The formation maintenance of multiple unmanned aerial vehicles(UAVs)based on proximity behavior is explored in this study.Individual decision-making is conducted according to the expected UAV formation structure and t...The formation maintenance of multiple unmanned aerial vehicles(UAVs)based on proximity behavior is explored in this study.Individual decision-making is conducted according to the expected UAV formation structure and the position,velocity,and attitude information of other UAVs in the azimuth area.This resolves problems wherein nodes are necessarily strongly connected and communication is strictly consistent under the traditional distributed formation control method.An adaptive distributed formation flight strategy is established for multiple UAVs by exploiting proximity behavior observations,which remedies the poor flexibility in distributed formation.This technique ensures consistent position and attitude among UAVs.In the proposed method,the azimuth area relative to the UAV itself is established to capture the state information of proximal UAVs.The dependency degree factor is introduced to state update equation based on proximity behavior.Finally,the formation position,speed,and attitude errors are used to form an adaptive dynamic adjustment strategy.Simulations are conducted to demonstrate the effectiveness and robustness of the theoretical results,thus validating the effectiveness of the proposed method.展开更多
Multiple UAVs are usually deployed to provide robustness through redundancy and to accomplish surveillance,search,attack and rescue missions.Formation reconfiguration was inevitable during the flight when the mission ...Multiple UAVs are usually deployed to provide robustness through redundancy and to accomplish surveillance,search,attack and rescue missions.Formation reconfiguration was inevitable during the flight when the mission was adjusted or the environment varied.Taking the typical formation reconfiguration from a triangular penetrating formation to a circular tracking formation for example,a path planning method based on Dubins trajectory and particle swarm optimization(PSO)algorithm is presented in this paper.The mathematic model of multiple UAVs formation reconfiguration was built firstly.According to the kinematic model of aerial vehicles,a process of dimensionality reduction was carried out to simplify the model based on Dubins trajectory.The PSO algorithm was adopted to resolve the optimization problem of formation reconfiguration path planning.Finally,the simulation and vehicles flight experiment are executed.Results show that the path planning method based on the Dubins trajectory and the PSO algorithm can generate feasible paths for vehicles on time,to guarantee the rapidity and effectiveness of formation reconfigurations.Furthermore,from the simulation results,the method is universal and could be extended easily to the path planning problem for different kinds of formation reconfigurations.展开更多
In order to improve the battle effectiveness of the unmanned aerial vehicle （UAV） under the increasingly complex threat environment, a three-dimension path planning method based on an A ＊ al- gorithm is proposed an...In order to improve the battle effectiveness of the unmanned aerial vehicle （UAV） under the increasingly complex threat environment, a three-dimension path planning method based on an A ＊ al- gorithm is proposed and simulated in this paper which makes the UAV satisfy requirements of different missions. At first, the digital map information is processed vdth an integrated terrain smoothing algorithm, and a safe flight surface which integrates the vehicle dynamic is built and added on the terrain, and then, models of the complicated threats are established and integrated into the digital terrain. At last, an improved A ＊ algorithm is used to plan the three-dimension path on the safe sur- face, and then smooth the path. Simulation results indicate that the approach has a good perform- ance in creating an optimal path in the three-dimension environment and the path planning algorithm is more simple, efficient and easily realized in the engineering field.展开更多
In this series of 65 cases of aplastic anemia, 26 cases were treated by the kidney-tonifying and mediating method, 19 cases by western drugs, and the remaining 20 cases only by tonifying the kidney as controls. The re...In this series of 65 cases of aplastic anemia, 26 cases were treated by the kidney-tonifying and mediating method, 19 cases by western drugs, and the remaining 20 cases only by tonifying the kidney as controls. The results showed that the kidney-tonifying and mediating method was significantly superior in the total effective rate to the method of western drugs and that of tonifying the kidney alone (P展开更多
The construction and shape of UUVs are described in the paper. UUV design is the shape of the overall design of unmanned underwater vehicle should first be resolved UUV underwater vehicle directly affects the shape of...The construction and shape of UUVs are described in the paper. UUV design is the shape of the overall design of unmanned underwater vehicle should first be resolved UUV underwater vehicle directly affects the shape of the resistance and noise, which is related to energy, payload, maneuverability and concealment UUV problem The main characteristic and parameter tables for foreign torpedo shape, fiat shape and anomalous shape are also given in the paper. The general layout of typical foreign UUVs is analyzed in detail. And the total layout figure and interior constructive figure are introduced. Torpedo-type because of its good water power and low noise, no one has been the main form of underwater vehicle-like, and many designers are now highly favored because of its stable performance, anti-environmental interference capability. Other irregular shapes designed primarily for the completion of a specific task, according to the specific environment and mission requirements. According to comparing and summarizing, some suggestions and conclusions are oresented.展开更多
The passive flight of large numbers of mitospores ensures propagation and survival of many fungal species. Moreover, many fungi have a surplus DNA context which allows for easier manipulation and tampering, especially...The passive flight of large numbers of mitospores ensures propagation and survival of many fungal species. Moreover, many fungi have a surplus DNA context which allows for easier manipulation and tampering, especially when inserting eukaryotic genes and translation systems. These facts taken together suggest a high prominence of the sporogonic airborne fungi in biosecurity/biodefence priority lists, but due to the low virulence and mortality of the fungal pathogens, they do not figure high, or, sometimes, not at all. The disruptive effect of biosecurity fungal threats is important per se and genetic manipulations are to further it. Novel, long range and high-persistence sampling methods, using robotics and unmanned systems already fielded in other applications may extend surveillance and responsive sampling. Effects-based, proteomic approaches may provide a solution for deliberate incidents, while polyphasic taxonomy may resolve spontaneous incidents and assist medical diagnosis, but in the biosecurity context, where mass collection and processing of samples and speed in producing robust results are vital, complex approaches might be proved more of a hindrance than an asset.展开更多
文摘The formation maintenance of multiple unmanned aerial vehicles(UAVs)based on proximity behavior is explored in this study.Individual decision-making is conducted according to the expected UAV formation structure and the position,velocity,and attitude information of other UAVs in the azimuth area.This resolves problems wherein nodes are necessarily strongly connected and communication is strictly consistent under the traditional distributed formation control method.An adaptive distributed formation flight strategy is established for multiple UAVs by exploiting proximity behavior observations,which remedies the poor flexibility in distributed formation.This technique ensures consistent position and attitude among UAVs.In the proposed method,the azimuth area relative to the UAV itself is established to capture the state information of proximal UAVs.The dependency degree factor is introduced to state update equation based on proximity behavior.Finally,the formation position,speed,and attitude errors are used to form an adaptive dynamic adjustment strategy.Simulations are conducted to demonstrate the effectiveness and robustness of the theoretical results,thus validating the effectiveness of the proposed method.
