No-Load Formation Control of Dual AGVs Based on Container Terminals

To improve the efficiency of container terminal transshipment, the process of dual AGV's no-load formation running to the handling point from the control point of view is studied in this paper. It focuses on the formation process stability and the accuracy of dual AGVs parking at the destination. In this study, the leader-follower formation strategy is used to calculate the desired position and posture of the follower AGV. The position and posture errors are analyzed based on the kinematics model of AGV with nonholonomic constraints. Moreover, the sliding mode controller is designed, which uses position and posture errors as the control parameters. Finally, linear and curvilinear conditions are used to test the comprehensive performance of the formation strategy and controller. Simulation results show that the designed controller achieves fast formation and stable formation kept of dual AGVs with different initial errors. Foremost, the high accuracy in position and posture of dual AGVs parking at the destination can shorten adaptation time between the spreader and AGVs, which proves the dual AGVs formation scheme and controller designed in this paper are feasible and effective.