| UAV group has a wide application prospect in the fields of accident search and rescue,national defense security,military reconnaissance,and so on.Due to the working characteristics of the small UAV group on standby for a long time and the airborne battery-based power supply mode,it is necessary to consider the energy saving and balance in the hardware and software design of the system.Wireless mobile ad hoc network(Mobile Ad-hoc Network,MANET)is the main way of UAV communication networks.The routing protocol design of UAV network layer is also a way to improve the energy saving of UAV and improve the balance of energy consumption.Focusing on the clustering routing protocols in energy-constrained networks,this dissertation studies the Low Energy Adaptive Clustering Hierarchy(LEACH)protocol and its improved protocols.The main contents are as follows:(1)Aiming at the problem of uneven distribution of cluster heads in the classical LEACH protocol,the cluster head election mechanism of the protocol is improved.After the conventional cluster head election process of LEACH is completed,the cluster head is deleted in the area where the cluster head is too dense among the nodes,and the sparse area is by-elected,so as to improve the uniformity of the distribution of the cluster head in the network area.Simulation results show that the improved election mechanism can improve the distribution uniformity of LEACH cluster heads in the network area without affecting the energy-saving performance.(2)In view of the limitations of the classical LEACH protocol in energy balance,an improved scheme for re-election in the clustered network is proposed.In order to reduce and balance the energy consumption,the node which is the most suitable to be the cluster head is re-elected as the cluster head within the range of each subnet after the clustering of the LEACH protocol,so as to achieve the purpose of reducing and balancing the energy consumption.Two kinds of evaluation formulas are designed,which involve two groups of parameters: the position of the cluster and the base station,the residual energy,the distance of the best cluster head position and the residual energy.In order to better find the best position of the cluster head,the bat algorithm is introduced,and the optimal position of the cluster head is taken as the solution,and the number and location of nodes in the cluster are the population size and initial position.The simulation results show that the LEACH protocol for cluster head re-election can better balance the node energy consumption and prolong the network lifetime.(3)In view of the deficiency of classical LEACH protocol in dealing with the distribution of cluster heads,the location and energy information of nodes in the network are collected by the base station to elect cluster heads.In order to quickly combine position and energy information to select cluster heads,genetic immune algorithm(GA)is introduced.The cluster head was selected through the process of heredity,crossover,mutation and immunity.The evaluation parameters of cluster head fitness are average intra-cluster distance,cluster size variance and average residual energy of cluster head.The simulation results show that the cluster head election scheme of the immune genetic algorithm carried out by the base station can better prolong the working time of the node and network compared with the classical LEACH protocol. |
