JOURNAL OF BEIJING INSTITUTE OF TECHNOLOGY

Numerical study on the shock responses of submunition drop on various mediums

WANG Shu-you, JIANG Jian-wei, NAN Yu-xiang, MEN Jian-bing

2013, 22(4): 427-431.

[Abstract](901) [PDF 465KB](72)

Abstract:
The shock responses of submunition drop on various ground-mediums are modeled and investigated by numerical simulation in this paper. Submunition impacts on concrete surface, gravel ground or sand with various drop velocities, different drop angles and attack angles are calculated in a finite element program. The loads and dynamic responses of submunition are analyzed, curves of various drop velocities, drop angles and attack angles related to peak overload are calculated and law of interaction time on different ground mediums is obtained.

Comparisons of STRETCH meat grinders based on two different topologies of ICCOS

LIU Hui, BI Shi-hua, LI Jun, LIU Pei-zhu, CHEN Zhen

2013, 22(4): 432-439.

[Abstract](666) [PDF 377KB](30)

Abstract:
Inductive energy storage systems(IES)require opening switches which are technically much more difficult to realize than closing switches. Institute of Advanced Technology (IAT) puts forward a meat grinder with an inductive pulse power topology called slow transfer of energy through capacitive hybrid (STRETCH). In this topology, an integrated gate-commutated thyristor (IGCT) is capable of breaking the charging currents on the order of 4.kA, and it may encounter difficulties in expanding to higher energy systems. German-French Institute of Saint Louis (ISL) has developed a high-power opening switch based on standard high-power thyristors by using their so-called inverse current commutation with semiconductor devices (ICCOS) countercurrent commutation principle. Two topologies of the STRETCH meat grinder with ICCOS are analyzed. And they are compared based on the voltage across the main switch, the current multiplication factor and other aspects by using Matlab simulations. The advantages and disadvantages of the two topologies are shown through the comparisons. Therefore a more suitable topology can be chosen for realistic applications according to their performances.

Design and study on variable nozzle mixed-flow turbocharger

HUANG Ruo, SHANG Wen-tao, YU Zhi-yi

2013, 22(4): 440-446.

[Abstract](1062) [PDF 1163KB](30)

Abstract:
A spatial motion mechanism was designed which could make all the nozzle vanes rotate around the center of ball with the same radius synchronously to realize control of the variable nozzle mixed-flow turbocharger (VN-MT). The back and abdomen of the nozzle vane was designed as arc-shaped. A variable nozzle ring perfectly combined with the mixed-flow turbine was made available. The turbine geometric model of VN-MT was established through the computational fluid dynamics(CFD). Compared with nozzleless mixed-flow turbine, the flow range of variable nozzle mixed-flow turbine was broadened tremendously while the peak turbine efficiency point was lower slightly. Flow field analysis in turbine stage showed that the energy loss of the VN-MT under designed condition was larger and the blade load of rotor was lower than the nozzleless mixed-flow turbocharger.

Fuzzy adaptive PID control on hydraulic servo system of quadruped robot

LI Jie, LUO Qing-sheng, WANG Lei, CHANG Qing

2013, 22(4): 447-453.

[Abstract](1041) [PDF 360KB](34)

Abstract:
Quadruped robot driven by high power density hydraulic device works in unstructured environment. With variable load and various external disturbance, the hydraulic servo system has features such as nonlinear, time-varying parameters. Traditional control method has some limitation. In order to help the hydraulic servo system of the quadruped robot to adapt to harsh environments, and to obtain high control quality and control precision, an incremental fuzzy adaptive PID controller based on position feedback is designed to solve the related technical problems. Matlab/Simulink simulation and experimental results show that the incremental fuzzy adaptive PID controller improves the dynamic performance of the system, enhances the respond speed and precision of the hydraulic servo system, and has some theory significance and practical value.

Multi-level gait transition model for a new type of arthropod robot

CHANG Qing, HAN Bao-ling, LUO Qing-sheng, NA Qi

2013, 22(4): 454-460.

