| This report provides a framework for the design and configuration of joints and links for the assembly of modular robots. This report is founded on two premises. First, that a modular strategy will improve the robot design process, by narrowing the focus to manageable and experimentally verifiable joint and link modules. The second premise is that a module data base can be used to evaluate combinations of joints and links to identify the best modular arm for a user specified task.; These modules were tested in isolation using the UT Modular Robotics Testbed developed specifically for this effort. A set of four joint modules and seven link modules was designed for this effort, in addition to dozens of mounting accessories for a total of over seventy separate components. A supporting electronics facility was designed to derive the actuators and sensors built into these modules, along with the operational software required for the initial experiments.; Given these modules and their experimentally verified performance, a design process has been described for matching module combinations with user specified task requirements. Two design space formulations are described, within which nine optimization methods are used to search for the best solution. These design methodologies are evaluated on the basis of run time, reliability, and sensitivity to changes in the scale of the design problem.; Recommendations for future module designs have been suggested based on the experimental results, with an emphasis on improving the drive trains that were found to limit the performance of most actuators. A series of concept drawings will be described as starting points for future design teams, such as those at UT that are now focusing on the design of joint and link prototypes. Recommendations for improving the modular configuration methodology are described in terms of increasing the number of performance criteria and expanding the design process to include broader architectures of manipulators. Finally, future experiments are proposed to use the UT Modular Robotics Testbed to answer many of the questions uncovered during this effort. (Abstract shortened with permission of author.)... |
