Studies On Active Disturbance Rejection Control Based Inertial Navigation Platform Level Loop

With the development of inertial technology,it has been greatly applied in aerocraft.Due to its high-precision and high anti-interference capability,platform inertial navigation system has become a preferred choice of high-precision navigation field.Aerocraft needs to achieve initial alignment before it works,it is urgent to reduce the adjusting time and overshoot for aerocraft such as missile,vessel,etc under the situation of rapidly and precision.Taking an inertial platform as the object of study,this paper proposes Fuzzy-PID &ADRC controllers of level loop of platform INS to solve these problems and compares advantages and disadvantages of different control algorithms through simulation.The main studies of this paper include following aspects:The paper firstly analyzes the present situation,development trends as well as study direction of the level loop.It introduces the compositions and principles of the level loop,analyzes the dynamic equations and deduces the transfer functions.A model is given which can reflect time domain and frequency domain characteristics via simulations.And then,the principles and designs of Fuzzy-PID controller are introduced briefly.According to the model of level loop,the membership functions and fuzzy rule table of fuzzy controller are designed,and then fuzzy control table is calculated.A simulation model based on Fuzzy-PID controller is established,the simulation results show that compared with existing schemes,the adjusting time of the level loop applying Fuzzy-PID control algorithm is cut down at least 6s,the overshoot is cut down 20%,and the interference rejection capability achieves 60 d B.The dynamic process of the level loop is improved.Besides,the paper designs an ADRC controller based on level loop to solve former problems in chapter IV.After introducing the compositions and principles of ADRC,the error equations of platform are presented,and the first-order-linear ADRC is designed according to the equations.At the same time,the simulation model is built,which indicates that the adjusting time has been cut down 10 s,and the overshoot has been reduced to 5.6% in time domain;And in the frequency-domain analysis,the magnitude margin and phase margin are improved compared with original schemes,with interference rejection capability achieving 68 dB.Finally,the level loop controller is programmed and debugged.Select several platform tests and analysis experiment data to verify the level loop function.It shows that compared with existing schemes,the adjusting time of level loop applying LADRC is cut down 15 s,the overshoot is reduced 30%,and the stability of torque current is improved.The paper provides a new method of the industrial level loop design,and it is also the basis of shortening aerocraft launching time and improving the accuracy.