Reconfigurable Intelligent Surface-Based Hybrid Phase and Code Modulation for Symbiotic Radio

Reconfigurable intelligent surface(RIS)-assisted symbiotic radio is a spectrum-and energy-efficient communication paradigm,in which an RIS performs passive beamforming to enhance active transmission,while using the electromagnetic waves from the active transmission for additional information transfer(i.e.,passive transmission).In this paper,a hybrid RIS-based modulation,termed hybrid phase and code modulation(HPCM),is proposed to improve the reliability of RIS-assisted symbiotic radio.In RIS-HPCM,the RIS simultaneously performs direct sequence spread spectrum and passive beamforming on incident signals.Moreover,both the spreading code and phase offset are exploited to carry the RIS’s own information.A low-complexity detector is designed,in which the receiver first detects the spreading codes and then demodulates the constellation symbols.We analyze the bit error rate(BER)performance of RIS-HPCM over Rician fading channels.BER upper bounds and approximate BER expressions are derived in closed-form for maximum-likelihood and low-complexity detectors,respectively.Simulation results in terms of BER verify the analysis and show the superiority of RIS-HPCM over the existing RIS-based modulation.

Differential Scheme for Reconfigurable Intelligent Surface-Based Spatial Modulation System

In this paper,a differential scheme is proposed for reconfigurable intelligent surface(RIS)assisted spatial modulation,which is referred to as RISDSM,to eliminate the need for channel state information(CSI)at the receiver.The proposed scheme is an improvement over the current differential modulation scheme used in RIS-based systems,as it avoids the high-order matrix calculation and improves the spectral efficiency.A mathematical framework is developed to determine the theoretical average bit error probability(ABEP)of the system using RIS-DSM.The detection complexity of the proposed RIS-DSM scheme is extremely low through the simplification.Finally,simulations results demonstrate that the proposed RIS-DSM scheme can deliver satisfactory error performance even in low signal-to-noise ratio environments.

Intelligent Automation Module-Based Gear Edge Grinding System

As industry progresses toward intelligent production and development,on-site workers that perform repetitive tasks will be replaced by intelligent machines.Currently,automation applications still have the following problems:(1)on-site personnel are required to line up the workpieces before a robot arm can pick it up;(2)the trajectory generated by offline programming software must be adjusted by on-site personnel in accordance with the processing results;and(3)because of workpiece positioning errors and tool wear,achieving acceptable processing results is difficult.This study developed intelligent application modules that solve the aforementioned automation application problems.These modules predict processing quality,generate trajectory,enable robot arms to load and unload randomly positioned workpieces,and automatically calibrate the system.An automatic gear edge grinding system was developed by integrating each module;the system increases the processing efficiency and solves the current problem of manual grinding being required after gear processing.

Research progress of cholesteric liquid crystals with broadband reflection characteristics in application of intelligent optical modulation materials

Cholesteric liquid crystals（CLCs） have recently sparked an enormous amount of interest in the development of soft matter materials due to their unique ability to self-organize into a helical supra-molecular architecture and their excellent selective reflection of light based on the Bragg relationship.Nowadays,by the virtue of building the self-organized nanostructures with pitch gradient or non-uniform pitch distribution,extensive work has already been performed to obtain CLC films with a broad reflection band.Based on authors＇ many years＇ research experience,this critical review systematically summarizes the physical and optical background of the CLCs with broadband reflection characteristics,methods to obtain broadband reflection of CLCs,as well as the application in the field of intelligent optical modulation materials.Combined with the research status and the advantages in the field,the important basic and applied scientific problems in the research direction are also introduced.

RIS Assisted Dual-Function Radar and Secure Communications Based on Frequency-Shifted Chirp Spread Spectrum Index Modulation

Reconfigurable intelligent surface(RIS)assisted dual-function radar communications(DFRC)system is a promising integrated sensing and communication(ISAC)technology for future 6G.In this paper,we propose a scheme of RIS-assisted DFRC system based on frequency shifted chirp spread spectrum index modulation(RDFI)for secure communications.The proposed RDFI achieves the sensing and transmission of target location information in its radar and communication modes,respectively.In both modes,the frequency-shifted chirp spread spectrum index modulation(FSCSS-IM)signal is used as the baseband signal for radar and communications,so that the signal sent by the radar also carries information.This scheme implements the RIS-assisted beamforming in the communication mode through the azimuth information of the target acquired in the radar mode,so that the signal received from the eavesdropper is distorted in amplitude and phase.In addition,this paper analyzes the radar measurement accuracy and communication security of the FSCSS-IM signal using ambiguity function and secrecy rate(SR)analysis,respectively.Simulation results show that RDFI achieves both excellent bit error rate(BER)performance and physical layer security of communications.

