This paper describes a semi-global exponentially stable output feedback control law for automatic heading control of ships described by a nonlinear model. Only compass (yaw angle) feedback is used. The yaw rate signal is reconstructed by a linear observer. A wave lter is included in the observer to reduce wear and tear on the rudder servo due to 1st-order wave-induced disturbances. Integral act...

Scientific applications often require an exact reconstruction of object positions and distances from digital images. Therefore, the images need to be corrected for perspective distortions. We present CameraTransform, a python package that performs a perspective image correction whereby the height, tilt/roll angle and heading of the camera can be automatically obtained from the images if additio...

A standard approach to tracking is to use the Extended Kalman Filter (EKF) applied to a non-linear state-space model. We will compare two conceivable choices of state variables for modeling civil aircrafts. One where Cartesian velocities are used and one where absolute velocity and heading angle are used. In both choices, Cartesian coordinates are used for position and angular velocity for turn...

Electromechanical nose-wheel steering systems give the Medium-haul air-crafts the needed maneuverability and durability. These air-crafts are of intermediate size. They must be able to utilize small airfields, having little or no service and maintenance facilities. During take-off, the nose-wheel steering keeps proper heading. Feedback from the nose-wheel heading is compared with the pilot comm...

If pulsar magnetic fields are associated with the intrinsic magnetic moment of neutrons inside the stellar crust, the gravitational spin effect can induce the magnetic axis to align with the rotation axis. Our theoretical results show that the decay time scale is inversely proportional to the magnetic field strength, and that longer initial period pulsars can delay the alignment process. Theref...

A model predictive control strategy is developed for an autonomous parafoil and payload system. Since the technique requires a linear dynamic model of the system, a reduced state linear model based on a nonlinear 6 degree-of-freedom parafoil and payload model is established and validated. In order to use the reduced state linear model for model predictive control the desired trajectory in the x...

In this paper, we consider using angle of arrival information (bearing) for localization in robot networks. The essential property we require in this paper is that a node can infer heading information from its neighbors. We address the uniqueness of network localization solutions by the theory of globally rigid graphs. We show that while the parallel rigidity problem for formations with bearing...