A Hybrid Controller for Control of a 3-DOF Rotary Crane System

This paper presents the development of a hybrid input shaping for anti-sway control of a three degree-of freedom (3-DOF) rotary crane system. A nonlinear equation of motion in a state space form obtained using Euler-Lagrange technique is considered for the crane´s tower in order to control and reduce the sway angle during the rotation. To study the effectiveness of the controllers, initially a Linear Quadratic Regulator (LQR) control is developed for the tower rotation angle of the rotary crane. This controller is then extended to incorporate input shaping techniques for antiswaying control of the system for different payload. Input shaping with different derivative orders was designed based on the properties of the system. Implementation results of the response of the rotary crane with the controllers are presented in time and frequency domains. The performances of input shaping in hybrid control schemes are examined in terms of level of input tracking capability, swing angle reduction, and time response specifications. Finally, a comparative assessment of the proposed control techniques is presented and discussed.