Motion and vibration control of a stacker crane by 2-degree-of-freedom model-following control using an internal characteristic of the model

Abstract

In the logistic system, it is necessary to reduce the weight of the structure to realize energy-saving and highly efficient conveyance of a stacker crane that conveys packages in a warehouse. On the other hand, a lightweight stacker crane becomes a flexible structure, and its movement and vibration control are very important and has been discussed by many studies from long ago. Many designs of dynamic FF controllers have been discussed. In this paper, we propose model following two degree of freedom control using a simple reference model that can simultaneously control vibration and motion by utilizing the internal integral characteristics of the model. We discuss FF command and reference signal considering constraints of actuator. As an FB controller with 2 degrees of freedom control, vibration sensor-less active control using motor position-controlled FB torque is proposed and its effectiveness is verified by simulation and experiment.

Keywords

• positioning control
• vibration control
• flexible structure
• 2-degree freedom control