To overcome the shortcomings of the traditional artificial potential field method in mobile robot path planning, an improved artificial potential field model （IAPFM） was established, then a new path planning method ...To overcome the shortcomings of the traditional artificial potential field method in mobile robot path planning, an improved artificial potential field model （IAPFM） was established, then a new path planning method combining the IAPFM with optimization algorithm （trust region algorithm） is proposed. Attractive force between the robot and the target location, and repulsive force between the robot and the obstacles are both converted to the potential field intensity; and filled potential field is used to guide the robot to go out of the local minimum points ; on this basis, the effect of dynamic obstacles velocity and the robot＇s velocity is consid thers and the IAPFM is established, then both the expressions of the attractive potential field and the repulsive potential field are obtained. The trust region algorithm is used to search the minimum value of the sum of all the potential field inten- sities within the movement scope which the robot can arrive in a sampling period. Connecting of all the points which hare the minimum intensity in every sampling period constitutes the global optimization path. Experiment result shows that the method can meet the real-time requirement, and is able to execute the mobile robot path planning task effectively in the dynamic environment.展开更多
The authors state briefly the possibility of various simulators to handle propagation of electromagnetic waves along some interconnections, in 3D RF （Radio Frequency） circuits. The studies are first derived in the t...The authors state briefly the possibility of various simulators to handle propagation of electromagnetic waves along some interconnections, in 3D RF （Radio Frequency） circuits. The studies are first derived in the time domain： a Finite-Difference Time-Domain method is applied, taking spectra via FFTs （Fast Fourier Transform） as post-processors. Electric and magnetic field distributions, pulse propagations along stripline structures or vias are highlighted. The scattering parameters for various cases are extracted and compared. Some original issue of this work is an insight on crosstalk or shielding phenomena between lines.展开更多
To enhance electric fields around nanorods,a Ag nanorod-groove system is presented and its electric field distribution is studied using the finite difference time domain method.Since the superposition of the electric ...To enhance electric fields around nanorods,a Ag nanorod-groove system is presented and its electric field distribution is studied using the finite difference time domain method.Since the superposition of the electric fields of the split multi-beam of light works as excitation for electron oscillations in the nanorods,enhanced electric fields occur around the nanorods.In addition,the effects of topological parameters of the nanorod-groove system,such as the oblique angle of the groove,displacement of the nanorod to the bottom of the groove,and separation between the nanorods on electric field distributions are also studied.These results may be helpful for designing substrates to obtain larger electric fields around nanorods.展开更多
基金Supported by the National High Technology Research and Development Programme of China（ No. 2006AA04Z245 ） and China Postdoctoral Science Foundation （ No. 200904500988 ）.
文摘To overcome the shortcomings of the traditional artificial potential field method in mobile robot path planning, an improved artificial potential field model （IAPFM） was established, then a new path planning method combining the IAPFM with optimization algorithm （trust region algorithm） is proposed. Attractive force between the robot and the target location, and repulsive force between the robot and the obstacles are both converted to the potential field intensity; and filled potential field is used to guide the robot to go out of the local minimum points ; on this basis, the effect of dynamic obstacles velocity and the robot＇s velocity is consid thers and the IAPFM is established, then both the expressions of the attractive potential field and the repulsive potential field are obtained. The trust region algorithm is used to search the minimum value of the sum of all the potential field inten- sities within the movement scope which the robot can arrive in a sampling period. Connecting of all the points which hare the minimum intensity in every sampling period constitutes the global optimization path. Experiment result shows that the method can meet the real-time requirement, and is able to execute the mobile robot path planning task effectively in the dynamic environment.
文摘The authors state briefly the possibility of various simulators to handle propagation of electromagnetic waves along some interconnections, in 3D RF （Radio Frequency） circuits. The studies are first derived in the time domain： a Finite-Difference Time-Domain method is applied, taking spectra via FFTs （Fast Fourier Transform） as post-processors. Electric and magnetic field distributions, pulse propagations along stripline structures or vias are highlighted. The scattering parameters for various cases are extracted and compared. Some original issue of this work is an insight on crosstalk or shielding phenomena between lines.
基金supported by the National Natural Science Foundation of China (Grant No. 11004160)
文摘To enhance electric fields around nanorods,a Ag nanorod-groove system is presented and its electric field distribution is studied using the finite difference time domain method.Since the superposition of the electric fields of the split multi-beam of light works as excitation for electron oscillations in the nanorods,enhanced electric fields occur around the nanorods.In addition,the effects of topological parameters of the nanorod-groove system,such as the oblique angle of the groove,displacement of the nanorod to the bottom of the groove,and separation between the nanorods on electric field distributions are also studied.These results may be helpful for designing substrates to obtain larger electric fields around nanorods.
