Robust adaptive control of underwater vehicles in 6 DOF is analyzed in the context of measurement noise. The performance of the adaptive control laws of Sadegh and Horowitz (1990) and Slotine and Benedetto (1990) are compared. Both these schemes require that all states are measured, that is the velocities and positions in surge, sway, heave, roll, pitch and yaw. However, for underwater vehicles...

The biomechanical properties of an animal's locomotor structures profoundly influence the relationship between neuromuscular inputs and body movements. In particular, passive stability properties are of interest as they may offer a non-neural mechanism for simplifying control of locomotion. Here, we hypothesized that a passive stability property of animal flight, flapping counter-torque (FCT), ...

Many extant studies proposed various stabilizing control methods for humanoids during the stance phase while hopping and running. Although these methods contribute to stability during hopping and running, humanoid robots do not swing their legs rapidly during the flight phase to prevent rotation in the yaw direction. Humans utilize their torsos and arms when running to compensate for the angula...

Three-dimensional unsteady computations of the flow past a fruit fly Drosophila under hovering and free flight conditions are computed. The kinematics of the wings and the body of the fruit fly are prescribed from experimental observations. The computed unsteady lift and thrust forces are validated with experimental results and are in excellent agreement. The unsteady aerodynamic origin of the ...

Background Deficits in motor movement in children with autism spectrum disorder (ASD) have typically been characterized qualitatively by human observers. Although clinicians have noted the importance of atypical head positioning (e.g. social peering and repetitive head banging) when diagnosing children with ASD, a quantitative understanding of head movement in ASD is lacking. Here, we conduct a...

In this paper, an antilock–antiskid braking system controller, which has been designed for stability enhancement of vehicles during braking and turning, is presented. Using available signals, a novel structure is proposed for vehicle stability improvement for critical driving conditions such as braking on slippery or μ-split road surfaces. In conventional vehicles, undesired lane changes may oc...

BACKGROUND AND PURPOSE Variability in patient head positioning may yield substantial interstudy image variance in the clinical setting. We describe and test three-step technologist and computer-automated algorithms designed to image the brain in a standard reference system and reduce variance. METHODS Triple oblique axial images obtained parallel to the Talairach anterior commissure (AC)-post...

In recent years several Parameter Identification (PID) techniques have been proposed for on-line real-time applications. Historically aircraft parameter estimation has been performed off line using recorded flight data from specifically designed maneuvers. Flight data from the NASA F/A-18 High Alpha Research Vehicle (HARV) aircraft is used for this study and is compared with baseline wind tunne...

In this paper, finite element analysis was used to compare the dynamic rollover performance of a midsized SUV with a strengthened roof in a Jordan Rollover System (JRS) test with an Un-Constrained (UC) rollover under the same initial conditions. The JRS has the ability to closely control the initial conditions of a vehicle being subjected to a rollover test. This research was proposed to study ...

Several approaches for modelling the longitudinal aerodynamic coefficients of a fighter aircraft at high angles of attack, including the unsteady effects are presented. A traditional approach where the model of the coefficient arises in the form of the steady and unsteady effects, the unsteady effect being modelled by means of transfer functions. The second approach uses an internal variable de...