煤矿井下设备位姿自监测传感器设计

针对煤矿井下关键设备由于安装位姿偏移或者人为移动,致使设备性能下降和功能缺失,最终引发安全事故等问题,设计了一种适用于煤矿井下自主监测设备位姿的传感器;传感器采用模块化设计思想进行软硬件设计,硬件上以ARM嵌入式芯片为核心,集UWB模块、超声波模块和惯性测量单元(IMU)为一体,预留串口、网口和WIFI等接口用于数据交互;软件上融合UWB一维定位数据和超声波测高数据,实现井下空间厘米级定位精度;通过对惯性测量单元数据进行互补滤波姿态解算,实时感应设备姿态角。

特种设备检验单位如何规避风险

国务院于2003年3月11日颁发了<特种设备安全监察条例>.同时废止了国务院1982年发布的<锅炉压力容器安全监察暂行条例>.

基于虚拟仪器的脉冲堆棒位显示设备的研制

介绍了基于虚拟仪器技术研制的脉冲堆棒位显示设备的原理和组成,以及设备的硬件设计、软件设计、调试试验等情况。该设备能够完成脉冲堆控制棒的棒位数据测量、存储、报表生成以及软件校准等功能,同时因性价比高、智能化程度高、可操作性强、兼容性强等特点使该设备便于推广使用。

高效多刀位推进式全自动坚果取仁装置应用研究

坚果取仁是坚果加工过程中一道重要工序,取仁装置是该工序的主要设备。传统取仁装置分为人工取仁和人工协同取仁装置取仁,存在费时费力、自动化程度低、进料不均、效率低、质量差、易堵塞、不防滑等缺点。根据坚果取仁工艺存在的问题,研制出了多刀位推进式全自动坚果取仁装置,具有进料均匀、全自动、取仁效率高、取仁质量好、省时省力、不易堵塞和打滑等优点,经济效益和社会效益较好,有显著的推广应用前景。

数控焊接变位机运动精度的影响因素

通过试验测定和计算机软件对试验数据进行处理 ,研究了工作台在不同倾斜角时的回转角、载荷阻力矩、回转速度等单因素和多因素综合作用下 ,对数控座式焊接变位机工作台回转运动到位精度的影响。研究结果对设计、开发弧焊机器人用的数控焊件变位设备 。

半导体国产设备行业中勇于创业的带头人——记北京华峰测控技术有限公司总工程师 孙铣

每个时代都有一些走在前列的人,每个领域也都有一些负有强烈责任感、执着向前的带头人。他们克服了常人难以想象的困难,双肩挑起时代赋予的使命。

基于信标的降级运行列车定位及防护方案

[目的]当车载信号设备发生故障时,若通过轨旁次级定位设备来完成降级运行列车的定位及防护,需要增设轨旁信号设备数量,成本较高。对此,有必要在不增设轨旁设备的前提下,研究基于信标的降级运行列车定位及防护方案。[方法]介绍了方案的基本原理及设备组成,详细阐述了列车定位原则和防护原则。列车降级运行时,车载基于信标的次级定位设备能读取信标信息,并通过车-地无线通信网络发送至轨旁ATP(列车自动防护)设备;轨旁ATP设备基于故障列车报告的位置信息完成对降级运行列车的位置检测,并结合线路情况控制降级运行列车前方防护信号开放,安全引导降级运行列车快速地下线退出运营,同时为后续正常列车发送计算移动授权,以保证相邻列车间的安全运行间隔。[结果及结论]基于信标的降级运行列车定位方案,不需增设轨旁设备,能使降级运行列车与正常列车防护间隔较近,对后续列车正常运行的影响小,故障情况下的运营组织效率高。相关工程应用及现场测试验证了该方案的可行性。

Speed-assigned Position Tracking Control of SRM With Adaptive Backstepping Control

A novel speed-assigned method is applied to the position tracking control of switched reluctance motor(SRM).A speed control freedom can be drawn into the position control through speed assignment. Adaptive backstepping control is used to design the position controller for the SRM. The accuracy of position tracking of the SRM can be enhanced with speed assignment. A disturbance observer is further designed to enhance the estimation accuracy of the unknown load torque. Simulation results certify that the design scheme is right and effective.

