Development of a Drilling and Coring Test-bed for Lunar Subsurface Exploration and Preliminary Experiments

Drill sampling has been widely employed as an effective way to acquire deep samples in extraterrestrial exploration. A novel sampling method, namely, flexible-tube coring, was adopted for the Chang＇e mission to acquire drilling cores without damaging stratification information. Since the extraterrestrial environment is uncertain and different from the terrestrial environment, automated drill sampling missions are at risk of failure. The principles of drilling and coring for the lunar subsurface should be fully tested and verified on earth before launch. This paper proposes a test-bed for conducting the aforementioned experiments on earth. The test-bed comprises a rotary-percussive drilling mechanism, penetrating mechanism, drilling medium container, and signal acquisition and control system. For granular soil, coring experiments indicate that the sampling method has a high coring rate greater than 80%. For hard rock, drilling experiments indicate that the percussive frequency greatly affects the drilling efficiency. A multi-layered simulant composed of granular soil and hard rock is built to test the adaptability of drilling and coring. To tackle complex drilling media, an intelligent drilling strategy based on online recognition is proposed to improve the adaptability of the sampling drill. The primary features of this research are the proposal of a scheme for drilling and coring a test-bed for validation on earth and the execution of drilling experiments in complex media.

Design and Test of the Semi-Automatic Test-Bed with Inclined Belt of Garlic Transplanting Machine

In order to verify the feasibility of semi-automatic garlic planter with inclined belt program and determine its reasonable operating parameters, the semi-automatic test-bed with inclined belt of garlic transplanting machine was designed, and the garlic box experiments were conducted. The angle of inclined belt on the test-bed and its running speed were adjustable. Single factor test results showed that the program of the semi-automatic garlic planter with inclined belt was feasible, and the angle of inclined belt and the test bed running speed affected the indicators. Orthogonal experiment results showed that the angle of inclined belt was the main factor affecting the test indicators. It is also found that the best angle was 30 degrees, while the most reasonable running speed was 0.75 Km/h.

Simplified Removable Ground Test-Bed for Testing Turbofan Engine

A new simplified removable ground test-bed was designed for testing a certainturbofan engine. The facilities are 5.5 m long, 1.5 m wide, 2.2 m high and not more than 4. 5 t ofits empty weight. There are four rubber wheels that could be towed. There is an independentelectrical measurement and control system to test the rotational speed of rotors, the gas pressureof the compressor, the exhaust gas temperature, etc. Cooperated with the oil truck and the electricpower supply truck, the turbofan engine could be preserved on the ground and started to the idlingregime. While running, the parameter of the engine could be recorded, disposed and displayed. Inaddition, the facilities were successfully applied to the plateau experiment in order to researchhow the atmosphere pressure affects the start of engines. Some data are given in the paper.

DESIGN OF NOVEL HIGH PRESSURE-RESISTANT HYDROTHERMAL FLUID SAMPLE VALVE

Sampling study is an effective exploration method, but the most extreme environments of hydrothermal vents pose considerable engineering challenges for sampling hydrothermal fluids. Moreover, traditional sampler systems with sample valves have difficulty in maintaining samples in situ pressure. However, decompression changes have effect on microorganisms sensitive to such stresses. To address the technical difficulty of collecting samples from hydrothermal vents, a new bidirectional high pressure-resistant sample valve with balanced poppet was designed. The sample valve utilizes a soft high performance plastic ＂PEEK＂ as poppet. The poppet with inapposite dimension is prone to occur to plastic deformation or rupture for high working pressure in experiments. To address this issue, based on the fmite element model, simulated results on stress distribution of the poppet with different structure parameters and preload spring force were obtained. The static axial deformations on top of the poppet were experimented. The simulated results agree with the experimental results. The new sample valve seals well and it can withstand high working pressure.

