CN-121994280-A - Random polymorphic wave modulation method of interference type integrated optical gyroscope

CN121994280ACN 121994280 ACN121994280 ACN 121994280ACN-121994280-A

Abstract

The invention discloses a random polymorphic wave modulation method of an interference type integrated optical gyroscope, aiming at the scene that the integrated optical gyroscope improves the integration level by compressing the length of an interference loop, the modulation frequency is obviously increased and crosstalk noise is introduced, firstly, according to constraint conditions And Presetting a modulation sequence library to generate a pseudo-random number sequence Constructing a multi-state selector, randomly selecting the sequence output at the current moment, and simultaneously generating another pseudo-random number sequence And constructing a time-varying composite modulation generation matrix, and uniformly characterizing and outputting random polymorphic wave modulation signals. The invention realizes the randomization of modulation voltage by a random polymorphic wave sequence state transfer path, thereby inhibiting the crosstalk noise mean value to 0, effectively inhibiting the crosstalk noise introduced by high modulation frequency in the integrated optical gyroscope, and finally reducing the dead zone of the gyroscope.

Inventors

LI HUI
XU YIXIN
LI LIJING
Tian Muyuan
YU XINHUI

Assignees

北京航空航天大学

Dates

Publication Date: 20260508
Application Date: 20260330

Claims (8)

