Experimental test of a robust formation controller for marine unmanned surface vessels

Abstract

Experiments with two formation controllers for marine unmanned surface vessels are reported. The formation controllers are designed using the nonlinear robust model-based sliding mode approach. The marine vehicles can operate in arbitrary formation configurations by using two leader-follower control schemes. For the design of these controller schemes 3 degrees of freedom (DOFs) of surge, sway, and yaw are assumed in the planar motion of the marine surface vessels. Each vessel only has two actuators; therefore, the vessels are underactuated and the lack of a kinematic constraint puts them into the holonomic system category. In this work, the position of a control point on the vessel is controlled, and the orientation dynamics is not directly controlled. Therefore, there is a potential for an oscillatory yaw motion to occur. It is shown that the orientation dynamics, as the internal dynamics of this underactuated system, is stable, i.e., the follower vehicle does not oscillate about its control point during the formation maneuvers. The proposed formation controller relies only on the state information obtained from the immediate neighbors of the vessel and the vessel itself. The effectiveness and robustness of formation control laws in the presence of parameter uncertainty and environmental disturbances are demonstrated by using both simulations and field experiments. The experiments were performed in a natural environment on a lake using a small test boat, and show robust performance to parameter uncertainty and disturbance.the first experimental verification of the above mentioned approach, whose unique features are the use of a control point, the zero-dynamic stability analysis, the use of leaderfollower method and a nonlinear robust control approach.

Interior Point Algorithm for Multi-UAVs Formation Autonomous Reconfiguration

“…In (6), represents a positive definite weighting matrix; the second term is used to normalize the original optimization problem and ensure that the optimal solution will not depart the true solution. Similarly two other cost functions coming from the missile and radar interference are given:…”

“…In total there are UAVs lying in the formation geometry. Combining (6), 7, and (8), we consider the following cost function:…”

“…In [5] the methods about how to fuse the multiple sensor information are analyzed to obtain state estimates from the perspective of information fusion. In [6] the particle filter algorithm is applied to track path under the non-Gaussian condition. In [7] one interacting multiple model algorithm based on particle filter is proposed.…”

Alternative trajectory-tracking control approach for marine surface vessels with experimental verification

“…The details of the zero-dynamic stability analysis for the vessel used for experiments in this paper is found in ref. [22], where relative distances of two adjacent vessels with respect to each other are controlled (i.e. formation control).…”

Formation control of underactuated ships with elliptical shape approximation and limited communication ranges

“…The leader-follower approach plus the Lyapunov and sliding mode methods were used in Lapierre et al (2003), Fahimi (2007), Schoerling et al (2010), Cui et al (2010) to design cooperative controllers for a group of underactuated vessels. A combination of line-of-sight path-following and nonlinear synchronization strategies was studied in Borhaug et al (2006), Borhaug et al (2010) to make a group of underactuated vessels asymptotically follow a given straight-line path with a given forward speed profile.…”