Mihalachi, Marius Alexandru (2011)
Position Acquisition and Control for Linear Direct Drives with Passive Vehicles.
Technische Universität Darmstadt
Dissertation, Erstveröffentlichung
Kurzbeschreibung (Abstract)
For combined processing and transportation of materials in industrial production lines, a long primary, linear synchronous drive with passive, lightweight vehicles, is being designed and experimentally tested. This thesis concentrates on position acquisition and motion control of the proposed system. In order to allow a high degree of independency in the movement of the vehicles,the stator (primary) of the linear machine is divided into many segments. Each segment of the track is fed by a dedicated power stack, and control information is exchanged between all power stacks and all vehicle controllers via an Inverter Bus. A number of processing stations are spread along the track of the linear drive, being connected by transport sections. Inside the processing stations, high quality speed and position control of the vehicles is required. For this, precise and fast position measurement is necessary, so position sensors must be used. The passive vehicles impose additional challenges for the position acquisition system, as neither energy nor information must be transmitted to the moving parts. The evaluation of two position acquisition systems, which comply with this requirement, is presented in this thesis. The first system is based on a high-resolution optical encoder. For this application, the scale of the optical sensor is mounted at the vehicle and several active read-heads are installed along the track, such that at each position the scale covers at least one readhead. When the scale is passing from one read-head to the next one, the position information from both read-heads must be evaluated simultaneously and synchronised, so that a continuous position signal will result for the entire measuring length. The second position acquisition system uses a comparatively lower resolution capacitive sensor, and is intended as a simpler and cost effective alternative to the optical system. The principle of operation of a capacitive sensor is first analysed, and a model is determined. Then, based on this model, two methods of extracting the position information are presented: one uses instantaneous (sampling-based) demodulation, while the other is based on phase measurement. In the transport sections of the linear drive the requirements concerning the accuracy and dynamic of the position measurement are less demanding than in the processing stations. In this sections sensorless control, based on the evaluation of the electromotive force (EMF) is implemented. The distinctive parameters of the different stator segments are taken into consideration. Due to mechanical constraints, there are gaps in the winding arrangement between consecutive segments of the machine, which means that the EMF vectors of two consecutive segments can have an arbitrary phase difference, providing additional challenges, especially for the sensorless control. At the transition between processing stations and transport sections, a synchronisation procedure between the measured position and the estimated one is described and experimentally evaluated.
| Typ des Eintrags: | Dissertation | ||||
|---|---|---|---|---|---|
| Erschienen: | 2011 | ||||
| Autor(en): | Mihalachi, Marius Alexandru | ||||
| Art des Eintrags: | Erstveröffentlichung | ||||
| Titel: | Position Acquisition and Control for Linear Direct Drives with Passive Vehicles | ||||
| Sprache: | Englisch | ||||
| Referenten: | Mutschler, Prof. Dr.- P. | ||||
| Publikationsjahr: | 8 März 2011 | ||||
| Datum der mündlichen Prüfung: | 23 November 2010 | ||||
| URL / URN: | urn:nbn:de:tuda-tuprints-24853 | ||||
| Kurzbeschreibung (Abstract): | For combined processing and transportation of materials in industrial production lines, a long primary, linear synchronous drive with passive, lightweight vehicles, is being designed and experimentally tested. This thesis concentrates on position acquisition and motion control of the proposed system. In order to allow a high degree of independency in the movement of the vehicles,the stator (primary) of the linear machine is divided into many segments. Each segment of the track is fed by a dedicated power stack, and control information is exchanged between all power stacks and all vehicle controllers via an Inverter Bus. A number of processing stations are spread along the track of the linear drive, being connected by transport sections. Inside the processing stations, high quality speed and position control of the vehicles is required. For this, precise and fast position measurement is necessary, so position sensors must be used. The passive vehicles impose additional challenges for the position acquisition system, as neither energy nor information must be transmitted to the moving parts. The evaluation of two position acquisition systems, which comply with this requirement, is presented in this thesis. The first system is based on a high-resolution optical encoder. For this application, the scale of the optical sensor is mounted at the vehicle and several active read-heads are installed along the track, such that at each position the scale covers at least one readhead. When the scale is passing from one read-head to the next one, the position information from both read-heads must be evaluated simultaneously and synchronised, so that a continuous position signal will result for the entire measuring length. The second position acquisition system uses a comparatively lower resolution capacitive sensor, and is intended as a simpler and cost effective alternative to the optical system. The principle of operation of a capacitive sensor is first analysed, and a model is determined. Then, based on this model, two methods of extracting the position information are presented: one uses instantaneous (sampling-based) demodulation, while the other is based on phase measurement. In the transport sections of the linear drive the requirements concerning the accuracy and dynamic of the position measurement are less demanding than in the processing stations. In this sections sensorless control, based on the evaluation of the electromotive force (EMF) is implemented. The distinctive parameters of the different stator segments are taken into consideration. Due to mechanical constraints, there are gaps in the winding arrangement between consecutive segments of the machine, which means that the EMF vectors of two consecutive segments can have an arbitrary phase difference, providing additional challenges, especially for the sensorless control. At the transition between processing stations and transport sections, a synchronisation procedure between the measured position and the estimated one is described and experimentally evaluated. |
||||
| Alternatives oder übersetztes Abstract: |
|
||||
| Sachgruppe der Dewey Dezimalklassifikatin (DDC): | 600 Technik, Medizin, angewandte Wissenschaften > 620 Ingenieurwissenschaften und Maschinenbau | ||||
| Fachbereich(e)/-gebiet(e): | 18 Fachbereich Elektrotechnik und Informationstechnik > Institut für Stromrichtertechnik und Antriebsregelung 18 Fachbereich Elektrotechnik und Informationstechnik |
||||
| Hinterlegungsdatum: | 10 Mär 2011 10:10 | ||||
| Letzte Änderung: | 05 Mär 2013 09:46 | ||||
| PPN: | |||||
| Referenten: | Mutschler, Prof. Dr.- P. | ||||
| Datum der mündlichen Prüfung / Verteidigung / mdl. Prüfung: | 23 November 2010 | ||||
| Export: | |||||
| Suche nach Titel in: | TUfind oder in Google | ||||
 |
Frage zum Eintrag |
Optionen (nur für Redakteure)
 |
Redaktionelle Details anzeigen |
Drucken
Impressum