Indoor Positioning And Following Of Mobile Robot Base On UWB

As a new type of human-machine collaboration,following technology has become a hot topic of research in recent years.Meanwhile,with the development of mobile robot technology and the gradual improvement of people’s working and life quality,there is an increasing demand for indoor robots in terms of positioning and following.In the process of indoor following,due to the interference of indoor environmental factors,the traditional positioning method is difficult to meet the requirements of accurate positioning in the application,while UWB technology can overcome the multi-path effect of wireless signals and improve positioning accuracy effectively.Thus,in order to further address effects of non-line-of-sight factors in UWB localization,and to improve the accuracy and smoothness of following motion,this thesis carries out research on indoor localization and following of mobile robots based on UWB.The main research contents and innovations of this thesis are as follows:(1)Research on localization algorithm based on UWB technology.Firstly,the practical problem that UWB positioning technology is easily disturbed by non-line-ofsight factors in indoor environment is analyzed,and a method based on the difference between the first path position and the peak path position is proposed,which can determine the existence of non-line-of-sight factors effectively.Meanwhile,a method that combines relative and absolute positioning is proposed to reduce the impacts of non-line-of-sight on positioning results.Finally,by combining the speed of the robot,the extended Kalman filter algorithm is proposed to obtain accurate localization results by absolute localization of the mobile robot.(2)Research on following control algorithm of mobile robot.On the basis of accurate positioning of the mobile robot,a following control strategy combining fuzzy control and PID control is proposed.The information of distance,direction,position deviation between the robot and the following target are used to determine the PID correction parameters and the desired state of the robot during the following process,and the linear and angular velocity of the robot are controlled by PID to achieve smooth following of the target.(3)Platform construction and experimental verification.The software and hardware system of mobile robot are designed and the robot following experimental platform is built.The experiments of UWB ranging and positioning,non-visual range judgment and robot following have been completed to verify the ranging and positioning accuracy and following control algorithms.The experimental results reveal that the accuracy of the designed non-line-of-sight judgment method is more than 92%,and the designed positioning algorithm can achieve a deviation of ±5cm in range and±3°in angle,and the positioning accuracy can reach within 9cm.Based on the above accurate positioning information,the robot can finally follow the target and complete the following motion stably.