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dc.contributor.advisorLongoria, Raul G.en
dc.contributor.advisorKuipers, Benjaminen
dc.creatorGulati, Shilpaen
dc.date.accessioned2011-10-26T16:12:38Zen
dc.date.available2011-10-26T16:12:38Zen
dc.date.created2011-08en
dc.date.issued2011-10-26en
dc.date.submittedAugust 2011en
dc.identifier.urihttp://hdl.handle.net/2152/ETD-UT-2011-08-3992en
dc.descriptiontexten
dc.description.abstractAssistive mobile robots, such as intelligent wheelchairs, that can navigate autonomously in response to high level commands from a user can greatly benefit people with cognitive and physical disabilities by increasing their mobility. In this work, we address the problem of safe, comfortable, and customizable motion planning of such assistive mobile robots. We recognize that for an assistive robot to be acceptable to human users, its motion should be safe and comfortable. Further, different users should be able to customize the motion according to their comfort. We formalize the notion of motion comfort as a discomfort measure that can be minimized to compute comfortable trajectories, and identify several properties that a trajectory must have for the motion to be comfortable. We develop a motion planning framework for planning safe, comfortable, and customizable trajectories in small-scale space. This framework removes the limitations of existing methods for planning motion of a wheeled mobile robot moving on a plane, none of which can compute trajectories with all the properties necessary for comfort. We formulate a discomfort cost functional as a weighted sum of total travel time, time integral of squared tangential jerk, and time integral of squared normal jerk. We then define the problem of safe and comfortable motion planning as that of minimizing this discomfort such that the trajectories satisfy boundary conditions on configuration and its higher derivatives, avoid obstacles, and satisfy constraints on curvature, speed, and acceleration. This description is transformed into a precise mathematical problem statement using a general nonlinear constrained optimization approach. The main idea is to formulate a well-posed infinite-dimensional optimization problem and use a conforming finite-element discretization to transform it into a finite-dimensional problem for a numerical solution. We also outline a method by which a user may customize the motion and present some guidelines for conducting human user studies to validate or refine the discomfort measure presented in this work. Results show that our framework is capable of reliably planning trajectories that have all the properties necessary for comfort. We believe that our work is an important first step in developing autonomous assistive robots that are acceptable to human users.en
dc.format.mimetypeapplication/pdfen
dc.language.isoengen
dc.subjectAssistive robotsen
dc.subjectRobot motion planningen
dc.subjectSafe and comfortable motion planning for wheeled mobile robotsen
dc.titleA framework for characterization and planning of safe, comfortable, and customizable motion of assistive mobile robotsen
dc.date.updated2011-10-26T16:12:55Zen
dc.identifier.slug2152/ETD-UT-2011-08-3992en
dc.contributor.committeeMemberDjurdjanovic, Draganen
dc.contributor.committeeMemberSreenivasan, S.V.en
dc.contributor.committeeMemberStone, Peteren
dc.description.departmentMechanical Engineeringen
dc.type.genrethesisen
thesis.degree.departmentMechanical Engineeringen
thesis.degree.disciplineMechanical Engineeringen
thesis.degree.grantorUniversity of Texas at Austinen
thesis.degree.levelDoctoralen
thesis.degree.nameDoctor of Philosophyen


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