This paper describes an integrated approach for crane automation at the Kwangyang steel works, POSCO. Unmanned cranes are composed of several technologies,which include anti-sway control, precision position control, optimal trajectory computation, and coil shape recognition. Crane position while traveling and the traverse axis are controlled by PID position controllers. In order to prevent sway...

This study considers a practical overhead crane control problem of designing a fuzzy control to ensure that the trolley arrives precisely at its destination; the load swing angle approaches to zero, and the energy of input and states is minimized. Furthermore, the constraints for the overhead crane operation are also considered and satisfied. Those constraints are that when the crane is moving,...

Tower cranes are major and expensive equipment that are extensively used at building construction projects and harbors for lifting heavy objects to demand points. The tower crane locating problem to position a tower crane and supply points in a building construction site for supplying all requests in minimum time, has been raised from more than twenty years ago. This problem has already been so...

This paper proposes a novel anti-swing control strategy for an overhead crane. The controller includes both position regulation and anti-swing control. Since the crane model is not exactly known, fuzzy rules are used to compensate friction, gravity as well as the coupling between position and anti-swing control. A high-gain observer is introduced to estimate the joint velocities to realize PD c...

In multiprocessor systems, redundant scheduling is a technique that trades processing power for increased reliability. One approach, called primary-backup task scheduling, is often used in real-time multiprocessor systems to ensure that deadlines are met in spite of faults. Briefly, it consists in scheduling a secondary task conditionally, in such a way that the secondary task actually gets exe...

In real-time systems, tasks have deadlines to be met despite the presence of faults. Primary-Backup (PB) scheme is one of the most common schemes that has been employed for fault-tolerant scheduling of real-time tasks, wherein each task has two versions and the versions are scheduled on two different processors with time exclusion. There have been techniques proposed for improving schedulabilit...

In real-time systems, tasks have deadlines to be met despite the presence of faults. Primary-Backup (PB) scheme is one of the most common schemes that has been employed for fault-tolerant scheduling of real-time tasks, wherein each task has two versions and the versions are scheduled on two different processors with time exclusion. There have been techniques proposed for improving schedulabilit...

Extensions of the ML type system based on con strained type schemes have been proposed for lan guages with overloading Type inference in these sys tems requires solving the following satis ability prob lem Given a set of type assumptions C over nite types and a type basis A is there is a substitution S that satis es C in that A CS is derivable Un der arbitrary overloading the problem is undecid...

Method overloading is a controversial language feature, especially in the context of Object Oriented languages, where its interaction with overriding may lead to confusing semantics. One of the main arguments against overloading is that it can be abused by assigning the same identity to conceptually different methods. This paper describes a study of the actual use of overloading in JAVA. To thi...