Adaptive Control of a Hydraulic Crane Using On-line Identi cation

In this paper we present an approach to adaptive control of hydraulic actua tors with exible mechanical loads The approach is based on recursive identi cation of low order models of the dynamics from valve input to actuator position and e ective load pressure respectively The model parameters are used to com pute a regulator that gives a well damped system with good servo properties The identi cation is carried out on line in closed loop with no other signals than those present in normal operation Here RLS with variable forgetting factor is used The method does not however need not more parameters to be set a priori than ordinary RLS with x forgetting factor In this way an easily tuned and robust identi cation algorithm is obtained Results from experiments carried out on a lorry crane are presented