A self-disturbance rejection attitude control method for elastic aircraft

Abstract

Disclosed is an elastic aerial vehicle auto-disturbance-rejection attitude control method. The elastic aerial vehicle auto-disturbance-rejection attitude control method comprises the steps of, 1 designing an elastic filter; 2, designing an extended state observer (ESO) containing a displacement and speed measurement mixed elastic model; 3, designing auto-disturbance-rejection control (ADRC) ruleswith attitude motion total disturbance compensation and elastic mode inhibition. Specifically, the method comprises, when first-stage elastic mode frequency is close to the bandwidth of a control system, designing the elastic filter to filter out other elastic modes except a first-stage elastic mode to reduce loss of system stability margin and increase system phase margin; through the extended state model, rigid body signals, acquiring first-stage elastic mode signals and estimated attitude motion total disturbance; controlling the PD (proportional differential) feedback of rigid body motionstate estimated signals and the compensating part of rigid body total disturbance in the ADRC rules to achieve consistency of dynamic response and control precision of attitude motion with disturbingforces and torques such as parameter deviation, multimode elastic coupling and wind.

Description

technical field [0001] The invention belongs to the design field of elastic aircraft attitude control, and the specific content relates to the problem of aircraft attitude control with model uncertainty, aircraft elastic coupling and external disturbance. Background technique [0002] In order to make the aircraft have better performance, the design of aircraft nowadays tends to be lighter and longer. This makes the elastic mode, which is originally negligible, to be taken into consideration when designing the control law. The reasons are as follows: [0003] 1. Due to the light and long body, the frequency of each order elastic mode is reduced, and even the frequency of the first order elastic mode is closer to the bandwidth of the control system; [0004] 2. Due to the influence of the elastic mode, the system measurement is no longer the rigid body mode but the superposition of the rigid body mode and the elastic mode. If the system output is directly used for feedback, t...

AI Technical Summary

Problems solved by technology

[0003] 1. Due to the light and long body, the frequency of each order elastic mode is reduced, and even the frequency of the first order elastic mode is closer to the bandwidth of the control system;

[0004] 2. Due to the influence of the elastic mode, the system measurement is no longer the rigid body mode but the superposition of the rigid body mode and the elastic mode. If the system output is directly used for feedback, the elastic mode will be excited or even the system will be unstable. ;

[0005] 3. The coupling between the elastic mode and the rigid body mode is strengthened. At this time, if the vibration of the elastic mode is not well controlled, the control accuracy of the rigid body attitude will be affected. Conversely, the dynamic response of the rigid body attitude will also affect the elastic mode. the convergence

Both methods have limitations

The premise of the first type of method is difficult to establish in practice, because in the case of elastic vibration, the measurement signal includes the motion of the equivalent rigid body and the additional motion of the projectile caused by elastic deformation. If the measurement signal is regarded as the rigid body mode State design control law, easy to make the system unstable

The control method using the notch filter, when the elastic mode frequency is close to the bandwidth of the control system, has poor robustness, and is very prone to instability when the parameters are pulled out.

In addition, the above two types of methods do not consider the suppression of elastic vibration

Therefore, the existing control design methods for elastic aircraft are difficult to effectively control the attitude of elastic aircraft when the elastic mode frequency is close to the bandwidth of the control system.

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