Two Dimensional Rate Gyro Bias Estimation for Precise Pitch and Roll Attitude Determination Utilizing a Dual Arc Accelerometer Array

摘要

In this thesis, a previously developed, novel one-dimensional attitude estimation device is expanded through the development and implementation of an innovative method for estimation of two-dimensional attitude making use of a unique low-cost, dual arc accelerometer array measuring longitudinal and transverse rotational rates in real-time. The device and method proposed is an expansion of a previously developed method for one-dimensional attitude determination and rate gyro bias estimation utilizing a one-dimensional accelerometer array. This new revolutionary device utilizes a dual arc accelerometer array and an algorithm for accurate and reliable two-dimensional attitude determination and rate gyro bias estimation in real-time. The method determines 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. However, attitude estimates and measurements produced by instantaneous rate sensors and gyroscope integration tend to drift over time 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 estimate. For this thesis, simulations of the proposed method and device will be conducted with the inclusion of characteristic, real-world sensor noise and bias estimates produced from corrupted and biased sensors to analyze and assess the feasibility and validity of the proposed method and system configuration for two-dimensional attitude determination. 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 produce highly accurate and reliable pitch and roll angle tracking in real-time while under subjection to simulated flight conditions and scenarios. While this thesis is an expansion of a previously developed device and method, it is a departure from past works in that a new, two-dimensional accelerometer array arc is utilized and additional rotational dimensions are being included in the simulated analysis.