Table of Content

28 October 2019, Volume 53 Issue 10 Previous Issue    Next Issue

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Design and Experiment of Expanding Mechanism and Power Receiving Coil for Micro Intestinal Robot PU Pengxian,YAN Guozheng,WANG Zhiwu,HAN Ding 2019, 53 (10):  1143-1150.  doi: 10.16183/j.cnki.jsjtu.2019.10.001 Abstract ( 1238 )   PDF (3428KB) ( 624 )   Save A new type expanding mechanism for micro intestinal robot is designed to move and anchor in the intestinal tract. The mechanism is expanded by Archimedes spiral legs whose maximum expanding diameter reaches to 32mm, and the variable diameter ratio is 2.13. The reduction ratio of the reducer is up to 489 to ensure large output torque. The dynamic characteristics of the expanding arm are analyzed, and the expanding force is tested through experiments. Then, the power receiving coil is modeled and analyzed. The results show that the overall trends of the experimental test value of the expanding force and the theoretical analysis are basically the same, and the minimum expanding force is 1.5N, which satisfies the demand of intestinal expansion. The performance of the wireless power transmission can be improved by optimizing the thickness of the coil core, the winding layer and the specification of the strand wire. When the driving current of the transmitting coil is 1.4A, the corresponding transmission power of the receiving coil is 812mW and the energy transfer efficiency is 8.3%, which can satisfy the power requirements of the intestinal robot. References | Related Articles | Metrics

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Design and Experimental Verification of a Novel Puborectalis-Like Artificial Anal Sphincter LU Shan,WANG Zhiwu,YAN Guozheng,ZHOU Zerun 2019, 53 (10):  1151-1158.  doi: 10.16183/j.cnki.jsjtu.2019.10.002 Abstract ( 1918 )   PDF (23291KB) ( 328 )   Save In order to treat severe fecal incontinence, a novel puborectalis-like artificial anal sphincter (PAAS) based on three rings is designed to pull and angulate the rectum. The gear box can be fully encapsulated inside the PAAS, and the motor power is transmitted from inside to outside. In addition, a flexible pressure sensor is designed and customized to detect the force exerted on the intestinal wall when the pulling arm pulls the rectum with the O-rings to achieve good waterproof effect. Finally, the mechanical and waterproof properties are assessed, and the animal implantation is conducted. The results indicate that: the final transmission efficiency of PAAS is 49%～59%, the output torque is 2.04～2.51N·m; there is good linearity between the output of flexible pressure sensor and the force exerted on the intestinal wall; PAAS can maintain the intraluminal pressure up to 98cm water column with clamping pressure of 6.6kPa; no leakage occurrs after 4050 movements; the anastomosis can be effectively avoided in implantation and PAAS works effectively in a Sipsongpanna miniature pig model. PAAS proposed in this paper has a good all-round performance of waterproof as well as maintaining continence. References | Related Articles | Metrics

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Order Quantity Collaborative Model and Algorithm Research on Inbound Logistics ZHANG Xuan,CHEN Feng 2019, 53 (10):  1159-1164.  doi: 10.16183/j.cnki.jsjtu.2019.10.003 Abstract ( 1106 )   PDF (702KB) ( 674 )   Save The order collaboration in automobile inbound logistics is studied. A mixed integer programming model is established. A heuristic algorithm and a branch and bound method are proposed. The numerical experiments are carried out to verify the feasibility of the model and algorithm. The results show that the proposed heuristic algorithm and branch and bound method are superior to CPLEX in computing speed and result. Collaboration of order quantity can effectively reduce the total cost. References | Related Articles | Metrics

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Location and Relocation of Ambulance for Time-Dependent Environments HU Huize,YANG Zhitao,CHEN Erzhen,LIU Ran 2019, 53 (10):  1165-1172.  doi: 10.16183/j.cnki.jsjtu.2019.10.004 Abstract ( 1189 )   PDF (894KB) ( 525 )   Save Pre-hospital first aid is very important for saving the lives of emergency and critically patients. Scientific and reasonable location of ambulance stations can reduce the response time of ambulances to emergency needs and is essential to improve the quality of pre-hospital first aid. In this paper a mix integer programming model for ambulance location and relocation in time-dependent environments is established and an effective genetic algorithm is designed. Numerical experiments prove the effectiveness of the proposed model and the algorithm. References | Related Articles | Metrics

