Publication
DFKI-X2D: Design and Testing of a Quasi-Direct Drive Motor for Space Applications
Jonas Eisenmenger; Zhongqian Zhao; Pierre Willenbrock; Wiebke Brinkmann
In: 15th EASN International Conference on Innovation in Aviation & Space Towards Sustainability Today & Tomorrow. EASN International Conference on Innovation in Aviation & Space towards Sustainability Today & Tomorrow (EASN-2025), October 14-17, Madrid, Spain, MDPI, Engineering Proceedings, volume 133, 4/2026.
Abstract
Due to the high level of innovation involved, and the requirements arising from a new environment, the use of a quasi-direct drive motor for space applications presents not only several challenges, but also great opportunities. Such a motor is particularly well-suited to dynamic applications like walking robots or robotic arms. To ensure that it can withstand the environmental challenges, the motor must undergo extensive testing. This paper briefly outlines the development of such a motor based on prior prototypes with different design concepts. It addresses the specific requirements of a space variant and describes the selected final design. Additionally, the development of corresponding motor electronics is described. Finally, the results of a test campaign are presented. The campaign included internal functional tests to characterize the motor and external environmental tests necessary for space qualification. These tests included vibration, thermal vacuum chamber (TVAC) and electromagnetic compatibility (EMC) tests. Together, they showcased a highly dynamic motor with an efficiency of up to 90% and moved it towards a technology readiness level (TRL) of 5.