The overhead crane is required to operate fast and precisely with minimal sway. However, high-speed operations cause undesirable load sways, hazardous to operating personnel, the payload being handled, and the crane itself. Thus, a high-quality control is required. In this work, the nonlinear model of the overhead crane was established and the sliding mode control (SMC) was proposed that ensured the existence of sliding motion in the presence of payload and hoisting height variations, and viscous frictions. To maximize the benefits derived from the proposed control method, novel sliding slope-update based on intelligent neural-network and fuzzy algorithms were developed to tune the controller, guaranteeing precise tracking of the actuated variables as well as regulation of the unactuated variables. The proposed methods adjust predetermined value of the sliding manifold’s slope in response to variations in hoisting heights. Control applications were conducted, and results based on graphical, integral absolute error (IAE), and integral time absolute error (ITAE) proved the effectiveness of the proposed algorithms. It was observed that the response of the controller with back-propagation-trained neural-network was more effective relative to that of the fuzzy algorithm.

No abstract

No abstract

No abstract

The research paper focuses on studying the robust stability and performance of suboptimal H_∞ control on mass-spring-dashpot systems subject to parametric uncertainty and external disturbance on output response. The objective is keeping the vertical oscillation of the system constant under uncertainty and disturbance. For the control system to achieve satisfactory performance, suitable weighting filter functions for performance and control effort were designed respectively. Model order reduction for the synthesized controller based on Hankel norm approximation was conducted where a third order controller is obtained. Numerical results based on µ-analysis, frequency response and transient response show that the closed-system achieved robust stability and robust performance to parametric uncertainty and disturbance at all frequencies over the entire frequency bandwidth of study.