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Transition Flight Control Strategy of Multiple Flight Mode Vertical Take-Off and Landing Unmanned Aerial Vehicle LIU Zhihao,MIN Rong,FANG Cheng,YI Chao,LU Cunyue,MA Yixin 2019, 53 (10):  1173-1181.  doi: 10.16183/j.cnki.jsjtu.2019.10.005 Abstract ( 1545 )   PDF (5557KB) ( 707 )   Save The flight control strategy for vertical take-off and landing(VTOL) unmanned aerial vehicle(UAV) in mode transition is essential to ensure a safe and reliable flight. This paper studies the flight control strategy in the transition mode of tail-mounted VTOL UAV, and proposes a strategy of the fastest transition speed with constant altitude control. Simulation and experiment are used to analyze and compare the flight effect of this strategy, classical proportion-intergration-differentiation(PID) control and the fastest transition speed control. Strategy of the fastest transition speed with constant altitude control optimizes the change of flight speed and altitude, synchronizes the time of cruise attack angle and cruise speed, and maintains the vertical force balance of UAV in the mode transition. The simulation results show that the fastest transition speed with constant altitude control’s time decreases by 0.98 and 0.48s than that of the classical PID control and the fastest transition speed control, while the change of altitude decreases by 2.27 and 0.91m. The flight control effect of the fastest transition speed with constant altitude control is obviously superior to the classical PID control and the fastest transition speed control. The proposed control strategy solved the problem of large altitude change during the mode transition, and ensured the rapid and steady flight mode transition of UAV in the transition mode. References | Related Articles | Metrics

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An Estimating Method of Compressive Strength of Composite Laminates After Low-Velocity Impact SHENG Mingjian,CHEN Puhui,QIAN Yibin 2019, 53 (10):  1182-1186.  doi: 10.16183/j.cnki.jsjtu.2019.10.006 Abstract ( 1200 )   PDF (608KB) ( 453 )   Save The compressive strength after low-velocity impact is a key performance index of the composite laminates. By analyzing data of compressive strength experiment of CCF300/5428 composite laminates after low-velocity impact (LVI) under different energy levels, a prediction model based on generalized regression neural network technology of compressive strength after LVI is proposed. This model uses the impact energy, the dent depth and the damage area as input parameters and the Gauss function as the hidden layer excitation function. The model uses part of the experimental data to train for finding the optimal smoothness coefficient. Then, the model is reconstructed with the optimal smoothness coefficient, and is simulated with part of the experimental data. Results show that the model has good generalization ability of experimental data and is feasible to estimate the compressive strength after low-velocity impact. References | Related Articles | Metrics

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Effect of PAO Based Lubricating Oil on Particle Emission Performance of Diesel Engine TIAN Qiang，GAO Shen，ZHAO Lei，WANG Zhiyu，ZHANG Wugao 2019, 53 (10):  1187-1193.  doi: 10.16183/j.cnki.jsjtu.2019.10.007 Abstract ( 1047 )   PDF (1236KB) ( 326 )   Save On a test bench with a turbocharged, intercooler and high-speed diesel engine, the effects of various lubricating oils, including poly alpha olefin (PAO)-based fully synthetic lubricant on particle emission were investigated using a DMS500 fast response particle analyzer. The change of particle emission under different engine working loads and speeds was studied. We laid special stress on analyzing the influence of working temperature and ash content of lubricating oil on particle emission. On this basis, the particle emission characteristics of PAO-based lubricating oil under typical working conditions were summarized. The results showed that the total particle emission peak decreases when the engine load increases, and the peak increases when the engine speed increases. For PAO-based lubricating oil, higher working temperature helps reduce the peak value of particle emission. A lower ash content of lubricating oil can lead to a less total particle emission especially under low engine load. The base composition of lubricating oil has significant influence on engine particle emission. PAO-based lubricating oil has excellent particle emission performance at high operating temperature and high engine load. References | Related Articles | Metrics

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Design Calculation Model of Cylindrical Straight-Through Heat Exchanger ZENG Weijie，GU Bo，LI Qianglin 2019, 53 (10):  1194-1202.  doi: 10.16183/j.cnki.jsjtu.2019.10.008 Abstract ( 1120 )   PDF (1431KB) ( 352 )   Save For the purpose of digital design and calculation of cylindrical straight-through heat exchanger, design model based on sub-row-parameter model is established. The dichotomy iteration, based on thermodynamics and heat transfer theory, is employed. Model calculated results of cylindrical heat exchanger in different cooling conditions were compared with the experimental data of fin-tube heat exchanger. The results show that total cooling capacity of cylindrical heat exchanger is higher in standard condition. The reduction of water inlet temperature don’t have obvious impact on heat transfer while fin-tube heat exchanger will provide larger cooling capacity with the increase of air inlet temperature. The cooling capacity distribution of each row of tubes is also studied through calculation: the tubes with smaller diameter, which are closer to the air inlet, have better heat exchange performance and higher cooling capacity. References | Related Articles | Metrics

