基于APM飞控系统与单片机的巡逻车的设计与实现

针对大型工业园区人工巡逻工作量大、效率低下、危险性较高的问题,设计一款基于APM飞行控制系统与单片机的多功能巡逻车。该巡逻车装有报警系统和消防灭火系统,可以实现远程监控、自动巡逻、灭火等功能,在各种环境下,都可以很好地完成巡逻任务,具有很高的实用性。

APM(自动旅客捷运系统)轨道错台检测研究及应用

[目的]为解决传统APM(自动旅客捷运系统)轨道错台人工检测方法的检测效率低、精度低等问题,需对APM轨道错台检测技术进行研究。[方法]利用线激光传感器获取轨道数据,基于多维图像处理技术和点云处理技术对错台进行识别和测量。对轨道轮廓数据进行图像化处理,通过图像处理技术识别轨道错台并定位,同时融合动态数列,判断在连续的时间段内图像识别算法识别的轨面状态是否一致,解决单个轨道断面误判的干扰,提高错台识别定位的准确性;错台精准识别和定位后,扫描获取轨道的点云数据,对数据进行滤波、平面拟合等处理,获取错台值的大小。[结果及结论]上海地铁浦江线的实际线路试验结果表明,采用多维图像处理技术和点云处理技术能够实现轨道错台的准确识别和定位,且识别的错台值的测量精度高、重复性好,满足轨道巡检要求。

APM轨道常见病害检测系统研制与应用

针对目前缺少APM轨道病害自动化检测装备的情况,研发了一种APM轨道病害检测系统。系统运用图像处理技术、高精度激光传感器和避障设备等可在不影响线路正常运行的情况下,实现对APM轨道各类病害检测项目的针对性检测。与现有人工检测相比,检测效率更高,检测精度更高。APM轨道病害检测系统已在上海APM浦江线上完成轨道全线检测,实践验证了该系统的高效性和准确性。

APM轨道检测设备导向机构设计

针对上海APM浦江线线路运维需求,根据轨道检测设备的评价指标,提出了一种新型轨道检测设备导向机构的设计方案。并利用多体系统动力学理论,建立了检测设备在导向轨错台激扰下过曲线段线路的动力学模型,通过分析检测设备的曲线通过性、摇头角、横向稳定性、导向力,对导向机构性能参数进行了优化。最后,在上海浦江线进行相关试验,验证了导向机构新设计方案的可行性与优越性。

Influence of sampling on three-dimensional surface shape measurement

In order to accurately measure an object’s three-dimensional surface shape,the influence of sampling on it was studied.First,on the basis of deriving spectra expressions through the Fourier transform,the generation of CCD pixels was analyzed,and its expression was given.Then,based on the discrete expression of deformation fringes obtained after sampling,its Fourier spectrum expression was derived,resulting in an infinitely repeated"spectra island"in the frequency domain.Finally,on the basis of using a low-pass filter to remove high-order harmonic components and retaining only one fundamental frequency component,the inverse Fourier transform was used to reconstruct the signal strength.A method of reducing the sampling interval,i.e.,reducing the number of sampling points per fringe,was proposed to increase the ratio between the sampling frequency and the fundamental frequency of the grating.This was done to reconstruct the object’s surface shape more accurately under the condition of m>4.The basic principle was verified through simulation and experiment.In the simulation,the sampling intervals were 8 pixels,4 pixels,2 pixels,and 1 pixel,the maximum absolute error values obtained in the last three situations were 88.80%,38.38%,and 31.50%in the first situation,respectively,and the corresponding average absolute error values are 71.84%,43.27%,and 32.26%.It is demonstrated that the smaller the sampling interval,the better the recovery effect.Taking the same four sampling intervals in the experiment as in the simulation can also lead to the same conclusions.The simulated and experimental results show that reducing the sampling interval can improve the accuracy of object surface shape measurement and achieve better reconstruction results.

导向轮预压力对APM车辆动力学性能的影响研究

本文分析了APM车辆转向架的结构,建立了APM车辆动力学仿真模型,分析了导向轮预压力变化对车辆曲线通过性和运行平稳性的影响。结果表明:预压力设置过大会增大导向轮径向力和导向力矩,导向性能差;预压力为零或轮轨存在间隙会使导向轮径向力和导向力矩瞬态响应过大,车辆运行姿态左右摆动;走行轮最大侧偏力随导向轮预压力增加而增大;导向轮预压力为零或轮轨存在间隙会导致车辆横向平稳性恶化。综合考虑,导向轮应设置一定的预压力,但不能过大,推荐预压力600N~1800N。

Bunch-length measurement at a bunch-by-bunch rate based on time–frequency-domain joint analysis techniques and its application

