Neural adaptive output feedback formation control of type (m, s) wheeled mobile robots

This study introduces a general framework for the formation tracking control of all types of wheeled mobile robots (WMRs). On the basis of a coordinate transformation, a second-order input-output model is developed for the general type (m, s) WMR with the mobility m and the steerability s. Then, a saturated feedback linearising controller in conjunction with a non-linear velocity observer is proposed in order to leave out the velocity sensors in all agents. In addition, a radial basis function neural network and an adaptive robust compensator are incorporated in the formation controller design to improve the tracking performance in the presence of uncertain non-linearities and unknown parameters. Semi-global stability of the closed-loop formation system is proved using direct Lyapunov method. Moreover, a generalisation of the proposed controller is introduced for the cooperative control of mobile manipulators. Finally, simulation examples are given to illustrate the effectiveness of the proposed formation control system for two types of WMRs.