Evaluation of labview based control for a reconfigurable manufacturing subsystem

Masendeke, Darlington M. (2015-03)

Thesis (MEng)--Stellenbosch University, 2015.

Thesis

ENGLISH ABSTRACT: This thesis considers the evaluation of LabVIEW based control for reconfigurable manufacturing systems (RMSs), and in particular for an RMS subsystem. The evaluation used a rivet feeder station as a case study. The architecture of the rivet feeder station included a vibratory bowl feeder, a singulation device, a pick-n-place mechanism and an XYZ positioning table. The objective of the research was to determine whether LabVIEW is a suitable development environment for implementing holonic control. The motivation for considering LabVIEW in this thesis was that other control approaches, such as IEC 61499 function blocks, agent-based control and object-orientated control, that have been used in most RMS research, have not found favour with industry. The PROSA holonic reference architecture was adopted here, with the following holons: Coms Holon, Request Manager Holon, Order Holon, Product Holon Manager, Pick-n-Place Holon and XYZ Table Holon. The holons, constituting the controller, were designed based on LabVIEW’s producer/consumer and state machine architectures. The controller was aimed at making the rivet feeder station reconfigurable. Furthermore, the controller was interfaced with a cell controller through a TCP/IP connection and an XML format of messaging was adopted for communication. The main limitations and disadvantages of LabVIEW, for the implementation of holonic control systems, were found to be: the graphical programming which makes the block diagram cumbersome to follow, for complex applications; and that dynamic instantiation of objects or memory cannot be achieved in LabVIEW. However, LabVIEW holds the following advantages: shared variables and TCP/IP components simplify communication over a network; easy construction of the graphical user interface using controls and indicators on LabVIEW front panels; the XML standard format in LabVIEW provides flexibility to create your own unlimited tags; and immediate compilation of LabVIEW programs. Furthermore, LabVIEW easily can be integrated with hardware such as the compactRIO with a CANopen card. The reconfigurability assessment of the rivet feeder station included three experiments which involved changing the product type, adding new devices and performing station diagnostics. From these experiments, it was concluded that the key characteristics of reconfigurable manufacturing systems were achieved, thereby demonstrating the suitability of LabVIEW for implementing holonic control.

AFRIKAANSE OPSOMMING: Hierdie tesis beskou die evaluering van LabVIEW-gebaseerde beheer vir herkonfigureerbare vervaardigingstelsels (RMSs), en in besonder vir 'n RMS substelsel. Die evaluering het 'n klinknaelvoerstasie as gevallestudie gebruik. Die voerstasie se argitektuur het 'n vibrerende bakvoerder, 'n singuleringstoestel, 'n optel-en-plaas-robot en 'n XYZ-posisioneringstafel ingesluit. Die doelwit van die navorsing was om te bepaal of LabVIEW 'n geskikte ontwikkelingsomgewing vir die implementering van holoniese beheer bied. Die motivering vir die oorweging van LabVIEW in hierdie tesis was dat ander beheerbenaderings, soos IEC 61499 funksieblokke, agent-gebaseerde beheer and objek-georiënteerde beheer, wat in die meeste RMS-navorsing gebruik is, nie aanvaarding in die nywerheid gevind het nie. Die PROSA holoniese verwysingsargitektuur is hier gebruik, met die volgende holone: Coms Holon (kommunikasieholon), Request Manager Holon (versoekbestuurholon), Order Holon (bestellingholon), Product Holon Manager (produkholonbestuurder), Pick-n-Place Holon (optel-en-plaasholon) en XYZ Table Holon (XYZ-tafelholon). Die holone, wat die beheerder uitmaak, se ontwerp is gebou op LabVIEW se vervaardiger/verbruiker- (producer/consumer) en toetstandmasjien-argitekture. Die beheerder was daarop gemik om die klinknaelvoerstasie herkonfigureerbaar te maak. Verder, die beheerder het 'n koppelvlak met 'n selbeheerder gehad, waarin 'n TCP/IP-verbinding en 'n XML-formaat vir die kommunikasie-boodskappe gebruik is. Die belangrikste beperkings en nadele van LabVIEW, vir die implementering van holoniese beheerstelsels, het geblyk te wees: die grafiese programmering wat die blokdiagramme moeilik maak om te volg, vir komplekse toepassings; en dat objekte en geheue nie in LabVIEW dinamies geskep kan word nie. LabVIEW het, egter, die volgende voordele: gedeelde veranderlikes en TCP/IP-komponente vereenvoudig netwerkkommunikasie; gerieflike skepping van die grafiese gebruikerskoppelvlak met behulp van beheerders en meters (controls and indicators) op LabVIEW se voorpanele (front panels); die XML-standaard-formaat in LabVIEW voorsien buigsaamheid om jou eie onbeperkte etikette (tags) te skep; en onmiddellike vertaling van LabVIEW programme. Verder, LabVIEW kan maklik geïntegreer word met hardeware soos die "compactRIO" met 'n "CANopen" kaart. Die beoordeling van die herkonfigureerbaarheid van die klinknaelvoerstasie het drie eksperimente ingeluit waarin die verandering van die produktipe, die byvoeging van nuwe toestelle en die uitvoering van stasie-diagnoses betrokke was. Uit hierdie eksperimente kan afgelei word dat die sleutel-eienskappe van herkonfigureerbare vervaardigingstelsels behaal is, waardeur aangetoon is dat LabVIEW geskik is om holoniese beheer te implementeer.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/97130
This item appears in the following collections: