The crane robust control

Abstract

The article is about a control design for complete structure of the crane: crab, bridge and crane uplift. The most important unknown parameters for simulations are burden weight and length of hanging rope. We will use robust control for crab and bridge control to ensure adaptivity for burden weight and rope length. Robust control will be designed for current control of the crab and bridge, necessary is to know the range of unknown parameters. Whole robust will be split to subintervals and after correct identification of unknown parameters the most suitable robust controllers will be chosen. The most important condition at the crab and bridge motion is avoiding from burden swinging in the final position. Crab and bridge drive is designed by asynchronous motor fed from frequency converter. We will use crane uplift with burden weight observer in combination for uplift, crab and bridge drive with cooperation of their parameters: burden weight, rope length and crab and bridge position. Controllers are designed by state control method. We will use preferably a disturbance observer which will identify burden weight as a disturbance. The system will be working in both modes at empty hook as well as at maximum load: burden uplifting and dropping down. For uplift drive we will use an asynchronous motor fed from frequency converter. Simulations are proposed for situation that firstly we do uplift and then switching block realize simultaneous crab and bridge motion. At simulations it is possible to choose different burden weight, rope length, crab and bridge positions and speeds.