Research On Indoor Integrated Navigation Based On Radar-scanner And Inertial Navigation System With Control For Micro Rotor UAV

Indoor navigation system is an important component of autonomous flight in indoor environment for Micro Rotor UAV. In an indoor environment, GPS/INS navigation system is denied, so, this paper presents an indoor integrated navigation solution based on Radar-scanner and inertial navigation system (INS). Furthermore, this paper models quadrotor and designs controllers for flight control. The main work and contributions of this paper are as follows:Firstly we select quadrotor as the experimental platform, and considering the factors of cost, function, performance and load, we build up a hardware platform for navigation and control system, and develop the software system.Then this paper proposes an indoor integrated navigation solution for Micro Rotor UAV based on Radar-scanner and INS. In order to satisfy real-time requirement of navigation system, we use D&C SLAM algorithm based on EKF with radar data to estimate the position and map. We extract environment features from contour map composed by radar data to be used for feature matching. Scan matching algorithm is used in the process of D&C SLAM to improve the accuracy of state update with the fusion of INS and radar data. And a heuristic logic is proposed to screen the radar data to accommodate the strong perturbations of the map’s profile caused by the motion of attitude. High accuracy guided pairs in the JCBB feature matching procedure are given by the result of scan matching and the transfer of feature matching to improve the matching accuracy in3D environment. Finally, integrated D&C SLAM and INS navigation algorithms are implemented based on EKF to give the state estimation.In order to validate that the proposed D&C SLAM/INS integrated navigation system can be used for actual flight control system, this paper builds up a four-channel object model around the hovering state based on quadrotor. The four channels are pitch channel, roll channel, yaw channel and vertical channel. Then, establish four-channel cascade PID controllers according to the characteristics of the model, and decide the parameters of the controllers based on the combination of control theory, the expected control results and the actual flight control results.Finally, this paper designs three experiments on quadrotor. The first is outdoor flight control experiment based on GPS/INS while the inner loop track control response is so rapid, and the step response of the outer loop control can meet the desired dynamic performance requirements, also the actual flight route is consistent with the preset route. The results show that the flight control system has been built can be used for actual quadrotor platform. Then this paper gives the results of the positioning performance test of D&C SLAM and the comparative experiment between the D&C SLAM/INS and GPS/INS without the paddles rotation. The results show that D&C SLAM positioning and mapping errors are lower than10cm which is a high positioning accuracy and the horizontal position difference variances of D&C SLAM/INS and GPS/INS are0.02m2and0.05m2which are small. The last one is indoor flight control based on D&C SLAM/INS integrated navigation including takeoff, hover and fly forward. The hovering accuracy is up to0.2m, which verify that the D&C SLAM/INS integrated navigation system is able to offer good and real-time state estimations for actual flight control system.