Online dynamic calibrating method for errors of inner and outer lever arms of two rotary inertial navigation systems

Abstract

The invention discloses an online dynamic calibrating method for errors of inner and outer lever arms of two rotary inertial navigation systems. The method comprises the steps: firstly, establishing measuring models for respective inner lever arms, a measuring model for intersystem outer lever arm errors and a measuring model for intersystem speed difference of the two rotary inertial navigation systems; secondly, realizing a principle and way of separation of the respective inner lever arms of the two rotary inertial navigation systems on the basis of model analysis, and designing a rotationpolicy of the two rotary inertial navigation systems; then, separately controlling frameworks of RINS1 and RINS2 to rotate according to the preset rotation policy, carrying out navigation resolving, and outputting speed information on the two rotary inertial navigation systems; finally, calculating speed difference between the two rotary inertial navigation systems, constructing a Kalman filter bytaking the speed difference as a measurement amount, so as to achieve the online dynamic calibration on the errors of the inner and outer lever arms of the two rotary inertial navigation systems. According to the method, the required calibration time is short, the calibration process is simple, the accuracy in calibration of the inner and outer lever arms is high, the dependence on other outsidereference information is not required, the independence is high, and the implementation is facilitated.

Description

technical field [0001] The invention belongs to the technical field of error parameter calibration of inertial navigation systems, and in particular relates to an online dynamic calibration method for errors of inner lever arms and outer lever arms of two sets of rotary inertial navigation systems, which can simultaneously realize the respective inner lever arms and system of two sets of rotary inertial navigation systems. On-line dynamic calibration of external lever arm. Background technique [0002] The inertial measurement unit (IMU) of the inertial navigation system is composed of three gyroscopes and three accelerometers. The three gyroscopes and the three accelerometers can respectively measure the angular velocity component and the linear acceleration component in the three directions of the carrier. Through the angular velocity and acceleration The integration of the carrier can obtain the attitude, speed and position information of the carrier in real time. Howeve...

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Problems solved by technology

However, in the actual inertial navigation system, the accelerometer is a physical element with a certain size and volume, so the installation positions of the three accelerometers cannot completely coincide with the center position of the IMU, and due to the inevitable installation error, the three The extension lines in the direction of the acceleration sensitive axis cannot intersect at one point, which causes the sensitive measurement points of each accelerometer to be different from each other

The line vectors from the center of the IMU to the measurement points of the accelerometer constitute a set of inner lever arms. When there is an angular velocity excitation, a "lever arm effect" will occur, causing acceleration errors. After the integral solution, the velocity errors and position errors will be caused respectively. error

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