Research On Autopilot For BTT Missile Based On Extended State Observe-Backstepping

As modern battlefield environment of increasingly complex, high request of technology indicators have been put forward for the tactical missile, in order to meet the needs of future war, tactical missile need to solve some problems in the future,such as dealing with large maneuvering flight, large airspace operations interception,the target of a low-level interception., Therefore, the motor ability of missile and the guidance precision must further improved in control technology, to better coordinate the contradiction between speediness and stability, which improve the reliability and anti-interference ability of the missile.In this paper, the theory of extended state observer(ESO), backstepping control theory, the sliding mode control theory have been used to design the BTT missile’s autopilot, and make BTT missile under different conditions can meet tracking performance indications. The main works are summarized as follow:Firstly, the mathematical model of BTT missile is established. At the same time,the model of BTT missile’s autopilot is set up by quaternion parameters, so it can avoid the singularity at some angles. Missile autopilot kinematics and dynamics model expressed in quaternion parameters should be transformed into the form of suitable backstepping algorithm, according to the characteristics of the backstepping control method of the form.Secondly, the disturbance is observed by the extended state observer, in the case that BTT missile suffered continuous periodic external disturbance. Actually, ESO has played an important in a feedforward compensation, compared to other observer, it not only can observer interfere, but also observer the state of the original system. ESO has the characteristics of fast convergence speed and simple algorithm, and is widely applied. In addition, the backstepping algorithm is based on Lyapunov function, so the backstepping controller is designed based on ESO has the better stability.Finally, the missile is running in space, and has been influenced not only by all kinds of interferences but also the condition of parameter uncertainty, it may make the missile attitude cannot run on the desired trajectory. Sliding mode control theory to external disturbances and internal parameter perturbation has the invariance, in view of the merits and demerits of the sliding mode and backstepping control theory. In view of the situation described, controller of backstepping sliding mode has been designedbased on ESO to simulate. Results show the designed autopilot based on backstepping sliding mode based on ESO, has good stability and robusness.