Off-campus UMass Amherst users: To download dissertations, please use the following link to log into our proxy server with your UMass Amherst user name and password.
Non-UMass Amherst users, please click the view more button below to purchase a copy of this dissertation from Proquest.
(Some titles may also be available free of charge in our Open Access Dissertation Collection, so please check there first.)
A unified exact gradient approach for optimal synthesis of mechanisms
Abstract
This research presents the development of a comprehensive and unified solution procedure for solving general problems in mechanism synthesis. The uniqueness of this approach lies in its ability to derive the exact gradient relationships for the purposes of finding optimal solutions to generic mechanism problems. In this approach, mechanism problems are modeled using a generalized matrix-based method and the exact gradients necessary for optimization are systematically generated for any type of mechanism. The availability of these exact gradients eliminates the use of highly time consuming finite difference techniques and the problems associated with gradient approximation. From the application point of view, the use of exact gradients significantly enhances the efficiency of optimization process, improves the accuracy of final solutions, and avoids premature termination of optimization algorithms due to bad gradient approximation. One of the main problems in the synthesis of mechanisms is the occurrence of circuit defects. They occur when the desired orientations of a linkage assembly fall in different mobility regions during its cycle of motion. In this research, a sub-Jacobian based approach has been developed and integrated into the mechanism synthesis process to guarantee circuit free optimal solutions. The systematic development of exact gradients for various design objectives, its integration in the mechanism synthesis process, and the ability of this approach to eliminate circuit defects offer a unified as well as comprehensive approach for general mechanism synthesis. Several examples are presented to illustrate the effectiveness of this approach for designing industrial mechanisms. The generality and efficiency of exact gradient methodology make it the most viable approach for mechanism synthesis. The potential application of this approach to other domains of engineering design with an example from structural shape optimization is presented.
Subject Area
Mechanical engineering|Industrial engineering|Automotive engineering
Recommended Citation
Mariappan, Jawaharlal, "A unified exact gradient approach for optimal synthesis of mechanisms" (1994). Doctoral Dissertations Available from Proquest. AAI9510502.
https://scholarworks.umass.edu/dissertations/AAI9510502