信道估计是正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)技术数据解调与均衡的基础,文章在分析电力线信道特性的基础上,分析了采用离散导频技术的信道估计算法的性能,针对其抗噪声干扰能力弱的特点,提出了通过截短...信道估计是正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)技术数据解调与均衡的基础,文章在分析电力线信道特性的基础上,分析了采用离散导频技术的信道估计算法的性能,针对其抗噪声干扰能力弱的特点,提出了通过截短时域冲击响应长度来提高估计精度的算法。在电力线信道环境下的仿真计算证明了该算法具有良好的估计性能。展开更多
在无线直放站反馈干扰抵消的过程中,自适应滤波器的误差信号可以接收目标信号与残余回波的混合,是阻碍滤波器根据残余回波强度,快速调整抽头系数.利用误差信号的特点,给出了一种基于信噪比的改进变步长最小均平方(least mean square,LMS...在无线直放站反馈干扰抵消的过程中,自适应滤波器的误差信号可以接收目标信号与残余回波的混合,是阻碍滤波器根据残余回波强度,快速调整抽头系数.利用误差信号的特点,给出了一种基于信噪比的改进变步长最小均平方(least mean square,LMS)自适应算法.该算法利用误差信号和滤波器的输出信号作为目标信号和反馈干扰信号的估计,根据目标与干扰信号的功率比值来调整自适应滤波器的步长.计算机仿真结果表明,该算法具有快速的初始收敛速率和较小的超量均方误差.在稳态情况下,对于干扰的突变能够快速地再次收敛,表明该算法在反馈干扰抵消方面的性能优于已有的算法.展开更多
针对三维点云数据中存在的异常点会对平面拟合过程产生不利的影响,提出了一种将最小平方中值算法(Least Median of Squares,LMedS)与特征值法相结合的点云平面拟合新方法。首先,通过LMedS算法进行多次迭代确定最佳阈值并剔除点云数据中...针对三维点云数据中存在的异常点会对平面拟合过程产生不利的影响,提出了一种将最小平方中值算法(Least Median of Squares,LMedS)与特征值法相结合的点云平面拟合新方法。首先,通过LMedS算法进行多次迭代确定最佳阈值并剔除点云数据中的异常点。然后,采用特征值法对剔除完异常点后的点云数据进行平面拟合,以获得更加精确的拟合平面参数解。最后,分别采用最小二乘法、特征值法、RANSAC+主成分分析法与所提出方法对仿真和实测点云数据进行平面拟合计算。实验结果表明,相比于其他方法,该方法的平面拟合精度更高,适用于对含有异常点的点云数据进行平面拟合,具有较高的鲁棒性。展开更多
In order to characterize the voltage behavior of a lithium-ion battery for on-board electric vehicle battery management and control applications,a battery model with a moderate complexity was established.The battery o...In order to characterize the voltage behavior of a lithium-ion battery for on-board electric vehicle battery management and control applications,a battery model with a moderate complexity was established.The battery open circuit voltage (OCV) as a function of state of charge (SOC) was depicted by the Nernst equation.An equivalent circuit network was adopted to describe the polarization effect of the lithium-ion battery.A linear identifiable formulation of the battery model was derived by discretizing the frequent-domain description of the battery model.The recursive least square algorithm with forgetting was applied to implement the on-line parameter calibration.The validation results show that the on-line calibrated model can accurately predict the dynamic voltage behavior of the lithium-ion battery.The maximum and mean relative errors are 1.666% and 0.01%,respectively,in a hybrid pulse test,while 1.933% and 0.062%,respectively,in a transient power test.The on-line parameter calibration method thereby can ensure that the model possesses an acceptable robustness to varied battery loading profiles.展开更多
This paper provides theoretical foundation tor the problem ot localization in multi-robot formations. Sufficient and necessary conditions for completely localizing a formation of mobile robots/vehicles in SE(2) based ...This paper provides theoretical foundation tor the problem ot localization in multi-robot formations. Sufficient and necessary conditions for completely localizing a formation of mobile robots/vehicles in SE(2) based on distributed sensor networks and graph rigidity are proposed. A method for estimating the quality of localizations via a linearized weighted least-squares algorithm is presented, which considers incomplete and noisy sensory information. The approach in this paper had been implemented in a multi-robot system of five car-like robots equipped with omni-directional cameras and IEEE 802.11b wireless network.展开更多
