Rail guided automated transportation system for directly transporting cassettes for FPD panels to the stockers or process equipment. "RGV" is the abbreviation for Rail Guided Vehicle. As the vehicle is guided on rail, it can be run safely and smoothly at high speed. A highly sophisticated motion control system is used for high speed and high acceleration, deceleration, to achieve a high throughput capability in the inter-bay and/or the intra-bay transportation.