1. The invention discloses a random polymorphic wave modulation method of an interference type integrated optical gyroscope, which is characterized in that aiming at the scene that the integrated optical gyroscope has obviously increased modulation frequency and crosstalk noise is introduced while the integration level is improved by compressing the length of an interference loop, the random polymorphic wave sequence state transition path is designed, and the random polymorphic wave modulation sequence is generated to realize the randomization of modulation voltage, so that the random polymorphic wave modulation sequence has white noise characteristic and the crosstalk noise average value is 0; the method comprises the following specific steps: Step one, designing a feedback shift register LSFR to generate a pseudo-random number sequence And constructing a multi-state selector according to constraint conditions And Presetting a modulation sequence library According to the output of the multi-state selector Randomly selecting a sequence output at a current time ; Wherein, the sequence library , Set to the power of 2N Strip sequence Symbol(s) , Taking the value as the power N of 2 for the set sequence length; Sequence library Each sequence of the sequence satisfies the constraint condition And : For sequence, the consistency constraint of the head and tail states is that Initial state And final state The following requirements are satisfied: ; Wherein, the Representing state transition paths based on random polymorphic wave sequences, and the state transition paths are sequenced Symbol sequence transfer of (2) Secondary composite state transitions; Constraint for maximum continuous homodromous hopping sequence The run length of (c) must satisfy: ; Is a sequence A set of all runlengths in the run; Is a preset maximum allowable run length; Step two, according to the sequence Current symbol value of (2) A transition state for storing the multi-state wave modulation signals generated in the process of moving the random multi-state wave modulation state and constructing a time-varying modulation generation matrix Simultaneously judging the sequence If the code element of the code element is completely traversed, the step III is entered, otherwise, the output sequence is continued Is the next symbol of (a) ; Step three, generating a pseudo-random number sequence based on another LSFR According to the current value Transition state, while judging If the random polymorphic wave modulation state is successfully output, storing the polymorphic wave modulation signals generated in the process of moving the random polymorphic wave modulation state, and constructing a time-varying modulation generation matrix Step two, if not, re-outputting ; Fourth, generating a matrix based on modulation And (3) with Constructing a time-varying complex modulation generator matrix The method comprises the steps of uniformly representing and outputting random polymorphic wave modulation signals, collecting the corresponding digital quantity of light intensity signals in the moving process of random polymorphic wave modulation states, outputting the angular speed and the modulation coefficients, establishing a crosstalk noise model of an integrated optical gyroscope, and verifying the noise suppression capability of a random polymorphic wave modulation scheme.
2. The method of claim 1, wherein in the first step, the random polymorphic wave sequence state transition path satisfies the condition: End to form a loop link, an ; Refers to the state number of random polymorphic wave sequences, Is that The number of times of the transition, Is the modulation depth.
3. The method of claim 1, wherein the step-is a constraint In the process, the ; Is code element Is used for the state transition direction of the (c), 。
4. The method of claim 1, wherein in the second step, the modulation generation matrix is generated Is a deterministic mapping of discrete digital codes to continuous optical phase modulation voltages, defining how to rely on The symbol sequence of the medium sequence changes the modulation voltage amplitude, which is described mathematically as: wherein the first row of blocks represents drive symbols Is used for generating a path of the (c) signal, Is a sequence symbol extraction matrix whose function is to feature vectors from a sequence library Extracting the code element to be output at the current moment ; The second row of blocks represents the update path of the phase state, Is a symbol A corresponding random polymorphic wave state transition matrix; the third row of blocks represents the modulation voltage Wherein Is a diagonal matrix whose diagonal elements are discrete phase state values, Is a unit matrix with the function of randomly polymorphic wave state vectors Conversion to voltage ; For the half-wave voltage of the modulator, For modulating signal bias, the value is generally 。
5. The method of claim 4, wherein in the third step, the modulation generates a matrix Is the physical nature of (2) Similarly, for deterministic mapping of discrete digital codes to continuous optical phase modulation voltages, it is specified how to rely on random symbols Changing the amplitude of the modulation voltage, which is mathematically described as: Wherein in the first row of blocks The function is to randomize the process feature vector Medium random bits Extracted as drive symbols ; The second row of blocks represents the update path of the phase state, Is a symbol A corresponding random polymorphic wave state transition matrix; Third row block The third row of blocks has identical meaning.
6. The method according to claim 4 or 5, wherein in the fourth step, the complex modulation generator matrix Based on sequence The generated modulation generation matrix And based on pseudo-random numbers The generated modulation generation matrix Sequentially switched, and the mathematical description is as follows: Wherein, the Is a system output vector containing the drive code element at the current moment Phase state Modulating voltage ; Is an augmented system state vector, which is composed of random polymorphic wave state vectors Feature vector of sequence library Random process feature vector Constructing; For demodulating the first in the sequence A value.
7. The method of claim 6, wherein in the fourth step, the driving symbol is used as a basis And the position of the current state on the random multi-state transition path is used for obtaining the modulation depth corresponding to the modulation voltage at the current moment, establishing the modulation depth at each moment, obtaining a demodulation sequence corresponding to the angular velocity/modulator coefficient, completing angular velocity calculation and modulation coefficient error calculation, respectively constructing an angular velocity closed loop and a modulation coefficient closed loop based on the angular velocity calculation value, the modulation coefficient error calculation value and the controller, and finally completing the construction of the double closed loop signal detection loop.
8. The method of claim 5, wherein in the fourth step, the crosstalk noise model is: Wherein, the In order to modulate the voltage of the power supply, In the event of crosstalk noise, Noise introduced for the capacitive cross-talk, The noise introduced for the inductive crosstalk is, As a capacitive cross-talk attenuation coefficient, To interfere with the characteristic impedance at any point of the line, Is the mutual inductance capacitance of the unit length of the transmission line, For the coupling length, For a capacitive noise bias to be present, For the attenuation coefficient of the inductive crosstalk, Is a mutual inductance of a unit length of a transmission line, Bias for perceptual noise; Crosstalk noise is involved in demodulation as an error voltage, and thus sequence correlation is demodulated by the modulation sequence and angular velocity To characterize the effect of crosstalk noise, specifically: Wherein, the Is the relevant length; for the angular velocity demodulation sequence, A digital delay; In order for the coefficients of the modulator to be chosen, As a coefficient of capacitive cross-talk, Is an inductive crosstalk coefficient; To modulate voltage The corresponding modulation phase, due to the randomness of the sequence, Has white noise characteristics and expected value Therefore, it is Is uniformly distributed in ; For demodulating the sequence, the phase difference is modulated Determining; Then at this time there is: thus, the present modulation scheme satisfies the constraint condition by constructing And A specific random polymorphic wave modulation signal is generated, and the randomization of the modulation voltage is realized, so that the random polymorphic wave state transition path has the white noise characteristic, and the crosstalk noise average value is suppressed to be 0.