This paper presents a new technique for measuring the bunch length of a high-energy electron beam at a bunch-by-bunch rate in storage rings.This technique uses the time–frequency-domain joint analysis of the bunch signal to obtain bunch-by-bunch and turn-by-turn longitudinal parameters,such as bunch length and synchronous phase.The bunch signal is obtained using a button electrode with a bandwidth of several gigahertz.The data acquisition device was a high-speed digital oscilloscope with a sampling rate of more than 10 GS/s,and the single-shot sampling data buffer covered thousands of turns.The bunch-length and synchronous phase information were extracted via offline calculations using Python scripts.The calibration coefficient of the system was determined using a commercial streak camera.Moreover,this technique was tested on two different storage rings and successfully captured various longitudinal transient processes during the harmonic cavity debugging process at the Shanghai Synchrotron Radiation Facility(SSRF),and longitudinal instabilities were observed during the single-bunch accumulation process at Hefei Light Source(HLS).For Gaussian-distribution bunches,the uncertainty of the bunch phase obtained using this technique was better than 0.2 ps,and the bunch-length uncertainty was better than 1 ps.The dynamic range exceeded 10 ms.This technology is a powerful and versatile beam diagnostic tool that can be conveniently deployed in high-energy electron storage rings.

A New Device for Gas-Liquid Flow Measurements Relying on Forced Annular Flow

A new measurement device,consisting of swirling blades and capsule-shaped throttling elements,is proposed in this study to eliminate typical measurement errors caused by complex flow patterns in gas-liquid flow.The swirling blades are used to transform the complex flow pattern into a forced annular flow.Drawing on the research of existing blockage flow meters and also exploiting the single-phase flow measurement theory,a formula is introduced to measure the phase-separated flow of gas and liquid.The formula requires the pressure ratio,Lockhart-Martinelli number(L-M number),and the gas phase Froude number.The unknown parameters appearing in the formula are fitted through numerical simulation using computational fluid dynamics(CFD),which involves a comprehensive analysis of the flow field inside the device from multiple perspectives,and takes into account the influence of pressure fluctuations.Finally,the measurement model is validated through an experimental error analysis.The results demonstrate that the measurement error can be maintained within±8%for various flow patterns,including stratified flow,bubble flow,and wave flow.

Enhancing Energy Efficiency with a Dynamic Trust Measurement Scheme in Power Distribution Network

The application of Intelligent Internet of Things(IIoT)in constructing distribution station areas strongly supports platform transformation,upgrade,and intelligent integration.The sensing layer of IIoT comprises the edge convergence layer and the end sensing layer,with the former using intelligent fusion terminals for real-time data collection and processing.However,the influx of multiple low-voltage in the smart grid raises higher demands for the performance,energy efficiency,and response speed of the substation fusion terminals.Simultaneously,it brings significant security risks to the entire distribution substation,posing a major challenge to the smart grid.In response to these challenges,a proposed dynamic and energy-efficient trust measurement scheme for smart grids aims to address these issues.The scheme begins by establishing a hierarchical trust measurement model,elucidating the trust relationships among smart IoT terminals.It then incorporates multidimensional measurement factors,encompassing static environmental factors,dynamic behaviors,and energy states.This comprehensive approach reduces the impact of subjective factors on trust measurements.Additionally,the scheme incorporates a detection process designed for identifying malicious low-voltage end sensing units,ensuring the prompt identification and elimination of any malicious terminals.This,in turn,enhances the security and reliability of the smart grid environment.The effectiveness of the proposed scheme in pinpointing malicious nodes has been demonstrated through simulation experiments.Notably,the scheme outperforms established trust metric models in terms of energy efficiency,showcasing its significant contribution to the field.

A portable instrument for measurement of atmospheric Ox and NO2 based on cavity ring-down spectroscopy

Atmospheric O_(x)(nitrogen dioxide(NO_(2))+ozone(O_(3)))can better reflect the local and regional change character-istics of oxidants compared to O_(3)alone,so obtaining O_(x)accurately and rapidly is the basis for evaluating the O_(3)production rate.Furthermore,O_(x)has proved to be a more representative indicator and can serve as a reflection of pollution prevention efficacy.A portable instrument for measuring atmospheric O_(x)and NO_(2)based on cavity ring-down spectroscopy(O_(x)/NO_(2)-CRDS)was developed in this work.The NO_(2)concentration is accurately mea-sured according to its absorption characteristic at 407.86 nm.Ambient O_(3)is converted into NO_(2)by chemical titration of high concentrations of nitrogen oxide(NO),and the O_(3)conversion efficiencies obtained are nearly 99%.The detection limit of the O_(x)/NO_(2)-CRDS system for O_(x)is 0.024 ppbv(0.1 s),and the overall uncertainty of the instrument is±6%.Moreover,the Kalman filtering technique was applied to improve the measurement accuracy of O_(x)/NO_(2)-CRDS.The system was applied in a comprehensive field observation campaign at Hefei Sci-ence Island from 26 to 30 September 2022,and the time concentration series and change characteristics of O_(x)and NO_(2)were obtained for five days.The measured O_(x)concentrations were compared with those of two com-mercial instruments,and the consistency was good(R^(2)=0.98),indicating that this system can be deployed to accurately and rapidly obtain the concentrations of atmospheric O_(x)and NO_(2).It will be a useful tool for assessing the atmospheric oxidation capacity and controlling O_(3)pollution.

