This article deals with a problem of the robot localization in the outdoor environment by using the GPS （global positioning system） data. In order to navigate the robot, it is necessary to transform the global posit...This article deals with a problem of the robot localization in the outdoor environment by using the GPS （global positioning system） data. In order to navigate the robot, it is necessary to transform the global position into the local map in the form of two-dimensional Cartesian coordinate system. The transformation is based on the model of the Earth-WGS 84 reference ellipsoid. The aim of this article is to experimentally evaluate a set of low-cost GPS receivers applicable as position sensors for small outdoor mobile robots. The evaluation is based on series of measurements executed in different times and places. The measured data is processed by given procedure and acquired positions are transformed into the local coordinate system. Accordingly the accuracy of the measured positions is statistically evaluated. The evaluation of used GPS receivers is done by comparison with data acquired by high-end geodetic GPS system Leica 1200, which is used as a reference GPS system.展开更多
For the missile with passive seeker,the improvement of passive ranger's precision is one of the key issues in development of the defense penetrate strategy. On the offensive warheads,the infrared imaging device wa...For the missile with passive seeker,the improvement of passive ranger's precision is one of the key issues in development of the defense penetrate strategy. On the offensive warheads,the infrared imaging device was used to measure the line-of-sight angle information of the blocker,and then using the algorithm of Kalman Filter under polar coordinates,the distance from the blocker to the warheads was obtained. The simulation result under polar coordinates was compared with that of Cartesian coordinate. The validity of the method was analyzed,and the schemes of improvement were brought out.展开更多
[Objective]The aim was to introduce T-DNA into watermelon for its molecular marker research.[Method]Based on the method of foreign DNA introduced to Arabidopsis thaliana via dipping flowers,the stigma smear was used t...[Objective]The aim was to introduce T-DNA into watermelon for its molecular marker research.[Method]Based on the method of foreign DNA introduced to Arabidopsis thaliana via dipping flowers,the stigma smear was used to transfer T-DNA into watermelon and its molecular marker research was carried out.[Result]The ideal transformed species was ZXG01078 for the highest fruit setting rate and the most deviant seedlings.The best concentration of kanamycin for treating watermelon seeds was 500-700 mg/L with differences among the species.The best position was spire leaf or young leaf and the best concentration of kanamycin for treating the watermelon leaf was 4 000-8 000 mg/L with no significant difference among species.The steadily variation appearing of growing pointless and conjoined twin seedlings indicated that the normal growth had been interfered by foreign DNA in the progeny.[Conclusion]This study had provided basis for the further research on watermelon.展开更多
A new filtering method is proposed to accurately estimate target state via decreasing the nonlinearity between radar polar measurements(or spherical measurements in three-dimensional(3D) radar) and target position in ...A new filtering method is proposed to accurately estimate target state via decreasing the nonlinearity between radar polar measurements(or spherical measurements in three-dimensional(3D) radar) and target position in Cartesian coordinate. The degree of linearity is quantified here by utilizing correlation coefficient and Taylor series expansion. With the proposed method, the original measurements are converted from polar or spherical coordinate to a carefully chosen Cartesian coordinate system that is obtained by coordinate rotation transformation to maximize the linearity degree of the conversion function from polar/spherical to Cartesian coordinate. Then the target state is filtered along each axis of the chosen Cartesian coordinate. This method is compared with extended Kalman filter(EKF), Converted Measurement Kalman filter(CMKF), unscented Kalman filter(UKF) as well as Decoupled Converted Measurement Kalman filter(DECMKF). This new method provides highly accurate position and velocity with consistent estimation.展开更多
文摘This article deals with a problem of the robot localization in the outdoor environment by using the GPS （global positioning system） data. In order to navigate the robot, it is necessary to transform the global position into the local map in the form of two-dimensional Cartesian coordinate system. The transformation is based on the model of the Earth-WGS 84 reference ellipsoid. The aim of this article is to experimentally evaluate a set of low-cost GPS receivers applicable as position sensors for small outdoor mobile robots. The evaluation is based on series of measurements executed in different times and places. The measured data is processed by given procedure and acquired positions are transformed into the local coordinate system. Accordingly the accuracy of the measured positions is statistically evaluated. The evaluation of used GPS receivers is done by comparison with data acquired by high-end geodetic GPS system Leica 1200, which is used as a reference GPS system.
文摘For the missile with passive seeker,the improvement of passive ranger's precision is one of the key issues in development of the defense penetrate strategy. On the offensive warheads,the infrared imaging device was used to measure the line-of-sight angle information of the blocker,and then using the algorithm of Kalman Filter under polar coordinates,the distance from the blocker to the warheads was obtained. The simulation result under polar coordinates was compared with that of Cartesian coordinate. The validity of the method was analyzed,and the schemes of improvement were brought out.
基金Supported by Crop Germplasm Resources Protection Project of Ministry of Agriculture(NB08-2130135-44)National Science and Technology Infrastructure Project(2005DKA21001-23)
文摘[Objective]The aim was to introduce T-DNA into watermelon for its molecular marker research.[Method]Based on the method of foreign DNA introduced to Arabidopsis thaliana via dipping flowers,the stigma smear was used to transfer T-DNA into watermelon and its molecular marker research was carried out.[Result]The ideal transformed species was ZXG01078 for the highest fruit setting rate and the most deviant seedlings.The best concentration of kanamycin for treating watermelon seeds was 500-700 mg/L with differences among the species.The best position was spire leaf or young leaf and the best concentration of kanamycin for treating the watermelon leaf was 4 000-8 000 mg/L with no significant difference among species.The steadily variation appearing of growing pointless and conjoined twin seedlings indicated that the normal growth had been interfered by foreign DNA in the progeny.[Conclusion]This study had provided basis for the further research on watermelon.
基金supported by the National Natural Science Foundation of China(Grant Nos.61301189 and 61101229)111 Project of China(Grant No.B14010)
文摘A new filtering method is proposed to accurately estimate target state via decreasing the nonlinearity between radar polar measurements(or spherical measurements in three-dimensional(3D) radar) and target position in Cartesian coordinate. The degree of linearity is quantified here by utilizing correlation coefficient and Taylor series expansion. With the proposed method, the original measurements are converted from polar or spherical coordinate to a carefully chosen Cartesian coordinate system that is obtained by coordinate rotation transformation to maximize the linearity degree of the conversion function from polar/spherical to Cartesian coordinate. Then the target state is filtered along each axis of the chosen Cartesian coordinate. This method is compared with extended Kalman filter(EKF), Converted Measurement Kalman filter(CMKF), unscented Kalman filter(UKF) as well as Decoupled Converted Measurement Kalman filter(DECMKF). This new method provides highly accurate position and velocity with consistent estimation.
