Experimental Benchmarking of Energy-saving Sub-Optimal Sliding Mode Control

TL;DR

This paper experimentally benchmarks an energy-saving extension of sub-optimal sliding mode control against a standard second-order sliding mode controller, demonstrating reduced energy consumption while managing disturbances and noise.

Contribution

It provides the first experimental comparison of energy-saving sub-optimal sliding mode control with traditional second-order SM control under realistic conditions.

Findings

Energy-saving SM control reduces energy consumption compared to standard SM.

Both controllers perform similarly in the presence of disturbances and noise.

Chattering effects are observed due to actuator dynamics.

Abstract

The recently introduced energy-saving extension of the sub-optimal sliding mode control allows for control-off phases during the convergence to second-order equilibrium. This way, it enables for a lower energy consumption compared to the original sub-optimal sliding mode (SM) algorithm, both commutating a discontinuous control signal. In this paper, the energy-saving sub-optimal SM control is experimentally benchmarked against a standard second-order SM controller which also has a discontinuous control action. Here the so-called terminal second-order SM algorithm is used. The controlled plant is affected by the matched bounded disturbances which are unknown, and the output is additionally subject to the sensor noise. Moreover, a first-order actuator dynamics can lead to chattering, which is parasitic for SM applications. For a fair comparison, the same quadratic terminal surface is designed when benchmarking both SM controllers. Both experimentally compared SM algorithms have the same (bounded) control magnitude and states initial conditions.