Research progress on micro-force measurement of a hydrate particle system

It remains a great challenge to understand the hydrates involved in phenomena in practical oil and gas systems.The adhesion forces between hydrate particles,between hydrate particles and pipe walls,and between hydrate particles and reservoir particles are essential factors that control the behaviors of clathrate hydrates in different applications.In this review,we summarize the typical micro-force measurement apparatus and methods utilized to study hydrate particle systems.In addition,the adhesion test results,the related understandings,and the applied numerical calculation models are systematically discussed.

Measuring small longitudinal phase shifts via weak measurement amplification

Weak measurement amplification,which is considered as a very promising scheme in precision measurement,has been applied to various small physical quantities estimations.Since many physical quantities can be converted into phase signals,it is interesting and important to consider measuring small longitudinal phase shifts by using weak measurement.Here,we propose and experimentally demonstrate a novel weak measurement amplification-based small longitudinal phase estimation,which is suitable for polarization interferometry.We realize one order of magnitude amplification measurement of a small phase signal directly introduced by a liquid crystal variable retarder and show that it is robust to the imperfection of interference.Besides,we analyze the effect of magnification error which is never considered in the previous works,and find the constraint on the magnification.Our results may find important applications in high-precision measurements,e.g.,gravitational wave detection.

Measurement and Analysis of Vibration Effect of Free-falling Corner Cube Driving Mechanism in Free Fall Absolute Gravimeter

The vibration interference of the reference corner cube runs through the free flight process of the free-falling corner cube,which is superimposed on the whole laser interference fringes.Thus,it is necessary to solve the interference fringes with the entire fringe to analyze the quantitative influence of vibration on gravity measurements.

Improved spatio-temporal alignment measurement method for hull deformation

In this paper,an improved spatio-temporal alignment measurement method is presented to address the inertial matching measurement of hull deformation under the coexistence of time delay and large misalignment angle.Large misalignment angle and time delay often occur simultaneously and bring great challenges to the accurate measurement of hull deformation in space and time.The proposed method utilizes coarse alignment with large misalignment angle and time delay estimation of inertial measurement unit modeling to establish a brand-new spatiotemporal aligned hull deformation measurement model.In addition,two-step loop control is designed to ensure the accurate description of dynamic deformation angle and static deformation angle by the time-space alignment method of hull deformation.The experiments illustrate that the proposed method can effectively measure the hull deformation angle when time delay and large misalignment angle coexist.

Unknown Environment Measurement Mapping by Unmanned Aerial Vehicle Using Kalman Filter-Based Low-Cost Estimated Parallel 8-Beam LIDAR

The measurement and mapping of objects in the outer environment have traditionally been conducted using ground-based monitoring systems,as well as satellites.More recently,unmanned aerial vehicles have also been employed for this purpose.The accurate detection and mapping of a target such as buildings,trees,and terrains are of utmost importance in various applications of unmanned aerial vehicles(UAVs),including search and rescue operations,object transportation,object detection,inspection tasks,and mapping activities.However,the rapid measurement and mapping of the object are not currently achievable due to factors such as the object’s size,the intricate nature of the sites,and the complexity of mapping algorithms.The present system introduces a costeffective solution for measurement and mapping by utilizing a small unmanned aerial vehicle(UAV)equipped with an 8-beam Light Detection and Ranging(LiDAR)system.This approach offers advantages over traditional methods that rely on expensive cameras and complex algorithm-based approaches.The reflective properties of laser beams have also been investigated.The system provides prompt results in comparison to traditional camerabased surveillance,with minimal latency and the need for complex algorithms.The Kalman estimation method demonstrates improved performance in the presence of noise.The measurement and mapping of external objects have been successfully conducted at varying distances,utilizing different resolutions.

Design and application of thickness measurement calibration system based on laser displacement sensor

This study aims to improve the accuracy and safety of steel plate thickness calibration.A differential noncontact thickness measurement calibration system based on laser displacement sensors was designed to address the problems of low precision of traditional contact thickness gauges and radiation risks of radiation-based thickness gauges.First,the measurement method and measurement structure of the thickness calibration system were introduced.Then,the hardware circuit of the thickness system was established based on the STM32 core chip.Finally,the system software was designed to implement system control to filter algorithms and human-computer interaction.Experiments have proven the excellent performance of the differential noncontact thickness measurement calibration system based on laser displacement sensors,which not only considerably improves measurement accuracy but also effectively reduces safety risks during the measurement process.The system offers guiding significance and application value in the field of steel plate production and processing.

