An Optimization Design Method for Strapdown Inertial Navigation System to Enhance Velocity Error Stability

Transfer alignment is a core technology for the rapid activation of subsystems, such as shipborne weapons, radar, and electro-optical systems, and the alignment accuracy critically affects the operational performance of these systems. The ship’s main inertial navigation system (m-INS) provides reference information for the transfer alignment of the subordinate inertial navigation system (s-INS), and the oscillation errors in the m-INS’s velocity information severely impact the transfer alignment accuracy of the s-INS. Velocity damping can improve the stability of velocity errors in the m-INS to a certain extent, but its effectiveness is constrained by factors, such as reference velocity errors and platform maneuvers, making it difficult to meet the real-time requirements for s-INS transfer alignment. To address this issue, this article, based on the working principles of the strapdown inertial navigation system (SINS), derives the velocity error equation, establishes a mathematical model for velocity error stability, and proposes an optimization design method for SINS to enhance velocity error stability. Using the requirements of a specific radar system as a background, an optimized improvement of a particular SINS was completed, and experimental validation was conducted. The results show that without altering the dimensions and with only marginal increases in weight, power consumption, and cost, the stability of the optimized SINS’s velocity error improved by 100%, thereby verifying the effectiveness of the optimization design method and the accuracy of the mathematical model. This provides theoretical guidance for the design of various types of INS.