Research On The Control Of DC Gyro Motor And Application In North Finding

This topic mainly aimed at the gyro motor control and its application in the north finding.Choosing the two phase brushless DC motor as the gyro motor,the brushless DC motor has smaller volume,higher efficiency and easier control method than hysteresis motor and asynchronous motor,which make it widely used in the life and industrial.Because of its unique structure design and the principle of reaction,suspension pendulum gyroscope can detect the true north of earth at the most place on the earth.The basic principle is based on high speed rotating rigid body has the characteristics of gyro,so the gyroscope can be used as north finding device,and the gyroscope plays an important role in the tunnel construction and mining,which can't tell the direction accurately.What's more,the gyroscope is also urgently demanded at military area,but because of blockade on techniques,it's hard to get the related technology,so the research and design of high precision gyroscope is an important research trend in domestic.This topic is aimed at improve the precision of gyroscope,starting from the analysis of the gyroscopic motion rule,getting the relation of gyro motor speed and north finding precision,so we carry on research about gyro motor control,and make the brushless DC motor applied on the north finding successfully.The main content of this topic are as follows:(1)Studying the development of gyro motor,and analyzing the characters of different kinds of motor,such as hysterics motor,asynchronous motor and brushless DC motor.Through the analysis of characteristic,we find the suitable motor which be applied on the gyroscope.(2)Making a theoretical analysis for gyroscopic motion,and getting the motion mathematical expressions about gyro sensitive parts,thus building the mathematical relation between rotor speed and the result of north,so we can give a quantitative result about the speed size and speed error on the result.And making a theoretical standard for the gyro motor control.(3)Simplifying the two phase brushless DC motor,and giving the fundamental of motor motion.Based on the construction of motor,we make a research on the mathematical model of the gyro motor.Through the mathematical model of the gyro motor,we can easily simulate the control algorithm about the gyro motor.A Preposition increasing frequency and improving the duty ratio start method and segmented duty cycle modulation scheme are shown in this topic.Through the simulation,we get a good result.(4)Analyzing the characteristic of gyroscope,building the signal acquisition system of gyroscope,researching the arithmetic of processing and operation about gyro motion data,which lay the foundation of the use of gyro motor on the north finding.Building motor control system,North signal acquisition system,and taking experiments of north finding at different control mode.