Research On Direct Thrust Control Methods Of Variable Cycle Engine

Nowadays,developing variable cycle engine technology has become an important part in the aviation engine research field and it is the main development direction of aviation engines.Based on the double-bypass variable cycle engine component level model,the direct thrust regulation schedule and multivariable control technology for variable cycle engine are researched in this dissertation:Firstly,the thrust estimation method based on adaptive model was researched.A hybrid Newton Steffensen-inverse Broyden method which can quickly converge was used to solve the co-working equations,and the real-time property of the model was improved.An unscented Kalman filter was used to estimate engine health parameters and the adaptive model was established to achieve accurate engine thrust estimation.Secondly,variable cycle engine thrust command optimization was studied based on the self-organizing migration algorithm.Only some of the particles are set active.The migration step size was modified according to the number of steps,and the effectiveness of the improvement was verified by simulations on a set of test functions.At the ground working point,the improved self-organizing migration algorithm was used to optimize the thrust command.The control schedule for each thrust level was obtained,and the command model was established.Thirdly,the decoupling method for two control blocks was studied for variable cycle engine.An improved non-dominated sorting self-organizing migration algorithm(NSSOMA)for multi-objective optimization was proposed to achieve decouple control peroperty.The results show that the block decoupling control method can reduce the coupling between the loops and the advantage of mulit-variable control is fully developed.The design of the direct thrust controller of the variable cycle engine was carried out.For the output selection and control structure analysis,the augmented LQR method was used to design the three-input and three-output thrust controller,and the simulation was verified.Finally,the modal switching control of the double-bypass variable cycle engine is studied,and the bidirectional switching simulation is verified.The results show that the variable cycle engine can work stably during the switching process.