Robotics Commons^™

Neuron Clustering For Mitigating Catastrophic Forgetting In Supervised And Reinforcement Learning, Benjamin Frederick Goodrich

Doctoral Dissertations

Neural networks have had many great successes in recent years, particularly with the advent of deep learning and many novel training techniques. One issue that has affected neural networks and prevented them from performing well in more realistic online environments is that of catastrophic forgetting. Catastrophic forgetting affects supervised learning systems when input samples are temporally correlated or are non-stationary. However, most real-world problems are non-stationary in nature, resulting in prolonged periods of time separating inputs drawn from different regions of the input space.

Reinforcement learning represents a worst-case scenario when it comes to precipitating catastrophic forgetting in neural networks. …

Using Eye And Head Movements As A Control Mechanism For Tele-Operating A Ground-Based Robot And Its Payload, Kathryn C. Hicks

Computational Modeling & Simulation Engineering Theses & Dissertations

To date, eye and head tracking has been used to indicate users' attention patterns while performing a task or as an aid for disabled persons, to allow hands-free interaction with a computer. The increasing accuracy and the reduced cost of eye- and head-tracking equipment make utilizing this technology feasible for explicit control tasks, especially in cases where there is confluence between the visual task and control.

The goal of this research was to investigate the use of eye-tracking as a more natural interface for the control of a camera-equipped, remotely operated robot in tasks that require the operator to simultaneously …

An Intelligent Attitude Determination And Control System Concept For A Cubesat Class Spacecraft, Jeremy Straub

Jeremy Straub

An attitude determination and control system (ADCS) is used to orient a spacecraft for a wide variety of purposes (e.g., to keep a camera facing Earth or orient the spacecraft for propulsion system use). The proposed intelligent ADCS has several key features: first, it can be used in multiple modes, spanning from passive stabilization of two axes and unconstrained spin on a third to three-axis full active stabilization. It also includes electromagnetic components to ‘dump’ spin from the reaction wheels. Second, the ADCS utilizes an incorporated autonomous control algorithm to characterize the effect of actuation of the system components and, …

An Onboard Distributed Multiprocessing System For A Cubesat Spacecraft Created From Gumstix Computer-On-Module Units, Michael Wegerson, Jeremy Straub, Ronald Marsh

Jeremy Straub

The OpenOrbiter Small Spacecraft Development Initiative at the University of North Dakota [1] aims to make ac-cess to space for research and educational purposes easier by enabling the creation of low-cost CubeSats. It is creating the Open Prototype for Educational Nanosats (OPEN), a framework for developing a 1-U CubeSat space-craft with a parts cost of less than $5,000 [2]. The designs [3], documentation and computer code from this will be made publically available to enable the development of programs at other institutions.

Considering Scheduling Algorithms For An Open Source Software Spacecraft, Calvin Bina, Jeremy Straub, Ronald Marsh

Jeremy Straub

The OpenOrbiter Small Satellite Development Initiative at the University of North Dakota [1] is working make space research and education more accessible world-wide [2], through the design and public release of a complete set of plans, software and other documents (see [3]) for a 1-U CubeSat. This design targets a parts cost of no more than $5,000 [4]. These lowered costs, combined with the efficiencies of the CubeSat form fac-tor [5] and free-to-qualified-developer launch services [6, 7] should facilitate greater access to space for the ed-ucational, research and other communities.

Learning Parameterized Skills, Bruno Castro Da Silva

Doctoral Dissertations

One of the defining characteristics of human intelligence is the ability to acquire and refine skills. Skills are behaviors for solving problems that an agent encounters often—sometimes in different contexts and situations—throughout its lifetime. Identifying important problems that recur and retaining their solutions as skills allows agents to more rapidly solve novel problems by adjusting and combining their existing skills. In this thesis we introduce a general framework for learning reusable parameterized skills. Reusable skills are parameterized procedures that—given a description of a problem to be solved—produce appropriate behaviors or policies. They can be sequentially and hierarchically combined with other …

Nanosatellite Scheduling Using A Dictionary Module And A ‘Useful Trick’ With Coded Unsigned Integers, Monilito Castro, Jeremy Straub

Jeremy Straub

Schedulers for small spacecraft must satisfy the dual requirement of generating very efficient schedules while concurrently minimizing the resources required to create the schedule. This paper proposes a technique for searching for tasks that can be utilized to fill particular schedule locations. This approach is based on a modular system for storing important variables. This modular system has three important variables: t0, x0 and y0. The variable y is latitude and x is longitude. Time variable t is an integer and each unit represents a time quantum. They are related to each other by three functions Ft, Fx, and Fy. …

Swarm Intelligence, A Blackboard Architecture And Local Decision Making For Spacecraft Command, Jeremy Straub

Jeremy Straub

Control of a multi-spacecraft constellation is a topic of significant inquiry, at present. This paper presents and evaluates a command architecture for a multi-spacecraft mission. It combines swarm techniques with a decentralized / local decision making architecture (which uses a set of shared blackboards for coordination) and demonstrates the efficacy of this approach. Under this approach, the Blackboard software architecture is used to facilitate data sharing between craft as part of a resilient hierarchy and the swarm techniques are used to coordinate activity. The paper begins with an overview of prior work on the precursor command technologies and then presents …

Reducing The Control Burden Of Legged Robotic Locomotion Through Biomimetic Consonance In Mechanical Design And Control, Caitrin Elizabeth Eaton

USF Tampa Graduate Theses and Dissertations

Terrestrial robots must be capable of negotiating rough terrain if they are to become autonomous outside of the lab. Although the control mechanism offered by wheels is attractive in its simplicity, any wheeled system is confined to relatively flat terrain. Wheels will also only ever be useful for rolling, while limbs observed in nature are highly multimodal. The robust locomotive utility of legs is evidenced by the many animals that walk, run, jump, swim, and climb in a world full of challenging terrain.

On the other hand, legs with multiple degrees of freedom (DoF) require much more complex control and …

An Embodied Approach To Evolving Robust Visual Classifiers, Karol Zieba

Graduate College Dissertations and Theses

From the very creation of the term by Czech writer Karel Capek in 1921, a "robot" has been synonymous with an artificial agent possessing a powerful body and cogitating mind. While the fields of Artificial Intelligence (AI) and Robotics have made progress into the creation of such an android, the goal of a cogitating robot remains firmly outside the reach of our technological capabilities. Cognition has proved to be far more complex than early AI practitioners envisioned. Current methods in Machine Learning have achieved remarkable successes in image categorization through the use of deep learning. However, when presented with novel …