Hybrid Input Shaping and Hierarchical Sliding Mode Control Design for Tower Crane

Abstract

During trolley translation along the jib and jib rotation, a tower crane with an underactuated drive system can cause a considerable amount of sway to the payload. A number of studies have been performed to address this issue, with particular attention being paid to the use of sliding mode control (SMC), which has demonstrated effectiveness in tracking position and reducing vibrations. Some side effects of relying solely on SMC, however, include chattering and saturation of input signals. Our paper proposes using a combination of feed-forward input shaping (IS) and sliding mode control to overcome the control problems associated with a tower crane. Hybrid Input Shaping and Hierarchical Sliding Mode Control can reduce not only payload vibration but chattering and control input as well. In addition, the controller's parameters can be determined using Particle Swarm Optimization (PSO) to optimize a performance index. To verify the effectiveness of the proposed controller, experiments were conducted on a laboratory tower crane. Results showed that the hybrid IS-SMC structure has a similar response time as SMC, but the the total swing angle is reduced by 40%.