Fixed‐time extended state observer‐based trajectory tracking control for autonomous underwater vehicles

Abstract

In this paper, we investigate the trajectory tracking control problem for autonomous underwater vehicles (AUVs) with time‐varying external disturbances of currents and waves in the sea. To solve the problem, a fixed‐time extended state observer (FTESO)‐based tracking controller is proposed. Firstly, by using the extended state observer, the FTESO is proposed for estimating the external disturbances and the velocities of the AUV within the fixed convergence time. Based on the FTESO, the fixed‐time controller is proposed for reducing the tracking errors and improving robustness performance. Theoretical analysis is given, which shows that the unknown external disturbances can be compensated and tracking error can converge to zero within the fixed time. Simulation results show that the proposed FTESO controller not only guarantees the fixed‐time convergence but also reduces the trajectory tracking errors of the AUV.

Fixed time output feedback control for quadrotor unmanned aerial vehicle under disturbances

“…A novel continuous finite time extended state observer was established to observe the attitude angular velocity and the synthetic failure simultaneously. A fixed time extended state observer-based tracking controller was proposed to solve trajectory tracking control problem for autonomous underwater vehicles with time-varying external disturbances of currents and waves in the sea by Zheng et al 20 It should be mentioned how to pursue fast convergence is a pivotal issue for control system, so finite time control which possess the nature of fast tracking and disturbance rejection was widely investigated. 21,22 However, the convergence time of finite time system are always correlated with initial conditions and it may increase to infinity if the initial conditions are sufficient large.…”

“…A novel continuous finite time extended state observer was established to observe the attitude angular velocity and the synthetic failure simultaneously. A fixed time extended state observer-based tracking controller was proposed to solve trajectory tracking control problem for autonomous underwater vehicles with time-varying external disturbances of currents and waves in the sea by Zheng et al 20…”

Arbitrary settling time control with prescribed performance for high‐order nonlinear systems

“…The unknown nonlinearities were modelled in fuzzy logic systems. Moreover, Zheng et al [20] investigated the trajectory tracking control problem for autonomous underwater vehicles. A fixed‐time extended state observer‐based tracking controller is proposed.…”

“…The cascade control law was proposed, and it was based on the fixed‐time distributed observer to achieve consensus tracking control. Although the initial state of the system is independent on the fixed‐time control's upper bound in other works [17–21], the actual convergence time is still influenced by system initial state, and the control gain is large. Therefore, a smooth control law needs necessarily to be designed.…”

“…Chen and Sun [16] firstly proposed the control method with fixed-time stable for the high-order systems. Since then, there were other results [17][18][19][20][21]. Hua et al [17] studied the problem of fixed-time prescribed tracking control for uncertain stochastic nonlinear systems that had quantized input and unknown measurement sensitivity.…”