Hybrid Fuzzy Logic Control with Input Shaping for Input Tracking and Sway Suppression of a Gantry Crane System

Problem statement: Most of the common gantry crane results in a sway motion when transporting the load as fast as possible. In addition, precise cart position control of gantry crane must required a zero or near zero residual sway. Approach: In this study, the development of hybrid control schemes for input tracking and anti-sway control of a gantry crane system was investigated. To study the effectiveness of the controllers, a Proportional-Derivative (PD)-type fuzzy logic control was developed for cart position control of a gantry crane. It was then extended to incorporate input shaper control schemes for anti-sway control of the system. The positive and new modified Specified Negative Amplitude (SNA) input shapers were designed based on the properties of the system for control of system sway. The new SNA was proposed to improve the robustness capability while increasing the speed of the system response. Results: Simulation results of the response of the gantry crane with the controllers were presented in time and frequency domains. The performances of the of the hybrid control schemes were examined in terms of input tracking capability, level of sway reduction and robustness to parameters uncertainty. Conclusion: A significant reduction in the system sways had been achieved with the hybrid controllers regardless of the polarities of the shapers.