Generalized ESO and Predictive Control Based Robust Autopilot Design

Abstract

A novel continuous time predictive control and generalized extended state observer (GESO) based acceleration tracking pitch autopilot design is proposed for a tail controlled, skid-to-turn tactical missile. As the dynamics of missile are significantly uncertain with mismatched uncertainty, GESO is employed to estimate the state and uncertainty in an integrated manner. The estimates are used to meet the requirement of state and to robustify the output tracking predictive controller designed for nominal system. Closed loop stability for the controller-observer structure is established. An important feature of the proposed design is that it does not require any specific information about the uncertainty. Also the predictive control design yields the feedback control gain and disturbance compensation gain simultaneously. Effectiveness of GESO in estimation of the states and uncertainties and in robustifying the predictive controller in the presence of parametric uncertainties, external disturbances, unmodeled dynamics, and measurement noise is illustrated by simulation.

Missile longitudinal autopilot design using a generalized extended state observer-based mixed H2/H∞ control method

“…As done in many disturbance estimator-based control methods, including ESOBC 23,25,26 and GESOBC, 29,31–34 Assumption 4 implicitly supposes that the disturbance de is independent from system states. This may be a little rigorous since practical systems often have state dependent uncertainties/disturbances.…”

“…29 proposed a generalized ESOBC method to extend the capability of standard ESOBC to MIMO nonintegral-chain systems with mismatched disturbances. The GESOBC shows many superiorities over the standard ESOBC and then successful applications in missile autopilots, 31–33 marine vessels steering controller, 34 and wheeled mobile robot tracking control, 35 illustrate the efficacy of the GESOBC method. However, these designs either require known disturbance input matrices, 31,34,35 or cannot explicitly consider multiple design objectives, 33–35 such as performance, robustness, and some transient behaviors.…”

“…The main advantages of the proposed method are as follows. From the point of DUEA technique, the proposed method circumvents the intractable issue of designing disturbance compensation gain encountered in NDOBC 20 and standard GESOBC 29,31,34,35 and avoids designing separated disturbance estimator and state observer in the classic EID approach. 36–38 From the point of robust mixed H2/H∞ control, the proposed method bypasses the implementation aspects of requiring all states available and a known disturbance input matrix. Compared with preceding works regarding GESOBC, 32,33 multiple control design criteria such as H ∞ performance, H2 performance, and the transient behaviors, can all be considered in the proposed control framework, and the optimal feedback gain are easy to tune owing to the tradeoff Pareto diagram of H∞ performance and H2 performance. …”

Research on Integrated Guidance and Control of Distributed Cooperation of Multi-Interceptor with State Coupling

“…According to the relative motion relation between the interceptor "leader" and target [25,26], the relative motion model of the interceptor "leader" and target is established as follows:̈=…”

“…Consider the integrated guidance and control system for the "leader" (equation (4)). If the convergence rate is calculated using (25), the disturbance values of the system (see (4)) are estimated using (10)- (12), and filter equations (16) and (21) are implemented; then finally under the dynamic surface sliding-mode control law (see (26)), imposing the constraint for ensuring the system (see (4)) output error converging into the adjacent area of the origin, an arbitrary adjacent area of the origin can be obtained with the appropriate design parameter determined.…”