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Hiroaki Kawamoto

Publications and source records attributed to Hiroaki Kawamoto.

2 recordsLinked to original sources

Safety-Aware Robust Model Predictive Control for Robotic Arms in Dynamic Environments

Robotic manipulators are essential for precise industrial pick-and-place operations, yet planning collision-free trajectories in dynamic environments remains challenging due to uncertainties such as sensor noise and time-varying delays. Conventional control methods often fail under these conditions, motivating the development of Robust MPC (RMPC) strategies with constraint tightening. In this paper, we propose a novel RMPC framework that integrates phase-based nominal control with a robust safety mode, allowing smooth transitions between safe and nominal operations. Our approach dynamically adjusts constraints based on real-time predictions of moving obstacles\textemdash whether human, robot, or other dynamic objects\textemdash thus ensuring continuous, collision-free operation. Simulation studies demonstrate that our controller improves both motion naturalness and safety, achieving faster task completion than conventional methods.

cs.RO↗

A 10.24-GHz-wide digital spectrometer array system for LMT-FINER: system design and laboratory performance verification

For efficient spectroscopic redshift identification of early galaxies in the northern hemisphere, we aim to combine the Large Millimeter Telescope (LMT) with a wide-band heterodyne receiver, FINER, which will cover radio frequencies of 120--360 GHz and offer a 3--21 GHz intermediate frequency (IF) per sideband and polarization. To take full advantage of such wide IFs, we present a novel 10.24-GHz-wide digital spectrometer, DRS4 (Elecs Industry Co., Ltd.). It incorporates 20.48 Gsps samplers with an FPGA-based digital signal processing module. To mitigate the noise contamination from the image sideband, it is equipped with a digital sideband separation function to improve the sideband rejection up to 25 dB. Laboratory performance evaluations show that it exhibits an Allan time of at least ~100 s and a total power dynamic range of at least 7 dB. These results demonstrate its capability of instantaneously wide-band spectroscopy toward high-redshift galaxies with position-switching observations.

astro-ph.IM↗