针对农业温室环境中,由于超宽带(Ultra-wideband,UWB)定位技术干扰免疫差和统计特性未知而面临定位精度不足的问题,本文提出一种基于改进自适应卡尔曼滤波(Improved adaptive Kalman filter,IAKF)算法的UWB定位技术。首先,引入异常检测...针对农业温室环境中,由于超宽带(Ultra-wideband,UWB)定位技术干扰免疫差和统计特性未知而面临定位精度不足的问题,本文提出一种基于改进自适应卡尔曼滤波(Improved adaptive Kalman filter,IAKF)算法的UWB定位技术。首先,引入异常检测机制,以识别滤波过程中的发散现象;进而,通过实时更新量测噪声协方差矩阵,抑制滤波发散,在噪声强波动情况下增强算法适应性;同时,开展3种不同环境噪声下仿真定位试验,对比分析UWB、IAKF、自适应卡尔曼滤波(Adaptive Kalman filter,AKF)及卡尔曼滤波(Kalman filter,KF)算法性能。仿真结果表明,IAKF算法展现出更强的适应性及鲁棒性。以自主开发农用履带车辆为定位载体,于农业温室环境中开展UWB定位试验。试验结果表明,温室环境中,履带车辆在视距(Line of sight,LOS)和非视距(Non line of sight,NLOS)场景下,较AKF和KF算法,IAKF算法定位精度分别提高22.2%、13.0%和20.0%、15.4%。展开更多
The experimental study of ultra-wideband (UWB) technology, its generation and on-line measurement are presented. An experimental repetitive UWB system is designed, manufactured, and tested. High-pressure spark gap swi...The experimental study of ultra-wideband (UWB) technology, its generation and on-line measurement are presented. An experimental repetitive UWB system is designed, manufactured, and tested. High-pressure spark gap switch and its components, as well as oil spark gap switch are studied experimentally on the system. Experimental results indicate that the system operates at a 200 pps repetitive rate with a stable performance. 100 MW peak power UWB pulses are obtained on the system. Fast-time response capacitive divider is designed and fabricated, allowing for an accurate measurement of the high power UWB signal. The main issues related to the design of the switch and the UWB signal online measurement are discussed.展开更多
Based on the analysis of impulse response properties, a scattering model of ultra wideband （UWB） radar targets is developed to estimate the target parameters exactly. With this model, two algorithms of multiple sign...Based on the analysis of impulse response properties, a scattering model of ultra wideband （UWB） radar targets is developed to estimate the target parameters exactly. With this model, two algorithms of multiple signal classification （MUSIC）, and matrix pencil （MP）, are introduced to calculate the scattering center parameters of targets and their performances are compared. The simulation experiments show that there are no differences in the estimation precision of MUSIC and MP methods when the signal-to-noise ratio （SNR） is larger than 13 dB. However, the MP method has a better performance than that of MUSIC method when the SNR is smaller than 13 dB. Besides, the time consuming of MP method is less than that of MUSIC method. Therefore, the MP algorithm is preferred for the parametric estimation of UWB radar targets.展开更多
To suppress the interference in the ultra-wideband （AI-UWB） system is a challenging problem. An anti-interference multiband orthogonal frequency-division multiplexing ultra-wideband （AI-UWB） system, based on sprea...To suppress the interference in the ultra-wideband （AI-UWB） system is a challenging problem. An anti-interference multiband orthogonal frequency-division multiplexing ultra-wideband （AI-UWB） system, based on spreading and interleaving is addressed. It will exploit the frequency diversity across the subcarriers and provide the robustness to narrow-band interference, by spreading the coded bit streams within each sub-band and interleaving across all sub-bands. Simulating results show that the spreading and interleaving provide about 5 dB to 10 dB advantages over the conventional multiband orthogonal frequency-division multiplexing ultra-wideband system in signal-to-interference ratio. Spreading and interleaving is an effective cure for enhancing the robustness to narrowband interference.展开更多
文摘针对农业温室环境中,由于超宽带(Ultra-wideband,UWB)定位技术干扰免疫差和统计特性未知而面临定位精度不足的问题,本文提出一种基于改进自适应卡尔曼滤波(Improved adaptive Kalman filter,IAKF)算法的UWB定位技术。首先,引入异常检测机制,以识别滤波过程中的发散现象;进而,通过实时更新量测噪声协方差矩阵,抑制滤波发散,在噪声强波动情况下增强算法适应性;同时,开展3种不同环境噪声下仿真定位试验,对比分析UWB、IAKF、自适应卡尔曼滤波(Adaptive Kalman filter,AKF)及卡尔曼滤波(Kalman filter,KF)算法性能。仿真结果表明,IAKF算法展现出更强的适应性及鲁棒性。以自主开发农用履带车辆为定位载体,于农业温室环境中开展UWB定位试验。试验结果表明,温室环境中,履带车辆在视距(Line of sight,LOS)和非视距(Non line of sight,NLOS)场景下,较AKF和KF算法,IAKF算法定位精度分别提高22.2%、13.0%和20.0%、15.4%。
文摘The experimental study of ultra-wideband (UWB) technology, its generation and on-line measurement are presented. An experimental repetitive UWB system is designed, manufactured, and tested. High-pressure spark gap switch and its components, as well as oil spark gap switch are studied experimentally on the system. Experimental results indicate that the system operates at a 200 pps repetitive rate with a stable performance. 100 MW peak power UWB pulses are obtained on the system. Fast-time response capacitive divider is designed and fabricated, allowing for an accurate measurement of the high power UWB signal. The main issues related to the design of the switch and the UWB signal online measurement are discussed.
基金supported by the Aerospace Science and Technology Foundation of China(2007CH080004).
文摘Based on the analysis of impulse response properties, a scattering model of ultra wideband （UWB） radar targets is developed to estimate the target parameters exactly. With this model, two algorithms of multiple signal classification （MUSIC）, and matrix pencil （MP）, are introduced to calculate the scattering center parameters of targets and their performances are compared. The simulation experiments show that there are no differences in the estimation precision of MUSIC and MP methods when the signal-to-noise ratio （SNR） is larger than 13 dB. However, the MP method has a better performance than that of MUSIC method when the SNR is smaller than 13 dB. Besides, the time consuming of MP method is less than that of MUSIC method. Therefore, the MP algorithm is preferred for the parametric estimation of UWB radar targets.
基金the National "863" High Technology Research Program of China (2005AA123320)Universities Natural Science Research Project of Jiangsu Province (05KJB510101).
文摘To suppress the interference in the ultra-wideband （AI-UWB） system is a challenging problem. An anti-interference multiband orthogonal frequency-division multiplexing ultra-wideband （AI-UWB） system, based on spreading and interleaving is addressed. It will exploit the frequency diversity across the subcarriers and provide the robustness to narrow-band interference, by spreading the coded bit streams within each sub-band and interleaving across all sub-bands. Simulating results show that the spreading and interleaving provide about 5 dB to 10 dB advantages over the conventional multiband orthogonal frequency-division multiplexing ultra-wideband system in signal-to-interference ratio. Spreading and interleaving is an effective cure for enhancing the robustness to narrowband interference.
