Reclaimer Control: Kinematic Analysis, Modeling, Identification, and a Robust Smith Predictor

Abstract The reclaimer is a type of industrial equipment that excavates and transports the raw materials like coal and iron ore in the raw yard of a steel company. In this paper, as a part of reclaimer automation, an inverse kinematics problem and a robust time delay control are investigated. Analyzing a job task in the field, a closed-form solution of the inverse kinematics problem is provided. A nominal plant model, for the purpose of control system design, with unknown parameters is introduced. The unknown parameters in the nominal model are estimated with a recursive least squares estimation method. One obstacle in obtaining a good control performance is a large output delay due to the non-collocation of an actuator and a sensor. In this paper, in the presence of both structured and unstructured uncertainties in the nominal model and with large time delay, a robust Smith predictor is designed. A robust stability criterion with an uncertainty is derived, and a procedure of quantifying the uncertainty bound that is allowed in the nominal model of the reclaimer is described. Experimental and simulation results are provided.