Analysis of IIR Filter with NCTF-PI control for sway and trajectory motion of a DPTOC system

This paper presents performance analysis of hybrid control schemes for trajectory motion and anti-swaying control of a double-pendulum-type overhead crane (DPTOC) system. A nonlinear DPTOC system is considered and the dynamic model of the system is derived using the Euler-Lagrange formulation. To study the effectiveness of the controllers, initially nominal characteristics following trajectory following (NCTF) is developed for position control of cart movement. The controller design, which is comprised of a nominal characteristic trajectory (NCT) and PI compensator, is used to make the cart motion follow the NCT. This is then extended to incorporate Infinite Impulse Response (IIR) filter schemes for anti-swaying control of the system. The Butterworth low-pass filter with different orders was design based on properties of the system. The analyses of the response with the controllers are presented in time and frequency domains. The performances of hybrid control schemes are examined in terms of level of input tracking capability, sway angle reduction and time response specifications in comparison to NCTF controller. Finally, a comparative assessment of the control techniques is discussed and presented.