An Attitude Determining Method Based on Combination of Mems with Arbitrary Attitudes Without Initial Alignment

Abstract

The invention relates to a random attitude MEMS (Micro Electro Mechanical System) combined attitude determination method without initial alignment. The method comprises the following steps of: 1) defining and correcting Rodrigues parameters; 2) establishing a nonlinear attitude error state equation based on the corrected Rodriges parameters; 3) establishing a nonlinear observation equation of themagnetometer; 4) performing linearization processing on the nonlinear attitude error state equation and the observation equation of the magnetometer to obtain a state error linearization state error model and a magnetometer linearization observation model; 5) utilizing the obtained nonlinear state error equation and observation equation; and combining the linear state model and the observation model, obtaining the optimal estimation of the corrected Rodrigues parameters by utilizing an extended Kalman filtering method, and taking the optimal estimation as an attitude result for guidance control, thereby realizing the MEMS and magnetometer combination attitude determination of any attitude.

Description

technical field

[0001] The invention belongs to the field of navigation and guidance, and relates to an arbitrary attitude MEMS combined attitude determination method without initial alignment. Background technique

[0002] The navigation system is built with MEMS inertial devices as the main navigation equipment to achieve attitude determination and positioning through integral calculations, so initial alignment is required before launch. Generally, the commonly used initial alignment scheme needs to establish a reference point on the ground, and conduct optical aiming through the ground photoelectric theodolite to obtain the initial attitude information of the initial navigation system. It needs to be equipped with corresponding ground equipment and production operation procedures, which takes a long time for alignment and complicated combat preparations. The initial alignment time consumption is an important factor affecting the launch preparation time, and shortening th...

Examples

Embodiment Construction

[0036] This project proposes a method to obtain the three-axis attitude information of the missile weapon system by using only the inertial group and the three-axis magnetometer without any initial attitude information. In the absence of any prior attitude information, the attitude error is no longer a small deviation, and the traditional small deviation linear equation cannot be used to establish the attitude error model. The quaternion model is usually used to describe the nonlinear attitude error. The quaternion has four variables, but only three are independent, so there is a redundancy problem, which will make the state error covariance matrix singular, and the quaternion solution is used at the same time There is still a problem of standardization. The traditional processing method is to use the vector part of the quaternion to model, and ignore the scalar part in the quaternion, that is, the size of the rotation angle, that is, assume that the quaternion error is a smal...

technical field

[0001] The invention belongs to the field of navigation and guidance, and relates to an arbitrary attitude MEMS combined attitude determination method without initial alignment. Background technique

[0002] The navigation system is built with MEMS inertial devices as the main navigation equipment to achieve attitude determination and positioning through integral calculations, so initial alignment is required before launch. Generally, the commonly used initial alignment scheme needs to establish a reference point on the ground, and conduct optical aiming through the ground photoelectric theodolite to obtain the initial attitude information of the initial navigation system. It needs to be equipped with corresponding ground equipment and production operation procedures, which takes a long time for alignment and complicated combat preparations. The initial alignment time consumption is an important factor affecting the launch preparation time, and shortening th...

Examples

Embodiment Construction

[0036] This project proposes a method to obtain the three-axis attitude information of the missile weapon system by using only the inertial group and the three-axis magnetometer without any initial attitude information. In the absence of any prior attitude information, the attitude error is no longer a small deviation, and the traditional small deviation linear equation cannot be used to establish the attitude error model. The quaternion model is usually used to describe the nonlinear attitude error. The quaternion has four variables, but only three are independent, so there is a redundancy problem, which will make the state error covariance matrix singular, and the quaternion solution is used at the same time There is still a problem of standardization. The traditional processing method is to use the vector part of the quaternion to model, and ignore the scalar part in the quaternion, that is, the size of the rotation angle, that is, assume that the quaternion error is a smal...

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