[Abstract](618) [PDF 1959KB](23)

Abstract:
To realize the continuous and variable gait transition for a new type of arthropod robot, a multi-level gait transition model is studied in this paper. The model is composed of central pattern generator (CPG) and saturation function. The CPG consists of four pairs of oscillators which can exhibit rhythmic activity when given stimulation signal S that lies in the range of saturation function. All oscillators receive the sameS, but each pair of oscillators has different saturation functions. Multi-level gait transition can be realized whenSchanges regularly, as the oscillators start or stop oscillating at different times. After computer simulation, the gait transition model is implemented in the arthropod robot. The experimental results show that ideal gait transition for the arthropod robot can be realized with the multi-level gait transition model.

Design, analysis and control for an antarctic modular manipulator

JIANG Zhi-hong, LI Hong-jie, XIAO Tao, YUAN Bao-feng, LI Hui, DONG Que, WEI Bo

2013, 22(4): 461-469.

[Abstract](731) [PDF 1650KB](24)

Abstract:
Antarctic scientific expedition has important strategic significance. It is an inevitable trend to apply robots to assist researchers during the Antarctic expedition. However, the robot manipulators at present have a series of problems and unable to meet the requirements of the Antarctic expedition. In this paper, a novel Antarctic modular robot manipulator is proposed, which has a compact structure with modular joints. The robot manipulator has high reliability, and quick assembling-and-disassembling ability. Through well wires arranging and thermal controlling, the manipulator can better adapt to the Antarctic environment. In addition, the work space of the manipulator is seriously analyzed, and a new hybrid position/force control method is adopted to make the manipulator perform better. Simulation results validate the control method and show that the robot manipulator has a good performance to meet the requirements of Antarctic expedition.

Design and modeling for a kind of humanoid dexterous hand with elastic palm

WEI Bo, JIANG Zhi-hong, XIAO Tao, YUAN Bao-feng, LI Hong-jie, LI Hui, DONG Que, LIU Shi-long

2013, 22(4): 470-476.

[Abstract](642) [PDF 1450KB](33)

Abstract:
With dexterous hands, robots can improve the work scope and work ability significantly. As palms of the existing multi-hand robots are made of steel plates that have small contact area, the robots cannot grab firmly. In this study, a new five-fingered dexterous robot hand is developed. Having flexible palm with 17 degree of freedoms (DOFs), the hand can grasp more stably and firmly. First, the forward kinematics and inverse kinematics of the fingers and the hand are calculated. Then, the connection between the force exerting on the end effectors and the torque exerting on the joint is set up, laying the foundation for the following control. Finally, through the analysis and simulation of the position, velocity and acceleration, the trajectory planning has a better performance.

Fuzzy control method to minimize the needle deflection during needle insertion therapy

ZHANG Shao-hua, JIN Xin, YE Xin, ZHANG Zhi-jing, LIU Bing-bing, DENG Yong-jun

2013, 22(4): 477-482.

[Abstract](736) [PDF 735KB](13)

Abstract:
A fuzzy control algorithm is adopted to help the needle hit the target more accurately. The experimental setup for the needle insertion is built up to validate the algorithm. How the forces during the insertion make the needle deflect away from the planned path is given, and the normal method correcting the deflection is obtained accordingly. Because the normal method cannot perform well for correction, a fuzzy controller is established. The input module, output module, fuzzification module, defuzzification module and inference engine for the controller are given respectively according to the fuzzy theory. Our experimental results show that the fuzzy controlling system presenting in the paper can better eliminate the deflection.

Research on the attitude regulation of 3-DOF hover system

HU Qiong, FEI Qing, WU Qing-he, GENG Qing-bo

2013, 22(4): 483-491.

[Abstract](1315) [PDF 533KB](22)

Abstract:
Quadrotor helicopter is emerging as a popular platform for unmanned aerial vehicle research, due to its simplicity of structure and maintenance as well as the capability of hovering and vertical take-off and landing. The attitude controller is an important feature of quadrotor helicopter since it allows the vehicle to keep balance and perform the desired maneuver. In this paper, nonlinear control strategies including active disturbance rejection control (ADRC), sliding mode control (SMC) and backstepping method are studied and implemented to stabilize the attitude of a 3-DOF hover system. ADRC is an error-driven control law, with extended state observer (ESO) estimating the unmodeled inner dynamics and external disturbance to dynamically compensate their impacts. Meanwhile, both backstepping technique and SMC are developed based on the mathematical model, whose stability is ensured by Lyapunov global stability theorem. Furthermore, the performance of each control algorithm is evaluated by experiments. The results validate effectiveness of the strategies for attitude regulation. Finally, the respective characteristics of the three controllers are high-lighted by comparison, and conclusions are drawn on the basis of the theoretical and experimental analysis.

