Indoor Localization And Navigation Of Cleaning Robot Based On A Combination Of Laser And Vision

Nowadays,the development of new sensor technology has promoted the development of robotics which get location and map based on the traditional odometer positioning information to the extensive visual and laser positioning.Most of the visual research areas focus on how to extract and describe the feature fast and the better robust match between the images.But there are problems such as poor real-time performance due to the large amount of image calculation,inaccurate positioning owing to rotation quickly in the engineering application.Some limitations exist on the application of laser like horizontal scanning and rotating speed low.Above the previous research,mainly research is the low-cost sweeping robot location and back to the charging station.The dissertation establishes the state and observation equations based on the information of the odometer and laser information of the ceiling.Through the AEKF,integrated information can realize the robot localization and help return the charging station according to the position information.When camera calibration,this dissertation discusses the influence of the different distances and angles on the calibration results in order to get a better calibration results.To reduce the influence of light on the laser,a filter is added to screen out the visible light.After extracting the feature of the laser crosses,we adopt many threshold settings to improve the correct recognition rate of the laser cross.Then it can obtain the pixel coordinates of the cross point by using the geometric relations.The position and angle information of the robot are obtained by way of the simplified camera model.In this dissertation,we will make a detailed experimental study on laser cross-point selection and can find that the cross point of the laser is stable.The endpoints of the laser lines are unstable due to the diffraction and the world coordinates of the robot have larger errors determined by unstable feature points.When stopping,the robot pose information obtained by the image is more accurate.However,the robot position is unstable because of the image changing rapidly when rotating.This dissertation proves the observability of system according to the differential geometric properties of the observability and the rank of the matrix.In order to return the charging station,the dissertation adopts the method of trajectory tracking of nonholonomic mobile robot with input saturation constraint when straight.In the last part of this dissertation,the experimental environment is set up.The experimental results verify the feasibility and effectiveness of the laser cross,ordinary camera to realize the low cost robot localization and return the charging station.