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针对磁通门需要什么参数的软磁铁芯的问题,在分析磁通门数学模型基础上,得出了正弦激励条件下磁通门的最佳激励磁场为铁芯饱和磁场强度的槡2倍;以带磁滞的双曲正切函数拟合软磁材料磁滞回线,分析了饱和磁感应强度、饱和磁场强度、矫顽力、矩形比和退磁系数对输出二次谐波幅值和激励电流的影响,得出高灵敏度磁通门铁芯应具有高磁导率和矩形比,低饱和磁场强度、矫顽力和退磁系数;低功耗磁通门铁芯应具有高磁导率,适当的矩形比,低饱和磁感应强度、饱和磁场强度、矫顽力和退磁系数;最后通过对比两组六种不同铁芯的磁滞回线和双铁芯磁通门输入输出特性,验证了以上结论的正确性。 相似文献
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提出了一种基于随电流变化的铁芯电感的磁通门HSPICE(High Simulation Program with IC Emphasis)模型,该磁通门模型铁芯的磁滞回线使用反正切函数来描述,其激励与测量线圈等效为一种随电流变化的电感电路模型。本文给出了全电路元件的磁通门模型的参数及提取方法,此模型可以在任意形状的电压激励波形下仿真,与已有的磁通门模型相比,具有仿真精度高、需要参数少且计算容易和可以方便进行输出信号处理的特点。实验和仿真结果对比表明,双铁芯磁通门HSPICE模型仿真的输入电流和输出电压的幅值分别为146 mA和1.03 V,与实际测试的146.6 mA和1.177 V相比,输入电流有0.6 mA的误差,输出电压有0.147 V的误差。 相似文献
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磁通门传感器主要由磁探头与电路部分组成,其输出不仅随磁场变化,而且易受温度的影响。为了确定磁通门传感器磁探头在宽温度范围下的温度漂移情况,通过试验将探头置于-40℃~150℃的温度环境下,记录得到探头在宽温度范围下,其温度特性曲线近似为正比线性关系。分析认为,磁芯磁滞回线受热偏移与线圈漆包线随温度热胀冷缩是磁探头温漂的主要原因。本文提出选用低磁导率磁芯和高温漆包线绕制探头,并优选一致性较好的探头,采用最小二乘法对温度漂移结果进行拟合补偿,有效地消除了温度对磁探头的影响,提高了磁通门传感器的温度稳定性与应用的广泛性。 相似文献
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在交变磁场下,针对铁磁材料中涡流效应对磁滞回线的影响在传统分析计算中存在的难题,提出一种基于HSPICE的磁通门铁芯涡流磁场计算和仿真方法.磁通门铁芯用考虑磁滞现象的Jiles动态模型描述,运用欧姆定律和毕奥-萨伐尔定律得到涡流产生的寄生磁场,再将寄生磁场与激励磁场叠加代入Jiles动态模型,即得到涡流对磁滞回线影响的数学模型.最后,利用HSPICE进行仿真验证,结果表明:在0.5 Hz、50 Hz、200 Hz和500 Hz 4种不同频率电压源激励下得到的铁芯磁滞回线波形,与实验结果拟合较好. 相似文献
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针对现有的磁通门信号处理电路仍以模拟元件为主,电路较为复杂的缺点,提出了一种以数字信号处理器(DSP)为主的信号处理系统,优化磁通门传感器的结构,提高了磁通门传感器的抗干扰能力.根据双磁芯磁通门的基本原理,建立了磁通门数学模型并采用Simulink信号处理模块模拟DSP对磁通门输出信号进行处理;针对双磁芯磁通门上、下磁芯不一致产生的磁通门信号噪声,采用带通滤波方法进行了滤波,仿真结果与理想状态下双铁芯磁通门的输出一致,系统分辨力达到3 nT.通过实验数据与仿真数据的对比,验证了DSP信号处理系统的可行性. 相似文献
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为分析磁通门磁场传感器的工作原理,基于Maxwell和Simplorer软件建立了磁通门磁场传感器的电磁联合仿真模型,仿真了磁通门非线性激励电路中电流波形和磁通门传感器的瞬态响应过程,分析计算了磁通门二次谐波灵敏度以及磁通门传感器的转换系数.为验证仿真模型的准确性,利用钴基非晶薄片制作了磁通门传感器探头并利用开关电源驱动电路激励磁通门工作.实际测量的激励电流波形与仿真结果基本一致,磁通门二次谐波灵敏度的测量值与仿真值误差小于1.1%.测量磁通门的频率响应曲线得到磁通门的转换系数为100 mV/μT,与仿真值几乎完全一致,两者误差小于1.5%.该仿真模型对理解磁通门传感器的工作原理、瞬态响应过程以及指导微型磁通门传感器设计具有重要意义. 相似文献
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Yanzhang Wang Shujun Wu Hao Lu Defu Cheng Chen Chen Na Pang Yunxia Wan Zhijian Zhou Siyu Chen 《中国科学:信息科学(英文版)》2016,59(11):112213
The output performance of residence times difference (RTD) fluxgate may vary under different driving conditions (driving currents and frequencies) and core materials. To optimize the RTD fluxgate and simplify its design process, an analytical model is employed to select the parameters and identify the effective factors that dominate the performance. The dynamic permeability parameters (Pi), which reflect the changes in the magnetization curve, are mathematically analyzed in detail. The linear variation functions of Pi in different driving conditions are fitted by using the dynamic arctangent hysteresis model. Consequently, the selection of driving conditions and core materials, which are assessed by comparing the experiment and simulation results, has an important role in achieving the optimal output performance of the RTD fluxgate. 相似文献
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During the winding process of stranded wire helical springs (SWHSs), uneven wire tension always results in high rejection rate and non-compliance service life of SWHSs. Combining the proportion integral neural network (PINN) with a simplified actuator model, this paper presents a new control scheme for the SWHS CNC machine to keep the wire tension uniform. The PINN is improved by introducing an error variance ratio, accounting for the interaction between wires, as a modifying factor in the second hidden layer. The actuator model is simplified based on the analysis of the dynamic characteristics of the actuator. The output value of the improved PINN is transferred into control voltage value by the simplified model. The tension of each wire is controlled by an improved PINN. In order to enhance the control performance, the network parameters are updated using the gradient-based back-propagation method. The