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本文详细介绍了基于RS485总线的PC机与多台单片机间利用串行通信组成的分布式通信系统的原理、实现方法和相应的通信硬件、软件设计。该设计是由PC机与单片机组成的主从控制系统,其中PC机做为主机对从机单片机实现控制和监视功能。单片机作为从机在整个系统中属于从属地位,主要用来接收上位机的命令并实时控制。本设计采用了RS485总线以满足长距离多机通信,本文讨论了总线接口转换、主从式通信协议设计方法,给出了采用中断式处理的通信过程流程图,实现了PC机对多个单片机组成采集终端的通信与管理。 相似文献
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基于串行通信的分布式数据采集系统设计研究 总被引:1,自引:0,他引:1
介绍基于串行通信的分布式数据采集系统(DDAS)的功能结构和工作原理,研究主处理机与前端数据采集机间通信控制器的设计、通信协议及通信过程中应答信号的设置,给出了前端数据采集机的硬件电路,结合温度测试实例分析采集的数据,验证DDAS的可行性。 相似文献
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介绍自备铁路信号系统远程通信的实施方案,整个系统分成三层通信模块:控制设备层的远程通信、监控站与控制设备层之间的通信以及关联系统之间的通信.可以使用串口通信和网络操作系统固有的功能实现远程通信,也可以使用基于TCP/IP自定义通信协议实现远程通信. 相似文献
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研究了航空器目标跟踪中继卫星的星间天线指向实时监视问题.设计了星间天线指向监视计算模型,通过对航空器实时位置和中继卫星轨道的求解,得到了惯性系下的天线指向矢量,再通过坐标转换和矢量投影,得到了航空器星间天线理论指向角.通过将计算得到的理论指向角与遥测的天线框架角作差,得到了天线指向误差.在此基础上完成了天线指向实时监视系统设计,并进行了跟踪过程天线指向精度的事后统计分析.该天线指向实时监视系统利用航空器的遥测信息实现了跟踪过程中星间天线的指向角及指向角误差的实时确定,取得了良好的应用效果,有效地保证了数据中继任务中航天器用户目标对中继卫星跟踪的准确监视. 相似文献
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本文介绍主从型巡回数据采集系统,研究主控PC机和数据采集站之间采用RS-422总线标准进行数据传输的接口电路和通信协议,讨论了通信过程中应答信号的设置,给出了通信接口电路和实现通信协议的程序流程图. 相似文献
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In the industrial transformer core assembly process, significant productivity gains can be achieved by utilizing a robotic gripper that is able to handle, and accurately position, multiple transformer laminations during each pick-and-place cycle. This paper reports on the development of a novel electromagnetic lifter for such applications. The lifter has the unique capability to selectively pick a given number of laminations at a time (the usual requirement is three) from a stack. By considering an analytical model of the magnetic circuit of the electromagnet-lamination stack combination, closed form solutions are obtained for the flux flow pattern and the lifting force on each lamination in the stack which closely agrees with the numerical results obtained using two-dimensional finite element analysis software. Results of experiments conducted on a prototype electromagnet are also presented that validate the analytical model findings 相似文献
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协作传输可以获得无线信道内在的空间分集,有效改善通信系统的性能,增加通信系统的覆盖范围。对水声通信系统中两中继节点协作的译码转发方案进行了研究,提出了基于译码转发协议(DF)的分布式空时分组扩频编码(DSTBSC)方案,该方案可以克服多径衰落对分布式空时分组码(DSTBC)信号正交性的影响。给出了DSTBSC方案的系统模型,着重分析了在采用两中继译码转发时,中继节点的误码对水声通信系统性能的影响。在接收端不考虑信号冲突的情况进行仿真,结果表明,与直接传输方案相比,采用两中继节点、译码转发的DSTBSC方案,在两中继节点处均无误码和一个中继有误码时在相同的比特误码率(BER)条件下均可获得约4dB的分集增益,增加了传输距离。 相似文献
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提出了一种基于压缩感知理论的多中继协作通信系统稀疏信道估计方法.采用正交匹配追踪(Orthogonal Matching Pursuit,OMP)压缩感知算法,对时域信道脉冲响应进行估计.对多中继协作通信系统进行稀疏建模;结合压缩感知理论构建观测矩阵,并给出卷积信道的稀疏表示;利用压缩信道感知算法重建了系统的卷积复合信道.仿真结果表明,与传统的最小二乘法(Least Square,LS)相比,采用压缩感知理论的信道估计算法,能利用较少的导频信号获得很好的信道估计性能,提高了频谱利用率. 相似文献
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为了满足水下航行体的大范围水下定位跟踪测试要求,针对基于座底式水声网络节点的跟踪测试技术进行深入研究。设计了一种紧凑型水声网络节点,该节点采用卧式安装结构,可通过水声或光电信号进行回收控制,具有结构轻便、布放效率高、回收可靠等特点。利用该水声网络节点,串行布放在某水域组成座底式长基线跟踪测试系统,该系统具备定位跟踪、航行参数遥测等功能。针对其定位跟踪及航行参数遥测功能进行湖上跑船试验,试验结果证明,该系统定位跟踪精度高,航行参数遥测功能可靠,遥测误码率低,总体覆盖范围大,可广泛应用于水下航行体的定位跟踪、导航测试等,具有较高的工程实用价值。 相似文献
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Eman S. Attia Ashraf A. M. Khalaf Fathi E. Abd El-Samie Saied M. Abd El-atty Konstantinos A. Lizos Osama Alfarraj Farid Shawki Imran Khan Ki-Il Kim 《计算机、材料和连续体(英文)》2022,72(2):2729-2748
With the emergence of the COVID-19 pandemic, the World Health Organization (WHO) has urged scientists and industrialists to explore modern information and communication technology (ICT) as a means to reduce or even eliminate it. The World Health Organization recently reported that the virus may infect the organism through any organ in the living body, such as the respiratory, the immunity, the nervous, the digestive, or the cardiovascular system. Targeting the abovementioned goal, we envision an implanted nanosystem embedded in the intra living-body network. The main function of the nanosystem is either to perform diagnosis and mitigation of infectious diseases or to implement a targeted drug delivery system (i.e., delivery of the therapeutic drug to the diseased tissue or targeted cell). The communication among the nanomachines is accomplished via communication-based molecular diffusion. The control/interconnection of the nanosystem is accomplished through the utilization of Internet of bio-nano things (IoBNT). The proposed nanosystem is designed to employ a coded relay nanomachine disciplined by the decode and forward (DF) principle to ensure reliable drug delivery to the targeted cell. Notably, both the sensitivity of the drug dose and the phenomenon of drug molecules loss before delivery to the target cell site in long-distance due to the molecules diffusion process are taken into account. In this paper, a coded relay NM with conventional coding techniques such as RS and Turbo codes is selected to achieve minimum bit error rate (BER) performance and high signal-to-noise ratio (SNR), while the detection process is based on maximum likelihood (ML) probability and minimum error probability (MEP). The performance analysis of the proposed scheme is evaluated in terms of channel capacity and bit error rate by varying system parameters such as relay position, number of released molecules, relay and receiver size. Analysis results are validated through simulation and demonstrate that the proposed scheme can significantly improve delivery performance of the desirable drugs in the molecular communication system. 相似文献
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用甲苯-2,4-二异氰酸酯(2,4-TDI)、聚醚二醇(PPO)和3,3’-二氯-4,4’-二氨基二苯基甲烷(MOCA)等原料合成了聚氨酯弹性体,在脉冲声管中测试了合成试样的声压反射系数和吸声系数,研究了合成工艺参数对其水下声学性能的影响。测试结果表明,TDI-PPO-MOCA合成型聚氨酯弹性体是一种良好的水下吸声材料,其吸声性能受到固化温度,扩链剂含量等参数的影响。加入填料和改变其结构可以进一步改善聚氨酯弹性体的水下声学性能,因此合理地设计实验工艺参数,可以得到水下声学性能更佳的聚氨酯弹性体。为工业生产提供了理论参考。 相似文献
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探究了拓扑优化设计方法在水下耐压结构设计中的应用。与固定载荷作用下结构的优化设计相比,此类问题需要正确地确定压力作用面。在拓扑优化过程中,利用变密度法得到的中间结构拓扑实际上可以看成是灰度图。基于此,提出了基于图像分割技术的压力加载面搜索方法,并利用距离正规化水平集方法(DRLSE)检测图像边界。利用数值算例验证了方法的有效性,并研究了静水压力作用下结构的拓扑优化设计问题。在给定材料约束的前提下,研究了不同边界条件下耐压壳体的最小柔顺度及最优结构拓扑形式。优化结果说明了该方法在多球交接耐压壳结构形式优化设计及复杂边界条件下耐压结构新形式探索中的工程应用价值。 相似文献
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An integrated scheme for crystal plasticity analysis: Virtual grain structure generation 总被引:1,自引:0,他引:1
An integrated scheme is developed based on the controlled Poisson Voronoi tessellation (CPVT) model to generate the polycrystalline grain structure for micromechanics simulations. The proposed model of CPVT involves a single control parameter that is used to produce the grain structure with regularity control, by which the yielded tessellation varies from the purely random Voronoi tessellation to the regular hexagonal tessellation. The system extends the standard CPVT model by the addition of two features: a one-parameter gamma distribution and a mapping from a set of quantitative metallographic measurements to the distribution parameter. Based on this scheme, a grain structure can be constructed such that the virtual tessellation is statistically equivalent to the expected grain size distribution. To validate the modules that utilise the physical parameters that dictate the regularity, a series of theoretical investigations is performed. Efforts are devoted to proving the uniqueness of the mapping from the physical parameters to the distribution parameter and the regularity parameter. An efficient numerical algorithm is provided to facilitate the mapping solution process. A software system (VGRAIN) is developed implementing the proposed CPVT model to generate the grain structure for crystal plasticity finite element (CPFE) analysis. To demonstrate the proposed scheme and the VGRAIN system, a plane strain CPFE analysis is conducted. Two microstructures are generated with different regularities, and the deformation under uniaxial tension is simulated. 相似文献