http://scholars.ntou.edu.tw/handle/123456789/189 Tue, 09 Jun 2026 08:27:42 GMT 2026-06-09T08:27:42Z https://scholars.ntou.edu.tw:443/retrieve/70/機械與機電工程學系.jpg http://scholars.ntou.edu.tw/handle/123456789/189 http://scholars.ntou.edu.tw/handle/123456789/26558 標題: Sensory Tool Holder for Thrust Measurement and Predictive Modeling of PCD Drill Life in Drilling 作者: Ho, Jihng-Kuo; Wen, Po-Chun; Lin, Hao-Yang; Chang, Tsung-Yu; Yau, Her-Terng 摘要: This research presents a systematic investigation of thrust force measurement and tool life modeling for drilling ceramic base on silicon dioxide tiles using a sensory tool holder (STH) integrated with polycrystalline diamond (PCD) drill bits. A piezoelectric sensing scheme is employed in STH to capture dynamic thrust forces during drilling under industrially relevant conditions. Thrust force data from repeated drilling operations are fitted to a quadratic-logarithmic life curve, relating the number of holes drilled to mean thrust force. Fifteen geometric features of PCD drills are measured; LASSO is used to select the most influential parameters for modeling the lifecurve coefficients. Subsequently, support vector regression constructs predictive models for the life-curve coefficients based on these selected features. The model achieves approximately 5% error relative to measured thrust magnitudes. The proposed approach offers a reliable tool life prediction framework to guide PCD drill geometry optimization and quality control, reducing operational risks and costs in ceramic tile installation. Wed, 01 Jan 2025 00:00:00 GMT http://scholars.ntou.edu.tw/handle/123456789/26558 2025-01-01T00:00:00Z http://scholars.ntou.edu.tw/handle/123456789/26468 標題: Globally smooth lemniscate trajectory with adaptive integral terminal sliding mode control and inversion-based hysteresis compensation for pi ezoelectric stage precise tracking 作者: Wu, Jim-Wei; Hsu, Ting-Kuei; Li, Jia-Cheng; Lin, Yu-Han; Chen, Sung-Hua 摘要: High-precision measurement systems use an xy-axis piezoelectric scanner following a pre-determined trajectory to achieve three-dimensional scanning at micro/nano-scales. Most systems employ a raster scanning trajectory due to ease of implementation; however, raster scanning generates infinite odd harmonics, which can induce mechanical resonance leading to image distortion. Moreover, the nonlinear response characteristics of piezoelectric materials frequently result in unexpected displacements. This paper presents a novel sequential scanning trajectory that eliminates the need for a step function and minimizes the risk of mapping errors. An advanced controller combining an inverse hysteresis model with adaptive integral terminal sliding mode control (AITSMC) was developed and first applied in the piezoelectric scanner through theoretical derivation and stability analysis to prove its feasibility. In simulations and experiments, the proposed controller significantly mitigated the effects of hysteresis during trajectory tracking and achieved superior tracking accuracy and lower RMSE compared to existing sliding mode controllers. Wed, 01 Jan 2025 00:00:00 GMT http://scholars.ntou.edu.tw/handle/123456789/26468 2025-01-01T00:00:00Z http://scholars.ntou.edu.tw/handle/123456789/26453 標題: Numerical analysis of flow configuration and channel design for thermoelectric OTEC systems 作者: Wu, Chun-, I; Tseng, Wei-Lun; Wang, Bo-Xiang 摘要: This research examines the optimized integration of Bi2Te3-based thermoelectric generators (TEGs) in Ocean Thermal Energy Conversion (OTEC) systems, evaluating their performance via detailed numerical analysis. We conducted finite element simulations using COMSOL Multiphysics to analyze thermoelectric generators (TEGs) placed between a warm surface and cold deep seawater channels under different operational conditions. The research examined parallel and counter flow configurations at Reynolds numbers between 3987 and 73,800, with channel heights varying from 0.002 to 0.072 m. Results indicate that Reynolds numbers above 12,000 ensure stable heat supply to TEGs, resulting in a consistent output power of 3.01 W. The optimal net power of 1.45 W was attained at a channel height of 0.002 m, attributed to reduced pump power consumption. A comparative analysis of Bi2Te3-based material combinations demonstrated that improved electrical and decreased thermal conductivity notably enhanced system performance. This study offers essential insights for improving the design and implementation of TEG-OTEC systems, especially in offshore contexts where operational efficiency and system durability are critical, thereby contributing to the advancement of sustainable ocean energy technologies. Wed, 01 Jan 2025 00:00:00 GMT http://scholars.ntou.edu.tw/handle/123456789/26453 2025-01-01T00:00:00Z http://scholars.ntou.edu.tw/handle/123456789/26389 標題: Investigations on the Effects of a Passive Standing-from-Squatting and Gait Assistive Exoskeleton on Human Motion 作者: Lin, Yu-Chih; Lin, Sih-You; Kao, Shih-Yu 摘要: The aim of this study is to examine the biomechanical interaction between an assistive wearable exoskeleton and the human body. For this purpose, a passive exoskeleton is designed to provide support during the transition from a squatting position to standing, while also enabling the resilient components to become active during the initial and mid-swing phases of level walking. The active period can be adjusted by a slot, which triggers the activation of the resilient components when the exoskeleton's flexion angle exceeds a critical value. This study also compares the effect of using different passive powered components in the exoskeleton. Electromyography (EMG) signals and angular velocity during human motion are collected and analyzed. Experimental results indicate that the designed assistive exoskeleton effectively reduces muscle effort during squatting/standing motion, as intended. The exoskeleton reduces the flexion/extension (x-axis) angular velocity during both squatting/standing and the swing phase of gait. The oscillation of the angular velocity curve about the y-axis during gait is larger without the exoskeleton, suggesting that the exoskeleton may introduce interference but also a stabilizing effect in certain dimensions during gait. This study provides a stronger foundation for advancing the design of both passive and active powered exoskeletons. Wed, 01 Jan 2025 00:00:00 GMT http://scholars.ntou.edu.tw/handle/123456789/26389 2025-01-01T00:00:00Z