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Flight Management System for Unmanned Reusable Space Vehicle Atmospheric and Re-entry Trajectory Optimisation
| Content Provider | Semantic Scholar |
|---|---|
| Author | Ramasamy, Subramanian Sangam, Manoj Sabatini, Roberto Gardi, Alessandro |
| Copyright Year | 2016 |
| Abstract | The design and trajectory computation algorithms of an innovative Flight Management System (FMS) for Unmanned Reusable Space Vehicle (URSV) are presented. The proposed FMS features a number of functionalities in common with modern aircraft FMS that enable flight planning in non-segregated airspace, as well as specific features for optimal trajectory generation and space segment monitoring of the flight mission. The general avionics architecture of the URSV is presented and the specific FMS algorithms are developed to cope with the flight vehicle optimal trajectory planning and monitoring. Simulation case studies are performed in a realistic operational scenario resulting in the rapid generation of feasible trajectories, ensuring no violation of the defined mission and vehicle dynamics constraints. Additionally, an error budget analysis is performed on the longitudinal profile trajectories to evaluate the performance of the URSV. Introduction Unmanned platforms are being increasingly adopted for both atmospheric and space applications, despite the access to the civil airspace remains currently restricted to segregated areas. Similar to the manned aircraft versions, Flight Management System (FMS) for unmanned platforms is the core avionics component to introduce extensive automation algorithms for a number of Navigation, Guidance and Control (NGC) tasks. In this paper we propose an innovative FMS design, which incorporates both conventional aircraft FMS capabilities [1 – 3] and spacecraft reentry trajectory generation algorithms, enabling non-segregated operations of an Unmanned Reusable Space Vehicles (URSV) in the civilian airspace. The Space Shuttle’s entry guidance system [4] is used as a reference for re-entry trajectory planning. Guidance systems based on angle of attack (α) and bank angle (μ) modulations [5], on the quasi-equilibrium glide condition [6] and on the tracking of aerodynamic acceleration [7] have been developed. An improved methodology for re-entry trajectory planning based on creation of a drag acceleration profile as a function of energy has been developed [8] and is used as a baseline. Avionic Systems Architecture The avionic systems conceived for the URSV include an FMS, a Communications System (CS), a Flight Control System (FCS), a Mission Management System (MMS) for strategic/space orbital management, a Remote Piloting Management System (RPMS), which manages data exchanged via the CS to the remote Human Machine Interface and Interaction (HMI 2 ) station, an Obstacle Avoidance System (OAS) and a Rendezvous and Docking System (RVDS). The FCS translates the FMS/RPMS/OAS guidance or manual steering command inputs to actuators commands. Fig. 1 illustrates the functional architecture of the spacecraft avionic systems including the FMS subsystems listed in Table 1. This is the author pre-publication version. This paper does not include the changes arising from the revision, formatting and publishing process. The final paper that should be used for referencing is: S. Ramasamy, M. Sangam, R. Sabatini, A. Gardi, “Flight Management System for Unmanned Reusable Space Vehicle Atmospheric and Re-entry Trajectory Optimisation”, Applied Mechanics and Materials, vol. 629, pp. 304-309, Trans Tech Publications, 2014. DOI: 10.4028/www.scientific.net/AMM.629.304 Table 1. FMS subsystems and associated functions. FMS Subsystem Function Navigation Subsystem (NS) Determines the state vector (position, attitude, linear and angular velocities) of the spacecraft incorporating a sensor suite, data fusion algorithms and processing logics. Guidance Subsystem (GS) Tracks the space vehicle’s relative position from the validated trajectory and calculates vertical, turn and reinsertion manoeuvres wherever necessary. Trajectory Planning and Optimisation Subsystem (TPOS) Generates optimised atmospheric and re-entry trajectories based on the updated state (NS), dynamics (VDPS), ATM constraints (CS) and vehicle health (VHMS). A set of optimal trajectories is then dispatched to the RPMS and the TNVS for pilot and ATM evaluation and validation respectively. Vehicle Dynamics and Performance Subsystem (VDPS) Performs dynamics and performance calculations based on a multimodel architecture, which are primarily used by the trajectory planning/optimisation loop and for vehicle health assessment tasks. Trajectory Negotiation and Validation Subsystem (TNVS) Manages the negotiation and validation loops of 4-Dimensional Trajectories (4DT) through the CS with the ground-based ATM systems for safe operations in non-segregated airspace. Surveillance Subsystem (SS) Includes Automated Dependent Surveillance Broadcast (ADS-B) receiver and transmitter (In and Out) as well as legacy aeronautical surveillance devices. Vehicle Data Management Subsystem (VDMS) Manages data storage of all the spacecraft parameters and interacts with other subsystems for data retrieval and analysis. Vehicle Health Management Subsystem (VHMS) Manages the health conditions of the spacecraft by monitoring the data obtained from other components and dispatches reports to the RPMS for downlinking via the CS. Vehicle Integrity Management System (VIMS) Assesses and manages the integrity levels of Communication, Navigation and Surveillance (CNS) systems and generates caution and warning flags when the set threshold limits are exceeded. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://researchbank.rmit.edu.au/view/rmit:32018/n2006048926.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