基金Project (61703414) supported by the National Natural Science Foundation of ChinaProject (3101047) supported by the Defense Science and Technology Foundation of China+1 种基金Project (2017JJ3366) supported by the Natural Science Foundation of Hunan ChinaProject (2015M582881) supported by the China Postdoctoral Science Foundation
文摘Multiple UAVs are usually deployed to provide robustness through redundancy and to accomplish surveillance,search,attack and rescue missions.Formation reconfiguration was inevitable during the flight when the mission was adjusted or the environment varied.Taking the typical formation reconfiguration from a triangular penetrating formation to a circular tracking formation for example,a path planning method based on Dubins trajectory and particle swarm optimization(PSO)algorithm is presented in this paper.The mathematic model of multiple UAVs formation reconfiguration was built firstly.According to the kinematic model of aerial vehicles,a process of dimensionality reduction was carried out to simplify the model based on Dubins trajectory.The PSO algorithm was adopted to resolve the optimization problem of formation reconfiguration path planning.Finally,the simulation and vehicles flight experiment are executed.Results show that the path planning method based on the Dubins trajectory and the PSO algorithm can generate feasible paths for vehicles on time,to guarantee the rapidity and effectiveness of formation reconfigurations.Furthermore,from the simulation results,the method is universal and could be extended easily to the path planning problem for different kinds of formation reconfigurations.
文摘In order to improve the battle effectiveness of the unmanned aerial vehicle （UAV） under the increasingly complex threat environment, a three-dimension path planning method based on an A ＊ al- gorithm is proposed and simulated in this paper which makes the UAV satisfy requirements of different missions. At first, the digital map information is processed vdth an integrated terrain smoothing algorithm, and a safe flight surface which integrates the vehicle dynamic is built and added on the terrain, and then, models of the complicated threats are established and integrated into the digital terrain. At last, an improved A ＊ algorithm is used to plan the three-dimension path on the safe sur- face, and then smooth the path. Simulation results indicate that the approach has a good perform- ance in creating an optimal path in the three-dimension environment and the path planning algorithm is more simple, efficient and easily realized in the engineering field.
文摘In this series of 65 cases of aplastic anemia, 26 cases were treated by the kidney-tonifying and mediating method, 19 cases by western drugs, and the remaining 20 cases only by tonifying the kidney as controls. The results showed that the kidney-tonifying and mediating method was significantly superior in the total effective rate to the method of western drugs and that of tonifying the kidney alone (P
文摘The construction and shape of UUVs are described in the paper. UUV design is the shape of the overall design of unmanned underwater vehicle should first be resolved UUV underwater vehicle directly affects the shape of the resistance and noise, which is related to energy, payload, maneuverability and concealment UUV problem The main characteristic and parameter tables for foreign torpedo shape, fiat shape and anomalous shape are also given in the paper. The general layout of typical foreign UUVs is analyzed in detail. And the total layout figure and interior constructive figure are introduced. Torpedo-type because of its good water power and low noise, no one has been the main form of underwater vehicle-like, and many designers are now highly favored because of its stable performance, anti-environmental interference capability. Other irregular shapes designed primarily for the completion of a specific task, according to the specific environment and mission requirements. According to comparing and summarizing, some suggestions and conclusions are oresented.
文摘The passive flight of large numbers of mitospores ensures propagation and survival of many fungal species. Moreover, many fungi have a surplus DNA context which allows for easier manipulation and tampering, especially when inserting eukaryotic genes and translation systems. These facts taken together suggest a high prominence of the sporogonic airborne fungi in biosecurity/biodefence priority lists, but due to the low virulence and mortality of the fungal pathogens, they do not figure high, or, sometimes, not at all. The disruptive effect of biosecurity fungal threats is important per se and genetic manipulations are to further it. Novel, long range and high-persistence sampling methods, using robotics and unmanned systems already fielded in other applications may extend surveillance and responsive sampling. Effects-based, proteomic approaches may provide a solution for deliberate incidents, while polyphasic taxonomy may resolve spontaneous incidents and assist medical diagnosis, but in the biosecurity context, where mass collection and processing of samples and speed in producing robust results are vital, complex approaches might be proved more of a hindrance than an asset.
