Theses and Dissertations
This collection includes both ASU Theses and Dissertations, submitted by graduate students, and the Barrett, Honors College theses submitted by undergraduate students.
Displaying 1 - 4 of 4
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- All Subjects: robotics
- Creators: Amor, Heni Ben
Description
Sports activities have been a cornerstone in the evolution of humankind through the ages from the ancient Roman empire to the Olympics in the 21st century. These activities have been used as a benchmark to evaluate the how humans have progressed through the sands of time. In the 21st century, machines along with the help of powerful computing and relatively new computing paradigms have made a good case for taking up the mantle. Even though machines have been able to perform complex tasks and maneuvers, they have struggled to match the dexterity, coordination, manipulability and acuteness displayed by humans. Bi-manual tasks are more complex and bring in additional variables like coordination into the task making it harder to evaluate.
A task capable of demonstrating the above skillset would be a good measure of the progress in the field of robotic technology. Therefore a dual armed robot has been built and taught to handle the ball and make the basket successfully thus demonstrating the capability of using both arms. A combination of machine learning techniques, Reinforcement learning, and Imitation learning has been used along with advanced optimization algorithms to accomplish the task.
A task capable of demonstrating the above skillset would be a good measure of the progress in the field of robotic technology. Therefore a dual armed robot has been built and taught to handle the ball and make the basket successfully thus demonstrating the capability of using both arms. A combination of machine learning techniques, Reinforcement learning, and Imitation learning has been used along with advanced optimization algorithms to accomplish the task.
ContributorsKalige, Nikhil (Author) / Amor, Heni Ben (Thesis advisor) / Shrivastava, Aviral (Committee member) / Zhang, Yu (Committee member) / Arizona State University (Publisher)
Created2016
Description
Autonomous systems that are out in the real world today deal with a slew of different data modalities to perform effectively in tasks ranging from robot navigation in complex maneuverable robots to identity verification in simpler static systems. The performance of the system heavily banks on the continuous supply of data from all modalities. These systems can face drastically increased risk with the loss of one or multiple modalities due to an adverse scenario like that of hardware malfunction, inimical environmental conditions, etc. This thesis investigates modality hallucination and its efficacy in mitigating the risks posed to the autonomous system. Modality hallucination is proposed as one effective way to ensure consistent modality availability thereby reducing unfavorable consequences. While there has been a significant research effort in high-to-low dimensional modality hallucination, like that of RGB to depth, there is considerably lesser interest in the other direction( low-to-high dimensional modality prediction). This thesis serves to demonstrate the effectiveness of this low-to-high modality hallucination in reducing the uncertainty in the affected system while also ensuring that the method remains task agnostic.
A deep neural network based encoder-decoder architecture that aggregates multiple fields of view in its encoder blocks to recover the lost information of the affected modality from the extant modality is presented with evidence of its efficacy. The hallucination process is implemented by capturing a non-linear mapping between the data modalities and the learned mapping is used to aid the extant modality to mitigate the risk posed to the system in the adverse scenarios which involve modality loss. The results are compared with a well known generative model built for the task of image translation, as well as an off-the-shelf semantic segmentation architecture re-purposed for hallucination. To validate the practicality of hallucinated modality, extensive classification and segmentation experiments are conducted on the University of Washington's depth image database (UWRGBD) database and the New York University database (NYUD) and demonstrate that hallucination indeed lessens the negative effects of the modality loss.
A deep neural network based encoder-decoder architecture that aggregates multiple fields of view in its encoder blocks to recover the lost information of the affected modality from the extant modality is presented with evidence of its efficacy. The hallucination process is implemented by capturing a non-linear mapping between the data modalities and the learned mapping is used to aid the extant modality to mitigate the risk posed to the system in the adverse scenarios which involve modality loss. The results are compared with a well known generative model built for the task of image translation, as well as an off-the-shelf semantic segmentation architecture re-purposed for hallucination. To validate the practicality of hallucinated modality, extensive classification and segmentation experiments are conducted on the University of Washington's depth image database (UWRGBD) database and the New York University database (NYUD) and demonstrate that hallucination indeed lessens the negative effects of the modality loss.
ContributorsGunasekar, Kausic (Author) / Yang, Yezhou (Thesis advisor) / Qiu, Qiang (Committee member) / Amor, Heni Ben (Committee member) / Arizona State University (Publisher)
Created2019
Description
Reinforcement Learning(RL) algorithms have made a remarkable contribution in the eld of robotics and training human-like agents. On the other hand, Evolutionary Algorithms(EA) are not well explored and promoted to use in the robotics field. However, they have an excellent potential to perform well. In thesis work, various RL learning algorithms like Q-learning, Deep Deterministic Policy Gradient(DDPG), and Evolutionary Algorithms(EA) like Harmony Search Algorithm(HSA) are tested for a customized Penalty Kick Robot environment. The experiments are done with both discrete and continuous action space for a penalty kick agent. The main goal is to identify which algorithm suites best in which scenario. Furthermore, a goalkeeper agent is also introduced to block the ball from reaching the goal post using the multiagent learning algorithm.
ContributorsTrivedi, Maitry Ronakbhai (Author) / Amor, Heni Ben (Thesis advisor) / Redkar, Sangram (Thesis advisor) / Sugar, Thomas (Committee member) / Arizona State University (Publisher)
Created2021
Description
Bimanual robot manipulation, involving the coordinated control of two robot arms, holds great promise for enhancing the dexterity and efficiency of robotic systems across a wide range of applications, from manufacturing and healthcare to household chores and logistics. However, enabling robots to perform complex bimanual tasks with the same level of skill and adaptability as humans remains a challenging problem. The control of a bimanual robot can be tackled through various methods like inverse dynamic controller or reinforcement learning, but each of these methods have their own problems. Inverse dynamic controller cannot adapt to a changing environment, whereas Reinforcement learning is computationally intensive and may require weeks of training for even simple tasks, and reward formulation for Reinforcement Learning is often challenging and is still an open research topic. Imitation learning, leverages human demonstrations to enable robots to acquire the skills necessary for complex tasks and it can be highly sample-efficient and reduces exploration. Given the advantages of Imitation learning we want to explore the application of imitation learning techniques to bridge the gap between human expertise and robotic dexterity in the context of bimanual manipulation. In this thesis, an examination of the Implicit Behavioral Cloning imitation learning algorithm is conducted. Implicit behavioral cloning aims to capture the fundamental behavior or policy of the expert by utilizing energy-based models, which frequently demonstrate superior performance when compared to explicit behavior cloning policies. The assessment encompasses an investigation of the impact of expert demonstrations' quality on the efficacy of the acquired policies. Furthermore, computational and performance metrics of diverse training and inference techniques for energy-based models are compared.
ContributorsRayavarapu, Ravi Swaroop (Author) / Amor, Heni Ben (Thesis advisor) / Gopalan, Nakul (Committee member) / Senanayake, Ransalu (Committee member) / Arizona State University (Publisher)
Created2023