| Due to the advantages of avoiding the singularity,avoiding obstacles and improving the performance of joint motion,redundant freedom mechanisms are widely used in the field of robotics to improve the flexibility of robots.A variety of structural forms of stabilization platform is also widely used in the field of attitude stabilization.The main work of ship antenna stabilization platform is adjusting the antenna stabilization platform coordinates to geographical coordinates remain unchanged in any carrier attitude.Thus isolate carrier disturbance,and provide protection for the communication with the satellite carrier.In this paper,we study the antenna platform with redundant degrees of freedom.For the multisolution problem when solving the redundant freedom platform axis angles based on terminal attitude of the platform.And the problem of computing platform model caused by the tandem type structure of the platform.According to the similarity of the antenna stabilization platform with redundant degrees of freedom robot mechanis,a research on the control of redundant freedom antenna stabilization platform based on kinematics planning and control method of redundant robot is conducted.Firstly,the attitude stabilization problem of mobile carrier antenna is briefly introduced.For the problem of traditional two and three axis antenna stabilization system,the advantages of the antenna platform with redundant degrees of freedom is analyzed.The inverse kinematics problem of stabilized platform which is needed to be solved by the redundant DOF antenna stabilization platform and the platform control problem in the case of the accurate mathematical model of each frame are proposed.Secondly,the kinematics analysis of the redundant freedom antenna stabilization system is carried out.In order to solve the inverse kinematics problem of redundant manipulators,the kinematics of the system is analyzed by means of the method of kinematic planning of redundant manipulators.Based on the analysis of the structure and motion characteristics of the stabilized platform,an optimization function is established to avoid the stability of the redundant freedom platform.And the potential function of the center position of each axis is constructed.Use optimization function to avoid singular configuration and potential function of each axis as the optimization index.The dynamic control method is used to solve the inverse kinematics of the stabilized platform.The optimal angle of each axis of the platform is obtained under any terminal attitude of the platform.Finaly,fuzzy adaptive PID control method is used to solve the problem of establishing accurate mathematical model of each frame caused by structural coupling of the series stabilized platform The fuzzy adaptive PID control algorithm is applied to the antenna platform with redundant degrees of freedom.Because the fuzzy adaptive PID control algorithm does not need the accurate mathematical model of the controlled object.A simulation is conducted with the dynamic control method as the platform inverse kinematics algorithm and the fuzzy adaptive PID algorithm as the platform control algorithm.The simulation results verify the feasibility of the scheme. |
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