A New Analytic Alignment Method for a SINS

Area of Science:

• Navigation Systems Engineering
• Geophysics and Geodesy
• Robotics and Control Systems

Background:

• Strapdown Inertial Navigation Systems (SINS) rely on analytic alignment for self-alignment.
• Traditional analytic coarse alignment uses all six inertial measurement unit (IMU) outputs.
• The TRIAD algorithm is a foundational method for attitude determination using two non-collinear vectors.

Purpose of the Study:

• To introduce a novel analytic alignment method called selective alignment for SINS.
• To reduce the number of required IMU outputs for attitude calculation.
• To enhance the precision of SINS alignment, particularly yaw accuracy.

Main Methods:

• Developed the selective alignment method, utilizing only three core IMU outputs and properties (sign, approximate value) of the remaining outputs.
• Extended the principles of the TRIAD algorithm for SINS attitude determination.
• Validated the method through simulations and experimental vehicle testing.

Main Results:

• Selective alignment successfully calculates SINS attitude using a reduced set of IMU data.
• Experimental results show improved yaw precision compared to traditional analytic coarse alignment.
• The method demonstrates validity and accuracy for stationary base applications.

Conclusions:

• Selective alignment offers an efficient and accurate alternative for SINS analytic alignment.
• The method is an extension of the TRIAD algorithm, providing enhanced yaw precision.
• Potential applications include SINS self-alignment, fault detection, and self-calibration.