A single freedom degree model of drilling bit-rock was established according to the vibration mechanism and its dynamic characteristics. Moreover, a novel identification method of rock and soil parameters for vibratio...A single freedom degree model of drilling bit-rock was established according to the vibration mechanism and its dynamic characteristics. Moreover, a novel identification method of rock and soil parameters for vibration drilling based on the fuzzy least squares(FLS)-support vector machine(SVM) was developed, in which the fuzzy membership function was set by using linear distance, and its parameters, such as penalty factor and kernel parameter, were optimized by using adaptive genetic algorithm. And FLS-SVM identification on rock and soil parameters for vibration drilling was made by changing the input/output data from single freedom degree model of drilling bit-rock. The results of identification simulation and resonance column experiment show that relative error of natural frequency for some hard sand from identification simulation and resonance column experiment is 1.1% and the identification precision based on the fuzzy least squares-support vector machine is high.展开更多
The problem of identification of friend-or-foe aircraft in the actual application condition is addressed.A hybrid algorithm combining fuzzy neutral network with probability factor（FNNP）,multi-level fuzzy comprehensi...The problem of identification of friend-or-foe aircraft in the actual application condition is addressed.A hybrid algorithm combining fuzzy neutral network with probability factor（FNNP）,multi-level fuzzy comprehensive evaluation and the DempsterShafer（D-S） theory is proposed.This hybrid algorithm constructs a complete process from generating the fuzzy database to the final identification,realizes the identification of friend-or-foe automatically if the training samples or expert’s experience can be obtained,and reduces the effect of uncertainties in the process of identification.At the same time,the whole algorithm can update the identification result with the augment of observations.The performance of the proposed algorithm is assessed by simulations.Results show that the proposed algorithm can successfully deduce the aircraft’s identity even if the observations have measurement errors.展开更多
准确判别燃爆状态是测量燃爆延滞期并计算爆发点参数的关键。针对单一传感器判别效果不佳、多个传感器判别结果相互冲突的问题,利用D-S(Dempster-Shafer)证据理论对冲突证据进行联合判别。首先根据含能材料燃爆特性和爆发点测试原理,设...准确判别燃爆状态是测量燃爆延滞期并计算爆发点参数的关键。针对单一传感器判别效果不佳、多个传感器判别结果相互冲突的问题,利用D-S(Dempster-Shafer)证据理论对冲突证据进行联合判别。首先根据含能材料燃爆特性和爆发点测试原理,设计了基于温度和声音的联合判别装置;从实验数据出发,采用模型拟合提取温度特征值,以及声音信号最大值为声音特征值。其次,根据Sigmoid模型求解出BPA(Basic Probability Assignment)函数,并通过信度熵对可能存在冲突的BPA函数值进行预处理;最终,利用D-S证据理论进行燃爆状态联合判别。实验结果表明,所提方法有效提高了实验装置的鲁棒性和状态判别的置信概率,燃爆判别准确率达到了96.5%,优于温度、声音等单一传感器的判别效果。展开更多
位于谐振区的雷达目标可由极点特征进行识别,但极点特征的物理意义及其对应的谐振机理并不明确。针对该问题,本文利用一致性几何绕射理论(uniform geometrical theory of diffraction,UTD),研究了曲面绕射的谐振机理,并提出了一种用于...位于谐振区的雷达目标可由极点特征进行识别,但极点特征的物理意义及其对应的谐振机理并不明确。针对该问题,本文利用一致性几何绕射理论(uniform geometrical theory of diffraction,UTD),研究了曲面绕射的谐振机理,并提出了一种用于谐振区含曲面目标识别的极点正向推算方法。首先,用投影递推寻迹算法在目标表面获取爬行波的闭合路径及几何参数;然后,基于UTD给出曲面绕射场表达式,推导出用于预测极点的谐振方程;最后,通过对理想导体球及椭球进行极点预测,与频域仿真提取的极点进行对比,综合误差在5%以内,验证了建模方法的准确性。展开更多
基金Project(2012BAK09B02-05) supported by the National Key Technology R&D Program of China during the Twelfth Five-year PeriodProject(51274250) supported by the National Natural Science Foundation of China
文摘A single freedom degree model of drilling bit-rock was established according to the vibration mechanism and its dynamic characteristics. Moreover, a novel identification method of rock and soil parameters for vibration drilling based on the fuzzy least squares(FLS)-support vector machine(SVM) was developed, in which the fuzzy membership function was set by using linear distance, and its parameters, such as penalty factor and kernel parameter, were optimized by using adaptive genetic algorithm. And FLS-SVM identification on rock and soil parameters for vibration drilling was made by changing the input/output data from single freedom degree model of drilling bit-rock. The results of identification simulation and resonance column experiment show that relative error of natural frequency for some hard sand from identification simulation and resonance column experiment is 1.1% and the identification precision based on the fuzzy least squares-support vector machine is high.
文摘The problem of identification of friend-or-foe aircraft in the actual application condition is addressed.A hybrid algorithm combining fuzzy neutral network with probability factor（FNNP）,multi-level fuzzy comprehensive evaluation and the DempsterShafer（D-S） theory is proposed.This hybrid algorithm constructs a complete process from generating the fuzzy database to the final identification,realizes the identification of friend-or-foe automatically if the training samples or expert’s experience can be obtained,and reduces the effect of uncertainties in the process of identification.At the same time,the whole algorithm can update the identification result with the augment of observations.The performance of the proposed algorithm is assessed by simulations.Results show that the proposed algorithm can successfully deduce the aircraft’s identity even if the observations have measurement errors.
文摘准确判别燃爆状态是测量燃爆延滞期并计算爆发点参数的关键。针对单一传感器判别效果不佳、多个传感器判别结果相互冲突的问题,利用D-S(Dempster-Shafer)证据理论对冲突证据进行联合判别。首先根据含能材料燃爆特性和爆发点测试原理,设计了基于温度和声音的联合判别装置;从实验数据出发,采用模型拟合提取温度特征值,以及声音信号最大值为声音特征值。其次,根据Sigmoid模型求解出BPA(Basic Probability Assignment)函数,并通过信度熵对可能存在冲突的BPA函数值进行预处理;最终,利用D-S证据理论进行燃爆状态联合判别。实验结果表明,所提方法有效提高了实验装置的鲁棒性和状态判别的置信概率,燃爆判别准确率达到了96.5%,优于温度、声音等单一传感器的判别效果。
文摘位于谐振区的雷达目标可由极点特征进行识别,但极点特征的物理意义及其对应的谐振机理并不明确。针对该问题,本文利用一致性几何绕射理论(uniform geometrical theory of diffraction,UTD),研究了曲面绕射的谐振机理,并提出了一种用于谐振区含曲面目标识别的极点正向推算方法。首先,用投影递推寻迹算法在目标表面获取爬行波的闭合路径及几何参数;然后,基于UTD给出曲面绕射场表达式,推导出用于预测极点的谐振方程;最后,通过对理想导体球及椭球进行极点预测,与频域仿真提取的极点进行对比,综合误差在5%以内,验证了建模方法的准确性。