Classification of Multi-User Chirp Modulation Signals Using Wavelet Higher-Order-Statistics Features and Artificial Intelligence Techniques

Higher order statistical features have been recently proved to be very efficient in the classification of wideband communications and radar signals with great accuracy. On the other hand, the denoising properties of the wavelet transform make WT an efficient signal processing tool in noisy environments. A novel technique for the classification of multi-user chirp modulation signals is presented in this paper. A combination of the higher order moments and cumulants of the wavelet coefficients as well as the peaks of the bispectrum and its bi-frequencies are proposed as effective features. Different types of artificial intelligence based classifiers and clustering techniques are used to identify the chirp signals of the different users. In particular, neural networks (NN), maximum likelihood (ML), k-nearest neighbor (KNN) and support vector machine (SVMs) classifiers as well as fuzzy c-means (FCM) and fuzzy k-means (FKM) clustering techniques are tested. The Simulation results show that the proposed technique is able to efficiently classify the different chirp signals in additive white Gaussian noise (AWGN) channels with high accuracy. It is shown that the NN classifier outperforms other classifiers. Also, the simulations prove that the classification based on features extracted from wavelet transform results in more accurate results than that using features directly extracted from the chirp signals, especially at low values of signal-to-noise ratios.

Controller Design of Intelligent Lighting Network

Studied are the controller design and basic principles of intelligent lighting network. TI’s MSP430F123 is used as a main controller. By using the ZigBee modules(Xbee/Xbee-PRO) and the GSM module(SIM300C) for wireless communications, the lighting control is enabled to access wireless network. This system uses a mobile phone to achieve light on-off directly, which can accomplish wireless control of intelligent lighting in families.

MODULE DEFINITION MODEL FOR MODULAR DESIGN AND MANUFACTU－RING OF HEAVY DUTY MACHINE TOOLS

The key techniques of modular design of heavy duty NC mathine tools are described. Amodule definition modelfor modular design and manufacturing of heavy duty NC machine tools isbulit and the essential composition of the module definition model (MDM) is discussed in detail. Itis composed of two models: the part definition model (PDM) and the module assembly model(MAM). The PDM and MAM are built and their structures are given. Using object-oriented know-ledge representation and based on these models, an intelligent support system of modular design forheavy duty NC machine tools is developed and implemented This system has been applied to thepractical use of Wuhan Heavy Duty Machine Tool Works

深海载人潜水器直流无刷电机驱动控制研究

为提高深海载人潜水器电机工作效率和故障诊断能力,并降低系统工作噪声,对直流无刷电机的高效低噪驱动控制技术进行研究。采用具有智能相位控制功能的三相全波正弦波控制芯片TB6605结合智能功率模块(IPM)设计直流无刷电机驱动器。采用单片机对系统的电压、电流、温度、转速、位置信息进行检测,为控制系统提供必要的信息反馈,对应用直流无刷电机的系统状态起到实时信息监测的功能。实验结果表明,研制的直流无刷电机驱动器在电机全转速范围内具有较高的工作效率,额定工况点效率高达90%以上,且在全转速范围内,提高了电机运转的平稳度,降低了系统噪声。研究成果对提高深海载人潜水器电机的工作效率和故障诊断能力,并降低系统工作噪声具有很好的支撑作用。

