Dynamic Modeling and Control of a Two Wheeled Robotic Vehicle with a Virtual Payload

ABSTRACT One of the challenging issues to consider in balancing a two-wheeled robotic machine (TWRM) is when the load carried by the machine is changing position along the vehicle intermediate body (IB). An issue of interest in this case is the resulting impact on the system behaviour due to changing position of the load. Further complications arise with changing the size of the load. This work presents investigations into controlling a TWRM with a payload positioned at different locations along its IB. Two types of control techniques are developed and implemented on the system, the traditional proportional-derivative (PD) control and fuzzy logic (FL) control. PD and PD-fuzzy logic control techniques are developed to balance the vehicle with a payload incorporating two different scenarios. Firstly, the payload is positioned at different locations along its IB. Secondly, it is considered to perform a continuous sliding motion along the IB. The balancing of the robot has to be achieved during the motion of the vehicle and the payload along the IB. An external disturbance force is applied to the rod which constitutes the IB in order to test the robustness of the developed controllers. Investigations are carried out on the effect of changing the level and duration of the disturbance force, and changing the speed of the payload on the system during the balancing mode. Simulation results of both control algorithms are analyzed on a comparative basis.