Arc Path Tracking Algorithm of Dual Differential Driving Automated Guided Vehicle

A dual differential driving Automated Guided Vehicle consists of two differential driving modules, suffering from low precision and difficult control in arc path tracking. In this paper, the speeds coordination of the two driving modules is analyzed based on circular geometric constraints; and a hybrid control strategy combining a yaw angle stability control of the two driving modules with an algorithm of real-time correction of deviations is proposed. The whole motion process is decomposed into arc starting segment, arc tracking segment and arc ending segment, where three sets of linear kinematic models are established respectively. The arc starting segment is the initial transition phase of the arc path tracking; the speeds constraint of the four driving wheels is established based on the angle constraint to adjust two differential modules to target yaw angle. The arc tracking segment analyzes the angular velocity coordination condition among the center of AGV and two differential modules. The arc ending segment describes the transition from the arc tracking segment to the straight track. The speed constraint smoothly decreases the yaw angle of two driving modules turning to zero. The MATLAB simulation and physical measurement show that the algorithm is simple, accurate and stable.