This paper provides a survey of modern nonlinear filtering methods for attitude estimation. Early applications relied mostly on the extended Kalman filter Since these applications, several new approaches have been developed that proven to be superior filter. Several maintain basic structure filter, but employ various modifications in order provide better convergence or improve other performance characteristics. Examples such include: QUEST, QUEST and backwards-smoothing Filters propagate...

A new spacecraft attitude estimation approach based on the unscented filter is derived. For nonlinear systems uses a carefully selected set of sample points to map probability distribution more accurately than linearization standard extended Kalman filter, leading faster convergence from inaccurate initial conditions in problems. The formulation attitude-vector measurements using gyro-based model for propagation. global parameterization given by quaternion, whereas generalized...

A sigma-point Kalman filter is derived for integrating GPS measurements with inertial from gyros and accelerometers to determine both the position attitude of a moving vehicle. Sigma-point filters use carefully selected set sample points more accurately map probability distribution than linearization standard extended (KKF), leading faster convergence inaccurate initial conditions in position/attitude estimation problems. The formulation based on navigation equations. global parameterization...

In this paper a novel approach is developed for relative state estimation of spacecraft flying in formation. The uses information from an optical sensor to provide multiple line-of-sight vectors one another. measurements are coupled with gyro and dynamical models extended Kalman filter determine attitude, position, biases. quaternion used describe the kinematics, whereas general orbital equations positional dynamics. Three different attitude formulations presented. first estimates individual...

In this paper new real-time approaches for three-axis magnetometer sensor calibration are derived. These rely on a conversion of the magnetometer-body and geomagnetic-reference vectors into an attitude independent observation by using scalar checking. The goal full problem involves determination bias vector, scale factors non-orthogonality corrections. Although actual solution to minimization quartic loss function, can be converted quadratic function centering approximation. This leads...

Introduction Spacecraft pointing poses a complex problem involving nonlinear dynamics with either linear and/or control laws. Primary actuators usually include thrusters for rapid and coarse attitude maneuvers, reaction wheels slow precise maneuvers. Other types of mechanisms gravity-gradient stabilization magnetic torquer assemblies. Control algorithms can be divided into open-loop systems closed-loop (feedback) systems. Open-loop require pre-determined maneuver, are typically determined...

This paper presents a new method, based on multiple-model adaptive estimation approach, to determine the most probable shape of resident space object among number candidate models while simultaneously recovering observed object's inertial orientation and trajectory. Multiple-model uses parallel bank filters, each operating under different hypothesis an estimate physical system consideration. In this work, model constitutes hypothesis. Estimates likelihood hypothesis, given available...

A real-time predictive e lter is derived for spacecraft attitude estimation without the utilization of angular rate measurements from gyros. The formulation shown using only sensors (three-axis magnetometers, sun sensors,startrackers, etc. ).Thenew real-timenonlineare predicts requiredtorquemodeling errorinput in ordertopropagatethespacecraftdynamicmodel,sothatmodelresponsesmatchthemeasuredvectorobservations. used to estimate Solar, Anomalous, Magnetospheric Particle Explorer (SAMPEX)...

A real-time predictive e lter is derived for nonlinear systems. The major advantage of this new over conventional lters that it providesa method determining optimalstate estimatesin the presenceof signie cant error in assumed (nominal)model. determines (predicts)the optimal model errortrajectorysothatthemeasurement-minus-estimatecovariancestatisticallymatchestheknownmeasurement- minus-truth covariance. found by using a one-time step ahead control approach. Also, because continuous used to...

This paper provides a survey of modern nonlinear filtering methods for attitude estimation. Early applications relied mostly on the extended Kalman filter Since these applications, several new approaches have been developed that proven to be superior filter. Several maintain basic structure filter, but employ various modifications in order provide better convergence or improve other performance characteristics. Examples such include: QUEST, super-iterated interlaced and second-order Filters...

A computationally efficient spacecraft attitude estimation particle filter is derived. The quaternion used to represent the global and modified Rodrigues parameters are local errors. mean computed through weighted sum of parameter particles. idea progressive correction employed ensure proper operation filter. Simulation results indicate that performance exceeds extended Kalman or unscented for very large initialization

Output-redefinition-based dynamic inversion (ORDI) control is proposed for a nonminimum phase hypersonic vehicle (HSV). When velocity and altitude are selected as outputs, an HSV exhibits behavior, preventing the application of standard due to unstable zero dynamics. This problem solved by ORDI architecture, where output redefinition utilized at first render modified dynamics stable, then, used stabilize new external Three kinds controllers with different choices investigated. The takes...

Traditionally, attitude estimation has been performed using a combination of external sensors and internal three-axis gyroscopes. There are many studies gyroscopes that read angular rates. Rate-integrating measure integrated rates or displacements, but these types not as fully investigated. This paper derives Kalman filtering framework for coupled with rate-integrating To account correlations introduced by gyroscopes, the state vector must be augmented, compared filters traditional Two...

The purpose of this paper is to provide a new method estimating the hip acceleration and trunk posture in sagittal plane during walking task using an extended Kalman filter (EKF) unscented (UKF). A comparison between these two estimation techniques also provided. Considering periodic nature gait, modified biomechanical model with Fourier series approximations are utilized as priori knowledge. Inertial measurement units (IMUs) placed on right side ankle, hip, middle twenty recruited...

An optimal control approach using variable-structure (sliding-mode) tracking for large angle spacecraft maneuvers is presented. The expands upon a previously derived regulation result quaternion parameterization the kinematic equations of motion. This used since it free singularities. main contribution this paper utilization simple term in law that produces maneuver to reference attitude trajectory shortest distance. Also, multiplicative error between desired and actual derive law....

A novel technique for Ž nding a point-by-point (deterministic) attitude solution of vehicle using Global Positioning System phase difference measurements is presented. This transforms general cost function into more numerically efŽ cient form by determining three-dimensional vectors in either the body or reference coordinate system. Covariance relationships new algorithm, as well methods that minimize function, are also derived. The equivalence functionand transformed shown case orthogonal...

A new method for star identification using planar triangles is developed and compared to a standard angle approach. The creates angles between stars within the field of view tracker matches them in catalog determine which they are. from tracker, determines their area polar moment, then way that faster more successful than method. Simulation results are provided show performance as well its robustness with respect false stars.

A new spacecraft attitude estimation approach using particle filtering is derived. Based on sequential Monte Carlo simulation, the filter approximately represents probability distribution of state vector with random samples. The formulation based star camera measurements a gyro-based or dynamics-based model for propagation. Modified Rodrigues parameters are used parametrization when sample mean and covariance computed. ambiguity problem associated modified in computation addressed as well....

This paper derives the full equations of motion for relative navigation air vehicles. An extended Kalman filter is used estimating position and attitude two vehicles designated leader follower. All states are assumed known, whereas estimated using line-of-sight measurements between along with acceleration angular rate Noise present on all measurements, biases only latter two. The global parameterized a quaternion, local error given by three-dimensional representation. application new...