Robust Longitudinal and Transverse Rate Gyro Bias Estimation for Precise Pitch and Roll Attitude Estimation in Highly Dynamic Operating Environments Utilizing a Two Dimensional Accelerometer Array

Abstract

In this paper, an innovative method for twodimensi onal attitude estimation making use of a unique, low cost, dual arc accelerometer array measuring longitudinal and transverse rotational rates in realtime through the use of rate gyroscopes is proposed. This revolutionary device utilizes a dual arc accelerometer array and an extended Kalman filter algorithm for accurate and reliable twodimensional attitude determination and rate gyro bias estimation in realtime. The method developed dete rmines the local gravitational field vector from which attitude information can be resolved. Upon determining the location of the local gravitational field vector relative to two consecutive accelerometer sensors, the orientation of the device may then be estimated and the attitude determined. However, this measurement is discrete in nature; therefore, integrated rate gyro measurements are used to determine attitude information resulting in a continuous signal. Attitude estimates and measurements produced by instantaneous rate sensors and gyroscope integration tend to drift over time however, due to drift and bias inherent to the rate gyro sensor. The integration of the acquired instantaneous rate signals amplify measurement errors leading to an undependable and imprecise estimate of the vehicles true attitude and orientation. A method for compensation of these errors is proposed in this work resulting in a highly accurate and continuous attitude estimates. For the work conducted in this study, simulations of the proposed method and device will be conducted with the inclusion of characteristic, realworld sensor noise and bias es timates produced from corrupted and biased sensors to analyze and asses the feasibility and validity of the proposed method and system configuration for twodimensional attitude determination. In this work, simulations are also performed utilizing a Dryden wind and turbulence model to inject severe operating conditions into the simulation models during the nonlinear aircraft simulations performed to verify and validate the proposed device and algorithms ability to accurately and repeatedly produce reliable longitudinal and transverse attitude estimates in realtime desp ite the presence of severe operating conditions. The end goal of this work is to produce a precise and reliable longitudinal and transverse attitude estimation array capable of measuring rate senor and gyro bias online so as to generate highly accurate and reliable pitch and roll angle tracking in realtime while subjected to highly dynamic simu lated flight conditions and scenarios. $omenclature