Tuning Procedure for Correction of Systematic Errors in a Quad Configuration AGV

Autonomous Guided Vehicle (AGV) is an ensemble of various parts and subsystems and hence prone to operational errors induced due to manufacturing and assembly tolerances. Moreover, the controls of the various actuators are also prone to inaccuracies due to technical limitation of the control hardware. These mechanical and control limitations along with actuator latencies manifest cumulatively as errors in the motion of the AGV. In presence of these errors, vehicle does not faithfully follow the commands issued by the control algorithm and in turn results in path following and stopping inaccuracies. It is imperative to minimize the effect of these errors to achieve the desired repeatability and precision required for the satisfactory operation of the system. The current paper discusses the methodologies for measurement and compensation of systematic errors like difference in wheels orientation and alignments, offset of laser navigator, uncertainty of wheel diameter, etc. The paper proposes formulation of the tuning procedure for a quad configuration AGV. The paper also presents the resulting improvements achieved in AGV performance, in path tracking and positional repeatability at material transfer stations.