基于LoRa通信的无线发射台信号智能监测技术研究

为实现大面积无线发射台信号覆盖监测,有效地抵御监测过程中多径干扰和频率选择性衰减等干扰因素的影响,研究基于LoRa通信的无线发射台信号智能监测技术。在无线发射台发出信号后,转换成数字信号进行对比,识别出有效发射台信号后,通过级联型LoRa组网方式以及LoRa通信技术,将数据发送到服务器中存储,实现无线发射台信号的传输。利用循环位移因子对基带产生的Chirp信号完成调频扩频调制,扩展信号频谱,增强信号抗干扰能力以及传输可靠性,增强信号监测的效果。实验结果表明:该方法能够在距离LoRa终端设备2.5 km处依旧接收到发射台信号,丢包率为12%,能够准确地监测到无线发射台是否存在发射信号。

人工智能辅助评价技术在火山岩气藏开发中的应用

结合COMOST人工智能辅助评价技术对典型火山岩气藏区块开展了多因素敏感性分析,自动历史拟合,方案最优化以及不确定分析等评价,建立了一种评价火山岩气藏开发指标预测、方案优化及风险分析的新方法,为以后气藏的合理指标预测及开发技术界限的界定提供参考和依据。

联合RIS子块与接收天线的索引调制方案性能分析

利用大量无源反射器件设计的可重构智能表面(RIS),具有拓展无线通信覆盖范围、降低系统成本/功耗和提升未来通信系统性能的优势;而索引调制(IM),通过激活通信资源的子集可实现信息的隐性传输,有望为无线通信带来更高的频谱效率和能量效率,因此,为进一步提升未来无线通信系统的性能,该论文融合RIS与IM技术,提出一种联合RIS子块与接收天线的IM方案。在该方案中,按照相邻原则,将RIS反射元件分割为若干子块,进而利用RIS子块索引与接收天线索引同时实现附加信息传递,即对待传输比特序列,将其分割为三部分,其中第一部比特被调制为星座符号,第二部分用于指示RIS子块划分,第三部分用于指示接收天线索引;在此基础上,根据最大似然(ML)检测的成对错误概率(PEP)解析形式,分四种情况,从理论上推导出对应的矩母函数(MGF),得到无条件PEP的解析表达式,最后得到该方案ML检测的平均误码率(ABER)性能上界。仿真结果表明,与现有RIS辅助的IM方案相比,无须增加额外频谱资源,所提方案的系统可达速率和系统差错性能方面均具有一定优势;同时,验证了ML检测的ABER上界具备严格一致性。

嵌入式机房多功能模块智能监控系统设计

为充分提高大型机房智能化运维能力,及时排除各种异常情况,实现高精度、低功耗的系统设计目标;提出基于嵌入式的机房多功能模块智能监控系统设计方法;设计针对机房空间的传感信号采集层、数据传输层、后台监控层的多层系统架构;硬件结构设计了用户登录模块、传感器运行模块、数据记录模块和监控显示模块,4个功能模块在多层架构下工作;软件部分通过数据传输程序连接终端设备与云计算中心,利用数据处理程序完成功能模块参数设置,完成嵌入式机房运行数据自动监控,针对系统的功耗问题,设计了微结构级功耗模型,降低系统功耗;实验结果表明:所设计系统容错率在80%以上,数据采集精度高,当浓度超过100 ppm时,自动对烟雾超标情况启动报警装置;可以实时响应接入设备,及时获取预警信息,功耗低,平均响应时间均在2.8 s以下,实现嵌入式机房自动智能监控。

道路环境与驾驶行为数据同步采集系统研发

高精度、可移植、多维度的在途车辆及其周边驾驶环境数据在L3级及以上自动驾驶汽车场景库测试、不良驾驶行为谱构建以及在途实时交通管控等领域有至关重要的作用,由单一传感器构成的数据采集系统在精度、维度上都受到了较大限制,导致其可靠度较低;为实现多类数据传感器协同一体化,研发了一款包含激光雷达、车载运动测量与组合定位、车载踏板与方向盘位移传感器和雷视道路多维感知一体机的多模块道路环境数据与驾驶行为同步采集系统,支持多项交通数据采集任务的并行处理,融合了用户的真实驾驶行为,并基于该系统设计了依维柯某车型的数据实车采集平台;该系统由上位机与下位机两个子系统构成,集成了多模块数据采集、储存、传输与标定等功能,且对各个模块完成了时间同步处理,适用于两客一危场景,并设计了易操作的上位机用户交互界面,对多模块数据实现实时可视化,直观查看各时段数据的变化规律,具有较高的应用价值。

