GPS-denied relative motion estimation for fixed-wing UAV using the variational pose estimator

Abstract

Abstract-Relative pose estimation between fixed-wing unmanned aerial vehicles (UAVs) is treated using a stable and robust estimation scheme. The motivating application of this scheme is that of "handoff" of an object being tracked from one fixed-wing UAV to another in a team of UAVs, using onboard sensors in a GPS-denied environment. This estimation scheme uses optical measurements from cameras onboard a vehicle, to estimate both the relative pose and relative velocities of another vehicle or target object. It is obtained by applying the Lagrange-d'Alembert principle to a Lagrangian constructed from measurement residuals using only the optical measurements. This nonlinear pose estimation scheme is discretized for computer implementation using the discrete Lagranged'Alembert principle, with a discrete-time linear filter for obtaining relative velocity estimates from optical measurements. Computer simulations depict the stability and robustness of this estimator to noisy measurements and uncertainties in initial relative pose and velocities.

Finite time stable attitude estimation of rigid bodies with unknown dynamics

“…The following estimation scheme is proposed for a rigid body whose kinematics equations are given by Equation (21) From here on z(Q) and Ψ(Q, ) are denoted as z and Ψ for convenience.…”

“…This subset is the set of equilibria and the largest invariant set of the system given by (21) and the estimation scheme (32) - (34). From Lemma 1, tr(K(I − Q)) is a Morse function on SO(3) and the identity matrix I ∈ SO(3) minimizes the function.…”

“…The set SO(3) is a matrix manifold and forms a Lie group under the operation of matrix multiplication. Attitude estimation schemes based on the Lagrange-d'Alembert principle of variational mechanics was first proposed in [20] and subsequently developed in [21,22]. The shortcomings such as unwinding and singularities can be avoided by making use of the unique global representation of attitude given by SO (3), to design the estimation scheme.…”

“…Complimentary filters proposed in are one of the most commonly used set of filter‐like algorithms for attitude estimation. Attitude estimation schemes based on the Lagrange‐d'Alembert principle of variational mechanics was first proposed in and subsequently developed in .…”

Stabilization of a Rigid Body Payload With Multiple Cooperative Quadrotors

“…Several aggressive maneuvers of a quadrotor UAV are demonstrated based on a hybrid control architecture, and a nonlinear robust control system is also considered in [22,23]. As they are directly developed on the special Euclidean/Orthogonal group, complexities, singularities, and ambiguities associated with minimal attitude representations or quaternions are completely avoided [24,25]. The proposed control system is particularly useful for rapid and safe payload transportation in complex terrain, where the position of the payload should be controlled concurrently while suppressing the deformation of the cables.…”