共查询到18条相似文献,搜索用时 93 毫秒
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针对现有测量火炮武器系统射击弹目偏差实时性差、漏测率高和设备庞大等问题,提出采用声学空间定位测量方法,并对弹丸N波特征进行了研究.建立了数学、物理模型和测量系统,攻克了全向接收弹丸激波的N波传感器、N波信号数字处理模块等关键技术,使测量系统具有抑制空中气动和高速飞行平台振动等外部环境噪声的能力,能够从复杂的背景噪声中正确提取出弹丸的N波信号信息.试验数据证明了超音速飞行弹丸所具有的特征,验证了测试系统的技术指标.声测量弹目偏差的测量方法较电子雷达或光电系统等其它测量方法具有响应快、漏测率低、不受环境影响和实时性强等优点. 相似文献
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本文介绍了一种新的利用无线电引信测量弹丸转速的方法,这种方法非常实用,弹丸上不需另研制新的装置,对弹丸本身的状态不需作任何改动,通用性强,不受天气条件影响。文章对原理和测量系统作了简介,该弹丸转速测量系统已研制成功,并已投入常规兵器试验场使用。 相似文献
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为实现固定翼双旋弹弹道修正,需对弹体和鸭舵滚转信息进行测量。该文针对双旋弹丸鸭舵反旋和弹体高速旋转的特点,建立弹体和鸭舵滚转姿态解算模型,设计基于地磁和霍尔传感器的滚转测量系统。采用波形变换方法将正弦波形式地磁信号转换为易于测量的方波信号,并使用高通滤波器和迟滞比较器对含噪地磁信号进行优化,通过定时器捕获分别得到弹体和鸭舵转速信息,在此基础上通过线性插值得到滚转角信息。地面半实物仿真平台实验表明该滚转测量系统弹体转速测量跳动为–0.3~0.2 Hz,鸭舵相对弹体转速测量跳动为–0.15~0.15 Hz,滚转角测量跳动为–2°~1°,能够满足双旋弹弹道修正的要求。 相似文献
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在计转数空炸引信测试中,可编程引信作用距离是关键量,而全备弹丸飞行转动圈数则是求取该关键量的测量难题.在分析连续波雷达测量弹丸瞬时转速的工作原理基础上,针对小口径弹丸特点,建立了转速调制模型,提出利用数字解调、运动补偿等处理方法,基于微多普勒信息提取榴弹转速,由瞬时转速求得转动圈数,并对其中产生的误差进行了有效消除,实现了高精度定距空爆.方法在相关试验中得到了验证,为小口径空炸弹的系统考核与毁伤效力发挥提供了技术支撑. 相似文献
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基于CCD立靶坐标交汇测量原理,提出了通过测量弹头和弹尾过靶坐标进而解算出弹丸攻角的方法,使CCD立靶测量系统在完成弹丸着靶坐标测量的同时,还可以完成弹丸攻角的测量.对CCD立靶坐标测量精度进行了分析,推导了攻角测量的相关公式;结合试验,对攻角测量精度作了分析,对方法的可行性进行了验证.结果表明,利用CCD立靶测量系统... 相似文献
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电场强度的传统测量系统是利用导体将具有测量仪器的天线连接起来 ,这就导致了由天线到测量仪器之间连接导体引起的电信号干扰和场强的变化。测量仪器可以安装在天线处 ,这又产生了使测量系统笨重和不方便的问题 ,因为这时在天线处必须装置电源和进行人工读数。本文给出的光纤—液晶电场强度测量系统解决了上述问题。该系统的测量原理是 :天线接收了电磁能使液晶显示器的反射率与待测场强成比例地变化 ,液晶显示器用光纤进行照射 ,入射光被液晶膜与场强成比例反射 ,反射光又通过光纤传送到光电探测器 ,它将光信号转换成电信号 ,然后进行显示… 相似文献
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Dan-chen Zhu Yong-xiang Zhang Qun-wei Zhu 《Journal of Failure Analysis and Prevention》2018,18(1):2-7
With rotating speed of rotating machinery, it is difficult to maintain stability in practical work which brings many difficulties to the condition monitoring of rotating machinery. When rolling element bearings work under variable speed, the corresponding vibration will contain obvious non-stationary characteristics, along with the presence of strong background noise, which makes it difficult for some traditional spectrum analysis methods to identify the characteristic frequency of bearings fault. In spite of the existence of strong non-stationary characteristics, the bearing fault signal has some hidden periodic components in the angle domain which makes it possible to extract the fault feature of bearings by means of spectral correlation analysis. Therefore, a fault feature extraction method based on Teager–Kaiser energy operator (TKEO) and fast spectral correlation (Fast-SC) in angle domain is proposed in this paper; Fast-SC is a newly proposed spectral correlation calculation method which can effectively improve the efficiency of computing; Teager–Kaiser energy operator can enhance the transient impact which also has a fast computing speed. In this paper, the instantaneous speed of each time is estimated by the time–frequency analysis method based on short-time Fourier transform and then, the original time-domain signal is resampled in angle domain; the TKEO is used to strengthen the fault impact components in signal; finally, the Fast-SC is applied to the strengthened signals, the enhanced envelope spectrum is calculated, and the fault features of rolling bearings are extracted. The effectiveness of the method is verified by measured signals. 相似文献
