Engineering Commons^™

3d-Printed Leg Design And Modification For Improved Support On A Quadruped Robot, Jasmin S. Collins

Undergraduate Research & Mentoring Program

The Agile and Adaptive Robotics Lab aims to uncover the biological and physiological complexities in animal agility and adaptive control, which can be replicated through robotics and provide further applications in biology and medicine. One project within the lab focuses on understanding structure, actuation, and control through the modeling of a canine quadruped robot.

The AARL has developed a full-body quadruped robot with artificial muscles that control limb movement and a body that is built from 3D-printed parts. This specific project involved modification of these existing parts to (a) minimize deflections in the front legs, causing unwanted lateral and abduction/adduction …

Compensation Of Vertical Position Error Using A Force–Deflection Model In Friction Stir Spot Welding, Jinyoung Yoon, Cheolhee Kim, Sehoon Rhee

Mechanical and Materials Engineering Faculty Publications and Presentations

Despite increasing need for friction stir spot welding (FSSW) for high-temperature softening materials, system deflection due to relatively high plunging force remains an obstacle. System deflection results in the vertical position error of a welding tool and insufficient plunge depth. In this study, we used adaptive control to maintain plunge depth, the plunging force was coaxially measured, and the position error was estimated using a force–deflection model. A linear relationship was confirmed between the force and deflection; this relationship is dependent on the stiffness of the welding system while independent of process parameters and base materials. The proposed model was …

A Multi-Agent System For Adaptive Control Of A Flapping-Wing Micro Air Vehicle, Michal Podhradský

Dissertations and Theses

Biomimetic flapping-wing vehicles have attracted recent interest because of their numerous potential military and civilian applications. In this dissertation is described the design of a multi-agent adaptive controller for such a vehicle. This controller is responsible for estimating the vehicle pose (position and orientation) and then generating four parameters needed for split-cycle control of wing movements to correct pose errors. These parameters are produced via a subsumption architecture rule base. The control strategy is fault tolerant. Using an online learning process, an agent continuously monitors the vehicle's behavior and initiates diagnostics if the behavior has degraded. This agent can then …

Emergent Criticality Through Adaptive Information Processing In Boolean Networks, Alireza Goudarzi, Christof Teuscher, Natali Gulbahce, Thimo Rohlf

Electrical and Computer Engineering Faculty Publications and Presentations

We study information processing in populations of Boolean networks with evolving connectivity and systematically explore the interplay between the learning capability, robustness, the network topology, and the task complexity. We solve a long-standing open question and find computationally that, for large system sizes N, adaptive information processing drives the networks to a critical connectivity K_{c}=2. For finite size networks, the connectivity approaches the critical value with a power law of the system size N. We show that network learning and generalization are optimized near criticality, given that the task complexity and the amount of information provided surpass threshold values. Both …

Case Study Evaluation Of Dynamic Traffic Assignment Tools, John Gliebe, Åsa Bergman

Urban Studies and Planning Faculty Publications and Presentations

A case study was undertaken in order to evaluate the potential use of dynamic traffic assignment (DTA) tools by Oregon Department of Transportation (ODOT) and its partner agencies. The objectives of this study were to provide insight into the nature of DTA models, to inform the program selection process, and to develop realistic expectations for potential DTA work plans. The overarching goal of this report is to describe the process followed and experiences of the study team in developing and testing DTA network models. Two available DTA programs were selected for in-depth analysis from a preliminary screening of available programs: …