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ADAPTIVE CONTROL FOR FAST ACQUISITION AND RE-ACQUISITION OF PRECISE SCIENTIFIC CONSTELLATIONS - EXPRO+

on 12 August 2019

ESA Open Invitation to Tender AO9983
Open Date: 06/08/2019
Closing Date: 01/10/2019 13:00:00

Status: ISSUED
Reference Nr.: 19.1EC.04
Prog. Ref.: Technology Developme
Budget Ref.: E/0901-01 - Technology Developme
Special Prov.: BE+DK+FR+DE+IT+NL+ES+SE+CH+GB+IE+AT+NO+FI+PT+GR+LU+CZ+RO+PL+EE+HU
Tender Type: C
Price Range: 200-500 KEURO
Products: Satellites & Probes / AOCS & GNC / AOCS & GNC Eng. SW / SW for AOCS&GNC design, analysis, simulation, etc.
Technology Domains: Space System Control / Control Techniques and Tools / Advanced Control, Estimation & Optimisation
Establishment: ESTEC
Directorate: Directorate of Tech, Eng. & Quality
Department: Systems Department
Contract Officer: Hertzog, Hendriline
Industrial Policy Measure: C3 - Activities restricted to SMEs & R&D organisations, prefe...
Last Update Date: 06/08/2019
Update Reason: Tender issue

Objectives: To develop a unified estimation and control system for precise scientific constellations that can dynamically adapt to cope with the range of disturbance rejection levels required from constellation acquisition/re-acquisition up to science, including the rejection of dynamic events such as micro-meteorite impacts. Scientific availability of science constellations (such as for the LISA mission) is highly dependent on the recovery time from high dynamic events such as micro-meteorite impacts or failures, which could cause laser link loss. Recovery from such events is traditionally a lengthy process involving numerous operational modes required to use different sensor inputs to acquire the links and gradually reduce the dynamics using progressively lower bandwidth controllers, each of which impose minimum convergence times.This activity would investigate cutting edge advanced control techniques for the development of a unified estimation and control system that can seamlessly utilize all available sensor information and dynamically adapt to cope with the range of disturbance rejection levels required from constellation acquisition/re-acquisition up to science,including the rejection of dynamic events such as micro-meteorite impacts. Such a seamless control system would reduce the requirednumber of mode transitions and thus the time to achieve science, significantly increasing science availability time and thus science yield. Note that the intention of this activity is not necessarily to employ adaptive control techniques to solve this problem. Instead, the goal is to research cutting edge control techniques that can be used to design a control system that can adapt dynamically to cover the entire range of disturbances while avoiding discrete operational stages and complex switching behavior with their associated large transients.Description: Current control designs for acquisition of precision science modes and constellations requireseveral operational modes that are stepped through in order to deal with the different sensor inputs, scan the instruments, acquirethe constellation links, and progressively reduce the residual motion in order to achieve the required performance levels for science. Even if such controllers might typically be designed using robust control methods, such as H-infinity, a cascade of control modes cannot be avoided in order to cover the range of bandwidths required from instrument scanning and constellation link acquisitionuptothe high fidelity science modes. This implies that several mode transitions are required, including minimum wait times for controller convergence. Therefore, the time required for entering and subsequently re-acquiring science mode is generally significant,reducing the overall science availability and scientific yield. For this reason, a novel estimation and control system that could adaptto control the different levels of disturbances using different sensors, without requiring mode transitions between different operational modes, would significantly reduce the recovery time and increase science availability. Such a system would also be inherentlyrobust to dynamic events such as micro-meteorite impacts or some failures, avoiding the need for triggering a safe mode in the first place. This activity would tackle the use of highly advanced control techniques for the development of an estimation and control systemfor science constellation missions that can dynamically adapt to cope with the range of disturbance rejection levels required from constellation acquisition/re-acquisition up to science, including the rejection of dynamic events such as micro-meteorite impacts. This would also include the development of any required estimation techniques to deal with the different sensors and/or sensor modes to implement such an adaptive system and allow recovery of science even after loss of the constellation links. The activityis applicable to any mission requiring a high degree off precision stabilization of the scientific platform. However, it is especially appealing for science constellations where all spacecraft are required to yield the scientific output, and the total science outage time isproportional to the number of spacecraft. For this reason, the LISA mission would serve as a benchmark application example forthe techniques developed during this project. Tasks: 1) Explore cutting edge control and estimation techniques currently not used for space systems focused on non-linear, adaptive, gain scheduled, and failure tolerant control. 2) Trade-off and select the most promisingand feasible technique to design a unified estimation and control system that cope with a wide range of disturbance rejectionlevelsrequired from constellation acquisition/re-acquisition up to science. 3) Design and implementation of the estimation and control system. 4) Implementation of a simplified LISA simulation environment for preliminary testing of the algorithms. 5) Characterization and testing of the proposed algorithms in the simplified LISA simulation environment. 6) Model-in-the-loop testing of thenew algorithms in the LISA DFACS simulator developed under a previous contract at ESA.Procurement Policy: C(3) = Activity restricted to SMEs RD Entities. For additional information please go to EMITS news "Industrial Policy measures for non-primes, SMEs and RD entities in ESA programmes".

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