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Experimental Study on Combustion of Diesel Oil in an Electric Preheating Porous Medium Burner LIU Hongsheng,WANG Songxiang,LIU Lin,JIANG Linsong,XIE Maozhao 2019, 53 (10):  1203-1209.  doi: 10.16183/j.cnki.jsjtu.2019.10.009 Abstract ( 1012 )   PDF (3586KB) ( 374 )   Save Experimental system of porous medium burner with electric preheating was developed to realize a self-sustaining combustion of liquid fuel without second ignition. Based on the stability of the electric preheating temperature field, the flame characteristics and the temperature variation of the diesel oil pre-evaporation combustion within porous media were analyzed, and the influences of the equivalence ratio and the air mass flow on the combustion characters were discussed. The results indicate that the electric preheating system shows a strong stability, and the minimum preheating temperature for a stable combustion is about 750℃. Two types of flame forms, the stable flame and the filtration combustion flame, are found during the process of the liquid fuel pre-evaporation combustion. The highest temperature of the stable flame which is similar to the premixed combustion is 1140.2℃, and the propagation velocity of the filtration combustion flame is near 1m/s. As the gas mass flow increases, the stable flame moves to downstream and the burning becomes more completely. Equivalence ratio has more significant effect on the temperature distribution than that on flame propagation. References | Related Articles | Metrics

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GPS/INS Delay Estimation and Delay Compensation Based on Residual Reconstruction FU Tingqiang，MA Taiyuan，WANG Yafei，YIN Chengliang 2019, 53 (10):  1210-1217.  doi: 10.16183/j.cnki.jsjtu.2019.10.010 Abstract ( 1293 )   PDF (2653KB) ( 575 )   Save Time-delay is an important issue in multi sensor data fusion. As a common positioning method of an intelligent vehicle, global positioning system/inertial navigation system (GPS/INS) always suffers from an internal time-delay which can cause an error estimation of the INS error state. Based on the traditional loosely coupled integrated navigation system, this paper proposed an algorithm for delay estimation and compensation. Firstly, the delay estimation model was formulated to estimate the time synchronization error. Then, the residual propagation equation was constructed, and the delay compensation was carried out by means of residual reconstruction. The time synchronization was implemented in a software-based scheme. According to the analysis of errors and root mean square errors of velocity and position in the experiment, the improved filtering algorithm was able to effectively reduce the error caused by GPS sampling delay and improve positioning and velocity measurement accuracy. References | Related Articles | Metrics

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Test Pattern Generation Method for Hardware Trojan Detection Based on Artificial Bee Colony WANG Xiaohan,WANG Tao,LI Xiongwei,ZHANG Yang,HUANG Changyang 2019, 53 (10):  1218-1224.  doi: 10.16183/j.cnki.jsjtu.2019.99.001 Abstract ( 992 )   PDF (806KB) ( 539 )   Save The exiting test pattern generation method have the problem of low trigger coverage for hardware Trojan detection. In order to solve this problem, a test pattern generation method based on artificial bee colony algorithm is proposed. Firstly, the distribution regularity of test patterns which can trigger the combination of inactive nets is analyzed. And the mathematical model is constructed to describe the test pattern. Then, the test pattern is generated by artificial bee colony algorithm. Combining with its distribution regularity, this method can search local regions efficiently to find test patterns that can trigger more combinations of inactive nets. At the same time, it can search global world quickly and effectively avoid the problem of "premature convergence". The experimental results show that using the test vectors generated by this method to test circuit, the average trigger coverage rate of hardware Trojan can reach 95.86%. Compared with the existing method, this method improves 22.43%, and has better hardware Trojan activation effect. References | Related Articles | Metrics

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Method in Conservative Estimation of Reliability Based on Damage Accumulation Model DING Ran，LI Qiang 2019, 53 (10):  1225-1229.  doi: 10.16183/j.cnki.jsjtu.2019.10.012 Abstract ( 931 )   PDF (559KB) ( 483 )   Save A method in estimating the conservative reliability by calculating algebraic sum of damage is proposed. The conditions that this method could be used to get the conservative estimation is calculated for several distributions. Combined with application examples, the feasibility and rationality of this method are validated by comparing the results of this method and Monte-Carlo simulation. References | Related Articles | Metrics

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Central Limit Theorems Proving for Independent and Non-Identically Distributed Uncertain Variables and Its Application MENG Xiangfei,WANG Ying,LI Chao,QI Yao,SUN Yun 2019, 53 (10):  1230-1237.  doi: 10.16183/j.cnki.jsjtu.2019.10.013 Abstract ( 2517 )   PDF (651KB) ( 632 )   Save In order to determine the distribution of uncertain variables, two central limit theorems for independent and identical variables are proposed. Firstly, the characteristic function of uncertain variables is defined and its calculation formula is given based on the expected value of uncertain variables. Secondly, the properties of the characteristic function are analyzed and the normal distribution in probability theory is introduced into uncertainty theory. It is proved that the distribution can also be regarded as an uncertain one. Finally, an example of shooting accuracy of a new kind of tanks moving at a high speed is given to verify the feasibility and effectiveness of the proposed theorems. References | Related Articles | Metrics