Study and application of monitoring plane displacement of a similarity model based on time-series images

In order to compensate for the deficiency of present methods of monitoring plane displacement in similarity model tests,such as inadequate real-time monitoring and more manual intervention,an effective monitoring method was proposed in this study,and the major steps of the monitoring method include:firstly,time-series images of the similarity model in the test were obtained by a camera,and secondly,measuring points marked as artificial targets were automatically tracked and recognized from time-series images.Finally,the real-time plane displacement field was calculated by the fixed magnification between objects and images under the specific conditions.And then the application device of the method was designed and tested.At the same time,a sub-pixel location method and a distortion error model were used to improve the measuring accuracy.The results indicate that this method may record the entire test,especially the detailed non-uniform deformation and sudden deformation.Compared with traditional methods this method has a number of advantages,such as greater measurement accuracy and reliability,less manual intervention,higher automation,strong practical properties,much more measurement information and so on.

Three-time rapid transfer alignment method of SINS/GPS navigation system of high-speed marine missile

The transfer alignment of SINS/GPS navigation system of a high-speed marine missile was investigated. With the help of the big acceleration of a high-speed missile, the transfer alignment was changed into a three-time alignment. The azimuth alignment was coarsely finished in 10s in the first time alignment, the horizontal alignment was accurately and rapidly finished in the second time alignment, and the azimuth alignment was accurately finished in the third time alignment. Because the second time alignment and the third time alignment were finished by GPS after the missile was launched, the horizontal alignment and the second azimuth alignment got rid of the influence of the warship body flexibility deforming. The precision and rapidity of the horizontal alignment were prominently increased due to the vertical launch of the marine missile with the big acceleration. Simulation verifies the effectiveness of the proposed alignment method.

基于放射性废物最小化的电气设计实践

基于废物最小化原则,在电气领域中提出新的混合控制技术和电流突变技术,同时优化电气设备的布置,灵活采用2种与常规电气或PLC/DCS的接口。试验及应用表明,该技术可有效减少放射性废物数量和人员受照剂量,在有毒、有害、易燃及易爆等领域有一定推广价值。

Domain adaptive methods for device diversity in indoor localization

To solve the problem of variations in radio frequency characteristics among different devices,transfer learning is applied to transform device diversity to domain adaptation in the indoor localization algorithm.A robust indoor localization algorithm based on the aligned fingerprints and ensemble learning called correlation alignment for localization(CALoc)is proposed with low computational complexity.The second-order statistical properties of fingerprints in the offline and online phase are needed to be aligned.The real-time online calibration method mitigates the impact of device heterogeneity largely.Without any time-consuming deep learning retraining process,CALoc online only needs 0.11 s.The effectiveness and efficiency of CALoc are verified by realistic experiments.The results show that compared to the traditional algorithms,a significant performance gain is achieved and that it achieves better positioning accuracy with a 19%improvement.

Cell and gene therapy for arrhythmias： Repair of cardiac conduction damage

Action potentials generated in the sinoatrial node （SAN） dominate the rhythm and rate of a healthy human heart. Subsequently, these action potentials propagate to the whole heart via its conduction system. Abnormalities of impulse generation and/or propagation in a heart can cause arrhythmias. For example, SAN dysfunction or conduction block of the atrioventricular node can lead to serious bradycardia which is currently treated with an implanted electronic pacemaker. On the other hand, conduction damage may cause reentrant tachyarrhythmias which are primarily treated pharmacologically or by medical device-based therapies, including defibrillation and tissue ablation. However, drug therapies sometimes may not be effective or are associated with serious side effects. Device-based therapies for cardiac arrhythmias, even with well developed technology, still face inadequacies, limitations, hardware complications, and other challenges. Therefore, scientists are actively seeking other alternatives for antiarrhythmic therapy. In particular, cells and genes used for repairing cardiac conduction damage/defect have been investigated in various studies both in vitro and in vivo. Despite the complexities of the excitation and conduction systems of the heart, cell and gene-based strategies provide novel alternatives for treatment or cure of cardiac arrhythmias. This review summarizes some highlights of recent research progress in this field.