基于WACCM+DART的临近空间SABER和MLS臭氧观测同化试验研究

本研究在WACCM+DART(Whole Atmosphere Community Climate Model,Data Assimilation Research TestBed)临近空间资料同化预报系统中加入SABER(Sounding of the Atmosphere using Broadband Emission Radiometry)和MLS(Microwave Limb Sounder)臭氧观测同化接口,并以2016年2月一次平流层爆发性增温(SSW)过程为模拟个例进行了SABER和MLS臭氧观测同化试验,得出以下结论:同化SABER和MLS臭氧体积浓度观测得出的WACCM+DART臭氧分析场能够较真实反映SSW期间北极上空平流层臭氧廓线随时间的演变特征,且与ERA5(Fifth Generation of ECMWF Reanalyses)再分析资料描述的臭氧变化特征具有很好的一致性;基于SABER和MLS臭氧观测的WACCM臭氧6 h预报检验表明同化臭氧观测对臭氧分析和预报误差的改善效果主要体现在南半球高纬平流层和北半球中高纬平流层中上层—中间层底部;基于ERA5再分析资料的WACCM+DART分析场检验表明同化SABER和MLS臭氧体积浓度资料可在提高北半球高纬地区上平流层—中间层底部臭氧场分析质量的同时减小该地区上平流层—中间层底部温度场和中间层底部纬向风场的分析误差;基于MLS臭氧资料的臭氧中期预报检验表明相对控制试验同化SABER和MLS臭氧体积浓度资料能更好改善0~5 d下平流层和中间层底部臭氧的预报效果。

Research and Progress of Service Driven Optical Switching Network in China

National R&D activities on optical switching networkare introduced. Optical switching network testbedswere established in China including 3T-net andOBS ring and mesh network test-bed with the supportof national '863' program. As an importantmodule in OPS network, a novel all-optical serialmulticast mode is discussed.

Control system of a performance test-bed for frost protection wind machines

To test the performance and optimize operational parameters of various frost protection wind machines,a control system of performance test-bed was designed and developed based on Programmable Logic Controller(PLC)and touch screen.The system realized automatic control of operational parameters including hydraulic platform height,impeller rotation speed,depression angle,rotation range and cycle.Field case study results shows that the control accuracy of all the parameters was achieved with the average errors of 2.11 cm for height,9.5 r/min for impeller rotation speed,0.83°for pan-tilt rotation range and 0.061 min for rotation cycle.With the control of the test-bed,the performances of various wind machines,such as the distribution of airflow and temperature,and frost protection effect,could be tested under various working conditions,which provide experiment supports for developing wind machines adapted to different conditions with higher frost protection effect.

A Monocular Vision Measurement System of Three-Degree-of-Freedom Air-Bearing Test-Bed Based on FCCSP

A monocular vision-based pose measurement system is provided for real-time measurement of a three-degree-of-freedom （3-DOF） air-bearing test-bed. Firstly, a circular plane cooperative target is designed. An image of a target fixed on the test-bed is then acquired. Blob analysis-based image processing is used to detect the object circles on the target. A fast algorithm （FCCSP） based on pixel statistics is proposed to extract the centers of object circles. Finally, pose measurements can be obtained when combined with the centers and the coordinate transformation relation. Experiments show that the proposed method is fast, accurate, and robust enough to satisfy the requirement of the pose measurement.

Situational Awareness Using DBSCAN in Smart-Grid

Synchrophasors are the state-of-the-art measuring devices that sense various parameters such as voltage, current, frequency, and other grid parameters with a high sampling rate. This paper presents an approach to visualize and analyze the smart-grid data generated by synchrophasors using a visualization tool and density based clustering technique. A MATLAB based circle representation tool is utilized to visualize the real-time phasor data generated by a smart-grid model that mimics a synchrophasor. A density based clustering technique is also used to cluster the phasor data with the aim to detect contingency situations such as bad-data classification, various fault types, deviation on frequency, voltage or current values for better situational alertness. The paper uses data from an IEEE fourteen bus system test-bed modeled in MATLAB/SIMULINK to aid system operators in carrying various predictive analytics, and decisions.

Underwater cylindrical sandwich meta-structures composed of graded semi re-entrant zero Poisson’s ratio metamaterials with pre-strained wave propagation properties

Zero Poisson’s ratio(ZPR)mechanical metamaterials can yield no transverse displacements when unidi-rectionally compressed,and cylindrical sandwich meta-structures composed of semi re-entrant(SRE)ZPR metamaterials are thus explored for applications on cylindrical shells of underwater equipment or sub-mersible structures.A group of ZPR unit cells with specified pre-strained wave propagation characteristics and adequate load-bearing capabilities is optimally designed based on the periodic boundary condition(PBC)and Bloch’s Theorem.The sound transmission and pressure-resistant performance of cylindrical sandwich meta-structures comprising the homogeneous and graded SRE ZPR unit cells are then investi-gated.The results show that the designed meta-structures can perfectly yield better vibroacoustic atten-uation behavior within the specified frequency regions corresponding to the pre-strained band gaps and safely bear the hydrostatic pressure equivalent to 1000 m depth with low weight-bulk ratios.In addition,the functionally graded metamaterial core can boost vibroacoustic performance within broader frequency ranges.