Three dimensional simulation of electromagnetic railgun’s exterior ballistics

JIN Feng, LU Xiao-fei, CHEN Yan-qiao

2013, 22(4): 492-496.

[Abstract](1362) [PDF 329KB](26)

Abstract:
In order to evaluate the electromagnetic railgun's practical combat capability as well as its tactic application prospects, a three dimensional simulation model of electromagnetic railgun's exterior ballistics is presented. On the hypothesis of the Earth's being round and ignoring the influence of rotation, the railgun's atmospheric environment and its motion equations are established by the Simulink Module of Matlab. And the railgun's characteristics of exterior ballistic under different muzzle energy and emission inclinations are discussed. Results show that its incomparable superiority in improving range and lethality to conventional artillery under the same launch condition based on railgun's range and variation of velocities. It is useful for the efficacy evaluation of railgun's combat capability and its practical applications in fields such as ground war, missile interception and so on.

Line-element based nonlinear adaptive piecewise compensating correction for LVDT sensors

WANG Li-peng, WANG Jun-zheng, ZHAO Jiang-bo, WU Jiang-feng

2013, 22(4): 497-503.

[Abstract](545) [PDF 725KB](22)

Abstract:
In order to solve the linear variable differential transformer (LVDT) displacement sensor nonlinearity of overall range and extend its working range, a novel line-element based adaptively segmenting method for piecewise compensating correction was proposed. According to the mechanical structure of LVDT, the output equation was calculated, and then the theoretic nonlinear source of output was analyzed. By the proposed line-element adaptive segmentation method, the nonlinear output of LVDT was divided into linear and nonlinear regions with a given threshold. Then the compensating correction function was designed for nonlinear parts employing polynomial regression technique. The simulation of LVDT validates the feasibility of proposed scheme, and the results of calibration and testing experiments fully prove that the proposed method has higher accuracy than the state-of-art correction algorithms.

Simulation of multiphase boost DC-DC converter with the stable control strategy

SOOMRO Amir Mahmood, KHAHRO Shahnawaz Farhan, SYED Feroz Shah, LIAO Xiao-zhong, FARHAN Manzoor

2013, 22(4): 504-508.

[Abstract](914) [PDF 283KB](22)

Abstract:
The multiphase boost DC-DC converter with stable control strategy is presented. Multiphase boost DC-DC converter is designed for high voltage and high power applications, and could be achieved by the adjustment of voltage doubler rectifiers on the secondary side of high frequency transformers. The stable control strategy for three phase boost DC-DC converter has been utilized during simulation in this study and this strategy can be extend to N-number of phases. The stable control strategy consists of only three voltage loops, which are sufficient for appropriate and efficient operation of three phase boost DC-DC converter. With the stable control strategy, the equal power balance sharing can be obtained between input and output. The stability of control strategy has been evaluated by simulating the multiphase boost DC-DC converter for the same and mismatch turn ratios of high frequency transformers. The simulation result is good and the objective of the strategy is achieved.

Design of thermal expansion measurement system based on virtual instrument

JIN Feng, LI Tian

2013, 22(4): 509-513.

[Abstract](693) [PDF 805KB](17)

Abstract:
System architecture is presented for an automatic measurement of thermal expansion. The dynamic measurement of the temperature and thermal expansion displacement of the material is carried out through the application of Labview. The expansion and temperature of material is stored and displayed in real-time. Then the thermal expansion coefficient can be obtained. The measurement system composes of SIOS-SP120D laser interferometer, high vacuum furnace, rbh8223h data acquisition card, rbhS104 conditioning board, constant computer power supply. The USB interface is adopted to collect the temperature and displacement data. Experimental results show that the system has high measurement accuracy and good man-machine interface properties.

Low spurious noise frequency synthesis based on a DDS-driven wideband PLL architecture

WANG Hong-yu, WANG Hao-fei, REN Li-xiang, MAO Er-ke

2013, 22(4): 514-518.

