F.R. Camisani-Calzolari

A contemplative stance on the automation of continuous casting in steel processing

Abstract This paper gives a contemplative stance on the automation of continuous casting in steel processing. It gives a brief overview of the control techniques used in this industry, typical applications of such techniques, and discusses supportive technologies that form a critical part of the implementation of such techniques. The casting process and operational issues are described. Particular attention is paid to production planning and scheduling, computer-aided quality control, and the crucial role that instrumentation plays in the automation of a caster. The importance of integrating casting automation systems into plant wide production systems, and the development of new instrumentation, are highlighted.

AN OVERVIEW OF THE AUTOMATION OF LOAD-HAUL-DUMP VEHICLES IN AN UNDERGROUND MINING ENVIRONMENT

Abstract This work is a survey on the automation of load-haul-dump trucks in underground mining. Background on the purpose of LHD vehicles is given and the need to automate LHDs discussed, with emphasis on the underground mining environment. Safety issues regarding mine personnel and mine vehicles are considered. Dynamic and kinematic modelling techniques including slip and no-slip models are discussed. Navigation of the LHD through the mine using absolute and reactive navigation are given and sensor technology is perused.

CONTROL STRUCTURE FOR THE REDUCTION OF DEFECTS IN CONTINUOUS CASTING

Abstract The causes for surface defects in the continuous casting process must be understood so that surface defects can be eradicated. The defects which were considered are presented and an approach to eliminate many of the influencing variables using statistical hypothesis testing is presented. These methods show that only the thermocouple temperature readings within the mould are necessary to accurately predict the occurance of defects. The use of ARX modeling is then presented for a predictor which uses thermocouple temperatures as inputs and defects as outputs. A mould model can be determined in the same way using controlled variables as inputs and the thermocouples as outputs. Optimal control and feedback control can be used to diminish the defects.

On the Control of the Secondary Cooling Zone in Continuous Casting

Abstract A steady model describing heat transfer in the secondary cooling zone (SCZ) of a continuous caster is shown. The advantage of open-loop control is presented by means of a simple example. It is shown how the effect of speed can be compensated for by feedforward control.

MODELLING THE DYNAMICS OF A LOAD-HAUL-DUMP VEHICLE

Abstract This paper provides an overview of the derivation of a dynamic model of a Load-Haul-Dump (LHD) vehicle. The model is derived using Lagrangian Dynamics and makes use of a simplified tyre model in an attempt to include the effect of basic tyre dynamics. Simulation results obtained from the vehicle model are provided and the results discussed and analysed.

A proposed control system/CAQC methodology and prediction system for the improvement of surface defects in the continuous casting of slabs

Abstract A control system or computer aided quality control system methodology is presented to determine surface defects in the continuous casting of steel slabs. When no defects are present, slabs can be either hot charged or direct rolled, thereby increasing the throughput of the system and decreasing energy consumption.

Control strategies for the secondary cooling zone in continuous casting

A brief overview is given of current research undertaken by the authors in the continuous casting process with specific emphasis on the secondary cooling zone. The dynamic and steady state heat transfer model, discretisation of the model, open-loop spray chamber redesign, systems identification procedure, feedforward controllers and feedforward-feedback controllers involved in system design are discussed.

Simplified Dynamic Model of an Load-Haul-Dump Vehicle

Abstract This paper provides an overview of the derivation of a dynamic model of a Load-Haul-Dump (LHD) vehicle for the purposes of autonomous navigation. The model is derived using Lagrangian Dynamics and makes use of a tyre model in an attempt to include the effect of basic tyre dynamics on the vehicle trajectory. An open loop nonlinear optimal control strategy is applied to the dynamic model and simulation results obtained from the vehicle model are provided and the results discussed and analysed.

Modeling of an Autonomous Underground Mine Vehicle

Abstract This paper focuses on the modeling of a Load-Haul-Dump (LHD) vehicle for the purposes of autonomous navigation. Two vehicle models are described, the first a no-slip model based purely on kinematic geometry and the second model which takes the effects of slip into account by means of an extended kalman filter (EKF). Simulations of a reactive navigation scheme based on both models of an LHD are performed and the results discussed and analysed.

A Review on Causes of Surface Defects in Continuous Casting

Abstract A review on the causes of the foremost defects in continuous casting, based on an extensive literature survey, is given. The specific defects which are considered are transversal and longitudinal cracking, inclusions, sticking, bleeding, oscillation marks, stopmarks and depressions.