Optimal Control for a Gantry Crane System Using Priority Fitness Strategy of Particle Swarm Optimization

The basic operating concept of a gantry crane system is to move payloads from one area to another, which requires precise trolley positioning with low payload sway. This paper investigates the impact of particle swarm optimization incorporating a priority fitness strategy in finding the optimal control approach for the gantry crane system. The research contribution of the proposed strategy lies in obtaining optimal proportional-integral-derivative and proportional-derivative control parameters simultaneously under six cases of the system’s transient responses, yielding targeted exploration and exploitation for each case and improved robustness across heterogeneous operating conditions. Therefore, a series of transient responses based on overshoot, steady-state error, and settling time are constructed and ranked in every possible configuration to replace the single static priority factor used in the previously developed priority fitness strategy. Interestingly, the simulation results with respective fitness strategies demonstrate the effectiveness of the proposed method. In fact, the trolley moves as fast as possible to the desired position with low payload sway, where Case 2 of the proposed method achieves zero overshoot, zero steady-state error, and a 49.7% improvement in settling time. Through extensive simulations, the proposed strategy also shows consistent performance across various trolley positions and payload masses, highlighting its adaptability and reliability under robust analysis. It is envisaged that the proposed method can be useful for other systems to find the required performances according to the needs and circumstances.