The fractal curve is proposed as a novel scanning path used in Layered Manufacturing. Aiming at a limitation that the fractal curve can only fill a square region, a method is developed to realize the trimming of frac...The fractal curve is proposed as a novel scanning path used in Layered Manufacturing. Aiming at a limitation that the fractal curve can only fill a square region, a method is developed to realize the trimming of fractal curve in arbitrary boundary layer by means of judging intersection points between parameterized arbitrary boundary and a FASS (space filling, self avoiding, simple and self similar) fractal curve. Accordingly, the related algorithm concerning with determining intersection points has been investigated according to the recursion feature of the fractal curve, and in the process of the fractal curve traversed, the rule of judging intersection points is ascertained as well, so that the laser scanning beam can “walk” along the fractal curve inside the desired boundary, and arbitrary contour components are fabricated.展开更多
论文提出了一种基于接收信号强度(Received Signal Strength,RSS)的测向交叉定位方法,解决无源测向交叉定位中的虚假点问题.首先推导了阵列协方差矩阵中接收信号强度与阵列流型之间的关系,利用协方差逆矩阵高阶幂逼近噪声子空间的特点,...论文提出了一种基于接收信号强度(Received Signal Strength,RSS)的测向交叉定位方法,解决无源测向交叉定位中的虚假点问题.首先推导了阵列协方差矩阵中接收信号强度与阵列流型之间的关系,利用协方差逆矩阵高阶幂逼近噪声子空间的特点,在已知阵列流型基础上准确获取各来波的信号强度,解决了同一信道多来波的RSS估计问题;然后运用电磁波传播相关理论,根据接收信号强度和传播路径衰减参数的关系判定各定位点的置信度,排除了虚假点.所提算法对存在一定角度估计误差、低信噪比等情况具有很好的鲁棒性,仿真结果验证了该算法的有效性和可行性.展开更多
文摘The fractal curve is proposed as a novel scanning path used in Layered Manufacturing. Aiming at a limitation that the fractal curve can only fill a square region, a method is developed to realize the trimming of fractal curve in arbitrary boundary layer by means of judging intersection points between parameterized arbitrary boundary and a FASS (space filling, self avoiding, simple and self similar) fractal curve. Accordingly, the related algorithm concerning with determining intersection points has been investigated according to the recursion feature of the fractal curve, and in the process of the fractal curve traversed, the rule of judging intersection points is ascertained as well, so that the laser scanning beam can “walk” along the fractal curve inside the desired boundary, and arbitrary contour components are fabricated.
文摘论文提出了一种基于接收信号强度(Received Signal Strength,RSS)的测向交叉定位方法,解决无源测向交叉定位中的虚假点问题.首先推导了阵列协方差矩阵中接收信号强度与阵列流型之间的关系,利用协方差逆矩阵高阶幂逼近噪声子空间的特点,在已知阵列流型基础上准确获取各来波的信号强度,解决了同一信道多来波的RSS估计问题;然后运用电磁波传播相关理论,根据接收信号强度和传播路径衰减参数的关系判定各定位点的置信度,排除了虚假点.所提算法对存在一定角度估计误差、低信噪比等情况具有很好的鲁棒性,仿真结果验证了该算法的有效性和可行性.
