Research On Key Technologies Of Quadrotor Simulation Test Platform Based On Unity3D

The test and evaluation of quadrotor is very important for the reliability of quadrotor.The traditional quadrotor test has the disadvantages of long cycle and high cost.Virtual reality engine is used to integrate virtual scene,quadrotor model and sensor model to realize a large number of tests on quadrotor under the condition of safety and low cost,which can significantly shorten the development cycle.Based on the graphics rendering and physical engine technology of Unity3 D,in the virtual test platform of quadrotor,the key technologies such as automatic generation of batch random test scene,rendering and Optimization for virtual vision sensor,simulation of quadrotor based on physical engine are the key research contents of this subject.In this thesis,a test scenario that accords with the specific parameter distribution is constructed,and analyze the key features and elements of the test scenario.The distribution of each parameter in the scenario is random and diverse,and there are too many combinations of all factors.In order to solve the problems of "dimension disaster" and "sample explosion",the test scenario is constructed based on Monte Carlo method,and the scene parameter distribution is effectively sampled and combined;Aiming at the obstacle avoidance condition of quadrotor,the metropolis Hastings algorithm of Markov chain Monte Carlo is used to sample the scene parameters;In order to speed up simulation testing,weighted Euclidean distance clustering is used to generate key test cases instead of test results of similar test cases.This thesis studies the BRDF lighting model based on physical rendering in computer graphics.In the diffuse and specular terms of BRDF,it adopts a more accurate parameter model than the traditional lighting model,which improves the material details of the model in the image;on the basis of fine material,it uses the normal texture of tangent space,which greatly increases the level of detail of the model;considering the influence of the material quality,it uses the normal texture of tangent space Considering the advantages of delay rendering to multi light source rendering,the delay rendering framework is studied and used.Based on the framework,screen space ambient shading(SSAO)and high dynamic range illumination(HDR)are used to further improve the image fidelity with less performance consumption.In order to improve the simulation accuracy,quadrotor model and environment model of Airsim are analyzed and adopted;In order to simulate the detection principle of quadrotor airborne sensors and get the original data,a physical model construction framework based on physical engine is proposed,and the perception simulation of each sensor is realized based on Unity3 D engine.Finally,the noise parameters of the real model are added to the original data;The overall structure of the quadrotor simulation platform is analyzed and designed,and the simulation environment based on Unity3 D is constructed,and the communication and data synchronization with Matlab/Simulink are realized.In order to further verify the key technologies of the test platform,based on the built quadrotor simulation test platform,verify the effectiveness of the test platform for quadrotor related algorithm testing.Aiming at the target tracking condition of quadrotor in complex forest scene,the forest scene library is constructed,and batch random forest scenes are constructed based on Monte Carlo method,and the images collected by virtual vision sensor are rendered and optimized;Using HOG+SVM algorithm to detect pedestrian and vehicle targets in virtual image and real image respectively,the authenticity of virtual vision sensor is verified;Finally,the test results are analyzed statistically.