Citation
Chen, I-Ming (1994) Theory and applications of modular reconfigurable robotic systems. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/2AAA-RY45. https://resolver.caltech.edu/CaltechETD:etd-10202005-090745
Abstract
A modular reconfigurable robotic system consists of various link and joint units with standardized connecting interfaces that can be easily separated and reassembled into different configurations. Compared to a fixed configuration robot, which is usually a compromised design for a limited set of tasks, a modular robot can accomplish a large class of tasks through reconfiguration of a small inventory of modules. This thesis studies how to find an optimal module assembly configuration constructed from a given inventory of module components for a specific task. A set of generalized module models that bear features found in many real implementations is introduced. The modular robot assembly configuration is represented by a novel Assembly Incidence Matrix (AIM). Equivalence relations based on module geometry symmetries and graph isomorphisms are defined on the AIMs. An enumeration algorithm to generate non-isomorphic assembly configurations based on this equivalence relation is proposed. Examples demonstrate that this method is a significant improvement over a brute force enumeration process. Configuration independent kinematic models for modular robots are developed, and they are essential for solving the task-optimal configuration problem. A task-oriented objective function is defined on the set of non-isomorphic module assembly configurations. Task requirements and kinematic constraints on the robot assembly are treated as parameters to this objective function. The task-optimal configuration problem is formulated as a combinatorial optimization problem to which genetic algorithms are employed for solutions. Examples of finding task-optimal serial revolute-jointed robot configurations are demonstrated. In addition, the applications of modular robots to planning multifinger grasping and manipulation are developed. Planning two-finger grasps is done through finding antipodal point grasps on smooth shaped objects. Planning n-finger grasps is achieved by defining a qualitative force-closure test function on the n-finger grasps on an object. Applications of this test function to manipulation task and finger gaiting are illustrated.
Item Type: | Thesis (Dissertation (Ph.D.)) |
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Subject Keywords: | configuration design; nonemodular robots; reconfigurable robots; Task-based optimization |
Degree Grantor: | California Institute of Technology |
Division: | Engineering and Applied Science |
Major Option: | Mechanical Engineering |
Thesis Availability: | Public (worldwide access) |
Research Advisor(s): |
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Thesis Committee: |
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Defense Date: | 14 March 1994 |
Non-Caltech Author Email: | michen (AT) ntu.edu.sg |
Record Number: | CaltechETD:etd-10202005-090745 |
Persistent URL: | https://resolver.caltech.edu/CaltechETD:etd-10202005-090745 |
DOI: | 10.7907/2AAA-RY45 |
Default Usage Policy: | No commercial reproduction, distribution, display or performance rights in this work are provided. |
ID Code: | 4189 |
Collection: | CaltechTHESIS |
Deposited By: | Imported from ETD-db |
Deposited On: | 20 Oct 2005 |
Last Modified: | 20 Dec 2019 19:39 |
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