On a novel equivalent control-based adaptive sliding mode approach for autopilot design of BTT missiles

Abstract

This paper presents a novel equivalent control-based adaptive sliding mode control (EASMC) approach for designing the autopilot of a bank-to-turn (BTT) missile under model uncertainties and external disturbances. The sliding surface is constructed with a tracking error between the real attitude angle and the reference command. The equivalent control technique works as a mechanism for the gains over-bounded by uncertainties and this information is implemented in the adaption progress. The method guarantees that the sliding surface reaches zero in finite time and the error tracks the command value asymptotically. The advantage of this method is that the gains will be adapted to counteract uncertainties and enable the control deflection magnitude to be reduced to the minimum value, keeping the property of a finite-time convergence. The skill in choosing the gains is also given in this paper. Simulation results demonstrate that the approach proposed is able to improve the dynamic performance and robustness of a BTT missile system.

Adaptive sliding‐mode control for Mars entry trajectory tracking with finite‐time convergence

“…As soon as the system trajectory leave the small region, the gains start increasing again to bring back the trajectories to the region in finite time. Note that the traditional ASMC methods adjusting the control gains to limit the uncertainties require the knowledge of uncertainties bounds, 26,28,29 which is difficult to used in practical systems. 41 Some literature does not need to know the bounds [30][31][32][33][34] but they may cause the unacceptable gain overestimating problem and decrease the control performance.…”

“…Remark 4. It should be noted that the gain adaptation laws (27) and (28) are used to alleviate the chattering problem. To show the advantages of the proposed method, a conventional SMC method with constant control gains can be presented as…”

“…Based on this, the SMC method with dynamical adaptation of the gain is presented to counteract uncertainties, 27 and it has been used in hypersonic missile control to yield the reduced chattering and improve the dynamic performance. 28,29 It should be noted that these methods require prior knowledge of the uncertainties upper bound, which often are not exactly known in practical system. The adaptive gain SMC methods proposed in other works [30][31][32][33][34] do not need to know the uncertainties bounds, yet the gain adaptive laws directly depend on the sliding variable so that the overestimation of control gain cannot be avoided effectively.…”

Robust adaptive dual layer sliding mode controller: Methodology and application of uncertain robot manipulator

“…Its design is based on a chosen slide surface function in system state space and the system trajectories to converge to the chosen surface by a high gain switching law. It should be noted that the high gains of the SMC controllers are usually chosen to be larger than the upper-bound of uncertainties (Guo et al, 2017; Guo, 2018). This excessive choice can ensure fast convergence and superior robustness but may cause the sever control chattering phenomenon, which is the major drawback of SMC.…”

An observer-based continuous adaptive sliding mode guidance against chattering for homing missiles

“…Kumar et al (2014) proved that sliding mode motion is not affected by external disturbances and parameter perturbations (Zhou et al, 1999). Recently, an integrated guidance and control strategy using SMC has been proposed by Guo et al (2018), a novel sliding mode equivalent control-based autopilot was designed for bank-to-turn (BTT) missiles by Guo (2018). As is well known, chattering is an undesirable phenomenon of continuous oscillations near the sliding surface, which leads to low control precision and extra energy consumption.…”