validity and consistency of the improved PINN are verified by experiments. The results indicate that (1) the computation load is slight; (2) the rising time of the step response is within 1 s; (3) 89%-96% of tension deviation values of the wire 1 and wire 3 under different process parameters are within 10% of the reference tension value; (4) the standard deviation of the wire 2 with large disturbance is 8.24 N. Compared with other algorithms (incremental PI, multiple PIDNN, PI based particle swarm optimization), the control scheme based on the improved PINN has less computation load, faster response speed and better performance in the time-varying and nonlinear system with larger disturbance. 相似文献
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对于运行在同构多核处理器上的周期性硬实时任务,设计了一个基于动态电压调节的节能调度方法。该方法首先将计算任务按照周期数降序排序并基于计算任务调度长度最短的原则安排任务映射。然后将各个处理核上具有最小通讯时间的计算任务设置为最后执行的计算任务而其它计算任务顺序保持不变。在初始映射中所有计算任务都被分配最高频率的情况下,每个处理核上的计算任务在执行时间扩展过程中确定最佳的计算任务顺序。基于 Intel PXA270的功耗模型,以几个随机任务集作实验。结果表明提出的方法能够有效地降低多核处理器的能量。 相似文献
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大规模集群已经发展到多核的时代,多核架构对并行计算提出了新的要求。消息传递接口(MPI)是最常用的并行编程模型,而群集通信又是MPI中的重要组成部分。研究高效的群集通信算法对并行计算效率的提升有着重要的作用。KD60平台是采用首款国产多核芯片——龙芯3号搭建的国产万亿次多核集群。首先分析了KD60平台多核集群的体系特征以及多核架构下通信具有的层次性特征;然后分析原有群集通信算法实现原理及其不足;最后以广播为例,在原有算法基础上,采用一种基于片上多核(CMP)架构改进算法,改变原有算法通信模式,同时结合实验平台KD60体系特征,对算法做了体系相关优化。实验结果表明,改进算法能够很好地利用多核结构的特点,提高了群集通信广播算法的性能。 相似文献
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The magnetic actuator is a device that transforms electric energy to mechanical energy. By mechanical energy transformation, some part of the electric energy creates force, and the other part is stored within the ferrous material. An actuator with improved magnetic force can be designed by reducing the stored energy within the ferrous material at the core or the armature. Topology optimization based on the homogenization design method (HDM) is used for the initial design by determining the porous hole size of each element created. The homogenized magnetic permeability is applied in calculation of the magnetic energy stored. The magnetic energy is calculated by finite element analysis and the sensitivity is calculated mathematically by determining the effects of the magnetic energy according to the permeability change at each element. Repeating the process of the porous hole size determination by the sequential linear programming (SLP), eventually leads to a design of an actuator that makes the most improved magnetic force within the limited volume. The initial actuator model derived from topology optimization uses parameter optimization for detail designs. In parameter optimization design, the response surface method (RSM) based on the central composite design is used to obtain a clear final design. 相似文献
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An accurate and computationally efficient method for predicting the performance of a class of parallel computations running on concurrent systems is described. A parallel computation is modeled as a task system with precedence relationships expressed as a series-parallel directed acyclic graph. Resources in a concurrent system are modeled as service centers in a queuing network model. Using these two models as inputs, the method outputs predictions of expected execution time of the parallel computation and the concurrent system utilization. The method is validated against both detailed simulation and actual execution on a commercial multiprocessor. Using 100 test cases, the average error of the prediction when compared to simulation statistics is 1.7%, with a standard deviation of 1.5%; the maximum error is about 10% 相似文献
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传统人工势场法在面对多障环境时易陷入局部最优,导致路径长度和拐点数量增多从而严重降低配送效率。为此,考虑复杂环境多障密集和离散分布特征,结合相对位置检测策略和边界条件判断决策,采用自主虚拟圆作用域设计,修正路径长度和拐点数量缺陷;进一步地,基于模型预测理论,建立四轮转向车辆稳定性控制器,实现理想模型路径的精准跟踪控制;采用MATLAB软件进行模拟避障实验,并与传统算法路径搜索关键要素特征进行对比仿真。研究结果表明,所提出的改进人工势场算法相比于传统算法,全局拐点数量减少10个,路径缩短21.06%,跟踪偏差率低于6%。通过研究,解决了车辆多障环境适配及避障安全性问题,实现了指定轨迹的平稳、安全配送,为无人配送车规划算法的改进提供了理论指导。 相似文献