office of Journal of System Simulation. All right reserved.


Yu J.,North China Institute of Science and Technology | Xu X.,China South Industries Research Academy
Xitong Fangzhen Xuebao / Journal of System Simulation | Year: 2015

Aiming at the problems of expensive multibeam system and bumpy ship in bathymetric survey for seafloor, a digital bathymetry model based on depth data according to principle of multibeam mathymetric sonar system was designed, and a correction method of water depth survey due to effect of angular beam-width, vehicle attitude and terrain was given. Accordingly, seafloor was scanned with this model and terrain map was constructed to mimic the realtime terrain. The model and correction were verified by using practical water depth data of certain seafloor. Simulation results show that the model is in accordance with theoretical analysis and practical situation, and the correction effect of water depth is obvious. This technology has certain application value in bathymetric survey for seafloor and imitating real multibeam bathymetric sonar system. ©, 2015, Xitong Fangzhen Xuebao/Journal of System Simulation. All right reserved.


Li X.-Y.,Hunan University | Yang H.-L.O.,Hunan University | Meng C.,China South Industries Research Academy | Yang C.,Hunan University
ICMT 2012 - 16th International Conference on Mechatronics Technology | Year: 2012

In this paper, a novel on-line dead time compensation method is proposed for the permanent magnet synchronous motor drive system. Using a sliding mode observer, this method does not require any additional hardware circuit and off-line experimental measurements. The output voltage errors caused by the dead time and nonideal switching characteristics of power devices are considered disturbance voltages. Disturbance voltages are online estimated based on the sliding mode observer and fed to the reference voltages to compensate the impact of the dead time. This method can avoid taking the zero-current clamping phenomenon into account. The proposed method is applied to permanent magnet synchronous motor system and implemented by MATLAB/Simulink simulation. The simulation results indicate that the compensation method can effectively improve the motor current waveforms and the inverter output performance.


Yao M.-T.,China South Industries Research Academy | Cao F.,China South Industries Research Academy | Que R.-Y.,China South Industries Research Academy | Li J.,China South Industries Research Academy | And 3 more authors.
Beijing Ligong Daxue Xuebao/Transaction of Beijing Institute of Technology | Year: 2016

In order to enhance performances for an engineering vehicle, mathematic models of its single chamber hydro-pneumatic spring were established to analyze the effects of stiffness and damping as well as friction on suspension dynamics. A fuzzy PID (F-PID) control model was established with vehicular suspension dynamic deflection as the control input. The fuzzy logic control rules were settled and a semi-active suspension F-PID controller was designed with Matlab/Simulink programming. The responses under instant excitation road input were simulated respectively. According to simulation results, the application of F-PID in semi-active suspension controlling not only improves vehicular ride performance, but also makes the responses rapidly and stably as well as decreases the oscillation. Research conclusions may provide some of references for studying the semi-active control of vehicle suspension. © 2016, Editorial Department of Transaction of Beijing Institute of Technology. All right reserved.


Chen A.,China University of Mining and Technology | Cao F.,China South Industries Research Academy | Hou W.,North University of China
Yingyong Jichu yu Gongcheng Kexue Xuebao/Journal of Basic Science and Engineering | Year: 2010

Flexible hinges are small in size, have no mechanical friction, no gap, no need for lubrication while offering smooth movement, and have been widely used in many instruments with unprecedented precision and stability. The calculation of flexibility is a critical part in flexible hinge design. This paper presented the compliance equations for biaxial right circular flexible hinges by utilizing the matrix theory, energy method, Castigliano's displacement theorem, and calculus. The calculation software was drawn up by VisualC++6.0, we could directly observe each of flexibility elements obtained by the analytic method by revising the biaxial right circular flexible hinge's geometric parameters, which facilitated being able to repeatedly revise the design of geometric parameters. The analytical model predictions were confirmed by the method of finite element software ANSYS11.0. The results showed that the flexibility calculation formulas for biaxial right circular flexible hinge were correct, and could be used in the design of biaxial right circular flexible hinges.


Yao M.-T.,China South Industries Research Academy | Long K.,North China Electrical Power University | Long K.,State Key Laboratory of Vehicle NVH and Safety Technology | He L.-P.,Beijing Institute of Radio Measurement and Metrology
Beijing Ligong Daxue Xuebao/Transaction of Beijing Institute of Technology | Year: 2013

In order to carry out a reliable control for a semi-active suspension system of an engineering vehicle, a mathematic model of single chamber hydro-pneumatic spring was established. The characteristics of spring rate and damping rate as well as the relationship between throttle area and damping force were analyzed. The control strategy of improving vehicle ride comfort without the frequent suspension breakdown was proposed. The fuzzy logic control (FLC) model with the inputs of suspension deflection and its change rate with time was established. The rules of fuzzy logic control were worked out and the fuzzy logic controller was designed. The responses were simulated under the conditions of road surfaces with sine, integrated random white noise and instant step input excitation, respectively. According to simulation results, the application of FLC in semi-active suspension controlling not only reduces the frequency of suspension breakdown, but also improves the ride performance from statistic point of view.

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