Study On Ultrasonic Localization And Obstacle Avoidance Of AGV

Taking the independently developed Automated Guided Vehicles(AGV) of our institute as research object, from the practical demand of engineering application, kinematic modeling, composition of control system, distance measure experiment by ultrasonic sensor, treating and fitting of sensor data, lateral localization and obstacle avoidance during practical development process of AGV are analyzed and researched deeply by mechanical engineer, computer control, sensor detection and signal process technology.The kinematics model was built and the component of the control system was analyzed about the two wheel differential steering AGV(XAUT.AGV100), which established the basis for the motion control in the behind. The exploring obstacle characteristics of analog ultrasonic sensor were analyzed and a precise calibration method was presented by experiments, the results indicated that this method was simple and effective. By data fitting and error compensating, the maximum relative error of measure system was decreased to 0.34% from 1.14% before error compensation and 1.84% of neglecting the effect of incident angle. The dual-ultrasonic combination measurement experiment was carried out and the measure precision of different measure modals was compared and analyzed. In order to reach the higher accuracy, the modeling and simulation of ultrasonic measure system were carried out by BP neural network. The traditional PID control method was used to carry on the lateral location experiment of AGV by the project of dual-ultrasonic measurement. The results indicated that the precision of location and pose could reach to±2.5mm and±0.42°. The avoiding obstacle of AGV path planning was discussed; the defects of artificial potential field were improved by building new potential field function and adjusting potential field area. The simulation results indicated that the local trap and path shock problems were solved essentially.As the study in this paper is completed in the process of developing several types of AGV, the new thoughts and methods presented in the paper can be tested practically and corrected in time. Thus, the methods and relevant conclusions in the paper are originated from practical development process and can be referenced in the design and development of AGV.