Computer Aided Design of a Linear Positioning System

Computer Aided Design of a Linear Positioning System Loránd SZABÓ – Ioan-Adrian VIOREL – Zoltán KOVÁCS Technical University of Cluj-Napoca, Romania

Abstract: Countless precise linear positioning systems used in industrial and laboratory processes are driven by permanent magnet excited variable reluctance linear motors. Thus rotary to linear gear-boxes or belt and pulleys, needed with rotary motors for linear drives are avoided. The greatest difficulty in the design of these frequently utilized motors consists of the necessity to consider the complex toothed configuration, the iron core saturation and the permanent magnet operating point change due to air-gap reluctance modifications and to control m.m.f. The dynamic performances and the positioning capabilities of the motor can be improved by operating it under a closed-loop control. An e.m.f. sensing based control strategy was developed in order to obtain optimum behavior for the motor. Results obtained by dynamic simulation of the linear positioning system confirm the advantages of the selected motor type and of the proposed optimal control strategy. Cite as: Szabó, L. – Viorel, I.A. – Kovács, Z.: Computer Aided Design of a Linear Positioning System, Proceedings of the Power Electronics, Motion Control Conference (PEMC '96), Budapest (Hungary), vol. II., pp. 263-267, 1996.

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VIOREL, I.A. – KOVACS, Z. – SZABO, L.: Sawyer Type Linear Motor Modelling, Proceedings of the International Conference on Electrical Machines (ICEM '92), Manchester (UK), pp. 697-701, 1992. EBIHARA, D.: Design of a PM Type Linear Stepping Motor for Automatic Conveyer System, Proceedings of the International Conference on Electrical Machines Design and Applications, London (UK), pp. 265-269, 1985. VIOREL, I.A. – BIRÓ, K. – SZABÓ L.: Transformer Transient Behavior Simulation by a Coupled Circuit-Field Model, Proceedings of the International Conference on Electrical Machines (ICEM '94), Paris (France), pp. 654659, 1994. SZABO, L. – VIOREL, I.A. – KOVACS, Z.: Computer Simulation of a Closed-Loop Linear Positioning System, Proceedings of the Power Conversion & Intelligent Motion Conference (PCIM '93), Nürnberg (Germany), vol. Intelligent Motion, pp. 142-151, 1993. VEIGNAT, N. – SIMON-VERMOT, M. – KARMOUS, M.: Stepper Motors Optimization Use, Proceedings of the International Conference on Electrical Machines (ICEM '94), Paris (France), pp. 13-16, 1994. JENKINS, M.K. – HOWE, D. – BIRCH, T.S.: An Improved Design Procedure for Hybrid Stepper Motors, IEEE Transactions on Magnetics, vol. 26., no. 5. (Sept. 1990), pp. 2535-2538. SZABÓ, L. – VIOREL, I.A.: Variable Reluctance Permanent Magnet Linear Motor Computer Aided Design, Proceedings of the International Conference on Optimization of Electric and Electronic Equipments (OPTIM '98), Braşov (Roamnia), pp. 305-310, 1998. VIOREL, I.A. – SZABÓ, L.: Permanent magnet variable reluctance linear motor control, Electromotion, vol. 1, no. 1, pp. 31-38, 1994.

worthwbile to identify this ilem again, since this may deteriorate the estimation of other parameters. A

Therefore, precise and direct identification parameter is very important and this is the

promising solution for the stator resistance effect could be setting this parameter as a constant value in the

of the proposed tecbnique. The use of power

motor transfer function (equations 4 and equation 1). Then it is necessary to perform the broadband excitation test at the same temperature in wbich the stalor resistance is defined or measured otherwise errors will result in estimated rOtor inductance. Figure 6 illustrates the results of the another test while the stator resistance fixed to the 150 mO (according to the motor data sbeet).

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REFERENCES

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295. {4] G.bii A ...o t.alaire P.: Ro,,,, time commnt induction JlX'I{or in iodUecf vectoc cont.roUed drives. EPE9S Spain, Vol. I. pp. 1.431-1.436. 15J lEEE Standard !l5·A 1987. -SlaOdard proce
syndlrOllani A. : Syncluoo_ �.. I"'a Electrical macrunes and Power Systems. 1992, No. m Kelemen A. and ...... M., 1992. "Vecta cooLroi I". Omikk Publisher, Budapes� Hungary. (S) !(hal'" F. H.• Lorenz R. D., Novotny D. W. and Tang cl n� level in fieJd oriented induction m.ad'tiue C(l OObSiderntioll dmagnetic saturalion dl'tcts. IEEE Trans. 1A.23.-No. 2. 1987.pp. 276-281. 191 KI"", N.R: Parameter identification d.

tesL The effect of the low level iron nonlinearity can be seen from the reSUlts. TIle identified lowest current !be unsaturated inductllnce. This proves that the

E.: Method for magnetizing curve identification controlled induct"'" madlines, ElE'. Vol. 2, No. S. SepJOc 309·314. {l2} Rull. M.. and Grotstollen H. : Identification of the _iii induc\tluO!: dan asyndu"ooous mol« at �dstiU by sq=es algootbm. Proceeding. d. EPE93 England. PI'­ Ill} ScIJouk... I. and Pin!gnmjs d. .1e