Command‐filtered fixed‐time trajectory tracking control of surface vehicles based on a disturbance observer

Abstract

Summary In this paper, we investigate trajectory tracking control of surface vehicles with model parameter uncertainties and external disturbances. The disturbances due to the wind, waves, and ocean currents are combined with the model parameter uncertainties as a compound disturbance. Then, a disturbance observer (DO) is introduced to estimate the compound disturbance, which can be achieved within a finite time independent of the initial estimation error. Based on the DO and, in the context of command filtered control, a novel fixed‐time backstepping control scheme is developed, by which the vehicle can track the desired trajectory with all the states globally stabilized in a given fixed time. The effectiveness and performance of the method are demonstrated by numerical simulations.

Event-Triggered Adaptive Practical Fixed-Time Trajectory Tracking Control for Unmanned Surface Vehicle

“…Nevertheless, noted that the derivation of the control law was dependent on the repeated differentiation of virtual control laws in the recursive procedure, which undoubtedly will cause the problems of computational complexity and over parametrization once the dimensionality of the system is too high. Inspired by [9], a novel trajectory tracking control scheme was proposed in [19] by introducing the command filtered backstepping technique. It should be pointed out that the method proposed in [19] is only available for the USV with fully known model dynamics.…”

“…Inspired by [9], a novel trajectory tracking control scheme was proposed in [19] by introducing the command filtered backstepping technique. It should be pointed out that the method proposed in [19] is only available for the USV with fully known model dynamics. Moreover, the aforementioned results in [2]- [6], [8], [9], [14]- [19] were based on the time-triggered control scheme, where a large number of network communication resources were required since the control signal need to be updated periodically.…”

“…It should be pointed out that the method proposed in [19] is only available for the USV with fully known model dynamics. Moreover, the aforementioned results in [2]- [6], [8], [9], [14]- [19] were based on the time-triggered control scheme, where a large number of network communication resources were required since the control signal need to be updated periodically. Therefore, it is significant to develop an event-triggered adaptive fixed-time trajectory tracking control method for guaranteeing the stability of the CLSs under any initial states and limited network transmission environment.…”

“…(i) This brief makes the first attempts to develop an event-triggered adaptive fuzzy fixed-time trajectory tracking control scheme for the USV with unknown dynamics. What's more, the computational complexity exposed in [16]- [18] is greatly relaxed and the exact inertia dynamics in [19] are not required under the proposed method. (ii) Distinct from [2]- [6], [8], [19], two kinds of compensation signals are constructed for achieving better tracking performance and improving the system robustness against the perturbations, where the negative effects caused by the filter errors, disturbances, and approximation errors are effectively reduced.…”

Finite‐time extended state observer‐based exact tracking control of an unmanned surface vehicle

“…Note that finite‐time control technique has attracted extensive attention because of its stronger robustness and disturbance rejection properties 42‐46 . In this respect, terminal sliding mode (TSM) technique 47,48 has been proposed for realizing finite‐time convergence.…”