Taste sensation recognition is a core for taste-related queries. Most prior research has been devoted to recognizing the basic taste sensations using the Brain–Computer Interface (BCI), which includes EEG, MEG, EMG, and fMRI. This research aims to recognize electronic taste (E-Taste) sensations based on surface electromyography (sEMG). Silver electrodes with platinum plating of the E-Taste device were placed on the tongue’s tip to stimulate various tastes and flavors. In contrast, the electrodes of the sEMG were placed on facial muscles to collect the data. The dataset was organized and preprocessed, and a random forest classifier was applied, giving a five-fold accuracy of 70.43%. The random forest classifier was used on each participant dataset individually and in groups, providing the highest accuracy of 84.79% for a single participant. Moreover, various feature combinations were extracted and acquired 72.56% accuracy after extracting eight features. For a future perspective, this research offers guidance for electronic taste recognition based on sEMG.

This paper presents the design and water-surface motion analysis of an amphibious spherical robot equipped with a dual-propulsion system (ASR-DPS). Owing to its unique spherical geometry, the robot exhibits significantly different hydrodynamic behavior from conventional vessels. A comparative analysis of the frontal wetted area is conducted, followed by computational fluid dynamics (CFD) simulations to evaluate its water-surface motion characteristics. Results reveal that the hemispherical front increases hydrodynamic resistance and induces large-scale vortex structures due to intensified flow separation. Despite the higher resistance relative to traditional hulls, the robot’s deeper draft and dual propulsion configuration offer enhanced stability and improved maneuverability during surface operations. To validate its performance in real-world conditions, standard maneuvering experiments, including the circle test and zig-zag test, are conducted to assess the effectiveness of the propeller propulsion system. In addition, experiments are conducted to evaluate the water-surface motion performance of the pendulum propulsion system. A four-degree-of-freedom kinematic and dynamic model is developed to describe the robot’s water-surface motion. To handle model uncertainties and external disturbances, two control strategies are proposed: one based on model simplification and the other on adaptive control. Both strategies aim to regulate surge velocity and yaw angle. Simulation results are presented to compare the control performance of the proposed methods.

This study introduces an amphibious spherical robot equipped with a dual-propulsion system (ASR-DPS) and investigates its water-surface motion characteristics. Due to its distinctive spherical geometry, the robot exhibits markedly different hydrodynamic behavior compared to conventional vessels. A comparative analysis of the frontal wetted area is performed, followed by computational fluid dynamics (CFD) simulations to assess water-surface performance. The results indicate that the hemispherical bow increases hydrodynamic resistance and generates large-scale vortex structures as a consequence of intensified flow separation. Although the resistance is higher than that of traditional hulls, the robot’s greater draft and dual-propulsion configuration enhance stability and maneuverability during surface operations. To validate real-world performance, standard maneuvering tests, including circle and zig-zag maneuvers, are conducted to evaluate the effectiveness of the propeller-based propulsion system. The robot achieves a maximum surface speed of 1.2 m/s and a zero turning radius, with a peak yaw rate of 0.54 rad/s under differential thrust. Additionally, experiments on the pendulum-based propulsion system demonstrate a maximum speed of 0.239 m/s with significantly lower energy consumption (220.6 Wh at 60% throttle). A four-degree-of-freedom kinematic and dynamic model is formulated to describe the water-surface motion. To address model uncertainties and external disturbances, two control strategies are proposed: one employing model simplification and the other adaptive control. Simulation results confirm that the adaptive sliding mode controller provides precise surge speed tracking and smooth yaw regulation with near-zero steady-state error, exhibiting superior robustness and reduced chattering compared to the baseline controller.