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Distributed high-gain attitude synchronization using rotation vectors ; Thunberg, Johan ; et al in Journal of Systems Science and Complexity (2015), 28(2), 289-304 This paper addresses attitude synchronization problems for systems of multiple rigid-body agents with directed interconnection topologies. Two scenarios which differ in available information are ... [more ▼] This paper addresses attitude synchronization problems for systems of multiple rigid-body agents with directed interconnection topologies. Two scenarios which differ in available information are considered. In the first scenario the agents can obtain their rotations and angular velocities relative to an inertial reference frame and transmit these information to their neighbors, while in the second scenario the agents can only obtain their own angular velocities and measure the relative rotations and relative angular velocities of their neighbors. By using rotation vectors and the high gain control, the authors provide torque control laws asymptotically synchronizing the rotations of the system almost globally for the first scenario and with initial rotations of the agents contained in a convex ball of SO(3) for the second scenario. An illustrative example is provided to show the synchronization results for both scenarios. [less ▲] Detailed reference viewed: 107 (4 UL)Distributed attitude synchronization using backstepping and sliding mode control Thunberg, Johan ; ; et al in Control Theory and Technology (2014), 12(1), 48-55 We consider the problem of attitude synchronization for systems of rigid body agents with directed topologies. Two different scenarios for the rotation matrices of the agents are considered. In the first ... [more ▼] We consider the problem of attitude synchronization for systems of rigid body agents with directed topologies. Two different scenarios for the rotation matrices of the agents are considered. In the first scenario, the rotations are contained in a convex subset of SO(3), which is a ball of radius less than π/2, whereas in the second scenario the agents are contained in a subset of SO(3), which is a ball of radius less than π. Using a control law based on backstepping and sliding mode control, we provide distributed, semi-global, torque control laws for the agents so that the rotations asymptotically synchronize. The control laws for the agents in the first scenario only depend on the relative rotations between neighboring agents, whereas the control laws in the second scenario depend on rotations defined in a global coordinate frame. Illustrative examples are provided where the synchronization is shown for both scenarios. [less ▲] Detailed reference viewed: 175 (0 UL)Distributed attitude synchronization control of multi-agent systems with switching topologies Thunberg, Johan ; ; et al in Automatica (2014), 50(3), 832-840 This paper addresses the attitude synchronization problem in multi-agent systems with directed and switching interconnection topologies. Two cases for the synchronization problem are discussed under ... [more ▼] This paper addresses the attitude synchronization problem in multi-agent systems with directed and switching interconnection topologies. Two cases for the synchronization problem are discussed under different assumptions about the measurable information. In the first case the agents can measure their rotations relative to a global reference coordinate frame, whilst in the second case they can only measure the relative rotations between each other. Two intuitive distributed control laws based on the axis–angle representations of the rotations are proposed for the two cases, respectively. The invariance of convex balls in SO(3) is guaranteed. Moreover, attitude synchronization is ensured under the well-known mild switching assumptions, the joint strong connection for the first case and joint quasi-strong connection for the second case. To show the effectiveness of the proposed control schemes, illustrative examples are provided. [less ▲] Detailed reference viewed: 118 (2 UL)Distributed attitude synchronization control of multi-agent systems with time-varying topologies ; Thunberg, Johan ; et al in Proceedings of the 10th World Congress on Intelligent Control and Automation (2012) This paper addresses the attitude synchronization problem of multiple rigid body agents in SO(3) with directed and switching interconnection topologies. Using the axis-angle representation of the ... [more ▼] This paper addresses the attitude synchronization problem of multiple rigid body agents in SO(3) with directed and switching interconnection topologies. Using the axis-angle representation of the orientation, a distributed controller based on differences between the orientations of agents in a global frame is proposed. In the case of the balanced interconnection graph, the attitude synchronization is achieved with the well-known mild assumption (that is, uniform joint strong connection). To demonstrate the effectiveness of the proposed control scheme, an illustrative example is provided. [less ▲] Detailed reference viewed: 93 (0 UL)Distributed attitude synchronization control of multi-agent systems with directed topologies Thunberg, Johan ; ; et al in the proceedings of the 10th World Congress on Intelligent Control and Automation (2012) In the present paper we consider the problem of attitude synchronization for a system of rigid body agents. We provide distributed kinematic control laws for two different synchronization problems. In the ... [more ▼] In the present paper we consider the problem of attitude synchronization for a system of rigid body agents. We provide distributed kinematic control laws for two different synchronization problems. In the two problems the objective is the same, i.e., to synchronize the orientations of the agents, but what is assumed to be measurable by the agents differs. In problem 1 the agents measure their own orientations in a global reference frame, and obtain the orientations of their neighbors by means of communication. In problem 2 the agents only measure the relative orientations to their neighbors. By using the axis-angle representation of the orientation, we show that simple linear control laws solve both synchronization problems. Moreover we show that our proposed control laws work for directed and connected topologies on almost all SO(3) for problem 1 and on convex balls in SO(3) for problem 2. [less ▲] Detailed reference viewed: 110 (0 UL) |
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