Recovery type space launch vehicle distributed navigation system initial alignment method

Abstract

The invention provides a recovery type space launch vehicle distributed navigation system initial alignment method. The method comprises the steps of: carrying out calibration calculation of azimuth installation coefficients between a first sub-stage inertial measurement unit and an instrument cabin inertial measurement unit and between a boosting-stage inertial measurement unit and the instrumentcabin inertial measurement unit in the erecting process of a rocket; carrying out horizontal self-alignment and orientation self-alignment by the instrument cabin inertial measurement unit to correspondingly obtain a horizontal self-alignment result and an orientation self-alignment result; carrying out horizontal self-alignment on the first sub-stage inertial measurement unit and the boosting stage inertial measurement unit to correspondingly obtain respective horizontal self-alignment results; enabling the first sub-stage inertial measurement unit and the boosting stage inertial measurementunit to complete calculation of the azimuth attitude angles of the first sub-stage inertial measurement unit and the boosting stage inertial measurement unit respectively according to the horizontalself-alignment result and the azimuth self-alignment result of the instrument cabin inertial measurement unit, the horizontal self-alignment results and the installation coefficient calibration resultof the first sub-stage inertial measurement unit and the boosting stage inertial measurement unit; and acquiring initial attitude angles of the instrument cabin inertial measurement unit, the first sub-stage inertial measurement unit and the boosting stage inertial measurement unit to finish initial alignment of the distributed navigation system. According to the invention, each stage of sub-navigation system can independently acquire a high-precision orientation alignment result.

Description

technical field [0001] The application belongs to the technical field of initial alignment of navigation systems, and in particular relates to an initial alignment method of a distributed navigation system of a recoverable space vehicle. Background technique [0002] With the continuous development of aerospace technology, how to reduce the cost of space launch has become one of the main challenges faced by the entire space industry, and the recyclability and reuse of space vehicles is an important measure to reduce launch costs. [0003] The overall configuration of the recoverable rocket is not significantly different from that of traditional space vehicles. However, due to the completion of the recovery of the first sub-stage and bundled boosters, compared with traditional space vehicles, except for the above In addition to installing navigation equipment in the instrument cabin of the first stage for the guidance and control of the ascent phase of the space vehicle, it i...

AI Technical Summary

Problems solved by technology

[0005] Traditional rockets generally use optical transmission schemes for azimuth aiming. Although optical aiming can obtain high initial azimuth aiming accuracy, the guarantee conditions are complex and require the cooperation of the ground optical aiming system. Adding an azimuth aiming prism is a complex system with high investment costs. In addition, it is necessary to eliminate the influence of environmental factors such as external wind disturbance and strong light.

[0006] Although some space vehicles no longer need complex optical aiming systems, the initial azimuth alignment can be achieved by using the output information of the inertial measurement combination itself, but this alignment method depends on the high-precision inertial measurement combination, which is suitable for the traditional one-time Due to the high price of high-precision inertial units, in order to control the launch cost in recyclable space vehicles, in addition to the use of high-precision products for the inertial units in the instrument cabin, the first-stage and booster navigation subsystems generally use Low-to-medium-precision inertial group products, when the low-to-medium-precision inertial group performs autonomous azimuth alignment, the initial azimuth that meets the accuracy requirements cannot be obtained

Therefore, this alignment method is not fully applicable to the retrievable space vehicle of the distributed navigation system with inertial navigation units installed on different sub-levels

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