The satellite laser ranging （SLR） data quality from the COMPASS was analyzed, and the difference between curve recognition in computer vision and pre-process of SLR data finally proposed a new algorithm for SLR was ...The satellite laser ranging （SLR） data quality from the COMPASS was analyzed, and the difference between curve recognition in computer vision and pre-process of SLR data finally proposed a new algorithm for SLR was discussed data based on curve recognition from points cloud is proposed. The results obtained by the new algorithm are 85 % （or even higher） consistent with that of the screen displaying method, furthermore, the new method can process SLR data automatically, which makes it possible to be used in the development of the COMPASS navigation system.展开更多
Abstract Satellite range scheduling with the priority constraint is one of the most important prob lems in the field of satellite operation. This paper proposes a station coding based genetic algorithm to solve this p...Abstract Satellite range scheduling with the priority constraint is one of the most important prob lems in the field of satellite operation. This paper proposes a station coding based genetic algorithm to solve this problem, which adopts a new chromosome encoding method that arranges tasks according to the ground station ID. The new encoding method contributes to reducing the complex ity in conflict checking and resolving, and helps to improve the ability to find optimal resolutions. Three different selection operators are designed to match the new encoding strategy, namely ran dom selection, greedy selection, and roulette selection. To demonstrate the benefits of the improved genetic algorithm, a basic genetic algorithm is designed in which two cross operators are presented, a singlepoint crossover and a multipoint crossover. For the purpose of algorithm test and analysis, a problemgenerating program is designed, which can simulate problems by modeling features encountered in realworld problems. Based on the problem generator, computational results and analysis are made and illustrated for the scheduling of multiple ground stations.展开更多
The traditional Range Doppler(RD)algorithm is unable to meet practical needs owing to the limit of resolution.The order of fractional Fourier Transform(FrFT)and the length of sampling signals affect SAR imaging perfor...The traditional Range Doppler(RD)algorithm is unable to meet practical needs owing to the limit of resolution.The order of fractional Fourier Transform(FrFT)and the length of sampling signals affect SAR imaging performance when FrFT is applied to RD algorithm.To overcome the above shortcomings,the purpose of this paper is to propose a high-resolution SAR image algorithm by using the optimal order of FrFT and the sample length constraints for the range direction.The expression of the optimal order of SAR range signals via FrFT is deduced in detail.The initial sample length and its constraints are proposed to obtain the best sample length of SAR range signals.Experimental results demonstrate that,when the range sampling-length changes in a certain interval,the best sampling-length will be obtained,which the best values of the range resolution,PSLR and ISLR,will be derived respectively.Compared with traditional RD algorithm,the main-lobe width of the peak-point target of the proposed algorithm is narrow in the range direction.While the peak amplitude of the first side-lobe is reduced significantly,those of other side-lobes also drop in various degrees.展开更多
A flying-body is considered as the reference model, the optimized mathematical model is established. The genetic operators are designed and algorithm parameters are selected reasonably. The scheme control signal in sh...A flying-body is considered as the reference model, the optimized mathematical model is established. The genetic operators are designed and algorithm parameters are selected reasonably. The scheme control signal in short range top attack flight trajectory is optimized by using genetic algorithm. The short range top attack trajectory designed meets the design requirements, with the increase of the falling angle and the decrease of the minimum range. The application of genetic algorithm to top attack trajectory optimization is proved to be feasibly and effectively according to the analyses of results.展开更多
The dominant error source of mobile terminal location in wireless sensor networks （WSNs） is the non-line-of-sight （NLOS） propagation error. Among the algorithms proposed to mitigate the influence of NLOS propagati...The dominant error source of mobile terminal location in wireless sensor networks （WSNs） is the non-line-of-sight （NLOS） propagation error. Among the algorithms proposed to mitigate the influence of NLOS propagation error, residual test （RT） is an efficient one, however with high computational complexity （CC）. An improved algorithm that memorizes the light of sight （LOS） range measurements （RMs） identified memorize LOS range measurements identified residual test （MLSI-RT） is presented in this paper to address this problem. The MLSI-RT is based on the assumption that when all RMs are from LOS propagations, the normalized residual follows the central Chi-Square distribution while for NLOS cases it is non-central. This study can reduce the CC by more than 90%.展开更多
Three dimensional(3-D)imaging algorithms with irregular planar multiple-input-multiple-output(MIMO)arrays are discussed and compared with each other.Based on the same MIMO array,a modified back projection algorithm(MB...Three dimensional(3-D)imaging algorithms with irregular planar multiple-input-multiple-output(MIMO)arrays are discussed and compared with each other.Based on the same MIMO array,a modified back projection algorithm(MBPA)is accordingly proposed and four imaging algorithms are used for comparison,back-projection method(BP),back-projection one in time domain(BP-TD),modified back-projection one and fast Fourier transform(FFT)-based MIMO range migration algorithm(FFT-based MIMO RMA).All of the algorithms have been implemented in practical application scenarios by use of the proposed imaging system.Back to the practical applications,MIMO array-based imaging system with wide-bandwidth properties provides an efficient tool to detect objects hidden behind a wall.An MIMO imaging radar system,composed of a vector network analyzer(VNA),a set of switches,and an array of Vivaldi antennas,have been designed,fabricated,and tested.Then,these algorithms have been applied to measured data collected in different scenarios constituted by five metallic spheres in the absence and in the presence of a wall between the antennas and the targets in simulation and pliers in free space for experimental test.Finally,the focusing properties and time consumption of the above algorithms are compared.展开更多
For impulse radio ultra-wideband (IR-UWB) ranging systems,effects of the settings of transmitter-related parameters, which include the pulse shape, the bandwidth and the pulse repetition interval (PRI), on ranging acc...For impulse radio ultra-wideband (IR-UWB) ranging systems,effects of the settings of transmitter-related parameters, which include the pulse shape, the bandwidth and the pulse repetition interval (PRI), on ranging accuracy were studied through theoretical analysis and simulations. Both the match-filtering based coherent TOA estimation algorithm and the energy-detection based non-coherent algorithm were used during simulations. Results show that the pulse shape has the least effect on the ranging accuracy. Increasing the pulse bandwidth can improve the ranging performance, but the performance is hardly improved any more when the bandwidth is increased beyond a certain level. PRI should be set long enough to guarantee the accurate ranging, because when PRI is shorter than the maximum excess delay of the channel, the ranging accuracy will be deteriorated by inter-pulse interference.展开更多
在雷达目标跟踪领域,当目标与雷达传感器存在相对运动时,多普勒(Doppler)效应致使接收信号产生频率偏移。这种频率变化与目标距离测量存在耦合关系,即多普勒距离耦合问题。在相控阵雷达采用线性调频(Linear Frequency Modulation,LFM)...在雷达目标跟踪领域,当目标与雷达传感器存在相对运动时,多普勒(Doppler)效应致使接收信号产生频率偏移。这种频率变化与目标距离测量存在耦合关系,即多普勒距离耦合问题。在相控阵雷达采用线性调频(Linear Frequency Modulation,LFM)信号进行常规跟踪时,虽然能获取大时宽带宽积提升距离分辨率,但脉冲压缩后产生的强距离多普勒耦合效应使传统的距离速度测量算法出现收敛速度慢、精度低的问题,尤其在航迹起始阶段对高速目标的跟踪极为不利,严重影响了雷达系统对目标的实时、精准监测。提出一种多普勒距离耦合下的三帧快速收敛算法。该算法利用3帧具有不同耦合系数的波形,构建多元约束方程,通过联合解算实现多目标速度和位置参数的同步获取。在验证处理流程中,采用迭代优化机制,对测量结果进行动态校准,有效降低距离与速度参数间的相互干扰,逐步逼近最优的距离和速度测量结果,从而实现快速、精准的目标跟踪。通过理论分析、蒙特卡罗仿真和外场实测数据验证,该三帧快速收敛算法展现出优异性能。在航迹起始阶段,对目标距离和速度测量解算的收敛速度是传统算法的4倍以上。所提出的多普勒距离耦合下的三帧快速收敛算法成功地解决了传统算法在处理多普勒距离耦合问题时存在的收敛慢、精度低等难题。该算法具有创新的波形设计和迭代优化策略,显著提升了相控阵雷达在复杂条件下的目标跟踪性能,为雷达目标跟踪技术的发展提供了新的思路和方法,具有较高的理论价值和实际应用前景。展开更多
荷电状态(state of charge,SOC)的准确估计对延长电池寿命、减少事故发生至关重要。针对锂电池系统存在建模误差及宽温度范围下传统方法适应性差的问题,设计一种自适应增益滑模观测器(adaptive gain sliding mode observer,AGSMO)以提...荷电状态(state of charge,SOC)的准确估计对延长电池寿命、减少事故发生至关重要。针对锂电池系统存在建模误差及宽温度范围下传统方法适应性差的问题,设计一种自适应增益滑模观测器(adaptive gain sliding mode observer,AGSMO)以提高宽温域SOC估计精度。采用二阶RC等效电路模型构造适用于AGSMO的状态方程,并结合遗忘因子最小二乘法(forgetting factor recursive least square,FFRLS)完成模型参数辨识。利用等效控制思想构建状态误差的等效表达式,基于此设计滑模观测器,同时采用自适应增益提高收敛速度并抑制抖振。结合案例应用仿真,结果表明:AGSMO在美国联邦城市运行工况FUDS和高加速循环工况US06的不同初值下均可实现SOC的准确估计,并通过上述两种工况验证宽温域环境下AGSMO相较于滑模观测器(sliding mode observer,SMO)、扩展卡尔曼滤波(extended Kalman filter,EKF)具有更好的估计精度及收敛速度,均方根误差不超过0.68%,且在温域两端呈现强鲁棒性。展开更多
针对机载激光雷达(LiDAR)点云数据中因地表形变不规则性与点云离散化特征导致的电力线提取精度不够问题,本文提出了一种基于空间分布特征的电力线提取方法。本文方法采用递进式处理流程。首先,提出一种改进曲面拟合滤波算法,有效实现了...针对机载激光雷达(LiDAR)点云数据中因地表形变不规则性与点云离散化特征导致的电力线提取精度不够问题,本文提出了一种基于空间分布特征的电力线提取方法。本文方法采用递进式处理流程。首先,提出一种改进曲面拟合滤波算法,有效实现了非电力目标的多尺度噪声抑制;其次,以去噪后的点云为基础,利用电力线点维度特征粗提取电力线点,并基于密度聚类算法完成电力线的语义分割;最后,在提取单根电力线的基础上,实现电力线三维几何结构的重建。基于点云库(PCL)和激光雷达航空测量库(libLAS)构建了算法体系,并在Visual Studio 2017 C++环境下完成了工程化实现。实验结果表明,本文方法在典型地理场景下的测试表现出色,电力线提取精确率为97.71%,召回率为99.65%,F1值达98.67%。本文方法实现了电力线要素的单流程自动提取,在保障定位精度的同时,处理效率较传统方法也有较大提升,为输电线路智能化巡检提供了有效的技术支撑。展开更多
文摘The satellite laser ranging （SLR） data quality from the COMPASS was analyzed, and the difference between curve recognition in computer vision and pre-process of SLR data finally proposed a new algorithm for SLR was discussed data based on curve recognition from points cloud is proposed. The results obtained by the new algorithm are 85 % （or even higher） consistent with that of the screen displaying method, furthermore, the new method can process SLR data automatically, which makes it possible to be used in the development of the COMPASS navigation system.
文摘Abstract Satellite range scheduling with the priority constraint is one of the most important prob lems in the field of satellite operation. This paper proposes a station coding based genetic algorithm to solve this problem, which adopts a new chromosome encoding method that arranges tasks according to the ground station ID. The new encoding method contributes to reducing the complex ity in conflict checking and resolving, and helps to improve the ability to find optimal resolutions. Three different selection operators are designed to match the new encoding strategy, namely ran dom selection, greedy selection, and roulette selection. To demonstrate the benefits of the improved genetic algorithm, a basic genetic algorithm is designed in which two cross operators are presented, a singlepoint crossover and a multipoint crossover. For the purpose of algorithm test and analysis, a problemgenerating program is designed, which can simulate problems by modeling features encountered in realworld problems. Based on the problem generator, computational results and analysis are made and illustrated for the scheduling of multiple ground stations.
基金This work is supported by the 13th Five-Year Plan for Jiangsu Education Science(D/2020/01/22)JSPIGKZ and Natural Science Research Projects of Colleges and Universities in Jiangsu Province(19KJB510022)。
文摘The traditional Range Doppler(RD)algorithm is unable to meet practical needs owing to the limit of resolution.The order of fractional Fourier Transform(FrFT)and the length of sampling signals affect SAR imaging performance when FrFT is applied to RD algorithm.To overcome the above shortcomings,the purpose of this paper is to propose a high-resolution SAR image algorithm by using the optimal order of FrFT and the sample length constraints for the range direction.The expression of the optimal order of SAR range signals via FrFT is deduced in detail.The initial sample length and its constraints are proposed to obtain the best sample length of SAR range signals.Experimental results demonstrate that,when the range sampling-length changes in a certain interval,the best sampling-length will be obtained,which the best values of the range resolution,PSLR and ISLR,will be derived respectively.Compared with traditional RD algorithm,the main-lobe width of the peak-point target of the proposed algorithm is narrow in the range direction.While the peak amplitude of the first side-lobe is reduced significantly,those of other side-lobes also drop in various degrees.
文摘A flying-body is considered as the reference model, the optimized mathematical model is established. The genetic operators are designed and algorithm parameters are selected reasonably. The scheme control signal in short range top attack flight trajectory is optimized by using genetic algorithm. The short range top attack trajectory designed meets the design requirements, with the increase of the falling angle and the decrease of the minimum range. The application of genetic algorithm to top attack trajectory optimization is proved to be feasibly and effectively according to the analyses of results.
基金supported by the State Key Program of National Natural Science of China (Grant No.60532030)the New Century Excellent Talents in University (Grant No.NCET-08-0333)the Natural Science Foundation of Shandong Province (Grant No.Y2007G10)
文摘The dominant error source of mobile terminal location in wireless sensor networks （WSNs） is the non-line-of-sight （NLOS） propagation error. Among the algorithms proposed to mitigate the influence of NLOS propagation error, residual test （RT） is an efficient one, however with high computational complexity （CC）. An improved algorithm that memorizes the light of sight （LOS） range measurements （RMs） identified memorize LOS range measurements identified residual test （MLSI-RT） is presented in this paper to address this problem. The MLSI-RT is based on the assumption that when all RMs are from LOS propagations, the normalized residual follows the central Chi-Square distribution while for NLOS cases it is non-central. This study can reduce the CC by more than 90%.
基金National Natural Science Foundation of China(No.62293493)。
文摘Three dimensional(3-D)imaging algorithms with irregular planar multiple-input-multiple-output(MIMO)arrays are discussed and compared with each other.Based on the same MIMO array,a modified back projection algorithm(MBPA)is accordingly proposed and four imaging algorithms are used for comparison,back-projection method(BP),back-projection one in time domain(BP-TD),modified back-projection one and fast Fourier transform(FFT)-based MIMO range migration algorithm(FFT-based MIMO RMA).All of the algorithms have been implemented in practical application scenarios by use of the proposed imaging system.Back to the practical applications,MIMO array-based imaging system with wide-bandwidth properties provides an efficient tool to detect objects hidden behind a wall.An MIMO imaging radar system,composed of a vector network analyzer(VNA),a set of switches,and an array of Vivaldi antennas,have been designed,fabricated,and tested.Then,these algorithms have been applied to measured data collected in different scenarios constituted by five metallic spheres in the absence and in the presence of a wall between the antennas and the targets in simulation and pliers in free space for experimental test.Finally,the focusing properties and time consumption of the above algorithms are compared.
基金Sponsored by the National Natural Science Foundation of China (Grant No.60432040)the Natural Science Foundation of Guangdong Privince(Grant No.9451805707003235)
文摘For impulse radio ultra-wideband (IR-UWB) ranging systems,effects of the settings of transmitter-related parameters, which include the pulse shape, the bandwidth and the pulse repetition interval (PRI), on ranging accuracy were studied through theoretical analysis and simulations. Both the match-filtering based coherent TOA estimation algorithm and the energy-detection based non-coherent algorithm were used during simulations. Results show that the pulse shape has the least effect on the ranging accuracy. Increasing the pulse bandwidth can improve the ranging performance, but the performance is hardly improved any more when the bandwidth is increased beyond a certain level. PRI should be set long enough to guarantee the accurate ranging, because when PRI is shorter than the maximum excess delay of the channel, the ranging accuracy will be deteriorated by inter-pulse interference.
文摘在雷达目标跟踪领域,当目标与雷达传感器存在相对运动时,多普勒(Doppler)效应致使接收信号产生频率偏移。这种频率变化与目标距离测量存在耦合关系,即多普勒距离耦合问题。在相控阵雷达采用线性调频(Linear Frequency Modulation,LFM)信号进行常规跟踪时,虽然能获取大时宽带宽积提升距离分辨率,但脉冲压缩后产生的强距离多普勒耦合效应使传统的距离速度测量算法出现收敛速度慢、精度低的问题,尤其在航迹起始阶段对高速目标的跟踪极为不利,严重影响了雷达系统对目标的实时、精准监测。提出一种多普勒距离耦合下的三帧快速收敛算法。该算法利用3帧具有不同耦合系数的波形,构建多元约束方程,通过联合解算实现多目标速度和位置参数的同步获取。在验证处理流程中,采用迭代优化机制,对测量结果进行动态校准,有效降低距离与速度参数间的相互干扰,逐步逼近最优的距离和速度测量结果,从而实现快速、精准的目标跟踪。通过理论分析、蒙特卡罗仿真和外场实测数据验证,该三帧快速收敛算法展现出优异性能。在航迹起始阶段,对目标距离和速度测量解算的收敛速度是传统算法的4倍以上。所提出的多普勒距离耦合下的三帧快速收敛算法成功地解决了传统算法在处理多普勒距离耦合问题时存在的收敛慢、精度低等难题。该算法具有创新的波形设计和迭代优化策略,显著提升了相控阵雷达在复杂条件下的目标跟踪性能,为雷达目标跟踪技术的发展提供了新的思路和方法,具有较高的理论价值和实际应用前景。
文摘荷电状态(state of charge,SOC)的准确估计对延长电池寿命、减少事故发生至关重要。针对锂电池系统存在建模误差及宽温度范围下传统方法适应性差的问题,设计一种自适应增益滑模观测器(adaptive gain sliding mode observer,AGSMO)以提高宽温域SOC估计精度。采用二阶RC等效电路模型构造适用于AGSMO的状态方程,并结合遗忘因子最小二乘法(forgetting factor recursive least square,FFRLS)完成模型参数辨识。利用等效控制思想构建状态误差的等效表达式,基于此设计滑模观测器,同时采用自适应增益提高收敛速度并抑制抖振。结合案例应用仿真,结果表明:AGSMO在美国联邦城市运行工况FUDS和高加速循环工况US06的不同初值下均可实现SOC的准确估计,并通过上述两种工况验证宽温域环境下AGSMO相较于滑模观测器(sliding mode observer,SMO)、扩展卡尔曼滤波(extended Kalman filter,EKF)具有更好的估计精度及收敛速度,均方根误差不超过0.68%,且在温域两端呈现强鲁棒性。
文摘针对机载激光雷达(LiDAR)点云数据中因地表形变不规则性与点云离散化特征导致的电力线提取精度不够问题,本文提出了一种基于空间分布特征的电力线提取方法。本文方法采用递进式处理流程。首先,提出一种改进曲面拟合滤波算法,有效实现了非电力目标的多尺度噪声抑制;其次,以去噪后的点云为基础,利用电力线点维度特征粗提取电力线点,并基于密度聚类算法完成电力线的语义分割;最后,在提取单根电力线的基础上,实现电力线三维几何结构的重建。基于点云库(PCL)和激光雷达航空测量库(libLAS)构建了算法体系,并在Visual Studio 2017 C++环境下完成了工程化实现。实验结果表明,本文方法在典型地理场景下的测试表现出色,电力线提取精确率为97.71%,召回率为99.65%,F1值达98.67%。本文方法实现了电力线要素的单流程自动提取,在保障定位精度的同时,处理效率较传统方法也有较大提升,为输电线路智能化巡检提供了有效的技术支撑。
