Optimal Control Technology Of Non-linear System For Gas Flow Adjustment Of Solid Fuel Ramjet

Solid fuel ramjet is an ideal propulsion system owing to its simple structure and good performance.Its advantages have enabled all countries to carry out relevant research on this technology.In this paper,the control system of flow adjustable gas generator for Solid fuel ramjet is studied.The research content includes research on dynamic response process of gas flow parameters based on numerical simulation,modeling and design of gas generator control system,optimization control algorithm design and experiment,etc.(1)A numerical simulation model was established based on the internal ballistic theory,and the simulation results were redeveloped in Ansys Fluent to simulate the unsteady working process of a variable flow solid fuel ramjet.The conclusion that undershoot would occur during flow adjustment was drawn.The simulation results of the typical adjustment process were evaluated and analyzed.The influence of parameters such as action form and free volume in the chamber on undershoot phenomenon characteristics and response time is discussed.The regulation relationship between pressure in combustion chamber and gas flow rate is studied according to several examples.(2)a neural network model based on machine learning strategy is established.The model has a three-layer network structure and uses the L-M algorithm for calculation.After many times of learning,a stable neural network result is obtained.The data prediction verification shows that the model predicts the dynamic response parameters of the gas generator accurately under different working conditions,and the error is less than 5%.(3)The hardware and software system of the gas generator with adjustable flow according to the slide valve solid rocket ramjet.A control system model with an optimized speed selector based on neural network is established,and the control performance of the closed-loop pressure control of the gas generator is analyzed.The simulation results show that the designed optimized control algorithm can not perform too much on other response indicators of the gas generator.In the case of interference,the negative adjustment phenomenon was suppressed in the adjustment process,and the negative adjustment amount was reduced by 6%,4% and 3.1% respectively in the three adjustments.The gas generator system has better working performance.(4)The gas flow adjustment experiment was carried out.First,the air-conditioning verification experiment was carried out to verify that the gas generator control system results showed that all parts of the control system were working properly to ensure that the control system can be started accurately;afterwards,a hot test run experiment was carried out.The experimental results showed that the designed The control system is working properly.Both flow adjustments can achieve a good pressure stabilization effect,and the steady-state error from the command is less than 0.05 MPa,and the deviation between the negative adjustment amount and the control simulation result is within the acceptable range,which proves that the control algorithm can make the gas generator have better The flow regulation performance.