Research On A Dithered Digitization Control Technology Of Laser Gyro

Due to the advantages of high-precision, high reliability, high resistance, and high costperformance, laser gyro has broad prospects in both military and civil markets. With the rapiddevelopment of digital processing chip, it is urgent to solve the problem of digitization andintegration of laser gyro products in China, especially the integration of dither control system.So far most gyro dither circuits adopt analogous circuit to construct control system. Becauseof the separate electric components and simulated IC chips, the systems of the products aretoo large and have weak expansion ability. At the same time, it is quite complex to deal withthe signals. Temperature drift and noises are also the problems to deal with. All the problemsrestrict the market demand. Therefore, the digital dither control system can promote thedevelopment of digital and miniature laser gyro products. In this article, DSP, a kind of digitalsignal processor is led into MDRLG. As the nuclear data processing and control unit, thesystem will control dither amplitude, trace frequency and remove noise.Firstly, dissertation states the theory of laser gyro work and the analysis of dither system.Through transfer function, analyze the frequency specialty of dithering mechanism, met thequalification of the jitter amplitude keeping stable and frequency synchronization tracking.Besides, this article also have a brief introduction of the way of noise injection and strengthrequirements. It has been put forward that collecting the root mean square value of thefeedback dither signal,and modulate duty cycle of outputting square wave to keep ditheramplitude stable. detect zero-point signals with Comparator, and design four port combinationto control output impelling square wave signal and make high voltage amplifier, at the sametime, it solves the problem of electro-discharge.Then use MATLA to simulate the gyro control loop and adopt PID to designamplitude-control, and meet the requirement of dither control. The amplitude frequencymargin, the phase margin, quick response time, and steady state error. In the design of DSPsoftware, combine the simulation experiment and engineering test method to make PIDadjustable parameters sure. Get the amplitude adjustment of PID dither control pumpingsignal and noise injection by changing the duty cycle. And make frequency tracking possibleby capture interruption.Finally, take board level test and system evaluation of integrated test by experiments and got the noise injection intensity. The results show that the digital dither control system in thisarticle is good enough to meet the requirement of control.