Research On Control Technology Of Marine Buoy's Attitude Correction

As a new type of marine buoy,satellite communication buoys have higher reliability and longer communication distance than traditional communication buoys.However,they have higher requirements on the working environment,especially on the buoy roll,pitch and yaw angle.The shaking of the buoy due to the influence of sea waves will seriously affect the communication efficiency and stability.The common solution is to optimize the antenna design,but it is still difficult to guarantee the success rate of communication under a large swing angle.This thesis proposes to actively correct the buoy's shaking to ensure the stability of the long-distance communication of the buoy.This thesis confirms the design scheme of marine buoy motion control system,researches the key technology of marine buoy motion control,and implements and verifies the control system.In this thesis,firstly,the force and movement of the buoy in the marine environment are analyzed and researched,and its three-degree-of-freedom kinematics and dynamics model are established.The fluid dynamics simulation analysis is carried out through ANSYS Fluent,and the movement law of the buoy under different sea conditions and waves is obtained.Adopting four propellers around the buoy as a power device can not only realize its three-degree-of-freedom rotation,but also reduce the mutual interference between the high-speed turbulence caused by each propeller,and ensure the normal generation of reverse thrust.Due to the existence of redundant drive and motion control coupling of each degree of freedom,the coupling characteristics are studied in detail,and appropriate drive constraints are added to realize the elimination of redundant drive and the decoupling of motion control.Aiming at the high-speed and high-precision correction control performance requirements of buoy roll,pitch and yaw,a three-degree-of-freedom independent compound control strategy is proposed;The PID controller and the second-order low-pass filter are used as the feedback controller,which eliminates noise interference,improves the control bandwidth and stability,and realizes high-precision motion control of the buoy attitude;Speed feedforward based on interference compensation is introduced to improve the response speed of the control system,which effectively shortens the correction time,and realizes the overshoot suppression and oscillation elimination,and achieves rapid stability.The software and hardware platform of the buoy control system with the embedded controller as the core is constructed.An experiment platform for the buoy attitude correction control system is built to test the correction performance on the ocean.The experiment results verify the correctness of the decoupling model;according to the experiment results,the control system can stabilize the roll,pitch,and yaw angles of the buoy within ±4° under three-level sea state,and can quickly correct the buoy that has already been deflected back to the equilibrium position in a short period of time,which has high and fast attitude correction performance and meets the expected design indicators,and is able to provide a better environment for the joint experiments with the laser and microwave communication module on the upper part of the buoy to ensure the stability of its communication.