Bionic Navigation Method For Autonomous Return Of UAV

Aiming at the autonomous return of small unmanned aerial vehicle(UAV)under the condition of satellite rejection,this thesis studies the bionic navigation method of UAV autonomous return from two aspects of bionic sensor measurement error compensation and bionic navigation method.The main work and contributions are as follows:A modeling and calibration method for coupling error of pixelated polarization imaging chip is proposed.The influence of coupling process error between array polarizer and imaging chip on transmittance and extinction ratio is analyzed,and the coupling error model and camera linear response error model are established.Based on Marius law,the light intensity response function including error parameters is derived,and a coupling error calibration method is designed.The accuracy of the error model and the effectiveness of the calibration method are verified by experiments using indoor standard light sources.Research the orientation error compensation method of bionic optical compass in typical application scenarios.Aiming at the orientation problem of bionic optical compass under tilt condition,the influence of carrier attitude tilt angle on orientation accuracy is analyzed,and the orientation method of bionic optical compass under tilt condition is given,which uses polarization information of incident light in zenith region to estimate heading angle.Aiming at the orientation problem in complex sky background,an adaptive segmentation method of sky region based on Rayleigh scattering model is designed,which can adaptively segment the sky region from the image in an unsupervised way.Experimental results show that the error compensation method can obviously improve the orientation accuracy of the optical compass.A location method based on the combination of scene sketch recognition and geometric constraint of feature points is proposed.Aiming at the problem of scene recognition,visual words are used to describe the image.The description of scene position is established based on the generation model.The similarity between images is inferred by using probability model.Then the rough recognition of scene is completed,and the position of UAV is roughly estimated.Aiming at the problem of feature point matching and positioning,a verification criterion of feature point matching based on essential matrix is designed,and a matching and positioning method based on geometric constraints of image feature points is given to realize accurate positioning of UAV.The effectiveness and availability of this method are verified by the UAV experiment.A navigation topology online construction and bionic navigation method for small UAV is proposed.Aiming at the autonomous return of small UAV,firstly,the navigation parameters and scene description information are recorded in the process of return tasks,and an online construction method of navigation topological graph based on distance criterion and node information association is designed to form navigation topological graph.Secondly,a bionic navigation method based on topological graph is proposed.By sensing the environmental information on the way back,the navigation topological graph is used to form position constraints,and the global pose estimation of the carrier is obtained by combining the heading information of the bionic optical compass with the local pose estimation parameters of visual-inertial navigation system.Finally,the effectiveness of the method is verified by the UAV experiment.