Unmanned clusters can realize collaborative work,fexible confguration,and efcient operation,which has become an important development trend of unmanned platforms.Cluster positioning is important for ensuring the norma...Unmanned clusters can realize collaborative work,fexible confguration,and efcient operation,which has become an important development trend of unmanned platforms.Cluster positioning is important for ensuring the normal operation of unmanned clusters.The existing solutions have some problems such as requiring external system assistance,high system complexity,poor architecture scalability,and accumulation of positioning errors over time.Without the aid of the information outside the cluster,we plan to construct the relative position relationship with north alignment to adopt formation control and achieve robust cluster relative positioning.Based on the idea of bionics,this paper proposes a cluster robust hierarchical positioning architecture by analyzing the autonomous behavior of pigeon focks.We divide the clusters into follower clusters,core clusters,and leader nodes,which can realize fexible networking and cluster expansion.Aiming at the core cluster that is the most critical to relative positioning in the architecture,we propose a cluster relative positioning algorithm based on spatiotemporal correlation information.With the design idea of low cost and large-scale application,the algorithm uses intra-cluster ranging and the inertial navigation motion vector to construct the positioning equation and solves it through the Multidimensional Scaling(MDS)and Multiple Objective Particle Swarm Optimization(MOPSO)algorithms.The cluster formation is abstracted as a mixed direction-distance graph and the graph rigidity theory is used to analyze localizability conditions of the algorithm.We designed the cluster positioning simulation software and conducted localizability tests and positioning accuracy tests in diferent scenarios.Compared with the relative positioning algorithm based on Extended Kalman Filter(EKF),the algorithm proposed in this paper has more relaxed positioning conditions and can adapt to a variety of scenarios.It also has higher relative positioning accuracy,and the error does not accumulate over time.展开更多
In order to provide the reference of improving the nutritional quality traits in carotenoids and screening its resources of wheat varieties, 185 wheat varieties or lines were selected as materials to test the caroteno...In order to provide the reference of improving the nutritional quality traits in carotenoids and screening its resources of wheat varieties, 185 wheat varieties or lines were selected as materials to test the carotenoids content, lipoxygenase activity, whiteness, yellowness and some other quality traits of whole mill in wheat.The results showed that there were highly significant variations in lipoxygenase activity,carotenoids content, whiteness and yellowness among those sample of wheat varieties; carotenoids content was significantly and positively correlated with yellowness.Cluster analysis was performed based on carotenoids content clustered all the varieties or lines into three major groups. Additionally, carotenoids were discussed in the application of nutritional quality improvement in wheat.展开更多
基金Science and Technology on Complex System Control and Intelligent Agent Cooperative Laboratory foundation(201101).
文摘Unmanned clusters can realize collaborative work,fexible confguration,and efcient operation,which has become an important development trend of unmanned platforms.Cluster positioning is important for ensuring the normal operation of unmanned clusters.The existing solutions have some problems such as requiring external system assistance,high system complexity,poor architecture scalability,and accumulation of positioning errors over time.Without the aid of the information outside the cluster,we plan to construct the relative position relationship with north alignment to adopt formation control and achieve robust cluster relative positioning.Based on the idea of bionics,this paper proposes a cluster robust hierarchical positioning architecture by analyzing the autonomous behavior of pigeon focks.We divide the clusters into follower clusters,core clusters,and leader nodes,which can realize fexible networking and cluster expansion.Aiming at the core cluster that is the most critical to relative positioning in the architecture,we propose a cluster relative positioning algorithm based on spatiotemporal correlation information.With the design idea of low cost and large-scale application,the algorithm uses intra-cluster ranging and the inertial navigation motion vector to construct the positioning equation and solves it through the Multidimensional Scaling(MDS)and Multiple Objective Particle Swarm Optimization(MOPSO)algorithms.The cluster formation is abstracted as a mixed direction-distance graph and the graph rigidity theory is used to analyze localizability conditions of the algorithm.We designed the cluster positioning simulation software and conducted localizability tests and positioning accuracy tests in diferent scenarios.Compared with the relative positioning algorithm based on Extended Kalman Filter(EKF),the algorithm proposed in this paper has more relaxed positioning conditions and can adapt to a variety of scenarios.It also has higher relative positioning accuracy,and the error does not accumulate over time.
基金Supported by the National Natural Science Foundation of China(No.31371615,31071404)
文摘In order to provide the reference of improving the nutritional quality traits in carotenoids and screening its resources of wheat varieties, 185 wheat varieties or lines were selected as materials to test the carotenoids content, lipoxygenase activity, whiteness, yellowness and some other quality traits of whole mill in wheat.The results showed that there were highly significant variations in lipoxygenase activity,carotenoids content, whiteness and yellowness among those sample of wheat varieties; carotenoids content was significantly and positively correlated with yellowness.Cluster analysis was performed based on carotenoids content clustered all the varieties or lines into three major groups. Additionally, carotenoids were discussed in the application of nutritional quality improvement in wheat.