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Flow Field Dynamic Characteristics of Slit Cylinders ZHU Rui,LI Shang,CHEN Ziyu,LIU Jinsheng,BAO Feng,LIU Zhirong 2019, 53 (10):  1238-1248.  doi: 10.16183/j.cnki.jsjtu.2019.99.002 Abstract ( 1009 )   PDF (13276KB) ( 287 )   Save The particle image velocimetry (PIV) experiments are carried out to qualitative and quantitative study the flow field dynamic characteristics for different slit cylinders in order to reveal the influence of the Re, the slit position, the incline angle and width of the slit on the overall flow characteristics. The transient flow field, the time-averaged flow field and the Sr are obtained and the detailed overall flow structures and its transformation disciplines are studied. The results show that the interactions of the shedding vortex and the circumflux around the cylinder surface induce the blow-suction effect of the 120° and 180° slits, which makes the wake shedding vortex coupling happen significantly earlier. The 240° slit is close to the cylinder trailing edge so that the flow separation already happens before the fluid reach the slit, which fails to generate the effective blow-suction effect. The wake flow resistances for the 120° and 180° slit cylinders are higher because the motion trajectory amplitudes of shedding vortex are higher than that of the basic and 240° types. Sr values for the slit cylinder with α=180° and s/d=0.15 (α is the slit angle, s is the gap width, d is the cylinder diameter) are in the range of 0.218～0.225, which exhibits the strongest linear stability. References | Related Articles | Metrics

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Nonstationary Non-Gaussian Wind Pressure Prediction Using Hermite Combination Kernel Based EMD-WT-LSSVM LI Chunxiang,PEI Yangcongqi,YIN Xiao 2019, 53 (10):  1249-1258.  doi: 10.16183/j.cnki.jsjtu.2019.10.015 Abstract ( 1047 )   PDF (4819KB) ( 420 )   Save Empirical mode decomposition (EMD) is used to decompose the non-stationary wind pressure of a long-span membrane structure into a series of relatively stationary intrinsic mode functions and a residual component. In order to eliminate the effect of noise on the intrinsic mode function in actual wind pressure measurement, each intrinsic mode function is denoised by using wavelet transform. The residual components and the intrinsic mode functions after denoising are input as samples. Radial basis kernel, Hermite kernel and Hermite combination kernel are combined with least square support vector machine (LSSVM) respectively. Subsequently, optimizations for penalty parameters and kernel parameters are conducted using particle swarm optimization (PSO) and thus three algorithms based on PSO-LSSVM are proposed for wind pressure prediction. In addition, the robustness of the combined model is verified based on the measured wind pressure on the super high-rise building. The single point predicting indexes show that the prediction algorithm using Hermite combination kernel based on PSO-LSSVM has higher prediction accuracy and generalization ability compared to the other two algorithms. The results of spatial point prediction further prove the validity of this method for non-stationary non-Gaussian wind pressure prediction. References | Related Articles | Metrics

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Prediction and Visualization of Crack Width for the Prototype Test on Special-Shaped Shield Segments ZHU Yeting,ZHU Yanfei,ZHANG Zixin,ZHUANG Qianwei,ZHENG Yifeng 2019, 53 (10):  1259-1268.  doi: 10.16183/j.cnki.jsjtu.2019.10.016 Abstract ( 1109 )   PDF (19658KB) ( 359 )   Save Prediction and visualization of the width and developing law of the key cracks are crucial to the invention of the standing prototype loading system and the further optimal design for special-shaped segmental structure. This paper conducted loading tests on a CF50 steel fiber reinforced concrete beam with a volume rate of 2% to improve the theoretical formula of the maximum crack width, and the non-contacting strain optical measuring technique was adopted for the first time in the field of prototype loading tests on segmental lining to monitor the cracking characteristics in key areas of the inner surface of the tunnel vault. The study shows that the determination method of crack initiation time and calculation method of crack width can be based on three-dimensional digital image processing technology (DIC-3D). The increment of the crack width experiences initial, stable and accelerated three stages, and the ultimate buried depth of special-shaped tunnel is finally determined to be 18.5m. The calculation parameters obtained from the beam loading tests for the theoretical maximum crack width are verified to be effective, and prediction of the crack width combined with the internal forces derived from shell-spring model is suggested. References | Related Articles | Metrics