基于无线传感器网络的分散目标跟踪:实际测试平台的开发应用(英文)

In the real world,centralized tracking in a large-scale wireless sensor network (WSN) may not be feasible due to the possible failure of fusion centre and the large communication delay in forwarding measurement data to the fusion centre. Distributed target tracking techniques can be employed by tasking sensor nodes near to the target to perform sensing,target state estimation and selection of future tasking sensor nodes. In this paper,the development and implementation of a prototype ultrasonic WSN test-bed to demonstrate distributed target tracking using the Extended Kalman Filter (EKF) algorithm is described. In the test-bed,a mobile robot is used to simulate the moving target,and static/mobile sensor nodes are deployed to detect and track the target. The sensor nodes and robots are equipped with sonar and MICAZ to receive and process instructions. Experimental evaluation of a number of sensor scheduling schemes are reported which shows the superior tracking performance of our distributed competition based sensor scheduling scheme.

Experimental study and industrial demonstration on utilization of Fe,Ti and V from vanadium-bearing titanomagnetite ore sands

In order to achieve highly efficient utilization of three valuable elements Fe,Ti and V simultaneously from vanadium-bearing titanomagnetite ore sands,an improved carbothermic reduction method was proposed and verified in both laboratory scale and industrial test-bed scale.The method combined the process of direct reduction and the process of further reduction and separation.Particularly,pulverized coal injection was introduced.In experimental tests,the effects of parameters such as carbon content in briquette,reduction duration and reduction temperature on the contents of metallic Fe and FeO as well as Fe metallization rate were analyzed.Experimental results indicated that Fe metallization rate in the carbon-containing briquette could reach 75.83%.In the industrial test-bed tests,the effects of carbon content in briquette,reduction duration and reduction temperature were also investigated,respectively.In addition,processes with and without pulverized coal injection were tested.The comparative analysis indicated that the content of TiO2 in titaniferous slag was increased by applying pulverized coal injection,and it can reach 82.5 wt.%.Meanwhile,the energy performance analysis showed that the equivalent electricity consumption of the test-bed dropped significantly to 2071 kWh per ton of slag,about 26.0%less than that of traditional method.Moreover,the investment payback of the test-bed is 3.4 years.Both experiments and industrial test-bed tests demonstrated that the proposed method has the advantages of highly efficient utilization,high energy efficiency as well as good economic performance.

A comparative study on mechanical and vibroacoustic performance of sandwich cylindrical shells with positive,negative,and zero Poisson’s ratio cellular cores

Deep-sea submersibles are significant mobile platforms requiring multi-functional capabilities that are strongly determined by the constituent materials.Their cylindrical protective cover can be advanced by designing their sandwiched cellular materials whose physical properties can be readily parameterized and flexibly tuned.Porous honeycomb materials are capable of possessing tuned positive,negative,or zero Poisson’s ratios(PPR,NPR,and ZPR),which is expected to produce distinct physical performance when utilized as a cellular core of cylindrical shells for the deep-sea submersibles.A novel cylindrical meta-structure sandwiched with the semi-re-entrant ZPR metamaterial has been designed as well as its similarly-shaped sandwich cylindrical shell structures with PPR and NPR honeycombs.The mechanical and vibroacoustic performance of sandwich cylindrical shells with cellular materials featuring a full characteristic range of Poisson’s ratios are then compared systematically to explore their potential for engineering applications on submerged pressure-resistant structures.The respective unit cells are designed to feature an equivalent load-bearing capability.Physical properties of pressure resistance,buckling,and sound insulation are simulated,respectively,and the orders of each property are then generalized by systematic comparison.The results indicate that the PPR honeycomb core takes advantage of higher structural strength and stability while the ZPR one yields better energy absorption and sound insulation behavior.The NPR one yields moderate properties and has the potential for lower circumferential deformation.The work explores the application of cellular materials with varied Poisson’s ratios and provides guidance for the multi-functional design of sandwich cylindrical meta-structures.