180 citations · 719 across the 46 of their papers we have counts for
49 papers
Sparsity in control problems: Recent trends and open challenges
Luca Ballotta, Geethu Joseph, Geethu Josephb +7
As in all fields of engineering, control engineers constantly face a dichotomy between achieving high performance and the limited availability of resources for sensing, actuation,…
Learning Reduced-Order Dynamics with Singularity via Latent-Augmented Neural Ordinary Differential Equations
Xiaorui Wang, Yu Zhou, Wenjie Mei +3
This paper addresses the issue of self-intersecting trajectories (in phase space) in industrial reduced-order modeling and proposes the Latent-Augmented Neural Ordinary Differentia…
Finite-Time Optimization via Scaled Gradient-Momentum Flows
Yu Zhou, Mengmou Li, Masaaki Nagahara
In this paper, we develop a scaled gradient-momentum framework for continuous-time optimization that achieves global finite-time convergence. A state-dependent scaling mechanism is…
Hypertracking and Hyperrejection: Control of Signals beyond the Nyquist Frequency
Kaoru Yamamoto, Yutaka Yamamoto, Masaaki Nagahara
This paper studies the problem of signal tracking and disturbance rejection for sampled-data control systems, where the pertinent signals can reside beyond the so-called Nyquist fr…
Sparse Packetized Predictive Control of Disturbed Plants Over Channels with Data Loss
Mohsen Barforooshan, Masaaki Nagahara, Jan Ostergaard
This paper investigates closed-loop stability of a linear discrete-time plant subject to bounded disturbances when controlled according to packetized predictive control (PPC) polic…
Necessary condition for sparse optimal control problem with intermediate constraints
Yogesh Kumar, Sukumar Srikant, Debasish Chatterjee +1
This article treats optimal sparse control problems with multiple constraints defined at intermediate points of the time domain. For such problems with intermediate constraints, we…
The turnpike property in the maximum hands-off control
Noboru Sakamoto, Masaaki Nagahara
This paper presents analyses for the maximum hands-off control using the geometric methods developed for the theory of turnpike in optimal control. First, a sufficient condition is…
CLOT Norm Minimization for Continuous Hands-off Control
Niharika Challapalli, Masaaki Nagahara, Mathukumalli Vidyasagar
In this paper, we consider hands-off control via minimization of the CLOT (Combined -One and Two) norm. The maximum hands-off control is the -optimal (or the sparsest) cont…
Min-Max Design of Feedback Quantizers for Netorwked Control Systems
Shuichi Ohno, Yuma Ishihara, Masaaki Nagahara
In a networked control system, quantization is inevitable to transmit control and measurement signals. While uniform quantizers are often used in practical systems, the overloading…
Continuous Hands-off Control by CLOT Norm Minimization
Niharika Challapalli, Masaaki Nagahara, Mathukumalli Vidyasagar
In this paper, we consider hands-off control via minimization of the CLOT (Combined L-One and Two) norm. The maximum hands-off control is the L0-optimal (or the sparsest) control a…
Rate-Distortion Analysis of Quantizers with Error Feedback
Shuichi Ohno, Teruyuki Shiraki, M. Rizwan Tariq +1
A Delta-Sigma modulator that is often utilized to convert analog signals into digital signals can be modeled as a static uniform quantizer with an error feedback filter. In this pa…
Characterization of maximum hands-off control
Debasish Chatterjee, Masaaki Nagahara, Daniel Quevedo +1
Maximum hands-off control aims to maximize the length of time over which zero actuator values are applied to a system when executing specified control tasks. To tackle such problem…
Maximum Hands-off Control without Normality Assumption
Takuya Ikeda, Masaaki Nagahara
Maximum hands-off control is a control that has the minimum L0 norm among all feasible controls. It is known that the maximum hands-off (or L0-optimal) control problem is equivalen…
Multiuser Detection by MAP Estimation with Sum-of-Absolute-Values Relaxation
Hampei Sasahara, Kazunori Hayashi, Masaaki Nagahara
In this article, we consider multiuser detection that copes with multiple access interference caused in star-topology machine-to-machine (M2M) communications. We assume that the tr…
Discrete-Valued Control by Sum-of-Absolute-Values Optimization
Takuya Ikeda, Masaaki Nagahara, Shunsuke Ono
In this paper, we propose a new design method of discrete-valued control for continuous-time linear time-invariant systems based on sum-of-absolute-values (SOAV) optimization. We f…
Symbol Detection for Frame-Based Faster-than-Nyquist Signaling via Sum-of-Absolute-Values Optimization
Hampei Sasahara, Kazunori Hayashi, Masaaki Nagahara
In this letter, we propose a new symbol detection method for faster-than-Nyquist signaling (FTNS) systems. Based on frame theory, we formulate a symbol detection problem as a under…
Digital Cancelation of Self-Interference for Single-Frequency Full-Duplex Relay Stations via Sampled-Data Control
Hampei Sasahara, Masaaki Nagahara, Kazunori Hayashi +1
In this article, we propose sampled-data design of digital filters that cancel the continuous-time effect of coupling waves in a single-frequency full-duplex relay station. In this…
Sampled-data Optimization for Self-interference Suppression in Baseband Signal Subspaces
Hampei Sasahara, Masaaki Nagahara, Kazunori Hayashi +1
In this article, we propose a design method of selfinterference cancelers for wireless relay stations taking account of the baseband signal subspace. The problem is first formulate…
Discrete Signal Reconstruction by Sum of Absolute Values
Masaaki Nagahara
In this letter, we consider a problem of reconstructing an unknown discrete signal taking values in a finite alphabet from incomplete linear measurements. The difficulty of this pr…
Value Function in Maximum Hands-off Control
Takuya Ikeda, Masaaki Nagahara
In this brief paper, we study the value function in maximum hands-off control. Maximum hands-off control, also known as sparse control, is the L0-optimal control among the admissib…
Communication Performance Analysis of Sampled-Data H-infinity Optimal Coupling Wave Canceler
Hampei Sasahara, Masaaki Nagahara, Kazunori Hayashi +1
In this manuscript, we propose a design method of digital filters which cancel coupling waves generated in single-frequency full-duplex wireless relay stations by using the sampled…
Continuity of the Value Function in Sparse Optimal Control
Takuya Ikeda, Masaaki Nagahara
We prove the continuity of the value function of the sparse optimal control problem. The sparse optimal control is a control whose support is minimum among all admissible controls.…
Loop-Back Interference Suppression for OFDM Signals via Sampled-Data Control
Hampei Sasahara, Masaaki Nagahara, Kazunori Hayashi +1
In this article, we consider the problem of loop-back interference suppression for orthogonal frequency division multiplexing (OFDM) signals in amplify-and-forward single-frequency…
Sparsity Methods for Networked Control
Masaaki Nagahara
In this presentation, we introduce sparsity methods for networked control systems and show the effectiveness of sparse control. In networked control, efficient data transmission is…