Browsing by Author "Tseng, Ching-Huan"

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A method for estimating subject-specific body segment inertial parameters in human movement analysis
(2011-04-01)
Chen, Sheng-Chang
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Hsieh, Hong-Jung
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Lu, Tung-Wu
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Tseng, Ching-Huan
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機械工程學系
An optimization-based, non-invasive, radiation-free method was developed for estimating subject-specific body segment inertial properties (BSIPs) using a motion capture system and two forceplates. The method works with accurate descriptions of the geometry of the body segments, subject-specific center of pressure (COP) and kinematic data captured during stationary standing, and an optimization procedure. Twelve healthy subjects performed stationary standing in different postures, level walking and squatting while kinematic and forceplate data were measured. The performance of the current method was compared to three commonly used predictive methods in terms of the errors of the calculated ground reaction force, COP and joint moments using the corresponding predicted BSIPs. The current method was found to be capable of producing estimates of subject-specific BSIPs that predicted accurately the important variables in human motion analysis during static and dynamic activities. With the differences in the BSIPs from the current method, the mean COP errors were less than 5 mm during stationary standing postures, while those from the existing comparative methods ranged from 11 to 25 mm. During dynamic activities, the existing methods gave COP errors three times as large as the proposed method, with up to 2.5 times RMSE in joint moments during walking. Being non-invasive and using standard motion laboratory equipment, the current method will be useful for routine clinical gait analysis and relevant clinical applications, particularly in patient populations that are not targeted by the existing predictive methods. (C) 2011 Elsevier B.V. All rights reserved.
A two-phase computational scheme for solving bang-bang control problems
(2006-12-01)
Huang, Chih-Hung
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Tseng, Ching-Huan
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機械工程學系
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Department of Mechanical Engineering
This paper focuses on numerical methods for solving time-optimal control problems using discrete-valued controls. A numerical Two-Phase Scheme, which combines admissible optimal control problem formulation with enhanced branch-and-bound algorithms, is introduced to efficiently solve bang-bang control problems in the field of engineering. In Phase 1, the discrete restrictions are relaxed, and the resulting continuous problem is solved by an existing optimal control solver. The information on switching times obtained in Phase I is then used in Phase 11 wherein the discrete-valued control problem is solved using, the proposed algorithm. Two numerical examples, including, a third-order system and the F-8 fighter aircraft control problem, are presented to demonstrate the use of this proposed scheme. Comparing to STC and CPET methods proposed in the literature, the proposed scheme provides a novel method to find a different switching structure with a better minimum time for the F-8 fighter jet control problem.
Analysis of stresses in adhesive joints applicable to IC chips using symbolic manipulation and the numerical method
(2006)
Cheng, Tung-Hua
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Tseng, Ching-Huan
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Hung, Ching-Hua
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機械工程學系
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Department of Mechanical Engineering
In this study, a concentrated force is applied to both adherends bonded by an adhesive under pin-pin boundary conditions. First a mathematical model is derived with governing equations and boundary conditions. These complicated, and analytically problematic, coupled equations are solved numerically using symbolic manipulation and singular value decomposition (SVD). Also discussed are the effects of major factors, including the relative thickness of adherends, joint length and the action point of the concentrated force on the peel and shear stresses in the adhesive layer. This study identifies the conditions under which the upper adherend without breakage can be fully separated from the lower adherend. Particularly, it is found that the thickness of the lower adherend should be greater than ten times that of the adhesive layer but less than one-third that of the upper adherend, the adhesive layer should be relatively thin (h(a) <= 0.01 mm), and the adhesive joint should be relatively short (thickness to length ratio gamma(1) >= 0.08).
Application of a Genetic Algorithm Associated With Adhesive Joint Analysis to the IC Chip Pick-up Process
(2008)
Cheng, Tung-Hua
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Tseng, Ching-Huan
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Hung, Ching-Hua
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機械工程學系
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Department of Mechanical Engineering
In the condition investigated here, a concentrated force is applied to both IC chip and blue tape bonded by an adhesive under pin-pin boundary conditions. The experimental results show that even though IC chips of 0.1 mm thickness are subjected to a concentrated force of 4.8 N, they cannot be fully separated from the blue tape and fail easily during the pick-up process. However, when IC chips of 0.34 mm thickness are subjected to a concentrated force of only 3.5 N, they can be fully separated from the blue tape without breakage. These two experimental findings are then explored analytically by applying the C++ program of the genetic algorithm associated with adhesively bonded joint analysis to the IC chip pick-up process. In accordance with the experimental results, the results for the 0.1 mm thick IC chips reveal no solutions for the material properties or adhesive thickness to satisfy the conditions of the IC chip successful pick-up process, although those for the 0.34 mm thick IC chips show solutions for the values of both the elastic modulus and the adhesive layer's thickness. As regards the easy failure of IC chips with 0.1 mm thickness, if the blue tape's mechanical properties are appropriately chosen and then used in this process and its elastic modulus is greater than one-tenth that of the IC chips, the probability of the IC chips being fully separated from the blue tape can be expected to increase. (C) Koninklijke Brill NV, Leiden, 2008
Conceptual innovation of a prosthetic hand using TRIZ
(2008-04-01)
Chang, Wen-Tung
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Tseng, Ching-Huan
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Wu, Long-Long
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機械工程學系
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Department of Mechanical Engineering
Planar linkages with one degree of freedom have been applied to prosthetic hands in the past years, but only one gripping configuration can be performed by these designs. This paper demonstrates the conceptual design processes for a patented prosthetic hand, which has the functions for switching the gripping forms and locking the gripping configuration. A systematically innovative methodology called the Theory of Inventive Problem Solving (TRIZ) is employed to generate the concepts for the desired functions. The skills of Contradiction and Substance-Field Analysis in TRIZ are effectively applied in this study. Also, motion simulation for an embodiment of the proposed prosthetic hand is given by using the Working Model 3D software. The simulating results show that the design is applicable to perform two different gripping forms for hand prostheses.
Simulation and analysis of synchronisation and engagement on manual transmission gearbox
(2007)
Liu, Yen-Chen
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Tseng, Ching-Huan
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機械工程學系
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Department of Mechanical Engineering
This paper presents a dynamic simulation and analysis model of the synchroniser, which is mainly used to avoid the abnormal impact during shifting in a Manual Transmission (MT) gearbox. Because the complicated mechanism and random engagement of the synchroniser occur in a short time, it is difficult to realise the synchronisation process by experiment. Using ADAMS(TM), not only the entire shift process but also two minor phase modules, separate from the entire shift process, can all be constructed to realise the synchronised action and random meshing between the sleeve and the clutch gear. After verifying the results from the simulation model, the paper discusses the influence of cone surface abrasion on synchronisation and the random meshing process. The results described here can help to understand the synchronisation process as well as it provides a way for improving two major demands, vehicle operational comfort and the lifespan of the synchroniser in a MT gearbox.