A new approach to overhead cranes parameter estimation and friction modeling

For the purpose of accurate position control in the majority of mechanical control systems, the parameters of the system should be determined either by the manufacturer or by using system identification techniques. In this paper, a new approach is presented for estimating the parameters of an overhead crane that includes the actuators´ parameters and Coulomb friction modeling as well. The main idea behind this approach is inspired by independent joint control strategy in robot manipulator control field in which the actuators are considered as the main process to be controlled. The nonlinear dynamics of the overhead crane is then modeled as disturbances acting on each actuator. The outcome is a decoupled model that enables us to determine the parameters of the overhead crane in each direction of motion independently using Recursive Least Squares technique. The experimental results on a laboratory-sized overhead crane indicate high accuracy in the identified system model and a potential of its application in the design of high-performance control systems for overhead cranes.