[Abstract](1078) [PDF 331KB](18)

Abstract:
An S-band frequency synthesizer for a stepped-frequency radar is presented. This frequency synthesizer is based on a direct digital synthesizer (DDS)-driven wideband phase-locked loop (PLL) architecture which can achieve low spurious noise and rapid frequency hopping simultaneously. The mechanism of introducing high level spurs by the images of DDS digital to analog convertor (DAC) output is analyzed. A novel DDS frequency planning method is proposed to ensure low colored noise within the entire bandwidth. The designed output frequency range is 3.765-4.085.GHz, and the step size is 5.MHz with frequency agility of less than 1. μ s. Measured results demonstrate that the average spurious free dynamic range (SFDR) is about 64 dBc in a 320.MHz bandwidth.

D2D communication in a cellular network based on link adaptation with truncated ARQ

LI Jun-long, FEI Ze-song, HUANG Gai-shi, FU You, XING Cheng-wen

2013, 22(4): 519-523.

[Abstract](1201) [PDF 305KB](19)

Abstract:
A device-to-device (D2D) communication mode underlaying cellular network in a single-cell environment is introduced. A practical method based on link adaptation with automatic repeat request (ARQ) is presented. Link adaptation technique, which combines adaptive modulation and coding (AMC) with truncated ARQ, can maximize the cellular UEs' data rate under prescribed delay and performance constraints. The proposed method can maximize the total transmission rate when an outage probability is determined. Numerical results show that with proper power control, the interference between the two links can be coordinated to increase the sum rate without overwhelming the cellular service.

Efficient solution of 3D electromagnetic scattering from large homogeneous targets

GOU Ming-jiang, WU Yue-qian, SHENG Xin-qing

2013, 22(4): 524-529.

[Abstract](576) [PDF 408KB](10)

Abstract:
Based on the combined tangential formulation of surface integral equation, a fast algorithm is presented for calculating electromagnetic scattering from electrically large 3D homogeneous objects. In the algorithm, the lower triangular approximate Schur preconditioner is combined with the multilevel fast multipole algorithm (MLFMA). The coefficient matrix of the near-field coupling element is selected to set up the approximate matrix. For large problems, the incomplete LU factorization with dual threshold (ILUT) has better performance than sparse approximate inverse (SAI) of accelerating the convergence of the generalized minimal residual method (GMRES) iteration. Numerical experiments validate the efficiency and robustness of the presented fast algorithm for homogeneous dielectric objects.

Comparison of phase unwrapping algorithms for living cell’s interference pattern

WANG Xia, TONG Jie, WANG Meng, SCHMIDT Greg, MOORE Duncan T., MCGRATH James L.

2013, 22(4): 530-535.

[Abstract](651) [PDF 2273KB](15)

Abstract:
A multiphase microscopic interference system is designed to measure the height of cell which is important to the research of collective cell migration in physiology and medicine. This system can quantitatively measure cell height across a living monolayer without knowing the refractive index of cells. For the interference pattern, because the phases are all wrapped between -π to π, it is necessary to get the real phase through phase unwrapping,a method to restore the wrapped phase data of the object by using numerical calculations. Three representative algorithms are selected to unwrap the interference pattern of cells: branch-cut method, quality-guided method and network method. Although each of them can restore the phase, their performances are obviously different. We compare these methods and find that branch-cut method needs the smallest execution time and can obtain good unwrapped patterns when noises are not serious.

Constant modulus semi-blind space-time equalizer based on structure risk minimum criterion

MAO Zhong-yang, WANG Hong-xing, SONG Heng, LI Jun

2013, 22(4): 536-543.

[Abstract](572) [PDF 399KB](12)

Abstract:
A new adaptive filtering principle based on capability control and semi-blind method is presented. A new semi-blind space-time equalizer based on constant modulus characteristic and structure risk minimum (SRM) criterion is also proposed. The equalizer sufficiently exploits the learning information of communication signals by using the structure information of filter itself through capability control technique. Namely, it maximizes the amount of learning information to improve filter tracking performance. Simulations are carried out and the result is compared with that of typical recursive least squares space-time equalizer (RLS-STE) and constant modulus semi-blind space-time equalizer (CM-SB-STE). The results show that, even if with insufficient training data, the SRM constant modulus semi-blind space-time equalizer (SCM-SB-STE) keeps good tracking performance, showing promises in mobile wireless communications.

Finite element analysis and experimental investigation of the hydrostatic extrusion process of deforming two-layer Cu/Al composite

ZHANG Zhao-hui, WANG Fu-chi, SUN Ming-yan, YANG Rui, LI Shu-kui

2013, 22(4): 544-549.