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提出了一种基于分数阶傅里叶变换(Fractional Fourier Transform, FRFT)的邻近阶比分离方法。根据变速器输入轴转速信号及传动比确定FRFT最佳阶次,对变速器升速过程振动信号进行最佳阶次FRFT,在该分数阶域分离邻近阶比分量,并对分离出的单分量信号进行阶比分析。试验结果表明,根据转速信号确定FRFT最佳阶次,准确、快速、鲁棒性好,并具有自适应性;最佳阶次的FRFT能准确分离提取邻近阶比分量,对分离出的目标阶比分量进行单分量分析,能有效解决邻近阶比胶合问题。 相似文献
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提出了一种稳健全息阶比谱方法,用于提取变速器变速过程的微弱故障特征。首先分析了转速波动对传统阶比方法分析精度的影响,构造了基于转速调整的改进阶比方法,对水平与垂直方向加速过程信号的改进阶比谱进行全息分析,构成稳健全息阶比谱,并与单测点改进阶比谱结果对比。试验表明,改进阶比谱能有效抑制转速波动对等角度采样的影响,提高了阶比谱分析精度,有效增强了全息阶比谱的稳健性;相对于任一方向单测点阶比谱,稳健全息阶比谱既能分析变速过程信号,又能融合多点信息,其量化参数能更准确评价诊断对象的技术状态,证明稳健全息阶比谱是一种全面、可靠提取变速过程微弱故障特征的有效方法。 相似文献
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基于支持向量机的转子振动信号故障分类研究 总被引:7,自引:0,他引:7
转子在运行过程中的振动加速度信号包含了转子运行状态大量信号,瞬态过程中故障加速度信号特征的提取及其识别对于旋转机械故障诊断是十分重要的。针对在升降速运行时的故障特征数据样本有限而制约有效智能诊断的问题,探讨和提出了基于支持向量机的加速度信号故障诊断方法。实验分析结果表明:该方法可实现转子的振动加速度信号对转子在升降速运行时的多故障的识别和诊断。 相似文献
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An analytical model for the normal impact of blunt, cylindrical and undeformable projectiles on thin metallic targets moving in a plane normal to the initial bullet trajectory has been developed. This analysis is intended to depict the principal phenomena that occur when such a projectile strikes the center of a circular plate mounted at the end of an arm rotating about the other end at constant angular velocity. The first step in the simulation constructions of the construction of a three-stage plugging process involving plastic wave propagation, joint projectile/target motion and tensile failure designed for impact on a stationary plate, using a membrane theory for the target response. This axisymmetric representation was then applied to moving targets by employment of impulse-momentum laws. Petaling failure was portrayed by an upper-bound plasticity approach, while projectile motion was described by rigid-body dynamics. The principal assumption inherent in this representation were guided by geometric considerations and observations from tests described in a companion paper.
Model evaluation was performed for several cases of projectile and target speed combinations. Relevant solutions were compared with results from corresponding experiments. In general, good correlation were obtained; discrepancies could be attributed to the effect of features that had not been incorporated in the model. 相似文献
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基于加速度信号全谱分析的转子碰摩故障特征提取实验研究 总被引:13,自引:2,他引:13
转子在运行过程中的振动加速度信号包含了转子运行状态大量信号,瞬态过程中故障加速度信号特征的提取及其识别对于旋转机械故障诊断是十分重要的。旋转机械振动的全谱分析是一种使一些典型故障尤萁是碰摩故障能被很清楚检测出来的有效方法,本文在对旋转机械转子中的一些典型碰摩故障进行了模拟试验,以及对故障发生过程中的加速度信号进行采集的基础上,对转子故障加速度信号的全谱特性进行了分析,提取和总结出由故障造成的加速度信号突变和对应的谱特征。分析结果表明:采用转子振动加速度信号对转子的碰摩故障进行诊断是有效的。加速度信号全谱图可以丰富旋转机械碰摩故障诊断系统知识库中的特征信息,对于更准确地诊断转子中的碰摩故障具有重要意义。 相似文献