Insulation Thickness Measurement in Hairpin Stator Production Using a Confocal Chromatic Line Sensor

Preitschaft A, Baader M, Wagner G, Franke J, Kühl A (2025)

Publication Language: English

Publication Type: Conference contribution

Publication year: 2025

Original Authors: (:Unkn) Unknown

Publisher: Offenburg

Series: Proceedings CPSL 2025

Pages Range: 310-319

Conference Proceedings Title: Proceedings of the Conference on Production Systems and Logistics: CPSL 2025

Event location: Lima PE

DOI: 10.15488/18876

Abstract

The insulation thickness of enameled flat wire is a critical parameter in electric motor production based on hairpin technology, directly affecting key manufacturing processes such as straightening, bending, stripping and welding. Adapting these processes based on accurate insulation measurements can significantly improve production efficiency and reduce scrap. This paper presents an inline confocal chromatic line sensor designed to measure the insulation thickness of polyamide-imide (PAI) coated flat wires. Unlike conventional point-based sensors, this advanced system measures a 1.8 mm line, capturing insulation thickness data over a wider range and providing comprehensive insight into wire properties. To investigate the applicability of this line sensor for the use case at hand, the measurement system is integrated into a hairpin production line before the straightening process, providing real-time measurements of the insulation thickness of the raw material prior to further processing. The sensor is first calibrated to determine its optimum operating range. A series of inline measurements are then taken and microsections of the measured wire samples are analyzed using a laser microscope to obtain ground truth values. The comparison between the inline and the offline measurements shows high accuracy, confirming the feasibility and reliability of the sensor for the application at hand. This study highlights the potential of confocal chromatic line sensors as a powerful tool for inline insulation thickness measurement, offering opportunities to optimize electric motor production processes such as straightening, bending, stripping and welding. The integration of such sensors into hairpin stator production lines represents a significant step towards data-driven process optimization, improving process quality, sustainability and efficiency.

Authors with CRIS profile

Anja Preitschaft Lehrstuhl für Fertigungsautomatisierung und Produktionssystematik (FAPS) Marcel Baader Lehrstuhl für Fertigungsautomatisierung und Produktionssystematik (FAPS) Jörg Franke Lehrstuhl für Fertigungsautomatisierung und Produktionssystematik (FAPS) Alexander Kühl Lehrstuhl für Fertigungsautomatisierung und Produktionssystematik (FAPS)

Involved external institutions

MARPOSS GmbH DE Germany (DE)

How to cite

APA:

Preitschaft, A., Baader, M., Wagner, G., Franke, J., & Kühl, A. (2025). Insulation Thickness Measurement in Hairpin Stator Production Using a Confocal Chromatic Line Sensor. In Proceedings of the Conference on Production Systems and Logistics: CPSL 2025 (pp. 310-319). Lima, PE: Offenburg.

MLA:

Preitschaft, Anja, et al. "Insulation Thickness Measurement in Hairpin Stator Production Using a Confocal Chromatic Line Sensor." Proceedings of the 7th Conference on Production Systems and Logistics, Lima Offenburg, 2025. 310-319.

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