Browsing by Author "Hsiao, Kuo-Mo"

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Cuckoo search and teaching-learning-based optimization algorithms for optimum synthesis of path-generating four-bar mechanisms
(2017-01)
Lin, Wen-Yi
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Hsiao, Kuo-Mo
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機械工程學系
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Department of Mechanical Engineering
The optimization of one-phase dimensional synthesis problems for path-generating four-bar mechanisms is a difficult task. Such problems have mainly been solved in the literature using the differential evolution (DE) algorithm and its variants, such as a combined-mutation DE (CMDE). The shortcoming of using DE or its variants lies in the time-consuming parameter tuning that can take up to a dozen iterations. In this study, two well-known population-based metaheuristic optimization methods, i.e. the cuckoo search (CS) and teaching-learning-based optimization (TLBO) algorithms are employed to solve five representative problems. Only one user-supplied parameter is needed for CS and none for TLBO. Findings show that the solution accuracy of CS is superior to that of DE and TLBO. Moreover, CS, with its advantage of parameter tuning only four times, rivals CMDE in solution accuracy. The reason for the superior exploitation capability of CS lies in the special combination of two search modes, i.e. the Levy flight with respect to the best individual and the random walk. To bring the performance of TLBO into full play, the number of function evaluations is two times the original one. However, TLBO still fails to provide much more accurate solutions for the first two problems.
Design of a new micro single flute drill
(2014)
Lee, An-Chen
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Horng, Jeng-Haur
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Nguyen Danh Tuyen
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Hsiao, Kuo-Mo
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機械工程學系
A new micro single flute drill was presented in this study. For the convenience of developing a solid model, and doing a geometrical analysis, its geometry including the flute and flank surfaces is presented mathematically. According to the geometrical analysis, the normal clearance angles and normal rake angles along the cutting lip of the new micro dill are always invariant, and positive, respectively. Hence its cutting force in drilling is reduced. Furthermore, with only one main flute, the new micro drill gets stronger, and its cutting torque can be also decreased. Therefore it is expected that the tool life of the new micro drill is much longer than that of the conventional drill.
Optimum design of involute tooth profiles for K-H-V planetary drives with small teeth number differences
(2019-01-01)
Lin, Wen-Yi
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Hsiao, Kuo-Mo
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Ke, Jun-Yu
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機械工程學系
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Department of Mechanical Engineering
The optimum design of an involute K-H-V PDSTND is restudied and remains a difficult task even using a profile shift for the design case discussed in the literature. In fact, the difficulty arises from the design with a very high efficiency and the peculiar tip interference. Because of the failure to obtain feasible designs using profile-shifted full-depth and stub teeth, another feasible design scheme is used by altering the addendums of involute profile-shifted full-depth teeth. In this study, the objective function of the optimum design is a weighted combination of two main performance factors, i.e., the reciprocal of the contact ratio and the working pressure angle. The optimization problem is solved using a combined-mutation differential evolution algorithm. The performance can be improved using the afore-mentioned design scheme; however, there is still room for improvements. Therefore, the use of different modules in mesh for involute profile-shifted full-depth teeth with variation in addendum is proposed and the corresponding meshing equation is derived. The findings show that further improvements on the performance can be achieved.
Optimum synthesis of a 10-link gripping mechanism using new grasping indices
(2016-10)
Lin, Wen-Yi
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Hsiao, Kuo-Mo
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機械工程學系
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Department of Mechanical Engineering
When the traditional grasping index is used as an objective function, the optimized mechanism obtained offers good force transmission performance but unsound motion transmission for a 10-link gripping mechanism. Therefore, we first propose a new grasping index that is the product of the traditional grasping index and the effective force ratio. The effective force ratio reflects the motion transmission for the output links. The proposed grasping index is similar to the force transmission index discussed in the literature; however, different views of the physical meaning of the two components of the index and the necessity of the effective force ratio for optimum synthesis of the mechanism are presented. The second new grasping index proposed is the product of the first grasping index and the cosine value of the angle between the contact force and the contact velocity, originally used as a constraint. Using these new grasping indices, one can obtain sound optimum mechanism designs with a very small input force and contact velocity and with the maximum opening dimension equal to the object size. Furthermore, optimum synthesis for the gripping mechanism with an opening dimension larger than the object size is also investigated.