Model Predictive Control for operator-in-the-loop overhead cranes

Abstract

In this paper, a Model Predictive Control approach for the velocity control of operator-in-the loop overhead cranes is proposed. The operator can select the maximum position overshoot as a tuning parameter for the method. Simulations provide a comparison between the proposed method and the well known Zero Vibration input shaping technique, showing its effectiveness in controlling the payload oscillations.

Comparison of Linear and Nonlinear MPC on Operator-In-the-Loop Overhead Cranes

“…For comparison purpose, adaptive and nonlinear MPC are compared with the linear MPC in [18] by means of simulations considering different maneuvers with both horizontal travelling and hoisting. Nonlinear MPC approach has been simulated with both the Assumptions explained in Section III for the inclusion of the varying cable length along the prediction horizon.…”

“…In order to quantify the performance of the simulated techniques, two indices have been computed: the total Integral Absolute Error (IAE) and the position overshoot after the travelling button is released. Results show that the technique in [18] yields an unsatisfactory performance when dealing with simultaneous travelling and hoisting manoeuvres, as its IAE always exceeds the ones of the other techniques. Moreover, it is also not effective in containing the position drift of the payload after the operator releases the travelling button.…”

“…In this paper, a comparison of different MPC techniques (linear, adaptive and nonlinear MPC) applied to the control of operator maneuvered overhead cranes has been presented. The obtained results show that a change in the length of the cable strongly affects the linear MPC approach proposed in [18], for which the performance strongly degrades when the cable length is varied. Adaptive and NMPC approaches can cope with cable length variations.…”

“…Therefore, the control problem in manually operated cranes is completely different, in particular because it is not possible to know in advance the future velocity reference given each instant by the operator, while for the position control of autonomous overhead cranes the position reference is known in advance and does not change along the predictive horizon. The control of Operator-In-the-Loop (OIL) overhead cranes has been addressed in [18]. Therein, the approach considers only the horizontal travel of the payload with constant cable length, limiting the point-to-point manoeuvres to be executed with separated and mutual-excluding sequences of horizontal travelling, hoisting and lowering, thereby increasing the total operation time.…”

MPC-PID control of operator-in-the-loop overhead cranes: A practical approach

“…Motivated by the increasing computational capacity of standard off-the-shelf control components and the decreasing cost of sensors for feedback controls, in this paper an MPC approach to the problem of OIL overhead cranes control is devised. The MPC approach has already been applied to the velocity control of overhead cranes in [36], and the performance has been compared to input shaping techniques. Therein, at every step, the force acting on the cart is calculated by solving an Optimal Control Problem (OCP) and is given as input to the system.…”