HEALTH MONITORING FOR RLVS: ARCHITECTURE SELECTION AND DISCUSSION
Creators: name:  A. VENNITTI 
Publisher: name: Proceedings of  the 9th European Conference for Aerospace Sciences. Lille, France, 27 June - 1 July, 2022
Year: 2022
Subjects: SPACE
REUSABILITY
REUSABLE LAUNCH VEHICLE

description: One of the most challenging sectors in the aerospace industry is represented by Reusable Launch Vehicles (RLVs) and the analyses improving their design. In this perspective, the ability to provide an autonomous, time-specific, accurate and reliable assessment of the systems health status is fundamental [1]. A standardized Health Monitoring (HM) architecture is fundamental for both the creation of an effective monitoring system [2] and a common substrate on which to promote the research activities in the field. Unfortunately, there is no concrete structure to be referenced in the literature. So, the goal of this work is to define the basis for the establishment of a common HM architecture as well as to discuss a possible architecture for defining a guideline. HM functionalities face up to several different working conditions and operate according to various configurations. The principal ones focus on single units (i.e. engines or structural elements) or the entire system (the whole vehicle) [3]. In this framework, a flexible and adaptable architecture should be developed. Thus, the proposed solution is hierarchical, distributed and hybrid. A hierarchical approach [4] is selected for covering both the case of unit and system HM, as well as for simplifying the overall system management. Having a standardized interfacing among the HM layers can be crucial for achieving high design modularity. The term \"distributed\" [5] identifies a system in which the processing and sensing capabilities are distributed over the entire system. This approach favors the local HM implementation as well as the reduction of workload with respect to a single unit. Concluding, a hybrid methodology [3] is proposed for observing the HM requirements concerning the different hierarchical levels of the system and the constraints imposed by the launchers design. In this sense, the number of sensing units is continually growing in space vehicles and relying just on a wired solution can lead to unsustainable conditions in terms of weight and the effectively applicable sensors number. An important aspect of the architecture is that it should be as platform independent as possible, for fitting different launchers with the minimal possible variation and allowing international researchers to cooperate w.r.t. the common HM goal. The publication is structured according to the following points. First, the goals of the HM implementation are presented for providing a logical basis on which to structure the work. In addition, the main possible configurations of the HM system are defined. The aspects defined in this part are used for motivating the architecture selections. Secondly, the architectural design alternatives are discussed, highlighting the benefits and drawbacks of each option. Consequently, the most promising architecture is defined and the motivations supporting the choices are discussed considering the advantages for the overall launcher. The architecture is also described with respect to its conceptual implementation, defining how the vehicle subsystems can be addressed. In this part, the analysis is approached from a sensing, processing, communication point of view. The outcome of this research activity will be also used for further investigations, leading to the development of a Health Monitoring system that supports the RLV operator to decide about the reuse of the vehicle. Furthermore, the intention of this publication is to promote a constructive discussion with other researchers for defining and deciding a common architecture to be used as the basis for the HM implementation. This study lies within the ASCenSIon (Advancing Space Access Capabilities-Reusability and Multiple Satellite Injection) project, an Innovative Training Network (ITN) funded by the EU Framework Programme for Research and Innovation (Horizon 2020).