基于STM32的智能航行系统设计

为解决航行器智能确定航向并航行的问题,本文采取模块化的思想设计了一款基于STM32的红外导引的智能航行控制系统。该智能航行系统利用红外接收模块进行红外导引信号的接收,采取线性加权法进行航向与导引信号之间的偏离角确定,利用比例-积分-微分(proportion-integration-differentiation,PID)控制算法对控制舵机转角的脉冲宽度调制(pulse width modulation,PWM)信号的占空比进行确定,从而对螺旋桨的转速与舵桨的转角进行可靠控制。根据水池测试结果,该智能航行控制系统能够对红外接收信号进行快速处理,在保持较高航速的条件下进行可靠的航行控制。

智能仓储交通信号与多AGV路径规划协同控制方法

针对智能仓储多AGV(automated guided vehicle)路径规划实时性差,障碍物识别能力弱,多AGV碰撞、死锁和拥堵等问题,提出了一种智能仓储交通信号控制与多AGV路径规划协同控制方法,将交通信号与多AGV路径规划视为一个整体,设计一种交通信号与多AGV路径规划协同控制框架,并提出LS-A3C(long short-asynchronous advantage actor-critic)算法和Bi-LSTM-CBAM(bi-long short-term memory-convolutional block attention module)算法作为框架的核心算法。LS-A3C算法使用长短时编码器和注意力机制分别对交通信号的长期信息和短期信息进行编码,以学习元特征表示,并使用A3C框架计算元Q值和控制策略,实现交通信号时间自适应AGV流量,解决多AGV碰撞、死锁和拥堵等问题。Bi-LSTM-CBAM算法通过计算本时刻和前置时刻状态特征,对输出结果进行拼接处理,可以有效解决神经网络梯度消失和爆炸的问题,提高AGV路径规划实时性;引入注意力机制模块CBAM,根据输入信息重要程度分配权重,加强AGV对障碍物识别能力。在Sumo和Gazebo联合仿真平台进行仿真实验,实验结果表明,该协同控制方法使AGV碰撞、死锁及拥堵情况明显降低,障碍物识别能力显著提高,路径规划实时性大幅增强,达到提升AGV作业效率的目的。

智能室内停车场定位导航系统设计

如今,各大商场的地下停车场日趋普遍化和复杂化。随着汽车持有量的急剧增长,车主在庞大的地下停车场中泊车寻车成为了难题。为此,提出了一种实现智能导航和停车管理的解决方案。依据室内定位及导航技术的应用需求,利用光敏模块、环形线圈检测及红外循迹技术,对停车场地形进行红外扫描,通过STM32单片机将数据传输到接收端。用户只需按照主控制器返回给终端的信息,即可快速实现点对点的定位服务。这一方案旨在提高人们出行的便捷性,并为加强城市停车规范管理提供可行性方案。

基于能量信息协同调控的LED智能调光技术

针对当前LED照明系统对智能化的迫切需求和对成本的高度敏感,而现有智能化调控方案在成本和可靠性等方面存在不足等问题,提出一种基于电力电子变换器能量信息协同调控的LED智能调光技术。该技术基于电力电子变换器驱动的LED线性调光照明系统,采用四进制差分相移键控(Quaternary differential phase shift keying,QDPSK)对公共直流母线上的开关纹波进行信息调制,从而在不额外增加硬件成本的条件下,实现四进制数字信号的调制、耦合与传输。从通信视角解构了DC/DC变换器的基本工作原理,揭示了LED调光系统中能量信息协同调控的实现方法,并以隧道LED照明系统的智能调光为例,围绕系统结构、通信协议、噪声干扰、通信速率等方面展开了具体分析。最后,搭建试验平台验证了所提方法的可行性。

智能功率模块驱动的反激式开关电源优化设计

为了实现智能功率模块(IPM)驱动电源的高效化与低成本化,利用反激式变压器的特点,设计了一款应用于IPM驱动的隔离型多路输出反激式开关电源,对控制芯片供电电路转换时电压进行稳定性优化。仿真及实验结果表明,优化后控制芯片供电波形稳定,反激式开关电源输出在5 ms时达到稳定,误差小于2%,波纹系数小于2%。