This paper proposes a globally and exponentially convergent predictive observer for attitude and position estimation based on landmark measurements and velocity (angular and linear) readings. It is assumed that landmark measurements are available with time-delay. The maximum value of the sensor delay under which the estimation error converges to zero is calculated. Synthesis of the observer is ...

The paper describes an Attitude & Heading Reference System able to achieve a high accuracy level by using a Kalman filter, which integrates the measurements coming from low cost inertial sensors, magnetometric sensors and a GPS receiver. The errors correction on attitude and heading angles, calculated through the integration of the gyroscopes measurements, is performed on the basis of their alt...

The QUEST measurement noise model for unit vector observations has been widely used in spacecraft attitude estimation for more than twenty years. It was derived under the approximation that the noise lies in the tangent plane of the respective unit vector and is axially symmetrically distributed about the vector. For large field-of-view sensors, however, this approximation may be poor, especial...

In this paper, an algorithm for autonomous stair climbing with a tracked vehicle is presented. The proposed method achieves robust performance under real-world conditions, without assuming prior knowledge of the stair geometry, the dynamics of the vehicle’s interaction with the stair surface, or lighting conditions. The approach relies on fast and accurate estimation of the robot’s heading and ...

For spacecraft attitude representation, the quaternion is preferred over other representations due to its bilinear nature of the kinematics and the singularity-free property. However, when applied in the attitude estimation filters, its unity norm constraint can be easily destroyed by the quaternions averaging operation. Although the brute-force quaternion normalization can be implemented, this...

This article presents an inexpensive inertial attitude and position reference system for a small unmanned aerial vehicle (UAV) that utilizes low cost inertial sensors in conjunction with a global positioning system (GPS) sensor. The attitude estimates are obtained from a complementary filter and a Kalman filter by combining the measurements from the inertial sensors with the supplementary attit...

This paper presents a study of star tracker attitude estimation algorithms and implementation on an indoor ground-based Three Axis Spacecraft Simulator (TASS). Angle, Planar Triangle, and Spherical Triangle algorithms are studied for star pattern recognition. Least squares, QUEST and TRIAD algorithms are studied for attitude determination. A star field image is suspended above TASS. The indoor ...

A method for relative attitude determination from planar line-of-sight observations is presented. Three vehicles are assumed to be equipped with sensors to provide measurements of the three inter-vehicle line-of-sight vectors. The line-of-sight vectors are further assumed to be always in the same plane. This information is combined with all the available measurements to find an optimal relative...

Small unmanned air vehicles (UAVs) and micro air vehicles (MAVs) have payload and power constraints that prohibit heavy sensors and powerful processors. This paper presents real-time attitude and position estimation solutions that use small, inexpensive sensors and low-power microprocessors. In connection with an Extended Kalman Filter attitude estimation scheme, a novel method for dealing with...

The QUEST measurement noise model for unit vector observations has been widely used in spacecraft attitude estimation for more than twenty years. It was derived under the approximation that the noise lies in the tangent plane of the respective unit vector and is axially symmetrically distributed about the vector. For large field-of-view sensors, however, this approximation may be poor, especial...