Research On Force Loading System Of Linear Actuator Based On Fuzzy PID

The linear actuator force loader is a kind of force loading mechanism which simulates the dynamic load generated by the air resistance on the rudder surface of an aircraft in flight.It is a very typical passive force loading servo control system.Based on the research of the analog force loading system at home and abroad and the demand of the national defense industry for the force loader,this paper develops a set of three-channel force loading testing system for linear steering gear,and optimizes the mechanical structure,software and hardware control system and fuzzy PID algorithm of the loading servo system.The linear motor with iron core is used as the power driving element to simulate the wind resistance to the steering gear.Four kinds of dynamic loads are simulated.Firstly,the loading mode and control mode of the control system are analyzed,and the key technologies of the linear actuator force loading system are studied.The mechanical structure,system composition and working principle of the three-channel loading system are proposed.Build mathematical model.The hardware and software structure of the force loading system of linear steering gear are analyzed,and the mechanical structure and control system structure are optimized.Through programming and debugging under Codes environment,the structure of the software system is optimized,and the main program,the point module and the force closed-loop module are designed.Secondly,the structure and working principle of linear motor are analyzed.The mathematical model of linear motor is optimized by combining SVPWM control method.The simulation model is built by using MATLAB/simulink.The servo control strategy of virtual axis is introduced.A virtual-real mapping algorithm of virtual axis is designed.The real axis motion is controlled by virtual axis as the input of the system to ensure the stability of the system.Fixed,safe and high precision operation.Aiming at the fact that the traditional PID control can not meet the high-precision loading requirement of the system,a kind of controller based on fuzzy PID algorithm is designed to make the system have good anti-jamming and excellent tracking performance.The force loading under step signal,linear signal and sinusoidal signal is tested by simulation,which proves that the control performance of the fuzzy PID algorithm in this system is obviously better than that of the traditional PID.Finally,the experimental platform of the force loading control system is built with the linear actuator as the load-bearing object,using the elements of iron-core linear motor,force sensor and optical ruler cutter,and the experiments under four modes of constant force loading,linear force loading,static force loading and sinusoidal force loading are tested under the condition of reciprocating motion of the linear actuator through the dynamic co-adjustment experiment of the servo system.The force-following response time of the system is between 100 ms and 300 ms,which is better than the technical specifications.The dynamic loading performance of the system is verified.It can meet the requirements of strong anti-jamming ability,no jitter,strong tracking performance and eliminating redundant force.