Segmentation of femurs in Anterior-Posterior x-ray images is very important for fracture detection, computer-aided surgery and surgical planning. Existing methods do not perform well in segmenting bones in x-ray images due to the presence of large amount of spurious edges. This paper presents an atlas-based approach for automatic segmentation of femurs in x-ray images. A robust global alignment...

This paper presents a time division multiple access medium access control protocol for wireless sensor / actuator networks implemented with a contention-free message scheduler. A message scheduler is used to determine which message has access to the medium at any time. A set of messages is contention-free if only one message is ready at a time. Otherwise, some other criterion such as priority m...

An important issue in designing manipulators for dynamic performance is the determination of the acceleration properties of (some reference-point on) the end-effector of the manipulator. Given the dynamical equations of the planar two degree-of-freedom manipulator and a set of constraints on the actuator torques and on the rates-ofchanges of the joint variables, we systematically develop (a) th...

When designing control laws for systems with more inputs than controlled variables, one issue to consider is how to deal with actuator redundancy. Two tools for distributing the control effort among a redundant set of actuators are control allocation and linear quadratic control design. In this paper, we investigate the relationship between these two design tools when a quadratic performance in...

In this article, the problem of steering control based on Takagi-Sugeno (T-S) fuzzy vehicle lateral dynamics is investigated for autonomous driving with nonlinearities, system uncertainties, and actuator constraints. During normal cruising, velocity always changes due to different road conditions and/or wheel maneuvers, moreover, also significantly influenced by tire/road forces under surface c...

A common problem with space suit systems is overly rigid gloves that resist astronaut finger motion and gripping. In this paper, the design of a mechanism is considered that exploits the small-scale nature of shape memory alloys for actuating glove fingers to assist hand gripping. The design problem is introduced by considering the objectives, constraints, and variables relevant to a spacesuit ...

An adaptive backstepping controller is designed for the automatic landing of a fixed-wing aircraft. The backstepping control scheme is adopted by using the nonlinear six degree-of-freedom dynamics of the aircraft during the landing phase. The adaptive law is integrated along with the backstepping controller in order to estimate the aircraft modeling errors as well as the external disturbance. T...

This paper develops design technology for active shape control of reflective surfaces using large spatially distributed sensor/actuator arrays. The classically-motivated design methodology achieves scalability to very large array sizes by imposing spatially localized fixed-form constraints on the control law structure. Linear program is solved to find parameters of this structure. The design is...

This work considers the problem of control actuator fault detection and isolation and fault-tolerant control for a multi-input multi-output nonlinear system subject to constraints on the manipulated inputs and proposes a fault detection and isolation filter and controller reconfiguration design. The implementation of the fault detection and isolation filters and reconfiguration strategy are dem...

Recently a planetary rover returned important scientific information from Mars. More ambitious missions are planned. New planning methods are required that allow rovers to explore challenging areas with a high level of autonomy. This paper presents a planning methodology based on a physics-based model of the rover and environment. Plans are developed that allow a rover to perform a mission whil...