Research On Ultrasonic Ranging And Localization Algorithm For Indoor Robots

Indoor robot positioning navigation is one important researching area on robots, while right now robots positioning has been given more and more attention combined by radio frequency synchronization and ultrasonic ranging in which measuring the accurate distance between the mobile robot and the fixed beacon node is crucial to achieve positioning for robots. A radio frequency ultrasound positioning system based on Wireless Sensor Networks is designed in this paper, an ultrasonic transceiver is adopted and the RF module's synchronization capabilities is combined to accurately measure the distance between the robot and the beacon node. In addition, because of the existing systematic errors of the positioning system model of itself and noises in external environment, a lot of errors still exist. Therefore, this paper further more adopts the combined algorithm based on Bayesian filter theory by Kalman filter and the sensor resetting localization to optimize the measured location information, so that the estimated value of the location is closer to the true value.The main research works completed include:1. Rather deeply analysing current researching situations and current progress of robot localization methods, and meanwhile taking into account system reliability, manufacturing costs, positioning accuracy and efficiency,the radio frequency ultrasound positioning method based on road signs is chosen to research.2. Integrating the mechanisms' advantages of the Active Bat system and the Cricket system, an indoor robot radio frequency ultrasound positioning system based on a wireless sensor network is designed,so that ensuring the localization privacy. and meanwhile meeting the real-time requirements for mobile robot localization.3. The TCT40-16TR1 type ultrasonic transceiver and CC1101 RF module are adopted to finish corresponding hardware design and circuit board production. as well as its program design and programming work. Thus the radio frequency and ultrasonic ranging between the robot and the beacon node is achieved.4. Controlled by the MCU, the analog multiplexer chip CD4052 connects the ultrasonic transceiver probe with the sending circuit and signal receiving circuit separately, and software filtering method is used to filter the received signal. Thus the robot ranging experiment with signal's sending process and receiving process integrated is more accurately achieved. In another word, the ranging device is not only suitable for ranging with one sending and the other receiving but also for sending and receiving integrated.5. After analysis and comparison of domestic and oversea robot localization algorithms, this paper proposes a positioning algorithm combined Kalman filter and the sensor resetting localization and conducts a simulation and comparative experiment by means of MATLAB. Experimental results show that the improved algorithm can effectively lower the calculation costs, and meanwhile has good robustness.