A fast forward computational method for nuclear measurement using volumetric detection constraints

Owing to the complex lithology of unconventional reservoirs,field interpreters usually need to provide a basis for interpretation using logging simulation models.Among the various detection tools that use nuclear sources,the detector response can reflect various types of information of the medium.The Monte Carlo method is one of the primary methods used to obtain nuclear detection responses in complex environments.However,this requires a computational process with extensive random sampling,consumes considerable resources,and does not provide real-time response results.Therefore,a novel fast forward computational method(FFCM)for nuclear measurement that uses volumetric detection constraints to rapidly calculate the detector response in various complex environments is proposed.First,the data library required for the FFCM is built by collecting the detection volume,detector counts,and flux sensitivity functions through a Monte Carlo simulation.Then,based on perturbation theory and the Rytov approximation,a model for the detector response is derived using the flux sensitivity function method and a one-group diffusion model.The environmental perturbation is constrained to optimize the model according to the tool structure and the impact of the formation and borehole within the effective detection volume.Finally,the method is applied to a neutron porosity tool for verification.In various complex simulation environments,the maximum relative error between the calculated porosity results of Monte Carlo and FFCM was 6.80%,with a rootmean-square error of 0.62 p.u.In field well applications,the formation porosity model obtained using FFCM was in good agreement with the model obtained by interpreters,which demonstrates the validity and accuracy of the proposed method.

Quantum block coherence with respect to projective measurements

Quantum coherence serves as a defining characteristic of quantum mechanics,finding extensive applications in quantum computing and quantum communication processing.This study explores quantum block coherence in the context of projective measurements,focusing on the quantification of such coherence.Firstly,we define the correlation function between the two general projective measurements P and Q,and analyze the connection between sets of block incoherent states related to two compatible projective measurements P and Q.Secondly,we discuss the measure of quantum block coherence with respect to projective measurements.Based on a given measure of quantum block coherence,we characterize the existence of maximal block coherent states through projective measurements.This research integrates the compatibility of projective measurements with the framework of quantum block coherence,contributing to the advancement of block coherence measurement theory.

A seismic elastic moduli module for the measurements of low-frequency wave dispersion and attenuation of fluid-saturated rocks under different pressures

Knowledge about the seismic elastic modulus dispersion,and associated attenuation,in fluid-saturated rocks is essential for better interpretation of seismic observations taken as part of hydrocarbon identification and time-lapse seismic surveillance of both conventional and unconventional reservoir and overburden performances.A Seismic Elastic Moduli Module has been developed,based on the forced-oscillations method,to experimentally investigate the frequency dependence of Young's modulus and Poisson's ratio,as well as the inferred attenuation,of cylindrical samples under different confining pressure conditions.Calibration with three standard samples showed that the measured elastic moduli were consistent with the published data,indicating that the new apparatus can operate reliably over a wide frequency range of f∈[1-2000,10^(6)]Hz.The Young's modulus and Poisson's ratio of the shale and the tight sandstone samples were measured under axial stress oscillations to assess the frequency-and pressure-dependent effects.Under dry condition,both samples appear to be nearly frequency independent,with weak pressure dependence for the shale and significant pressure dependence for the sandstone.In particular,it was found that the tight sandstone with complex pore microstructure exhibited apparent dispersion and attenuation under brine or glycerin saturation conditions,the levels of which were strongly influenced by the increased effective pressure.In addition,the measured Young's moduli results were compared with the theoretical predictions from a scaled poroelastic model with a reasonably good agreement,revealing that the combined fluid flow mechanisms at both mesoscopic and microscopic scales possibly responsible for the measured dispersion.

基于MODSafe方法的APM安全完整性等级分配

[目的]APM(旅客捷运系统)对安全性的要求非常高,既有的SIL(安全完整性等级)分配方法难以高效、准确满足APM项目的需求。为确保APM的安全性和可靠性,应对APM的SIL分配、确定安全目标进行更为深入的研究。[方法]阐述了APM既有的SIL分配方法,提出采用目前已获得多方认可的MODSafe(模块化城市交通安全保障分析)方法对APM的SIL进行分配。介绍了MODSafe方法的基本步骤,明确了高安全需求、低安全需求2种模式下APM的SIL分配步骤。进一步以APM的列车冲击控制功能为例,阐述了基于MODSafe方法进行SIL分配的技术思路。[结果及结论]在设计的初期就对安全功能进行识别并且确认安全目标,对APM项目的安全交付和开通运营等至关重要。MODSafe方法可用于定量确定APM安全功能的THR(可容忍危害率)及SIL。