Fluid Power Control of a Flexible Mechanical Structure

Control of a hydraulic crane is considered. Due to the oscillatory character of the system smooth the operation of the crane is a demanding task. In order to improve the handling properties feedback control of the crane is studied. Based on linearized models feedback regulators of both LQG and PID type are designed. The feedback is based on position, pressure and acceleration measurements. Since the properties of the system change with load and operating point adaptive control is also introduced. The use of accelerometer signals for impact detection is also discussed. The proposed solutions are tested in both simulations and experiments on a real crane. This work was sponsored by the CENIIT at Linkoping University. Report no. LiTH-ISY-R-1961 y Phone: +46-13-281747. Fax: +46-13-282622. E-mail: svante@isy.liu.se z Phone: +46-13-281792. E-mail: petkr@ikp.liu.se 1 Introduction There is a clear trend to introduce more automation in mechanical system controlled by fluid power actuat..