A dual laser radar based path planning method for mobile robot in general outdoor road environment is proposed. Firstly, the point-wise sequence and target library of the global optimal path are generated based on alg...A dual laser radar based path planning method for mobile robot in general outdoor road environment is proposed. Firstly, the point-wise sequence and target library of the global optimal path are generated based on algorithm A*. Secondly, the local target information and the perceptive information from dual laser radar are combined, and the different field information from both horizontal and aslant fixed laser radars is fused. Finally, the optimal driving angle is computed by the improved angle potential field(APF)algorithm. The practical experiment results validate the robustness and timeliness of the proposed approach.展开更多
A fold optical path is utilized to capture and launch atoms in the atomic fountain. This improved technique reduces the laser power needed by 60 percent, facilitates suppression of the laser power fluctuations, and le...A fold optical path is utilized to capture and launch atoms in the atomic fountain. This improved technique reduces the laser power needed by 60 percent, facilitates suppression of the laser power fluctuations, and leads to a more simple and stable system.展开更多
A seed laser oscillating at different frequencies is proved to have the potential to mitigate the stimulated Brillouin scattering（SBS） effect in a fiber amplifier,which may increase the emission power of a coherent ...A seed laser oscillating at different frequencies is proved to have the potential to mitigate the stimulated Brillouin scattering（SBS） effect in a fiber amplifier,which may increase the emission power of a coherent beam combination（CBC） system greatly.In this study,a basic mathematical model describing the multi-wavelength CBC is proposed on the fundamentals of CBC.A useful method for estimating the combination effect and analysing the feasibility and the validity of the multi-wavelength coherent combination is provided.In the numerical analysis,accordant results with four-wavelength four-channel CBC experiments are obtained.Through calculations of some examples with certain spectra,the unanticipated excellent combination effect with a few frequencies involved is explained,and the dependence of the combination effect on the variance of the amplifier chain length and the channel number is clarified.展开更多
We theoretically investigate the quantum path selection in an ultraviolet （UV）-assisted near-infrared field with an UV energy below the ionization threshold. By calculating the ionization probability with different ...We theoretically investigate the quantum path selection in an ultraviolet （UV）-assisted near-infrared field with an UV energy below the ionization threshold. By calculating the ionization probability with different assistant UV frequencies, we find that a resonance-enhanced ionization peak emerges in the region Euv 〈 Ip, where Euv is the photon energy and Ip is the ionization energy. With an attosecond pulse train （APT） centered in the resonance region, we show that the short quantum path can be well selected in the continuum case. By performing the electron trajectory analysis, we have further explained the physical mechanism of the quantum path selection. Moreover, we also demonstrate that in the resonance region, the harmonic emission from the selected paths is more efficient than that with the APT energy above the ionization threshold.展开更多
基金National Natural Science Foundations of China (No. 90820304,No. 61075027)
文摘A dual laser radar based path planning method for mobile robot in general outdoor road environment is proposed. Firstly, the point-wise sequence and target library of the global optimal path are generated based on algorithm A*. Secondly, the local target information and the perceptive information from dual laser radar are combined, and the different field information from both horizontal and aslant fixed laser radars is fused. Finally, the optimal driving angle is computed by the improved angle potential field(APF)algorithm. The practical experiment results validate the robustness and timeliness of the proposed approach.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10974215)the Science Foundation of State Key Laboratory of Precision Spectroscopy,East China Normal University
文摘A fold optical path is utilized to capture and launch atoms in the atomic fountain. This improved technique reduces the laser power needed by 60 percent, facilitates suppression of the laser power fluctuations, and leads to a more simple and stable system.
基金Project supported by the Innovation Foundation for Postgraduates in the National University of Defense Technology,China(Grant No. S090701)
文摘A seed laser oscillating at different frequencies is proved to have the potential to mitigate the stimulated Brillouin scattering（SBS） effect in a fiber amplifier,which may increase the emission power of a coherent beam combination（CBC） system greatly.In this study,a basic mathematical model describing the multi-wavelength CBC is proposed on the fundamentals of CBC.A useful method for estimating the combination effect and analysing the feasibility and the validity of the multi-wavelength coherent combination is provided.In the numerical analysis,accordant results with four-wavelength four-channel CBC experiments are obtained.Through calculations of some examples with certain spectra,the unanticipated excellent combination effect with a few frequencies involved is explained,and the dependence of the combination effect on the variance of the amplifier chain length and the channel number is clarified.
基金Project supported by the National Natural Science Foundation of China(Grant No.11204222)the Natural Science Foundation of Hubei Province,China(Grant Nos.2013CFB316 and 2014CFB793)
文摘We theoretically investigate the quantum path selection in an ultraviolet （UV）-assisted near-infrared field with an UV energy below the ionization threshold. By calculating the ionization probability with different assistant UV frequencies, we find that a resonance-enhanced ionization peak emerges in the region Euv 〈 Ip, where Euv is the photon energy and Ip is the ionization energy. With an attosecond pulse train （APT） centered in the resonance region, we show that the short quantum path can be well selected in the continuum case. By performing the electron trajectory analysis, we have further explained the physical mechanism of the quantum path selection. Moreover, we also demonstrate that in the resonance region, the harmonic emission from the selected paths is more efficient than that with the APT energy above the ionization threshold.