[Abstract](1122) [PDF 986KB](22)

Abstract:
A concave die with an equal-strain contour line was used in the hydrostatic extrusion process to deform the two-layer Cu/Al composite. The extruding process was simulated using the finite element method (FEM). The effect of the friction coefficients on the relative slippage of the contact surfaces between the internal and external metals was investigated, and the stress distribution in the extruded specimen was studied. The simulation results reveal that the relative slippage decreases with increasing friction coefficient at the contact surface of the two metals. However, the relative slippage increases rapidly with increasing friction coefficient at the contact surface between the specimen and die. No axial tensile stress appears in the plastic deformation zone near the axis, indicating that the inner fracture will not occur in internal metal in the hydrostatic extrusion process as the concave die with equal-strain contour lines is used. The experimental test reveals that the metallurgical bond is formed between Cu and Al when the friction coefficient at the surface between the two metals is 0.3 and the extrusion ratio is 12.

Acylation of 3, 4-Diaminofurazan

WU Min-jie, CHEN Shu-sen, XIONG Shu-ling, JIN Shao-hua, LI Li-jie

2013, 22(4): 550-556.

[Abstract](939) [PDF 421KB](29)

Abstract:
An acylation method of 3,4-diaminofurazan was developed. Under the catalysts of p-Toluenesulfonic acid, 3-amino-4-formylaminofurazan, 3-amino-4-acetylaminofurazan, 3-amino-4-propionylaminofurazan, 3-amino-4-butylramino-furazan and 3-amino-4-benzoylaminofurazan were synthesized by acylation of 3,4-diaminofurazan with formic acid, acetic acid, propionic acid, butyric acid and benzoic acid respectively. Also, 3,4-diacetylaminofurazan and 3,4-dipropionylaminofurazan were synthesized by acylation of 3,4-diaminofurazan with acetic anhydride and propionic anhydride respectively. Compared with the traditional method which uses acyl halogen as reagent, our method reduced the reaction time and increased the yield and purify. The 3-amino-4-acylaminofurazan could be hydrolyzed to 3,4-diaminofurazan in ethanol with acid catalyst.

Numerical simulations of stress wave propagation and attenuation at arc-shaped interface inlayered SiC/Al composite

SUN Ming-yan, ZHANG Zhao-hui, YANG Rui, WANG Fu-chi, LI Shu-kui

2013, 22(4): 557-562.

[Abstract](821) [PDF 1058KB](15)

Abstract:
The effects of interface shape on stress wave distribution and attenuation were investigated using finite element method (FEM). The simulation results indicate that when the stress wave propagates from SiC ceramic to Al alloy, the tensile stress decreases and the attenuation coefficient of the stress wave increases with increasing central angle of the concave interface between SiC and Al. But for the convex interface, the tensile stress increases and attenuation coefficient decreases with increasing central angle. As the stress wave propagates from Al alloy to SiC ceramic, the attenuation coefficient of stress wave decreases with increasing the central angle of the concave interface. For the convex interface, the attenuation coefficient increases with increasing central angle.

Establishment and optimization of peptide biomarker screening model in diabetes in vitro by HPLC/ESI-TOF mass spectrometry

ZHANG Mei, LÜ Dong-hua, DAI Rong-ji, DENG Yu-lin

2013, 22(4): 563-568.

[Abstract](803) [PDF 328KB](32)

Abstract:
Diabetes mellitus is an incurable disease, so it is necessary to establish a model to screen biomarkers for early warning in order to minimize the likelihood of long-term complications. Currently, advanced glycation end products (AGEs) are considered to be biomarkers of many diseases, such as diabetes and its complications. In this study, a model for further proteomics study was established to analyze the glycation of HSA with¹⁸O-labeling strategy. 30 peptides were randomly selected to optimize tryptic digestion and¹⁸O-labeling condition by HPLC-ESI/TOF. The best tryptic digestion condition was: HSA :Trypsin=50:1, w/w for 20.h. The best¹⁸O-labeling condition was to dilute urea to 1.M and adjust KH₂PO₄—K₂HPO₄buffer pH to 6.0 to give a final labeling efficiency of 98.5±0.7%. The inter-and intra-day precisions and stability were satisfactory. This model was established and optimized for further quantitative proteomics study.

2013 Vol. 22, No. 4