Study On Modeling And Digital Control Of Dynamically Tuned Gyroscope

Dynamically tuned gyroscope (DTG) is a 2-DOF(degree of freedom) inertial sensor with a flexible joint, it is used to measure the angular velocity in inertial space. As a medium-high precision and low cost inertial sensor, DTG has been widely used in military, aviation, spaceflight, navigation, robot, land vehicle navigation and earth gauging, and it is the most important component of intertial measurement for a long time in the future. The goal of this paper is to realize the digital control of DTG, new modeling method of DTG is studied and the rapid design and debug method is developed to improve the design and debug efficiency, to improve the dynamic performance, pricision, and reliability of DTG, and to improve the robustness of the DTG system to a certian extent.The modeling analysis method of traditional transfer function method has complex deduction and the transfer function model is intuitionless, it is difficult to describe the whole working process and drift error of DTG. Aiming at these problems, modeling method of DTG using bond graph principle is studied. Dynamics of DTG is analyzed using the built bond graph model, which is compared with the open-loop transfer function using simulation, and the validity of the bond graph model is proved.The DTG drift error source is analyzed on the basis of DTG bond graph model, the augmented bond graph model with drift error is derived according to the 8-position experiment of DTG model, which provides the basis of realization of the rebalance loop and compensation algrithms. The integrative simulation method of structure and controller is analyzed to solve the problems of incompact interconnection between DTG structure design, manufacture and controller design, debug, which form the basis of improving design efficiency and getting the optimized system performance of DTG.Considering the traditional DTG controller has long period of design and debug, it is difficult to meet the demand of research and production, the several key problems of DTG controller design are analyzed, based on which, rapid design method of the DTG digital controller is realized using HIL(Hardware-in-LOOP) simulation, which provides the canonical method of simulation, design, debug and performance evaluation for the DTG digital controller design. The robust controller is designed according to the rapid design method, which will ovecome the bad interchangeability of the controller caused by manufacture error.In order to improve the robustness of DTG discrete control system, and to solve the problem that the close loop pole is too close to the stability edge with high sample rate when discrete in z domain, the H_∞state feedback and output feedback robustcontroller design usingδoperator are discussed. Then, under the condition of not completely detectable of the system states, the robust controller of DTG rebalance loop using H_∞output feedback design based onδoperator is discussed, which makes theclose loop performance of discrete system close to the that of continuous system when sampled with high rate.The analog rebalance loop has complex circuit, inefficient debugging, and bad interchangeability of interface. To avoid these problems, the digital control system based on DSP is designed, including the 3-phase power source of motor, excitation power source of pickoffs and the hardware of digital rebalance loop. The structure of the system control software and its program flow are designed. At last, the performance of the whole DTG system is tested.