Navigation of automated guided vehicles using magnet spot guidance method

Automated guided vehicle systems (AGVSs) are used to transport goods and products in most manufacturing systems. In this research, we use a cylindrical magnet spot, which is widely used in industrial AGVSs, to develop a guidance system for indoor AGV navigation. This paper describes the navigation and control system of an AGV by magnet spot guidance with a differential drive. Furthermore, Hall-effect sensors, encoders, and counters are employed to achieve control and continuous guidance. Existing guidance methods use a gyro sensor and dead reckoning with encoders to calibrate against steering angle errors. Here, the maximum value of the magnetic flux density of the magnet spot, which is obtained by the Hall-effect sensor, is used to calibrate against steering angle errors and as a navigation guide for the AGV. Furthermore, real-time corrections for wheel-skidding errors are accomplished with a fuzzy controller. Thus, high-precision continuous guidance with stable and satisfactory navigation at high speeds is achieved. This guidance method was applied to real manufacturing processes in a ceramic plant and steel-bar reinforcement plant to examine its control ability, stability, and effectiveness. The proposed method was found to be robust to disturbances and uncertainty problems during tracking.

Graphical AbstractFigure optionsDownload as PowerPoint slideHighlights
► We report a guidance method for AGVSs using cylindrical magnet spot and differential drive.
► Hall-effect sensors, encoders, and counters have been used for control and continuous guidance.
► Maximum value of magnetic flux density of the magnet spot is used to calibrate against steering angle errors.
► High-precision continuous guidance with stable and satisfactory navigation at high speeds is achieved.
► This method was found to be robust to disturbances and uncertainty problems during tracking.