Research On The Adaptability Of The Fiber Optical Gyro Inertial Navigation System To The Uniaxial Rotary Modulation Technology

According to the development and application of the inertial technology at home and abroad, fiber optical gyroscope(FOG) has great development potential in the application area of high precision, and rotation modulation technology is an effective measure to improve the navigation precision of the inertial navigation system(INS). The structure and operation mode of the rotation modulation INS and the conventional strapdown INS is different, and the operational principle and the error characteristic of FOG is different from other kinds of gyro. So this paper aimed at these special technical matters and carry out the study of the FOG INS's adaptability to the uniaxial rotary modulation technology.At first, this paper studied the error model of rotation modulation FOG INS and the error propagation rule of the inertial instruments' constant bias error, scale factor error, fixed error, angle random walk and bias drift in uniaxial rotary INS. This is the theoretical basis for desiging the single axis rotaiton scheme. This paper studied the infulence of FOG's multi positions bais and small angular rate scale factor error to uniaxial rotary INS and gived the feasibility of the scheme to reduce these error.Secondly, this paper studied the single axis positive/negative rotation scheme and the single axis two positions rotation/stop scheme.It is concluded that the latter is superior to the former. A selection method of rotating angular rate and stop time was given in order to make the system's accuracy improved maximum. A modified scheme which can comensate the influence of vehicle steering motion was put forward. Advantages and disadvantages of the scheme which rotation axis FOG is separate from the indexing mechanism will be discussed.At last navigation experiments were carried out with this unit's single axis rotaiton FOG INS. Experiments' results indicated that uniaxial rotary modulation technology can make the FOG INS's position accuracy improve.This papar shows that the application of uniaxial rotary modulation technology can significantly improve the navigation precision of inertial navigation system under the condition of same FOG's precision. The theoretical derivation and experimental verification results in this paper show that the uniaxial rotary modulation technology's effectiveness and feasibility to improve the INS's precision.Research in this paper provides theoretical basises or technical references for the design of the subsequent engineering products.