Fast prototyping of a scaled AGV for the testing of stability control for industrial vehicles

Mechatronics is a multidisciplinary and application oriented science. Fast prototyping of a complete, scaled mechatronic system is very useful both for research and teaching activities. This work describes the development of a scaled AGV, using fast prototyping techniques, both for the design of the mechanical components and the development of the vehicle control system. The scaled AGV is used as a scaled demonstrator to verify the feasibility of an anti-capsize controller. Capsize is a typical problem that have to be avoided on industrial vehicles, forklifts and moving lifter where heavy and partially unknown loads have to be moved using vehicles with a design that privilege manoeuvrability and small costs against stability. The AGV is a three wheeled differential drive mobile robot, with front motorized wheels, driven by speed-controlled drivers. The vehicle is controlled through a Texas Instrument C2000 controller, programmable by using Matlab-Simulink Embedded Coder™. Forces exchanged between the wheels and the ground are monitored using low cost load cells. MEMS three-axial accelerometers and gyros are used to detect inertial loads and to estimate the vehicle pose and, through a proper filtering, the ground slope. The implemented strategy is able to identify the loading conditions of the vehicle by means of a dedicated algorithm. Once the vehicle is in motion, the controller, to prevent the vehicle capsize, is able to limit its forward speed without changing the geometry of the assigned trajectory. In this work, the results of preliminary testing activities are shown, in order to demonstrate the validity and the effectiveness of the proposed approach.