A three-arm Michelson-Fabry-Perot detector for gravitational waves is designed. It consists of three Michelson Fabry-Perot interferometers, one for each pair of arms. The new detector can be used to confirm whether th...A three-arm Michelson-Fabry-Perot detector for gravitational waves is designed. It consists of three Michelson Fabry-Perot interferometers, one for each pair of arms. The new detector can be used to confirm whether the gravitational waves are in general relativity polarization states and to set the strong constraints on non-GR gravitational wave polarization states. By the new detectors, the angular resolution of sources can be improved significantly. With the new detector, it is easier to search for and confirm a gravitational wave signal in the observation data.展开更多
The transplanting arm of two-arm transplanting mechanism is easy to cause seedlings injury and missing due to its faster speed relative to the seedlings.In order to solve the existed problems,a three-arm transplanting...The transplanting arm of two-arm transplanting mechanism is easy to cause seedlings injury and missing due to its faster speed relative to the seedlings.In order to solve the existed problems,a three-arm transplanting mechanism for rice potted seedlings was developed in this study.The developed three-arm transplanting mechanism for rice potted seedling can make the transplanting arm realize special trajectory and attitude through the unequal planetary gear transmission.The kinematic model of three-arm transplanting mechanism for rice potted seedling was established,and the optimal design software was developed.Based on the heuristic optimization algorithm named“parameter guide”,a set of satisfied mechanism parameters required by the rice potted seedling transplanting were obtained.The trajectory and attitude of three-arm transplanting mechanism used for the rice potted seedling were analyzed.Besides,the virtual simulation results were basically consistent with the optimization software results,and the correctness of theoretical analysis and virtual simulation were also verified by each other.When the developed transplanting mechanism picked up the seedling,the velocity of transplanting arm relative to the seedling was reduced by about 30%.The results showed that the injury rate of rice potted seedling transplanting mechanism was 0.04%,the missing rate of seedling was 1.4%,the integrity rate of seedling pot matrix was 96%,and the success rate of picking seedling was 99.92%.展开更多
针对当前路径规划算法在高维复杂环境下,存在障碍物信息处理不充分、搜索效率与路径质量难以平衡等问题,提出了一种基于自适应概率偏差的改进算法——APB-RRT*算法(Adaptive Probability Bias RRT*)。首先依据障碍物类型设定安全距离,...针对当前路径规划算法在高维复杂环境下,存在障碍物信息处理不充分、搜索效率与路径质量难以平衡等问题,提出了一种基于自适应概率偏差的改进算法——APB-RRT*算法(Adaptive Probability Bias RRT*)。首先依据障碍物类型设定安全距离,在保障安全的基础上将采样空间划分为m×m×m个子区域,引入参考路径邻近性评价函数,动态调整子区域采样概率,加快了算法的收敛速度,减少了冗余节点。同时,融合基于环境感知的自适应偏置策略和变步长调节机制,提高了路径搜索效率。最后,为遵循机械臂运动学特性,采用分段贪婪算法结合三次样条插值法对路径进行平滑约束,确保了路径的连续性和可执行性。仿真实验结果表明,该文算法规划出的路径最接近理想最优路径。展开更多
The optical properties of a three-arm plasmonic nanoantenna with and without broken symmetry were analyzed in detail. For the symmetrical structure, the local electric field can be significantly enhanced and well conf...The optical properties of a three-arm plasmonic nanoantenna with and without broken symmetry were analyzed in detail. For the symmetrical structure, the local electric field can be significantly enhanced and well confined within the feed gap, whilst the extinction spectrum illustrates polarization independence. With broken symmetry, multi-wavelength resonances are observed due to the single dipole resonance and dipole–dipole coupling effect, and wide tunability is also available through minor structural adjustment. Especially when illuminated by a circularly polarized light beam, the extinction and the electric field distribution can be effectively modulated by just varying the incident wavelength.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 11275207
文摘A three-arm Michelson-Fabry-Perot detector for gravitational waves is designed. It consists of three Michelson Fabry-Perot interferometers, one for each pair of arms. The new detector can be used to confirm whether the gravitational waves are in general relativity polarization states and to set the strong constraints on non-GR gravitational wave polarization states. By the new detectors, the angular resolution of sources can be improved significantly. With the new detector, it is easier to search for and confirm a gravitational wave signal in the observation data.
基金supported by the National Natural Science Foundation of China(Grant No.52005221)the Natural Science Foundation of Jiangsu Province(Grant No.BK20200897)the China Postdoctoral Science Foundation(Grant No.2021M691315).
文摘The transplanting arm of two-arm transplanting mechanism is easy to cause seedlings injury and missing due to its faster speed relative to the seedlings.In order to solve the existed problems,a three-arm transplanting mechanism for rice potted seedlings was developed in this study.The developed three-arm transplanting mechanism for rice potted seedling can make the transplanting arm realize special trajectory and attitude through the unequal planetary gear transmission.The kinematic model of three-arm transplanting mechanism for rice potted seedling was established,and the optimal design software was developed.Based on the heuristic optimization algorithm named“parameter guide”,a set of satisfied mechanism parameters required by the rice potted seedling transplanting were obtained.The trajectory and attitude of three-arm transplanting mechanism used for the rice potted seedling were analyzed.Besides,the virtual simulation results were basically consistent with the optimization software results,and the correctness of theoretical analysis and virtual simulation were also verified by each other.When the developed transplanting mechanism picked up the seedling,the velocity of transplanting arm relative to the seedling was reduced by about 30%.The results showed that the injury rate of rice potted seedling transplanting mechanism was 0.04%,the missing rate of seedling was 1.4%,the integrity rate of seedling pot matrix was 96%,and the success rate of picking seedling was 99.92%.
文摘针对当前路径规划算法在高维复杂环境下,存在障碍物信息处理不充分、搜索效率与路径质量难以平衡等问题,提出了一种基于自适应概率偏差的改进算法——APB-RRT*算法(Adaptive Probability Bias RRT*)。首先依据障碍物类型设定安全距离,在保障安全的基础上将采样空间划分为m×m×m个子区域,引入参考路径邻近性评价函数,动态调整子区域采样概率,加快了算法的收敛速度,减少了冗余节点。同时,融合基于环境感知的自适应偏置策略和变步长调节机制,提高了路径搜索效率。最后,为遵循机械臂运动学特性,采用分段贪婪算法结合三次样条插值法对路径进行平滑约束,确保了路径的连续性和可执行性。仿真实验结果表明,该文算法规划出的路径最接近理想最优路径。
基金supported by the National Natural Science Foundation of China(Grant Nos.61320106014,61405117,and 61675104)the K.C.Wong Magna Fund in Ningbo University,China
文摘The optical properties of a three-arm plasmonic nanoantenna with and without broken symmetry were analyzed in detail. For the symmetrical structure, the local electric field can be significantly enhanced and well confined within the feed gap, whilst the extinction spectrum illustrates polarization independence. With broken symmetry, multi-wavelength resonances are observed due to the single dipole resonance and dipole–dipole coupling effect, and wide tunability is also available through minor structural adjustment. Especially when illuminated by a circularly polarized light beam, the extinction and the electric field distribution can be effectively modulated by just varying the incident wavelength.
