Research On Sensor Optimal Deployment And Control Strategy For Space Monitoring

Mobile sensor networks(MSNs)are often used in dynamic space monitoring due to their self-organization,scalability and flexibility,such as battlefield monitoring,post-disaster search.Sensors' coverage in the monitoring area directly shows the quality of the sensing service they provide.Reasonable sensor deployment brings benefits to sensing the environment and obtaining information from the space.It also prolongs the survival time of the network.When sensor detects a target,it should cooperate with other sensors in the network to track the target,but it also needs to keep searching the monitoring area,which brings higher requirements to the collaboration and adaptability of sensors.This paper studies the optimal deployment and moving control strategies for sensors respectively for space monitoring,a typical MSN application.The contents of this paper are listed as follows:1.A fuzzy system based virtual force algorithm(FSVFA)is proposed for the deployment of heterogeneous sensors in space monitoring.Nodes in MSN analyze thier surroundings and the perception abilities of themselves via a fuzzy logic system.The iteration step length of virtual force algorithm is adjusted due to the output of the fuzzy logic system.The simulation results show that it effectively improves the coverage efficiency of sensors in MSN.2.An equivalent method of directional perception model based on virtual potential field is proposed to extend the optimization effects of FSVFA to heterogeneous directional sensors.First,the directional perception model of nodes is converted into an omnidirectional perception model,then FSVFA is applied on the omnidirectional model to optimize the coverage area.The directional perception model is restored according to the repulsive forces the sensor received from the virtual potential field.Simulation results show that this method can realize the optimal deployment of directional sensors with heterogeneous radii and angles,and increases the space coverage compared to traditional methods.3.A fuzzy system based adaptive flocking algorithm(FSAFA)is proposed for tracking and searching in the surveillance area.It combines the advantages of flocking algorithm and anti-flocking algorithm.When a target appears in the monitoring area,the mobile nodes should exchange information with their neighbors and cooperate to track the target.The sensor's state and its corresponding control law are updated via a fuzzy logic system based on the distance and the risk of the target.According to the system,multiple formations are formed to track the targets in the area whether the target is moving or stationary.Besides,the network can maintain a continuous search for the monitoring area while some of the sensors are tracking targets.The simulation results show that the sensors controlled by FSAFA can not only keep tracking the targets for a longer time,they also shorten the average undetected time of the monitoring area.In this paper,to find the optimal sensor deployment in MSN and their control strategies for space monitoring,we proposed two algorithms,FSFVA and FSAFA.The task of space monitoring can be efficiently accomplished when FSFVA increases nodes' coverage efficiency and FSAFA controls their movement.