Hybrid indoor/outdoor localization system to improve aeronautical maintenance works

This research work is carried out in the framework of a project focusing on the future of aeronautical maintenance. One of our main objectives is to localize continuously technicians in relation to the aircraft on which they intervene during maintenance session. This module will be part of a context-aware application that will deliver several services to maintainers. The challenge is hard, the expected precision is around a centimeter and constraints are numerous. As for examples, the system must work inside and outside a hangar, inside and outside the aircraft, whatever the hangar configuration, the weather, the luminosity are. This paper presents the early stages of our research methodology. It first provides initial steps that were dedicated to a study of the operational context and a discussion of the results of a state of art of available technologies for localization. They allowed us to concentrate our choices on a Hybrid Localization System (HLS) combining an Inertial Measurement Unit (IMU), a 3D model of the aircraft and a third technology that will be integrated later (optical or radio wave). Next, this document depicts methods that have been implemented and tested. Depending on the way covered by the technician during the maintenance session, the obtained error rate is around 5-10%. The 3D registration offers an interesting gain inside the aircraft or in the vicinity of binding elements. In this difficult context, the research path taken to design the HLS looks already promising. Localization will be improved when the vision module, on which we are still working, will be integrated.