Quaternion Walsh approximate output method based on angular velocities for aircraft during extreme flight

Abstract

The invention discloses a quaternion Walsh approximate output method based on angular velocities for an aircraft during extreme flight, which is used for solving the technical problem of poor precision of quaternion outputted by existing inertial equipment when an aircraft is in extreme flight. The technical scheme includes that approximate prescription is realized for a rolling angular velocity p, a pitching angular velocity q and a yawing angular velocity r by the aid of a Walsh function polynomial, a quaternion state transition matrix is directly obtained, and iterative computation precision of specified quaternion is guaranteed. Orders of Walsh approximate expansion for the rolling angular velocity p, the pitching angular velocity q and the yawing angular velocity r are determined according to the requirement of engineering precision, superlinear approximation for a quaternion state equation transition matrix phie[(k+1)T, kT] is realized, iterative computation precision of the specified quaternion is guaranteed, and accordingly output precision of inertial equipment is improved when the aircraft is in extreme flight.

Description

Technical field [0001] The invention relates to an attitude output method of an airborne inertial device of an aircraft, in particular to a quaternion Walsh approximation output method based on the angular velocity of the aircraft during extreme flight. Background technique [0002] Generally, the acceleration, angular velocity and attitude of rigid body motions all depend on the output of inertial equipment, so improving the output accuracy of inertial equipment has clear practical significance. Space motions such as aircraft, torpedoes, and spacecraft use rigid body motion differential equations in most cases; and the differential equations describing the attitude of rigid bodies are the core of them, usually with three Euler angles, namely pitch, roll and yaw. To describe, it is usually output by the pitch, roll and yaw angular velocity of the airborne inertial equipment. When the pitch angle of a rigid body is ±90°, the roll angle and yaw angle cannot be determined. At the s...

AI Technical Summary

Problems solved by technology

[0004] In order to overcome the problem that the existing quaternion output error is large, the present invention provides a quaternion Walsh approximate output method based on the angular velocity of the aircraft limit flight, the method adopts the Walsh function polynomial to roll, pitch, The yaw angular velocity p, q, r is approximated and described, and the quaternion state transition matrix is ​​directly obtained, which can ensure the iterative calculation accuracy of the quaternion, thereby improving the accuracy of the quaternion output by the inertial equipment during the extreme flight of the aircraft

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