Abstract:For ultra-large and heavy components which are never uncommon in the aerospace industry such as bay section,wing,and so on,employment of heavy-duty automated guided vehicle (AGV) can help improve delivery efficiency and safety.Differential wheel that features higher bearing and driving capacities with dual-wheel structure is widely applied to AGV.However,the special structure causes two wheels to restrict each other when the system works,at the same time,and multiple differential wheels on the same AGV are restricted by the body rigidity.Restricting effect,either between systems or within the same wheel system,results in bad coupling and inadequate tracking flexibility for the overall vehicle.By combining error-based and driving capacity-based control laws,a multi-differential cooperative control system was proposed specific for system driven by differential wheels.In the method,taking the dynamic characteristics of differential wheel and the overall rigid body into full consideration,to guarantee the smooth operation of AGV,all wheels were limited in terms of driving speed.Therefore,driving motors would not frequently switched between positive and negative rotation and driving speeds would not exceed the driving capacity.In addition,the rotation center of each differential wheel was not limited to the center axis of car body which made the method easy to be extended to more units.The simulation results show that the method can make pose position-based decisions and figure out conforming driving speed.Its ability in effectively coordinating attitude correction demand with the wheel systems movement performance can significantly eliminate standing error and help the vehicle to achieve a final stable state.It proves efficient in accomplishing an overall optimization of differential-driven AGVs tracking performance.