Sliding mode based neural adaptive formation control of underactuated AUVs with leader-follower strategy

In this brief, the leader-follower formation control of underactuated autonomous underwater vehicles subject to uncertain dynamics and ocean disturbances is addressed. A robust sliding mode formation control strategy is presented by utilizing backstepping method, adaptive neural network and dynamic surface control technique. The stability of the formation control system is proved based on the Lyapunov's direct method where all the signals are guaranteed to be uniformly ultimately bounded. The main advantages of this control strategy are summarized as: (i) the presented controller only depends on the position measurements of the leader, which is more convenient to implement in practice. (ii) the proposed controller does not require any prior knowledge about the hydrodynamic damping and disturbances from the environment. (iii) a continuous PI function is designed to avoid the effect of inherent chattering in standard sliding mode control. (iv) the computational explosion of the standard backstepping method is avoided by the command filter based on the dynamic surface control technique. At last, the comparative simulations are provided to verify the effectiveness of the presented control strategy.