Motion control is a sub-field of automation, in which the position and/or velocity of machines
are controlled using some type of device. In motion control the position, velocity, force, pressure,
etc., profiles are designed in such a way that the different mechanical parts work as an harmonious
whole in which a perfect synchronization must be achieved.
The real-time exchange of information in the distributed system that is nowadays an industrial
plant plays an important role in order to achieve always better performance, better effectiveness
and better safety. The network for connecting field devices such as sensors, actuators, field controllers
such as PLCs, regulators, drive controller etc., and man-machine interfaces is commonly
called fieldbus.
Since the motion transmission is now task of the communication system, and not more of kinematic
chains as in the past, the communication protocol must assure that the desired profiles, and
their properties, are correctly transmitted to the axes then reproduced or else the synchronization
among the different parts is lost with all the resulting consequences.
In this thesis, the problem of trajectory reconstruction in the case of an event-triggered communication
system is faced.
The most important feature that a real-time communication system must have is the preservation
of the following temporal and spatial properties: absolute temporal consistency, relative
temporal consistency, spatial consistency.
Starting from the basic system composed by one master and one slave and passing through
systems made up by many slaves and one master or many masters and one slave, the problems
in the profile reconstruction and temporal properties preservation, and subsequently the synchronization
of different profiles in network adopting an event-triggered communication system, have
been shown. These networks are characterized by the fact that a common knowledge of the global
time is not available. Therefore they are non-deterministic networks. Each topology is analyzed
and the proposed solution based on phase-locked loops adopted for the basic master-slave case
has been improved to face with the other configurations.
| Identifer | oai:union.ndltd.org:unibo.it/oai:amsdottorato.cib.unibo.it:637 |
| Date | 20 June 2008 |
| Creators | Spera, Manuel <1978> |
| Contributors | Rossi, Carlo |
| Publisher | Alma Mater Studiorum - Università di Bologna |
| Source Sets | Università di Bologna |
| Language | Italian |
| Detected Language | English |
| Type | Doctoral Thesis, PeerReviewed |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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