Based on the idea of the set-membership identification,a modified recursive least squares algorithm with variable gain, variable forgetting factor and resetting is presented.The concept of the error tolerance level is...Based on the idea of the set-membership identification,a modified recursive least squares algorithm with variable gain, variable forgetting factor and resetting is presented.The concept of the error tolerance level is proposed.The selection criteria of the error tolerance level are also given according to the min-max principle.The algorithm is particularly suitable for tracing time-varying systems and is similar in computational complexity to the standard recursive least squares algorithm.The superior performance of the algorithm is verified via simulation studies on a dynamic fermentation process.展开更多
文摘信道估计是正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)技术数据解调与均衡的基础,文章在分析电力线信道特性的基础上,分析了采用离散导频技术的信道估计算法的性能,针对其抗噪声干扰能力弱的特点,提出了通过截短时域冲击响应长度来提高估计精度的算法。在电力线信道环境下的仿真计算证明了该算法具有良好的估计性能。
文摘在无线直放站反馈干扰抵消的过程中,自适应滤波器的误差信号可以接收目标信号与残余回波的混合,是阻碍滤波器根据残余回波强度,快速调整抽头系数.利用误差信号的特点,给出了一种基于信噪比的改进变步长最小均平方(least mean square,LMS)自适应算法.该算法利用误差信号和滤波器的输出信号作为目标信号和反馈干扰信号的估计,根据目标与干扰信号的功率比值来调整自适应滤波器的步长.计算机仿真结果表明,该算法具有快速的初始收敛速率和较小的超量均方误差.在稳态情况下,对于干扰的突变能够快速地再次收敛,表明该算法在反馈干扰抵消方面的性能优于已有的算法.
文摘针对三维点云数据中存在的异常点会对平面拟合过程产生不利的影响,提出了一种将最小平方中值算法(Least Median of Squares,LMedS)与特征值法相结合的点云平面拟合新方法。首先,通过LMedS算法进行多次迭代确定最佳阈值并剔除点云数据中的异常点。然后,采用特征值法对剔除完异常点后的点云数据进行平面拟合,以获得更加精确的拟合平面参数解。最后,分别采用最小二乘法、特征值法、RANSAC+主成分分析法与所提出方法对仿真和实测点云数据进行平面拟合计算。实验结果表明,相比于其他方法,该方法的平面拟合精度更高,适用于对含有异常点的点云数据进行平面拟合,具有较高的鲁棒性。
基金Project(50905015) supported by the National Natural Science Foundation of China
文摘In order to characterize the voltage behavior of a lithium-ion battery for on-board electric vehicle battery management and control applications,a battery model with a moderate complexity was established.The battery open circuit voltage (OCV) as a function of state of charge (SOC) was depicted by the Nernst equation.An equivalent circuit network was adopted to describe the polarization effect of the lithium-ion battery.A linear identifiable formulation of the battery model was derived by discretizing the frequent-domain description of the battery model.The recursive least square algorithm with forgetting was applied to implement the on-line parameter calibration.The validation results show that the on-line calibrated model can accurately predict the dynamic voltage behavior of the lithium-ion battery.The maximum and mean relative errors are 1.666% and 0.01%,respectively,in a hybrid pulse test,while 1.933% and 0.062%,respectively,in a transient power test.The on-line parameter calibration method thereby can ensure that the model possesses an acceptable robustness to varied battery loading profiles.
文摘This paper provides theoretical foundation tor the problem ot localization in multi-robot formations. Sufficient and necessary conditions for completely localizing a formation of mobile robots/vehicles in SE(2) based on distributed sensor networks and graph rigidity are proposed. A method for estimating the quality of localizations via a linearized weighted least-squares algorithm is presented, which considers incomplete and noisy sensory information. The approach in this paper had been implemented in a multi-robot system of five car-like robots equipped with omni-directional cameras and IEEE 802.11b wireless network.
文摘Based on the idea of the set-membership identification,a modified recursive least squares algorithm with variable gain, variable forgetting factor and resetting is presented.The concept of the error tolerance level is proposed.The selection criteria of the error tolerance level are also given according to the min-max principle.The algorithm is particularly suitable for tracing time-varying systems and is similar in computational complexity to the standard recursive least squares algorithm.The superior performance of the algorithm is verified via simulation studies on a dynamic fermentation process.
