J. Michael Brady

YNIMG Journal 2004 Journal Article

Advances in functional and structural MR image analysis and implementation as FSL

• Stephen M. Smith
• Mark Jenkinson
• Mark W. Woolrich
• Christian F. Beckmann
• Timothy E.J. Behrens
• Heidi Johansen-Berg
• Peter R. Bannister
• Marilena De Luca

The techniques available for the interrogation and analysis of neuroimaging data have a large influence in determining the flexibility, sensitivity, and scope of neuroimaging experiments. The development of such methodologies has allowed investigators to address scientific questions that could not previously be answered and, as such, has become an important research area in its own right. In this paper, we present a review of the research carried out by the Analysis Group at the Oxford Centre for Functional MRI of the Brain (FMRIB). This research has focussed on the development of new methodologies for the analysis of both structural and functional magnetic resonance imaging data. The majority of the research laid out in this paper has been implemented as freely available software tools within FMRIB's Software Library (FSL).

IROS Conference 1995 Conference Paper

LICAs: a modular architecture for intelligent control of mobile robots

• Huosheng Hu
• J. Michael Brady
• J. Grothusen
• F. Li
• Penny J. Probert

A modular architecture used for intelligent control of mobile robots has been developed at Oxford University over the last few years. This architecture takes the form of multiple sensing and control layers, based on "locally intelligent control agents" (LICAs). Central to such a design is the concept of "communication sequential processes" (CSP). This paper describes briefly the LICA-based control architecture for an Oxford mobile robot. Two typical operations of sonar and active vision systems have been given to demonstrate its flexibility and efficiency. Such a modular and unified system has been licensed commercially and allows for the integration of all kinds of sensors and actuators to meet future needs.

IROS Conference 1993 Conference Paper

A decision theoretic approach to real-time obstacle avoidance for a mobile robot

• Huosheng Hu
• J. Michael Brady
• Penny J. Probert

Investigates how a car-like mobile robot handles unexpected static obstacles while following an optimal path planned by the global path planner. To find an optimal solution of the problem, the obstacle avoidance problem is formulated as a decision theoretic approach. The optimal decision rule we seek is to minimize the Bayes risk by trading off between deliberative maneuver and the alternatives. Real-time implementation is emphasized in order to provide a framework for real-world applications.

IROS Conference 1993 Conference Paper

Dynamic tracking of a wheeled mobile robot

• Zhongping Deng
• J. Michael Brady

Based on a dynamic model of a wheeled mobile robot (WMR), a dynamic control method is developed so that the WMR tracks a desired trajectory. The full nonlinear dynamics and the kinematic constraints are embodied in the controller. The steering and driving torques are chosen as the control inputs. Examples are presented that demonstrate the effectiveness of the model and the control methods.

UAI Conference 1992 Conference Paper

Sensor Validation Using Dynamic Belief Networks

• Ann E. Nicholson
• J. Michael Brady

The trajectory of a robot is monitored in a restricted dynamic environment using light beam sensor data. We have a Dynamic Belief Network (DBN), based on a discrete model of the domain, which provides discrete monitoring analogous to conventional quantitative filter techniques. Sensor observations are added to the basic DBN in the form of specific evidence. However, sensor data is often partially or totally incorrect. We show how the basic DBN, which infers only an impossible combination of evidence, may be modified to handle specific types of incorrect data which may occur in the domain. We then present an extension to the DBN, the addition of an invalidating node, which models the status of the sensor as working or defective. This node provides a qualitative explanation of inconsistent data: it is caused by a defective sensor. The connection of successive instances of the invalidating node models the status of a sensor over time, allowing the DBN to handle both persistent and intermittent faults.

ECAI Conference 1992 Conference Paper

The Data Association Problem when Monitoring Robot Vehicles Using Dynamic Belief Networks

• Ann E. Nicholson
• J. Michael Brady

IROS Conference 1991 Conference Paper

Coping with uncertainty in control and planning for a mobile robot

• Huosheng Hu
• J. Michael Brady
• Penny J. Probert

Describes a decision theoretic approach to real-time obstacle avoidance and path planning for a mobile robot. The mobile robot navigates in a semi-structured environment in which unexpected obstacles may appear at random locations. Twelve sonar sensors are currently used to report the presence and location of the obstacles. To handle the uncertainty of an obstacle's appearance, the authors adopt a Bayesian approach by assuming a prior distribution for the presence of unknown obstacles. The distribution is changed dynamically according to the information accumulated by sensors. When searching for an optimal path using dynamic programming, the authors take the probability into account in making a decision. Based on prior information and sensor data, they show that the proposed method allows the mobile robot to avoid unexpected obstacles and finds an optimal path to the goal in real time.

IROS Conference 1989 Conference Paper

Stereo Matching Of Curves By Least Deformation

• Andrew T. Brint
• J. Michael Brady

ECAI Conference 1985 Conference Paper

The Mechanic's Mate

• J. Michael Brady
• Philip E. Agre

ICRA Conference 1985 Conference Paper

Toward a surface primal sketch

• Jean Ponce
• J. Michael Brady

This paper reports progress toward the development of a representation of significant surface changes in dense depth maps. We call tile representation the Surface Primal Sketch by analogy with representations of intensity changes, image structure, and changes in curvature of planar curves. We describe an implemented program that detects, localizes, and symbolically describes: steps, where the surface height function is discontinuous, and roofs, where the surface is continuous but the surface normal is discontinuous. We illustrate the performance of the program on range maps of objects of varying complexity.

ICRA Conference 1984 Conference Paper

Representing shape

• J. Michael Brady

We summarize recent work by the author and his colleagues aimed at generating rich representations of shape for two and three-dimensional objects. An implementation of the smoothed local symmetries representation of 2D shapes is described and its use for inspection and the recognition of occluded objects sketched. The implementation uses an edge finder developed by Canny that is optimal in a precisely defined sense. The curvature patch representation of 3D shape is based on ideas of differential geometry.