Gino Cardarelli

Performance analysis of automated interbay material-handling and storage systems for large Wafer Fab

In this paper the performance of an automated interbay material-handling and storage system was analysed, considering the effects of design choices, production planning and scheduling, system management and operator behaviour. The results show the great importance of appropriate design of the storage capacity distribution along the Wafer Fab.

Comparing heat recovery schemes in solid bed cooling

Interesting perspectives are shown by heat recovery from beds of particulate solids which have to be cooled for process requirements. Sinter making plants for blast furnace feeding represent a typical application area where energy saving policies are very attractive. With reference to a sinter cooling bed of the Ilva steel works located in Taranto, several heat recovery schemes were presented under the hypothesis of unsteady-state operation. Assuming both uniform and non-uniform cooling air flow rates, solutions based on single and double (parallel or series) hoods were characterized in terms of arrangement, control criteria and performance. Finally, a comparison analysis was carried out based on plant complexities and benefits of examined heat recovery schemes.

Computer integrated manufacturing in small companies: a case study

A methodology for introducing computer integrated manufacturing (CIM) technology in small companies has been developed. With the aim to assess the capabilities in real applications of the proposed approach, a case study is presented in this paper. The case study refers to a small Italian company (Italpneumatica Sud) producing pneumatic components under one of the leading trademarks in the world (SMC). Results of first experimental tests demonstrate ability of the developed methodology in improving overall company performances, maintaining at the same time low implementation costs.

Design criteria for cooperating robots assembly cells

Abstract A pragmatic approach to aid in designing assembly cells with cooperating robots is presented in this paper. Conditions justifying the use of multiple cooperation have been previously defined. Effort is focused on the appropriate characterization of assembly tasks to help find solutions for solving collision and coordination problems. The laboratory used for experimental studies on cooperating robots is also illustrated. The presented criteria are applied to the cell setup of a mechanical assembly process.

An effective loading rule for FMS real time scheduling

FMS real time scheduling requires the concurrent solution of both loading and despatching problems. The loading strategy is the most critical and important scheduling decision in an FMS. Presents an effective loading rule (job‐group loading rule), based on experimental observations: a group of jobs, reflecting the ratios of the production mix, is loaded on the input warehouse every time that it is completely empty; all the jobs loaded on the input warehouse have to be accessible for the material handling system. Demonstrates how this job‐group loading works as a dynamic rule for real time scheduling of manufacturing systems, defining a part releasing policy able to guarantee reaching a periodic, steady state production. The capability of the job‐group loading rule has been verified when the FMS characteristics are closest to a real situation. Analyses the effects of the interferences on transport operations, the variability of machining times, the finite capacity of interoperational storage and the stops for preventive maintenance or breakdown. Research results show the capability in FMS management of real time scheduling based on the job‐group loading rule.

Critical aspects in multi‐robot co‐operation

Outlines current research into multiple co‐operative robots and discusses the practicality of a set of experiments developed to study robot applications better and to verify different solution methodologies. Looks at the design criteria for co‐operating robot systems and describes the laboratory set up to study them.

Comparison of conventional and dynamic FMS periodic loading rules

Reports on a comparison by computer simulation between conventional periodic loading (PL) and job‐group loading (JGL). When conventional PL is used, the search of the best part input sequence must be performed in order to optimize performance of a flexible manufacturing system (FMS). JGL works, instead, as a dynamic rule for real time scheduling of FMS, defining a part releasing policy able to guarantee the reaching of a periodic steady state without non‐productive times on the bottleneck workstation. However, JGL does not assure, in some cases, the same performance arising from the optimal part input sequence of conventional PL, in terms of non‐productive times in FMS filling and emptying phases, work in progress and throughput time. The paper demonstrates that using any JGL rule or the best PL part input sequence gives rise to negligible differences in FMS performance. Furthermore, the dynamic capabilities of the JGL also allow for spontaneously restoring the FMS periodic steady state without non‐productive times after any transient, for instance when production mix changes occur.

Some criteria to help the experimental setup of assembly cells with cooperating robots

A pragmatic approach for aid in the designing of assembly cells with cooperating robots is presented in this paper. The conditions justifying the use of multiple cooperation have been previously defined. Effort was then focused on the appropriate characterization of the assembly tasks with the aim of helping find solutions for solving both collision and coordination problems. The capability of the laboratory used for experimental studies on cooperating robots is also illustrated. The presented criteria have been applied to the cell setup of a mechanical assembly process.

Assembly with co‐operating robots

Looks at studies into the definition of design and management criteria for assembly cells with co‐operating robots. Examines task typologies into which the assembly process can be divided and discusses co‐ordination levels and control‐communication architectures. Also looks at the various phases of application development and how it covers many of the same areas of the manual assembly process. Concludes with a consideration of the three main classes of constraints between the actions which different robots have to carry out and states the co‐ordination level that robots have to maintain during constraint‐affected operations depends on these classes.