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