Study On The Speed Stability For The High Precision Fast Nongyroscopic North Seeking System

The orientating problem exists in military application fields, such as missile weapon system based on mobile launching and outside trajectory surveying system of mobile aerocraft. There are three key points on this problem: the first is independence; the second is the fast operation period; the third is the highly-orientated precision. Nongyroscopic north seeking system spurn the costly gyroscopic, so the produce cost decrease greatly. When the accelerator is used in the north seeking system, the whole equipment will have mang inimitable merits, such as the easily operation, speediness, higher orientating precision, inexpensive. The speed stability control is called choke point to the nongyroscopic north seeking system's development. So it is important to study the high precision speed stability control to the nongyroscopic north seeking system's develop and others stable speed control system. According to the nongyroscopic north seeking system need the high precision stable speed control, the paper carry through a series of analisis and study from the theory and practice, design and realize transformable parameter SPLL and the raster's speed measure of T based on DSP, and validate the methods'validity on the DC motor whose empty speed is 7970rpm. First, the working mechanism of the nongyroscopic north seeking system is analyzed in detail. The stability factors of the north seeking system is discussed in theory, and compensated in effect. Then the necessary of stable speed control and the specifically speed merit are point out. On the basis of it,the error sources of the north seeking system are analyzed. According to the north seeking target(the directional time is less than 5 minutes, directional precision is 10″~15″), the stable speed target is gained by simulation study. And two novelty speed stability measurement methods is proposed to the high precision speed stability control, one is the raster speed measurement method of T on DSP, the other is the speed and error measurement by accelerometers. And to the model characteristic, the former method id studied in experiments. Because the system need the higher speed stability, the speed PLL is adopted. The common speed PLL exist many shortcomings, such as the slower domanic answer, the lower anti-jamming power, and the narrow PLL scope. And the merits of plus adaptive control and dual modelcontrol are combined, the author design the transformable parameter SPLL, study and analyze emulayionally the realization methods. At last, the author carry through the performance test and experiment study used the raster speed measurement method of T on DSP and the transformable parameter SPLL. The stable speed precision, speed stability, repetition, stable speed scope and the low temperature characteristic of the DC motor are tested, and the validity and feasibility of the control method is validated by compare with the PID's results and the common speed PLL.