Localization For Mobile Robot Based On Optical Flow Sensors

With the advent of the era of intelligent, there is growing demand for the mobile robots applications in various industries. In order to complete the task set up in advance, robots must need its own position and attitude at first. So the robot localization is a fundamental research in the field of robotics. In that research, the mobile robot localization based on visual information is a hot spot in the field of robotics. The vision is an important way of the robot to get information from the world around and it can provide abundant information about the environment for the robot. With the development of computer vision, equipments based on the technology are invented continually. As a new type of the vision sensor, optical flow sensor has been used in varieties of navigation tasks like dead-reckoning, distance estimation, altitude hold, hovering and terrain following.Based on the models related to computer vision, the problem of indoor location of the mobile robot in a short distance was mainly studied in this thesis. In the positioning system, the positioning based on the vision sensor has become a hot research direction. As visual sensors, the traditional optical flow sensors are manufactured based on the main chip of the optical mouse. But the restrictions of high illumination requirement and installation location lead to a narrow range of applications. In this thesis, a new type of optical flow sensor was used to build a new positioning device and its application in the positioning of the indoor mobile robot localization was studied.The main work was as follows:Firstly, the basic mathematical principle of the existing optical flow algorithm was studied, and its application in navigation and positioning was analyzed. The performance index of the optical flow sensor and its application in navigation and positioning were also analyzed. What's more, the basic theoretical model of optical flow was established and the model was proved precise in positioning according to the simulation results.Secondly, to verify the feasibility of the optical flow localization on a mobile robot, the verification platform of localization model based on three optical flow sensors was constructed. In order to collect the data of the three sensors synchronously, the data acquisition module of the microprocessor based on the Cypress was adopted.Thirdly, after building the data acquisition module, each software part of the data acquisition module was developed, including the design of the data acquisition program. driver, and PC user'application program.As a result, the synchronous acquisition and the processing of the sensor data were realized.Lastly, according to the theoretical model, the localization simulation experiment of robot based on the optical flow sensors was performed.The experiments showed that the model had a high precision in a short distance. Simultaneously, the localization experiment of mobile robot on the hardware platform, to verify the feasibility of the positioning model, was also performed.