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Gray bootstrap method for estimating frequency-varying random vibration signals with small samples 总被引:2,自引:0,他引:2
During environment testing, the estimation of random vibration signals (RVS) is an important technique for the airborne platform safety and reliability. However, the available meth- ods including extreme value envelope method (EVEM), statistical tolerances method (STM) and improved statistical tolerance method (ISTM) require large samples and typical probability distri- bution. Moreover, the frequency-varying characteristic of RVS is usually not taken into account. Gray bootstrap method (GBM) is proposed to solve the problem of estimating frequency-varying RVS with small samples. Firstly, the estimated indexes are obtained including the estimated inter- val, the estimated uncertainty, the estimated value, the estimated error and estimated reliability. In addition, GBM is applied to estimating the single flight testing of certain aircraft. At last, in order to evaluate the estimated performance, GBM is compared with bootstrap method (BM) and gray method (GM) in testing analysis. The result shows that GBM has superiority for estimating dynamic signals with small samples and estimated reliability is proved to be 100% at the given confidence level. 相似文献
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旋转高频信号注入法注入信号较为稳定,且位置估计过程不依赖电机参数,因而十分适用于内置式永磁同步电机(IPMSM)的零、低速转子位置检测。针对传统高频信号注入法无法辨别磁极的问题,用电压方波注入法检测磁极,结合有限元软件仿真,来合理选取方波电压幅值和时长,有效缩短了磁极判断耗时。分析了滤波器和信号离散化对位置估计精度的影响,提出在低速段可用线段拟合带通滤波器中心频率处的相频特性曲线,推导所需补偿角度与电机转速的关系。在理论分析的基础上,采用基于DSP28335的样机平台进行试验,结果表明磁极判断过程稳定,耗时较短,补偿后的位置估计值相比补偿前有明显改善,调速过程中系统动态性能良好。 相似文献
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针对比例导引控制的拦截弹,建立高阶制导系统状态空间模型,基于脱靶量级数解公式,对目标最优机动突防策略及其影响因素进行了研究。首先,针对拦截弹的制导系统为线性一阶、线性高阶时,目标最优机动突防效果进行了仿真分析,结果表明拦截弹弹体模型的准确性对突防效果存在影响,高阶系统对应脱靶量更大且效果更真实;将结果与一次阶跃机动和蛇形机动对比,发现最优机动突防效果最佳。然后,建立弹目运动的二维非线性模型,仿真得出目标最优机动产生的脱靶量曲线与线性系统吻合度较高,线性模型选取合适。最后,研究了有效导引比和剩余飞行时间估计误差对最优机动突防效果产生的影响,结果表明有效导引比估计误差对最优机动突防效果影响不大,剩余飞行时间估计误差则会使目标最优机动突防性能大幅下降,甚至部分情况比蛇形机动突防效果差。 相似文献
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探索提高制导武器末制导系统抗噪声扰动鲁棒性的技术方法,研究了一种能将制导信号不确定噪声引起的滤波估计误差控制在一定边界范围内的鲁棒滤波算法,采用该算法对宽频被动雷达导引头测量输出信息滤波估计,可以弱化不确定随机噪声对制导系统的扰动,从而提高制导系统抗噪声扰动的鲁棒性.通过仿真验证了算法的有效性. 相似文献
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