Distributed observer based event‐triggered affine formation maneuver control for underactuated surface vessels with positive minimum inter‐event times

This paper proposes an adaptive observer for an active leader and designed a distributed observer‐based control law for the formation control of networked uncertain offshore vessels under the switching topologies. The design of the observer, only depending on the output of the leader system, is featured with the ability of accurately estimating the output of the leader system with an unknown input over the time‐varying communication network, satisfying the periodic switching condition. Then based on the output‐based observer, the formation problem of multiple offshore vessels is converted into the stabilization problem of a multi‐input multi‐output augmented system by further combining the internal model technique and performing a coordinate and input transformation. The original problem is finally solved through constructing a stabilizer for the time‐varying uncertain augmented system, and the efficiency of our design is validated by the formation control of a group of offshore vessels.

Section: Formation Control Of Multiple Offshore Vesselsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Adaptive output observer for a nonautonomous leader system over periodic switching topologies and its applications to the formation control of offshore vessels

Zhou

Dong

2023

“…1,2 As a basic branch of formation control, the formation maneuver technique endows multiple USVs with the ability to alter their relative geometric pattern to execute missions in complex water terrains, such as passing through reef waters, narrow waterways, and avoiding obstacles. 3,4 Tremendous efforts have been made by researchers to realize the formation maneuver goal for multiple USVs, for example, time-varying formation methods, 5,6 cooperative path maneuver methods, [7][8][9] formation containment maneuver methods [10][11][12] and bearing-based formation control methods. 13,14 Generally speaking, the USV formation system often operates in dynamically changing ocean environments that are real-time sensed by onboard sensors.…”

Section: Introductionmentioning

confidence: 99%

“…18,19 To enhance the control performance of AFM controllers, some fixed-time schemes, 20,21 prescribed-time schemes, 22,23 and historical states-based approaches 24,25 have been implemented to design the AFM control law. With the consideration of engineering practice, researchers also paid efforts to apply AFM theory in practical nonlinear systems, including multiple spacecrafts, 26,27 USVs, 4,[28][29][30][31] and unmanned aerial vehicles. 32,33 Although effective, it should be pointed out that the target formation under these methods is regulated by the pre-generated multi-leaders' parameterized trajectories, while producing these trajectories is not a feasible task in applications.…”

Section: Introductionmentioning

confidence: 99%

“…In addition, the designed reference signal system also possesses an intuitive and concise structure for nautic applications. Compared with existing USV AFM schemes, 4,[28][29][30][31] the tedious planning procedure of multiple-parameterized trajectories is not required anymore, which endows the USV formation maneuvering with high feasibility in real-time sensed surrounding environments. 2.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Two‐layer leader‐follower optimal affine formation maneuver control for networked unmanned surface vessels with input saturations

Zhou,

Huang,

et al. 2023

Self Cite

This article studies the two‐layer leader‐follower optimal affine formation maneuver (AFM) control problem for multiple unmanned surface vessels (USV). The basic idea of the developed two‐layer control framework is to realize the time‐varying formation for the leader group in advance, and then let the follower USVs agilely respond to the target formation affinely localized by leaders. To realize this goal, a time‐varying formation reference system is first synthesized to describe leaders' target formation in the affine map of the nominal configuration. The reference system is set up by virtual vessel velocity command and unrotated geometric command, which make it possesses an intuitive application structure for operators to plan AFM commands in real‐time sensed surrounding environments. Then, by means of optimized backstepping design and the adaptive dynamic programming technique, actor‐only reinforcement learning controllers are established for USVs in both two layers to realize the optimal target formation tracking objective. For the proposed optimal controllers, the persistent excitation condition that is required by common optimal control schemes is also removed, which endows the presented scheme with lower computational complexity. Finally, theoretical analysis and simulation results illustrate the closed‐loop stability and the effectiveness of the presented scheme.

Three‐dimensional path following control of underactuated autonomous underwater vehicles with nonzero roll dynamics: A novel line‐of‐sight‐guided approach

Zhang,

Li,

Wang

et al. 2024

Most existing path following control approaches for underactuated Autonomous underwater vehicles (AUVs) assumed that the roll angle can be passively stabilized at zero, and simplified the problem to the 5‐degree‐of‐freedom model. However, in practice, the roll motion suffers from undesirable oscillations induced by environmental disturbances, unbalanced propeller torque, etc. To preserve the stability of the system under nonzero roll dynamics, this paper proposes a novel line‐of‐sight‐ (LOS) guided path following control approach. Firstly, the spatial path following error dynamics model is derived to comprehensively reveal the negative effect of roll dynamics. Secondly, an improved LOS guidance law is designed to compensate for the nonzero roll angle. A salient feature is that the proposed guidance law can be applied to the underwater vehicle no matter it is underactuated in the roll motion or not. Thirdly, by assigning the guidance angles to the desired attitude angles, a robust attitude tracking controller is developed, in which the adaptive estimation technique is employed to handle the lumped uncertainties. The tanh‐based saturation function is incorporated such that the resultant control signals are inherently bounded. The closed‐loop path following and attitude tracking errors are proved to be globally asymptotically stable at the origin. Comparative simulation results are provided to substantiate the effectiveness and superiority of the proposed method.