Intelligent vehicles sense their dynamics and the environment to make proper decisions. Some of this information are hard to be measured or need expensive sensors. This paper addresses the estimation of road grade angles, along with tire-ground interaction forces, in a delayed interconnected cascade observer structure. A new approach using a Two-Stage Extended Kalman Filter is proposed, allowing a robust simultaneous estimation of the slow and fast dynamics variables. Experimental data is used to validate the estimator.

Addresses the issue of automatic hovering of an outdoor autonomous airship using image-based visual servoing. The hovering controller is designed using a full dynamic model of the airship, in a PD error feedback scheme, taking the visual signals as output and extracted from an on-board camera. The behavior and stability of the airship motion during the task execution and subjected to the wind disturbance is studied. The approach is finally validated in simulation using an accurate airship model.

Project AURORA aims at the development of an unmanned airship capable of autonomous flight over user-defined locations for aerial inspection and imagery acquisition. In this article the authors report a successful autonomous flight achieved through a set of pre-defined points, one of the first of its kind in the literature. The guidance control strategy is based on a path tracking error generation methodology that takes into account both the distance and the angular errors of the airship with respect to the desired trajectory. The control strategy uses a PI controller for the tail surfaces' deflection.

The development of an unmanned airship capable of autonomous flight over user-defined locations for aerial data and imagery acquisition is the objective of the AURORA project. One important mission problem is the flight path following of the vehicle through a set of pre-defined points at a given altitude and velocity. In this article, a path tracking error generation methodology is presented and two different strategies for the guidance problem, one based on a H/sub /spl infin// control technique and another based on a PI control, are proposed and compared through a simulated case study.

Development of reliable control systems for semi-autonomous unmanned aerial vehicles require the use of extensive simulation data provided by an accurate six-degrees-of-freedom dynamic model. In this article we describe a Simulink-based control system development environment for Project AURORA's unmanned robotic airship, as well as the control algorithms and supervisory level of AURORA's control system. A complete take-off to landing mission illustrates the utilization of this environment.