Research On Damping Technique For Shipboard SINS With Mechanically Dithered Ring Laser Gyroscope

Crucial weapons like nuclear submarine should possess the ability of concealment and long-endurance. The underwater accurate navigation of inertial navigation system(INS) can guarantee this ability. Now, the divergence of navigation error has been well solved by rotary INS, so the oscillation errors of INS become the main factor that affecting navigation accuracy. As the most common used automatic compensation error technique, damping technique can well suppress the oscillation errors and has great practical engineering value. This thesis carry out the research on damping technique for shipboard strapdown inertial navigation system(SINS) using mechanically dithered ring laser gyroscope(RLG). The main contents of this thesis can be generalized as the following parts:(1) The algorithm and experiment of non-damping rotary SINS. The basic working principles, concepts and machinery arrangement of rotary SINS are introduced in this part. On this basis, by taking the gyro drift and accelerometer bias as the research object, the error equations of rotary SINS are established. Taking the pure SINS, single-axis rotation SINS and double-axis rotation SINS for example, non-damping experiment is presented.(2) Damping network of INS. On the basis of deeply analysis on the structure and principle of the horizontal damping network and the azimuthal damping network, the error characteristics of damping rotary INS are analyzed, the influence of inner damping network parameters along with the errors of gyroscope and accelerometer to damping INS are emphatically studied. Strictly according to the allocation method of zero point principle, a new parameter design method is proposed and is proved to be reasonable. Also getting the assistant of Simulink, a more convenient design for damping network parameter design is given.(3) The algorithm of damping SINS. Facing up to the problems of present damping algorithm, such as multivariable introduction and difficult use etc, a discrete bilinear damping algorithm which is simpler and has strong universality is proposed, moreover, the discrete techniques based on compass damping network and tandem damping network are derived respectively. Static state navigational verification under the condition of 90-type RLG single-axis rotation SINS, 50-type RLG SINS and 50-type RLG double-axis rotation SINS combine with dynamic state navigational verification of 50-type RLG single-axis rotation SINS show that this damping algorithm can efficiently suppress the effect of Schuler oscillation and earth oscillation of SINS, significantly increase the navigation accuracy.