Passivity-Based Lag-Compensators With Input Saturation for Mechanical Port-Hamiltonian Systems Without Velocity Measurements

This paper investigates the attitude stabilization problem of rigid spacecraft subject to actuator constraints, external disturbances, and attitude measurements only. An output feedback control framework with input saturation is proposed to solve this problem. The general saturation function is utilized in the proposed controller design and a unified control method is developed for the asymptotic stabilization of rigid spacecraft without velocity measurements. Asymptotic stability is proven by Lyapunov stability theory. Moreover, a new nonlinear disturbance observer is designed to compensate for external disturbances. Then, a composite controller is presented by combining a unified saturated output feedback control with a nonlinear disturbance observer. Desirable features of the proposed control scheme include the intuitive structure, robustness against external disturbances, avoidance of model information and velocity measurements, and ability to ensure that the actuator constraints are not violated. Finally, numerical simulations have been carried out to verify the effectiveness of the proposed control method.

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Robust second-order tracking of multi-agent systems without velocity measurements and with input saturation

2015 34th Chinese Control Conference (CCC) ◽

10.1109/chicc.2015.7260805 ◽

2015 ◽

Author(s):

Qingling Wang ◽

Changyin Sun ◽

Jian Hou ◽

Yingjiang Zhou

Keyword(s):

Input Saturation ◽

Second Order ◽

Multi Agent Systems ◽

Velocity Measurements ◽

Agent Systems ◽

Order Tracking ◽

Multi Agent

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Distributed trajectory tracking and formation control without velocity measurements by the notion of prior bounded local neighborhood synchronization error

Measurement and Control ◽

10.1177/0020294019877501 ◽

2020 ◽

Vol 53 (3-4) ◽

pp. 577-588 ◽

Cited By ~ 1

Author(s):

Boxian Lin ◽

Te Zhang ◽

Bo Zhu ◽

Kaiyu Qin

Keyword(s):

Formation Control ◽

Controller Design ◽

Input Saturation ◽

Parameter Tuning ◽

Synchronization Error ◽

Velocity Measurements ◽

Tracking Errors ◽

Synchronization Errors ◽

Parameter Mapping ◽

Local Neighborhood

This paper investigates the robust consensus tracking and formation control problems of multiple second-order systems having exogenous disturbances and no velocity measurements. To account for the input saturation constraint in controller design, a novel notion of local neighborhood synchronization error is proposed, which is obtained using generalized saturation functions and can be regarded as a nonlinear variation of the well-known linear local neighborhood synchronization error. An important property of the notion is proved and then a continuous distributed controller is designed using it. To improve the robustness of the controller with respect to exogenous disturbance, a disturbance estimator–based design and a simple parameter mapping for parameter tuning are proposed. The resulting error system is proven to be small-signal [Formula: see text] stable and input-to-output stable. In particular, the synchronization errors and tracking errors converge asymptotically to zero if the disturbances converge to some constants. By the parameter mapping, the steady-state synchronization errors and tracking errors can be made arbitrarily small. The control scheme is finally modified to adapt to formation control applications by adding the desired position deviation from the leader’s trajectory. The performance of the scheme is demonstrated by the simulation results.

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