Research On Stabilization And Tracking Tecnologies For Antenna Platform Mounted On Ship

Ship-based antenna’s LOS will be inevitably affected by shake while antenna tracks moving targets,LOS’s shaking can’t ensure antenna tracks moving targets with high precision and therefore need to adopt stable tracking technology to make sure that the antenna isolates disturbance from ship and tracks moving targets with stable attitude in inertia space.The research subject of this paper is two degree of freedom stabilization platform on which carries antenna,in order to improve the antenna platform’s dynamic response capability,stability tracking accuracy and the capability of resistance to external interference,a systematically study of the antenna platform on stabilization and tracking control technologies is developed.The main contents of this paper are as follows:The model of ship motion is researched, and the effects on ship-based antenna caused by the motion of ship are described. The Ship-based antenna platform on kinematics is modeled, the mathematical mechanism of the platform’s isolation of ship’s angular motion is derived and therefore the installation scheme of gyroscope is disscussed.All the elements of the Uniaxial control loop of antenna platform are modeled and designed, the current loop is imported in order to make sure that the motor output torque tends to the ideal.The LOS stabilization loop adopts the scheme of double loop which consists of inner velocity loop and outer stabilization loop instead of the conventional sigle velocity loop,the current loop and velocity loop are designed and corrected.The models of stable loop and position loop are established,the importance of gyroscope filtering in the stabilization loop is discussed,and the capability of isolating disturbance of position loop is analyzed.In order to meet the requirements of the LOS stabilization system and from the perspective of improving the control structure and control strategy,A CVU-FUZZY-PID hybrid control method based on PSO optimization is developed,the method expands the input of FUZZY controller by dividing a power function type contraction-expansion factor whose absolute value is less than 1,and then multiplies the output of FUZZY controller with a adjustment factor,thus changing the universe conversely,then the parameters of contraction-expansion factor and adjustment factor are optimised off-line by utilizing the improved PSO algorithm,hybrid controller combines with CVU-FUZZY and PID is proposed to eliminate the static error,simulation results indicate that the method is feasible and effective.The affection on performance of tracking position loop caused by time delay is analyzed.In order to lower the bad effects on tracking caused by the mobility of target, the moving target is modeled by using current statistical model,a kind of adaptive kalman filter is adopted to filter tracking measurement noise and at the same time extrapolate the moving target’s trajectory by predicting the next position,thus ensure the antenna’s continuous and stable tracking for maneuvering target.In order to reduce the bad effects caused by the time delay,the position loop adopts the internal model control structure,the performance of internal model controller is analyzed in detail,and the two-port internal model controller is designed according to the combination of position loop features and hybrid control method,then the two-port internal model controller is implemented in position loop and achieves good control effect.A kind of FLP adaptive filter based on LMS method is adopted to filter output data of gyroscope, and then the filter is implemented by FPGA.A semi-physical simulation platform used for stabilizing the antenna is established, four different kinds of control algorithms are implemented by FPGA and applied in the platform mentioned above,at last,the effectiveness of the algorithms for LOS stabilization is analyzed and verified.