FPGA PLACEMENT OPTIMIZATION BY TWO-STEP UNIFIED GENETIC ALGORITHM AND SIMULATED ANNEALING ALGORITHM

Genetic Algorithm (GA) is a biologically inspired technique and widely used to solve numerous combinational optimization problems. It works on a population of individuals, not just one single solution. As a result, it avoids converging to the local optimum. However, it takes too much CPU time in the late process of GA. On the other hand, in the late process Simulated Annealing (SA) converges faster than GA but it is easily trapped to local optimum. In this letter, a useful method that unifies GA and SA is introduced, which utilizes the advantage of the global search ability of GA and fast convergence of SA. The experimental results show that the proposed algorithm outperforms GA in terms of CPU time without degradation of performance. It also achieves highly comparable placement cost compared to the state-of-the-art results obtained by Versatile Place and Route (VPR) Tool.

Traffic analysis on carrier accessing for WLAN indoor positioning system

Currently,the WLAN indoor positioning system attracts a lot of interests,not only because of the cheap implementation but also because of the high positioning accuracy comparing with other indoor positioning systems.The WLAN indoor positioning system contains two phases,which are offline phase and online phase.In the online phase,the WLAN equipment user(UE) has to access to the WLAN for the latest radio map and positioning software.Due to during the network allocation vector(NAV) duration,the WLAN channel is only reserved for one WLAN UE,others UEs' carrier accessing will be blocked.In addition,the blocked UE will make a retrial accessing,which will definitely introduce more traffic blocking to the WLAN.So In this paper,based on the analysis of the WLAN indoor positioning system architecture,a proper queuing model by using of the Extended Erlang B formula is proposed,which takes the retrial calling percentage into consideration in the proposed model.The simulation results show that the proposed method is more accurate and performs well to predict the blocking probability.

Prediction Model for Cooling of an Electrical Unit with Time-Dependent Heat Generation

The satisfactory performance of electrical equipments depends on their operating temperature. In order to maintain these devices within the safe temperature limits, an effective cooling is needed. High heat transfer rate of compact in size and reliable operation are the challenges of a thermal design engineer of electronic equipment. Then, it has been simulated the transient a three-dimensional model to study the heating phenomenon with two assumption values of heat generation. To control for the working of this equipment, cooling process was modeled by choosing one from different cooling technique. Constant low speed fan at one direction of air flow was used for cooling to predict the reducing of heating temperature through working of this equipment. Numerical Solution of finite difference time domain method （FDTD） has been utilized to simulate the temporal and spatial temperature profiles through two processes, which would minimize the solution errors.

The Use of Hydrogen as a Fuel for Inland Waterway Units

Escalating apprehension about the harmful effects of widespread use of conventional fossil fuels in the marine field and in internal combustion engines in general, has led to a vast amount of efforts and the directing of large capital investment towards research and development of sustainable alternative energy sources. One of the most promising and abundant of these sources is hydrogen. Firstly, the use of current fossil fuels is. discussed focusing on the emissions and economic sides to emphasize the need for a new, cleaner and renewable fuel with particular reference to hydrogen as a suitable possible alternative. Hydrogen properties, production and storage methods are then reviewed along with its suitability from the economical point of view. Finally, a cost analysis for the use of hydrogen in internal combustion engines is carried out to illustrate the benefits of its use as a replacement for diesel. The outcome of this cost analysis shows that 98% of the capital expenditure is consumed by the equipment, and 68.3% of the total cost of the equipment is spent on the solar photovoltaic cells. The hydrogen plant is classified as a large investment project because of its high initial cost which is about 1 billion US$; but this is justified because hydrogen is produced in a totally green way. When hydrogen is used as a fuel, no harmful emissions are obtained.