| In recent years,China has achieved a lot in the space field.Space science and technology is the most complex,the largest and the most risky field in the world.Due to the particularity of space activities,the simulation and verification of core technologies must be carried out on the ground in the process of technology research and development.Because of its advantages such as low manufacturing cost,long working time,high simulation accuracy,small introduction disturbance and large experimental platform,the air-floating platform control system can be used to effectively simulate the attitude and orbit control of spacecraft,rendezvous and docking and other important experiments.However,actuators saturation is a common limitation in the actuators control system.In the design of the actuators control system,if the influence of saturation factor is not considered,the performance of the system will be reduced,and even the instability of the closed-loop system will lead to serious consequences.In this paper,the corresponding controller is designed for a kind of 3-Do F air-floating platform control system with controller saturation,based on PID,parametric Lyapunov equation and discrete static gain scheduling.One of the discrete state gain scheduling method,Lyapunov equation method for parameters slow convergence rate,cannot make full use of the problem of actuator,by increasing the convergence rate of the representative system parameter values,greatly improve the convergence speed of the system,achieve the goal of improving system dynamic performance,has certain theoretical significance and engineering application value.Firstly,the development process of air-floating platform system is introduced from the background,significance and research status at home and abroad.Describes in detail the study of gas floating platform running environment,structure and working principle,according to the theory of gas floating platform parameters and mechanics knowledge,defines the air-floated inertial coordinate system and body coordinate system,to analyze of the forced state of a single gas floating platform,its dynamic model under two kinds of coordinate system is derived and the conversion relationship.In addition,the parametric Lyapunov equation and the theoretical basis of discrete static gain scheduling are introduced.Secondly,the software architecture of the wireless controller(STM32)is analyzed in detail,and the motion control system of the air floating platform is built.Three controllers based on PID,steady parameter Lyapunov equation and discrete static gain scheduling are designed respectively.The fixed-point flight motion of the air-floating platform is simulated by computer under Simulink.The effectiveness of the three kinds of control algorithms was verified,and the three kinds of control algorithms were compared to preliminarily explore the performance of each controller and summarize the control characteristics of different kinds of methods.The results show that the parameters of the discrete static gain scheduling controller based on the Lyapunov parameter are easy to be solved and the system debugging is fast.By increasing the parameter value representing the convergence rate of the system,the controller can greatly improve the convergence rate of the closed-loop system under the condition that the controller does not reach saturation.Finally,the single floating platform is simulated and verified,and the experimental data are analyzed.The results show that the three algorithms have successfully realized the effective control of the fixed-point flight motion.The experimental results of the discrete static gain scheduling method based on parameter Lyapunov are basically consistent with the simulation results,which can make full use of the actuator and improve the dynamic performance of the control system.But due to the marble surface is not smooth,the model is too ideal and other factors,there is a certain deviation between the experimental data and the simulation data. |
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