Journal articleIEEE Transactions on Medical Robotics and Bionics · January 1, 2026
Robot-assisted ultrasound scanning promises to advance autonomous and accessible medical imaging. However, ensuring patient safety and compliant human-robot interaction during probe contact poses a significant challenge. Most existing systems either have h ...
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Journal articleInternational Journal of Robust and Nonlinear Control · May 10, 2025
Externally switched systems have unique characteristics that make it is especially challenging to ensure their stability and feasibility. These challenges are exacerbated when the system contains modes with uncontrollable dynamics, tight input constraints, ...
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Journal articleSystems and Control Letters · May 1, 2025
This paper provides a method to analyze the local, small-signal L2-gain of control-affine nonlinear systems on compact sets via iterative semi-definite programs. First, a continuous piecewise affine storage function and the corresponding upper b ...
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Journal articleIEEE Control Systems Letters · January 1, 2025
Analogous to (Formula presented) -methods for linear time invariant systems, (Formula presented) -gain is an important input-output characterization of robustness for nonlinear systems. The Hamilton-Jacobi Inequality can be used to establish (Formula prese ...
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Journal articleInternational Journal of Robust and Nonlinear Control · September 10, 2024
Imitation learning enables synthesis of controllers for systems with complex objectives and uncertain plant models. However, ensuring an imitation learned controller is stable requires copious amounts of data and/or a known plant model. In this paper, we e ...
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Journal articleIEEE Transactions on Automatic Control · May 1, 2024
A controller synthesis method for state- and input-constrained nonlinear systems is presented that seeks continuous piecewise affine (CPA) Lyapunov-like functions and controllers simultaneously. Nonconvex optimization problems are formulated on triangulate ...
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Journal articleIEEE Transactions on Automatic Control · February 1, 2024
Practical controllers for large-scale systems must be low-order and sparsely communicating, as well as high-performing and robust to uncertainty. H2-conic design addresses the latter requirements where passivity and H∞ methods are inapplicable, but it has ...
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Journal articleIEEE Control Systems Letters · January 1, 2024
We present a novel direct data-driven method for computing constraint-admissible positive invariant sets for general nonlinear systems with compact constraint sets. Our approach employs machine learning techniques to lift the state space and approximate in ...
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Journal articleIEEE Control Systems Letters · November 1, 2021
Although state-based switching is well-studied in the context of model predictive control (MPC), the theory for exogenous switches is less advanced. External switching affects many systems and is of growing importance due to the increasing use of networked ...
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Journal articleIEEE Control Systems Letters · November 1, 2021
Dwell-time restrictions are critical to overcoming infeasibility caused by arbitrary switches in constrained time-dependent switched systems, especially when the system equilibrium is mode dependent. However, existing approaches to enforce constraints are ...
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Journal articleIEEE Control Systems Letters · October 1, 2021
A controller is designed through an alternating direction method of multipliers (ADMM) algorithm to maximize sparsity while providing similar closed-loop $\mathscr {H}_{2}$ performance to an optimal 'target' controller and imposing conic bounds that ensure ...
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Journal articleInternational Journal of Robust and Nonlinear Control · July 25, 2019
This paper proposes a method to synthesize controllers that minimize an upper bound on the closed-loop H2-norm while imposing desired controller conic bounds. An initial conic controller is synthesized and iteratively improved. Conic sectors can ...
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Journal articleInternational Journal of Robust and Nonlinear Control · June 2019
SummaryThis paper studies the control of constrained systems whose dynamics and constraints switch between a finite set of modes over time according to an exogenous input signal. We define a new type of control invariant se ...
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