Multi-layer barrier adaptation of the discrete-time super-twisting controller
For control engineers implementing sliding mode controllers digitally, this work provides a method to mitigate performance degradation from discretization, though validation is only numerical.
The paper addresses discretization-induced chattering and inter-sample blindness in digital sliding mode control by proposing a multi-layer barrier adaptation for the discrete-time super-twisting controller, preserving adaptive and robustness properties with consistent stability at the sampling level, validated through numerical simulations.
In digital sliding mode control implementations, discretization-induced chattering and inter-sample blindness can severely degrade the closed-loop performance, especially in case of fast perturbations. This paper addresses these challenges for a discrete-time implementation of the super-twisting sliding mode controller. Building upon recent results on barrier-function-modulated super-twisting algorithms, a nested architecture employing multiple barriers is discretized using an eigenvalue-based exact matching approach. The resulting discrete-time controller preserves the adaptive and robustness properties established in continuous time, while ensuring consistent stability behavior at the sampling level. The proposed framework is validated through numerical simulations. The results highlight the effectiveness of multi-layer barrier adaptation for discrete-time sliding mode control applications.