Research On The Algorithm Of The Team Cooperative Navigation

Pedestrian navigation is an autonomous navigation mode based on the micro inertial measurement unit(MIMU).When the satellite signals are severely blocked in the harsh environments such as in the room and in the valley,it still can provide continuous navigation information.Due to the limitation of the accuracy of MIMU measurement,the long-time navigation will cause error divergence.So it is difficult to meet the demand of long time and high precision positioning for pedestrian navigation.Research on navigation error divergence has attracted extensive attention in the field of navigation through a variety of constraint conditions.Cooperative navigation is a kind of navigation system by integrating and sharing of information from motion units.Through the mutual observation between the navigation carriers to form a binding relationship,the overall navigation accuracy is improved.There are a number of multiple pedestrian navigations in the practical application.Therefore,the divergence of pedestrian navigation error can be restrained by the way of cooperative navigation.This method is called the team cooperative navigation.The measurement of relative observation between the motion units in the cooperative navigation system is usually the distance or orientation.But in this paper,we only study the distance observation.Ultra wide band(UWB)has the advantages of small size,low power consumption and high precision,so it is particularly suitable for the use of team cooperative navigation.In this paper,two cooperative navigation algorithms are designed,and the algorithm is verified by the simulation experiment and the actual experiment based on MIMU and UWB range.The main researches are as follows:(1)Analysis and research pedestrian navigation algorithm and zero-velocity update algorithm.Analysis the principle and error model of UWB signal distance measurement.(2)Establish the cooperative navigation system model.The hierarchical kalman filtering algorithm is designed.The cooperative navigation is composed of two parts: the position estimation and the orientation correction.The member movement model is composed of the position of members only.Each member carries out its own orientation correction according to the location estimation results.By constructing the simulation model,the algorithm is validated and the influence of the precision of the distance measurement and information interaction on the positioning accuracy are studied.(3)In order to avoid the risk of system paralysis,which is caused by the fault of the processing center in the hierarchical algorithm.The distributed information filtering cooperative navigation algorithm is designed.In distributed algorithms,each unit is equivalent to a processing center.The algorithm is simulated and compared with the hierarchical kalman filtering algorithm.(4)The distance measurement performance is experimentally analyzed in the condition of LOS and NLOS.Design indoor and outdoor experiments,verify the cooperative navigation algorithm.The experimental results show that the team cooperative navigation algorithm can effectively use the navigation information of the members and the accuracy of navigation is greatly improved.