Online calibration method and device for laser Doppler velocimeter based on inertial measurement unit

Abstract

The invention relates to an online calibration method and device for a laser Doppler velocimeter based on an inertial measurement unit. The method comprises the following steps: using inertial navigation data in an initial time period, carrying out coarse calibration on a mounting angle and a transmitting inclination angle of a laser Doppler velocimeter based on a parameter analysis method, establishing a state equation of a combined navigation system, establishing an observation equation by taking a difference value between a speed error of the laser Doppler velocimeter and a speed error of inertial navigation equipment as an observed quantity, and carrying out calculation on the observed quantity; obtaining the installation angle error estimation value and the emission angle error estimation value of the laser Doppler velocimeter, correspondingly compensating the rough calibration value, and obtaining a high-precision online calibration result of the laser Doppler velocimeter. According to the method, the characteristics of inertial navigation equipment are fully utilized, online high-precision calibration is carried out on the laser velocimeter in real time without depending on a satellite navigation system, the equipment cost is reduced, the method has the characteristics of high autonomy, good environmental adaptability and the like, and the maneuverability of a carrier can be improved.

Description

technical field [0001] The present application relates to the technical field of integrated navigation, in particular to an online calibration method and device for an inertial group-based laser Doppler velocimeter. Background technique [0002] In the integrated navigation system composed of strapdown inertial navigation equipment (SINS) and laser Doppler velocimeter (LDV), it is necessary to calibrate the scale factor and installation angle of LDV. For the scale factor of LDV, the traditional calibration method is to use a turntable, a drum, etc. with a fixed speed as a standard speed source under laboratory conditions, and to achieve the calibration of the LDV scale factor by comparing the speed obtained by the speedometer with the standard speed. , and then install the speedometer together with the inertial navigation equipment on the measurement carrier. Although this offline calibration method has high calibration accuracy, it cannot guarantee the completion of the ca...

AI Technical Summary

Problems solved by technology

However, satellite positioning technology is a non-autonomous navigation method, and is greatly affected by the external environment. In areas with severe occlusion, such as tunnels and mountains, satellite navigation signals are easily lost, resulting in a decrease in online calibration accuracy.

In addition, in some special applications, the use of satellite navigation systems is prohibited, and accurate speed information cannot be obtained from the outside world as a calibration reference

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