The Indoor Robots Localization Algorithm Based On Multi-sensors

More and more mobile robots are widely used in indoor positioning.This paper mainly studies of three key issues of the robot navigation in indoor environments: robot self-localization,map building and path-planning.Robots use various sensors to sense the surrounding environment information and their position in the environment.This independent positioning technology is the precondition of robots can complete various tasks such as navigation.Firstly,this paper presents a new way of locating the RFID(Radio Frequency Identification Devices)labels to achieve signal strength location,and use empowerment algorithm to get the horizontal axis,combined with the ultrasonic distance measurement to obtain the vertical axis,so that we can get the accurate position of robot at some fixed point to decrease the cumulative error of the Dead Reckoning location.And this paper puts forwards an assistant localization algorithm by using the RFID tags as artificial landmarks.It saves sign information of location in the RFID tags.We can store some inherent location information,such as room door,corridor,corner location information in accordance with some rules,in the RFID tags.This way can help the robots to auxiliary locate the current location information when they walk to the location next time.In order to achieve the robot's locating and the map creating at the same time,this paper designs a local map building method based on multiple ultrasonic sensors to build the indoor environment local map.And in moments of mutations,it can detect and bulid overall map.After the map creation and the work of locating,this paper designs a robot control algorithm to ensure that robot walking parallel to the wall in the experiment based on RFID and ultrasonic localization algorithm and to adjust the real-time posture.This algorithm includes the robot walking straightly instructions and rotating control instructions.The algorithm is suitable for adjusting the basic indoor robots positions,and it can lay the good foundation to solve the problem of indoor path planning.Due to separately using RFID combined with ultrasonic to locate the robot indoor positioning will bring us the limitations of short positioning distance.This article takes the advantage of the large range of Zig Bee positioning and its low power consumption.It combines RFID and ultrasonic sensor and Zig Bee sensor to realize the indoor robot localization,making up for the deficiency of the use RFID combined with ultrasonic to locate position singly.And the RFID combined with ultrasonic locating algorithm can also compensate for the error of using Zig Bee singly sensor on the edge of the network or outside of the critical location's positioning.Because of the complexity of the indoor environment as well as the information limitations of the single sensor system and other kinds of factors,if the indoor robots perceive the external environment by using a certain mixing method,it will help more sensors to make better use of the environment information.It can get more effective and accurate data information than using single sensor to gain the environment information,which will records the external environment characteristics more comprehensively and accurately.And it can provide more accurate data for indoor robot to realize its own navigation and positioning and more complex functions.