A Smooth Wave‐Form Shaped Command with Flexible Maneuvering Time: Analysis and Experiments

Abstract

Shaped commands are used to eliminate residual oscillations of crane payloads. Command jerks are detrimental to the safe and efficient operation of cranes. Smooth shaped commands are recommended to avoid such jerks in motion commands to crane motors. The amplitude of the shaped command is governed by its time length. The time length of the shaped command is highly dependent on the natural period of oscillation of the payload. A flexible time length of the shaped command introduces flexibility in selecting the desired command amplitude that would lead to a reduced stress on the crane actuators. In this work, a smooth wave‐form acceleration command is proposed to eliminate residual oscillations in rest‐to‐rest maneuvers of cranes. The proposed shaped command is derived analytically. The system performance is simulated numerically and validated experimentally on a scaled model of an overhead crane. The proposed wave‐form is further modified to relax the dependence of the profile on the natural period of oscillation of the payload.

Payload pendulation and position control systems for an offshore container crane with adaptive‐gain sliding mode control

“…Equations (21) and (23) define a new system dynamic as follows: where z 1 = e y , z 2 = θ, and z 3 ¼ _ θ. The characteristic polynomial of the new system can be obtained as follows:…”

“…Cranes are widely used to load cargo, containers, heavy payload in transportation, construction, and manufacturing. Therefore, various control algorithms from classical control theory, such as optimal control [10,11] and state feedback control [12][13][14], to advanced techniques such as input shaping control [15][16][17][18][19][20][21][22][23][24], fuzzy control [25][26][27][28][29][30], robust control [31][32][33][34][35][36][37][38][39][40], and adaptive control [8,[41][42][43][44][45][46][47][48][49] have been developed to deal with sway suppression. However, the conventional control methods developed for inland container cranes may be ineffective for offshore container cranes due to ocean waves, wind, and currents [50].…”

Modeling and Control of Underactuated Three-Dimensional Overhead Crane Systems

“…Generally, there are two types of overhead crane models, the first type is two dimensional (2D) model [1][2][3][4][5][6][7][8], which is also called single-pendulum-type [9]. The 2D crane model is apparently nonlinear and has three states; trolley position, rope length and swing angle [7].…”

“…The 2D crane model is apparently nonlinear and has three states; trolley position, rope length and swing angle [7]. In general, during the operation, the rope length is fixed or slowly changing, hence, some studies [1][2][3][4][5][6]8] assume the rope length is fixed, which reduces the number of states to two. In addition, if the swing angle is assumed to be small, a linearized model can be used to describe the system dynamics [1] On the other hand, the model accuracy and complexity can be increased by considering the friction between the moving parts [7], adding uncertainties to the system [8] or considering external disturbances [3].…”

A smooth optimized input shaping method for two-dimensional crane systems using Bezier curves

“…Recent work (Peng et al, 2019) used an open-loop control method with command smoothing to reduce both the swinging and twisting of the payloads during slewing motions in tower cranes. However, smooth commands suffer from increasing rise-time and slow system motion (Alhazza et al, 2016). In most of these commands, the total motion is covered by three phases; acceleration, cruising, and deceleration, where the smooth commands are designed for the acceleration stage and reversed in the deceleration phase.…”