Description

Random polymorphic wave modulation method of interference type integrated optical gyroscope Technical Field The invention belongs to the field of inertial measurement, and particularly relates to a random polymorphic wave modulation method of an interference type integrated optical gyroscope. Background In recent years, new concept motion carriers such as unmanned aerial vehicle clusters and unmanned aerial vehicles are sequentially appeared, and the environmental complexity and diversity of the motion carriers are faced with the requirement that a guidance system has high-precision navigation positioning capability, and meanwhile, high stability and anti-interference capability are required to be maintained under various complex and extreme environments. Inertial navigation systems have created an urgent need for gyroscopic devices that are both high performance and compact, low cost, and lightweight. The integrated optical gyroscope has the advantages of low cost, extremely high transmission speed of optical signals and electric signals, capability of realizing instantaneous preheating starting, and becomes a research hot spot, and the integration degree of the gyroscope is improved by means of replacing an optical fiber ring, an integrated optical device and the like by a waveguide ring. But the method also brings new challenges to signal detection while improving the integration degree of the gyroscope, and is mainly because when the interference loop of the gyroscope is short, the gyroscope is limited by the transit time and the eigenfrequency, and needs higher modulation frequency for matching. Under the high frequency condition, crosstalk noise is very obvious, and the performance of the gyroscope is limited. However, the conventional square wave modulation and random modulation have certain limitations, the former can not inhibit crosstalk noise, and the latter has unstable demodulation period and poor dynamic performance. Therefore, how to realize the high dynamic signal detection of the integrated optical gyroscope under the condition of short interference length, effectively inhibit crosstalk noise while guaranteeing the dynamic performance of the gyroscope is still a challenge to be solved. Disclosure of Invention Aiming at the problem of effectively inhibiting crosstalk noise while guaranteeing the dynamic performance of the integrated optical gyroscope under the condition of short interference length, the invention provides the random polymorphic wave modulation method of the interference type integrated optical gyroscope, which can obviously inhibit the crosstalk noise while guaranteeing the closed-loop performance. The random polymorphic wave modulation method of the interference type integrated optical gyroscope comprises the following specific steps: in the first step, the integrated optical gyroscope improves the integration level through compressing the length of an interference loop, and meanwhile, the modulation frequency is obviously increased, so that crosstalk noise is inevitably introduced. The random polymorphic wave sequence state transition path is designed, the random polymorphic wave modulation sequence is generated to realize the randomization of the modulation voltage, so that the random polymorphic wave sequence state transition path has the white noise characteristic, the crosstalk noise average value is 0, the crosstalk noise is effectively reduced, and the reduction of the dead zone width is further realized. The random polymorphic wave sequence state transition path should satisfy the condition: End to form a loop link, an ;Refers to the state number of random polymorphic wave sequences,Is thatThe number of times of the transition,Is the modulation depth. Design feedback shift register (LSFR) to generate pseudo-random number sequencesAnd constructs a multi-state selector. According to constraint conditionsAndPresetting a modulation sequence libraryAccording to the output of the multi-state selectorRandomly selecting a sequence output at a current time; Sequence library,Setting to the power of 2 to the N; First, the Strip sequenceSymbol(s),Taking the value as the power N of 2 for the set sequence length; Sequence library Each of which satisfies the constraintAnd: For sequence, the consistency constraint of the head and tail states is thatInitial stateAnd final stateThe following requirements are satisfied: Wherein, the Representing state transition paths based on random polymorphic wave sequences, and the state transition paths are sequencedSymbol sequence transfer of (2)Secondary composite state transitions: ; is code element Is used for the state transition direction of the (c),; Constraint for maximum continuous homodromous hopping sequenceThe run length of (c) must satisfy: ; Is a sequence A set of lengths of all runs (segments of consecutive identical symbols); is a preset maximum allowed run length. Step two, according to the sequenceCurrent symbol value of (2)A t