In order to improve the accuracy and stability of transplanting machine seedling picking,a seedling pick-up mechanism was designed,which was controlled by a controller and driven by brushless DC servo motor.At the sam...In order to improve the accuracy and stability of transplanting machine seedling picking,a seedling pick-up mechanism was designed,which was controlled by a controller and driven by brushless DC servo motor.At the same time,the parameters of the seedling manipulator were optimized:the mathematical model for the seedling pick-up mechanism was established.According to the predetermined trajectory requirements,the objective function and constraint conditions were proposed,and then the optimal size was obtained by a multi-objective genetic algorithm.At last,Automatic Dynamic Analysis of Mechanical Systems(ADAMS)software was used to simulate and analyze the kinematics and trajectory of the seedling pick-up mechanism,and the mechanism was tested to verify the effectiveness of the mechanism prototype.The experiments showed that the success rate of seedling picking was 94.32%,the rate of acceptably planted seedlings was 96.67%,and the rate of excellently planted seedlings was 63.48%.展开更多
Electron Tomography （ET） is an important method for studying cell ultrastructure in three-dimensional （3D） space. By combining cryo-electron tomography of frozen-hydrated samples （cryo-ET） and a sub-tomogram ave...Electron Tomography （ET） is an important method for studying cell ultrastructure in three-dimensional （3D） space. By combining cryo-electron tomography of frozen-hydrated samples （cryo-ET） and a sub-tomogram averaging approach, ET has recently reached sub-nanometer resolution, thereby realizing the capability for gaining direct insights into function and mechanism. To obtain a high-resolution 3D ET reconstruction, alignment and geometry determination of the ET tilt series are necessary. However, typical methods for determining geometry require human intervention, which is not only subjective and easily introduces errors, but is also labor intensive for high-throughput tomographic reconstructions. To overcome these problems, we have developed an automatic geometry-determination method, called AutoGDeterm. By taking advantage of the high-contrast re-projections of the Iterative Compressed-sensing Optimized Non-Uniform Fast Fourier Transform （NUFFT） reconstruction （ICON） and a series of numerical analysis methods, AutoGDeterm achieves high-precision fully automated geometry determination. Experimental results on simulated and resin-embedded datasets show that the accuracy of AutoGDeterm is high and comparable to that of the typical ＂manual positioning＂ method. We have made AutoGDeterm available as software, which can be freely downloaded from our website http：//ear.ict.ac.cn.展开更多
基金This research was supported by the National Natural Science Foundation of China(Grant No.51775104).
文摘In order to improve the accuracy and stability of transplanting machine seedling picking,a seedling pick-up mechanism was designed,which was controlled by a controller and driven by brushless DC servo motor.At the same time,the parameters of the seedling manipulator were optimized:the mathematical model for the seedling pick-up mechanism was established.According to the predetermined trajectory requirements,the objective function and constraint conditions were proposed,and then the optimal size was obtained by a multi-objective genetic algorithm.At last,Automatic Dynamic Analysis of Mechanical Systems(ADAMS)software was used to simulate and analyze the kinematics and trajectory of the seedling pick-up mechanism,and the mechanism was tested to verify the effectiveness of the mechanism prototype.The experiments showed that the success rate of seedling picking was 94.32%,the rate of acceptably planted seedlings was 96.67%,and the rate of excellently planted seedlings was 63.48%.
基金supported by the National Natural Science Foundation of China (Nos. U1611263, U1611261, 61232001, 61472397, 61502455, and 61672493)the Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund (the second phase)+1 种基金the Strategic Priority Research Program of Chinese Academy of Sciences (No. XDB08030202)the National Key Research and Development Program of China (No. 2017YFA0504702)
文摘Electron Tomography （ET） is an important method for studying cell ultrastructure in three-dimensional （3D） space. By combining cryo-electron tomography of frozen-hydrated samples （cryo-ET） and a sub-tomogram averaging approach, ET has recently reached sub-nanometer resolution, thereby realizing the capability for gaining direct insights into function and mechanism. To obtain a high-resolution 3D ET reconstruction, alignment and geometry determination of the ET tilt series are necessary. However, typical methods for determining geometry require human intervention, which is not only subjective and easily introduces errors, but is also labor intensive for high-throughput tomographic reconstructions. To overcome these problems, we have developed an automatic geometry-determination method, called AutoGDeterm. By taking advantage of the high-contrast re-projections of the Iterative Compressed-sensing Optimized Non-Uniform Fast Fourier Transform （NUFFT） reconstruction （ICON） and a series of numerical analysis methods, AutoGDeterm achieves high-precision fully automated geometry determination. Experimental results on simulated and resin-embedded datasets show that the accuracy of AutoGDeterm is high and comparable to that of the typical ＂manual positioning＂ method. We have made AutoGDeterm available as software, which can be freely downloaded from our website http：//ear.ict.ac.cn.
