| With the rapid development of human science and technology,the current space technology puts more emphasis on studying various kinds of planetary landers to realize the exploration of other planets.Because of the complex and dangerous environment with low gravity in outer space,it is urgent to build a set of devices to simulate the gravity environment in space on the ground.In today's China,the research on gravity simulation devices with low motion speed,such as lunar rover,has been mature.Few studies have been done on high speed gravity simulation devices such as segment separation.As the launch date of chang 'e 5 is approaching,it is very important to study the gravity compensation of the longitudinal separated segments.For this reason,this paper takes the active suspension gravity compensation experimental platform as the research object to analyze the factors influencing the simulation precision.A new control algorithm is adopted to improve the accuracy of gravity simulation.Through experimental research to verify.In order to analyze the factors influencing the simulation precision of gravity compensation system,a mathematical model of gravity compensation system is established.Through the simulation analysis,the factors influencing the precision are determined,such as external disturbance,inter-ring transition,system resonance,torque coefficient and time lag.The external disturbance is caused by the vibration of the active separation system.The inter-ring transition is caused by the sudden acceleration of the wire rope on the drum.System resonance is caused by external excitation force applied to a constant tension system.Relevant parameters were taken into account,and the influence sizes of various factors were analyzed by Matlab,and corresponding improvement measures were proposed,which provided theoretical basis for subsequent experiments.A new control algorithm is designed to improve the torque coefficient and time lag.The transition process of parameter setting and parameter setting reduces the oscillation of step input.By improving the original Smith estimator,the influence of system lag was reduced.To improve the robustness of the system used the variable universe fuzzy control,according to the original variable universe fuzzy control shortcoming of scaling factor function in designing a new scaling factor expression,reasoning and the fuzzy rules of the system.The simulation results show that the system has good rapidity and good robustness against external disturbances,and reduces the adverse effects of parameter disturbances and time lag.In order to verify the effectiveness of the above system improvement measures,an experimental study was carried out.The effects of external disturbance,system resonance,interloop transition and other factors on the precision of gravity compensation are analyzed.Through the design of control algorithm,compared with the original controller and fuzzy controller can improve the performance,shows that the gravity compensation system adopts the system after the variable universe fuzzy control has good rapidity and stability.Above all,the theory and improvement measures proposed in this paper for the precision of gravity compensation system have effectively improved the precision of the system. |
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