Oliver O'Reilly

Oliver O'Reilly
5131 Etcheverry Hall, Mailstop 1740
University of California at Berkeley

Professor of Mechanical Engineering

1985: B.E. with first class honours in Mechanical Engineering, National University of Ireland, Galway, Ireland
1988: M. Sc. in Theoretical and Applied Mechanics, Cornell University, Ithaca, NY
1990: Ph. D. in Theoretical and Applied Mechanics, Cornell University, Ithaca, NY
1986-1990: Research and Teaching Assistant, Department of Theoretical and Applied Mechanics, Cornell University, New York
1990-1992: Postdoctoral Assistant, Institut für Mechanik, Swiss Federal Institute of Technology, Zürich, Switzerland.
1992-1998: Assistant Professor, Department of Mechanical Engineering, University of California at Berkeley
1998-2003: Associate Professor, Department of Mechanical Engineering, University of California at Berkeley
Since 2003: Professor, Department of Mechanical Engineering, University of California at Berkeley
Since 2009: Vice Chair for Graduate Study, Department of Mechanical Engineering, University of California at Berkeley


1995: Hellman Family Faculty Fund Award
1997 and 1998: Pi-Tau-Sigma Excellence in Teaching Awards
1999: University of California at Berkeley Distinguished Teaching Award
2003: Pi-Tau-Sigma Professor of the Year Award
2006: Graduate Women of Etcheverry Faculty Award for Excellence in Graduate Student Mentoring
2007: Science Foundation Ireland, E.T.S. Walton Research Visitor Award in the Department of Applied Mathematics at University College Cork, Ireland.

Professor O’Reilly’s interests span the fields of continuum mechanics and nonlinear dynamics. He has a broad range of specializations including directed (or Cosserat) theories of deformable bodies, constrained rigid body dynamics, contact mechanics, linear and nonlinear vibrations and linear and nonlinear dynamics of deformable bodies. He has applied these interests to a range of applications including MEMS resonators, brake squeal, the dynamics of toys, motorcycle navigation, axially moving media, artificial and natural satellites, spinal kinematics and vehicle collision dynamics. O’Reilly has published over 70 archival journal articles, written two books and is a co-inventor on two patents


Novelia A., O'Reilly O. M.
On Geodesics of the Rotation Group $SO(3)$
2015, vol. 20, no. 6, pp.  729-738
Geodesics on $SO(3)$ are characterized by constant angular velocity motions and as great circles on a three-sphere. The former interpretation is widely used in optometry and the latter features in the interpolation of rotations in computer graphics. The simplicity of these two disparate interpretations belies the complexity of the corresponding rotations. Using a quaternion representation for a rotation, we present a simple proof of the equivalence of the aforementioned characterizations and a straightforward method to establish features of the corresponding rotations.
Keywords: quaternions, constraints, geodesics, Listing’s law, Slerp
Citation: Novelia A., O'Reilly O. M.,  On Geodesics of the Rotation Group $SO(3)$, Regular and Chaotic Dynamics, 2015, vol. 20, no. 6, pp. 729-738
Lew E. S., Orazov B., O'Reilly O. M.
In the 1950s and 1960s, Charles F. Taylor designed and tested various prototype one-wheeled vehicles. These machines were stabilized and steered using gyroscopes. In this paper, a simple model of a one-wheeled vehicle is presented and analyzed. This analysis explains the ability of these machines to exhibit stable steady motions.
Keywords: one-wheeled vehicle, nonholonomic system
Citation: Lew E. S., Orazov B., O'Reilly O. M.,  The Dynamics of Charles Taylor’s Remarkable One-Wheeled Vehicle, Regular and Chaotic Dynamics, 2008, vol. 13, no. 4, pp. 257-266
Kessler P., O'Reilly O. M.
The Ringing of Euler's Disk
2002, vol. 7, no. 1, pp.  49-60
The motion of disks spun on tables has the well-known feature that the associated acoustic signal increases in frequency as the motion tends towards its abrupt halt. Recently, a commercial toy, known as Euler's disk, was designed to maximize the time before this abrupt ending. In this paper, we present and simulate a rigid body model for Euler's disk. Based on the nature of the contact force between the disk and the table revealed by the simulations, we conjecture a new mechanism for the abrupt halt of the disk and the increased acoustic frequency associated with the decline of the disk.
Citation: Kessler P., O'Reilly O. M.,  The Ringing of Euler's Disk, Regular and Chaotic Dynamics, 2002, vol. 7, no. 1, pp. 49-60

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