Optimal RTGC Non-linear Control System Based on Sliding Mode Controller

The high traffic of containers between countries and continents demands the implementation of automation at cargo seaports. Rubber Tyred Gantry Crane (RTGC) is one of the main components for loading and unloading at container yards which needs to move the container accurately to the desired position and minimize the sway during this process. This paper attempts to examine non-linear control using the sliding mode controller (SMC) method for MIMO control problems in RTGC. The control objective is to reduce the swing angle and move the container to the desired position and height by means of the force of two motors on RTGC. The detailed derivation of the nonlinear RTGC model, the design of SMC and its sliding surface are introduced in this paper. In order to optimize the performance of the SMC control action, the Particle Swarm Optimization (PSO) and Grid search methods are employed in the investigation. The obtained results demonstrate that the SMC exhibits satisfactory control performance and effectively reduces chattering across various initial conditions and system parameters.