A study on the performance improvement of discrete sliding mode control

Sliding mode control (SMC) uses a switching control action to direct a process along a user-specified path from an arbitrary initial state to the desired state. This paper evaluates experimentally the robustness of a discrete version of SMC (DSLM) as applied to an electric gantry crane apparatus. The original version was modified to use a variable sliding gain methodology and different weights to each of the states. The robustness of this novel DSLM (denoted as DSLM*) was evaluated by changing the natural frequency of the pendulum of the electric gantry. The results of the experimental study demonstrate that the performance of SMC improves considerably with the addition of state weights and a variable sliding gain