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Internal Research Fellow PostDoc in AOCS and Pointing Systems
2017-09-20 17:12:14| Space-careers.com Jobs RSS
Research Fellow opportunity in the Directorate of Technology, Engineering and Quality. ESA is an equal opportunity employer, committed to achieving diversity within the workforce and creating an inclusive working environment. Applications from women are encouraged. Post Internal Research Fellow PostDoc in AOCS and Pointing Systems This post is classified F2 on the Coordinated Organisations salary scale. Location ESTEC, Noordwijk, The Netherlands Description Within the Systems Department, the GNC, AOCS and Pointing Division is responsible for Engineering and research and development of Attitude and Orbit Control Systems AOCS for satellites including Failure Detection Isolation Recovery FDIR Engineering and research and development of Guidance, Navigation and Control GNC systems for space vehicles including interplanetary cruise, aero assistance, precision landing, ascent, rendezvous and docking, reentry, formation flying and dragfree systems Technology development for AOCS and GNC sensors Endtoend engineering and research and development on high pointing accuracy systems Research and development of advanced control, estimation optimisation techniques and tools Development of control engineering standards in the frame of ECSS and ESA Standardisation Boards. Within the Division, the AOCS and Pointing Systems Section is specifically in charge of Designing and implementing Attitude and Orbit Control Systems AOCS for satellites and highaccuracy Pointing Systems Proposing and managing Mission Enabling Technology RD activities in the following areas Generic AOCS architecture Building Blocks Competitive Earth Observation, Telecom, Science AOCS associated FDIR High accuracy pointing Systems Technology development for AOCS sensors and electromagnetic actuators Research and development of advanced control techniques and tools Defining, maintaining and operating the necessary computing and laboratory facilities in support of the above activities. The section objectives more particularly related to the proposed Research Fellowship activities are highlighted in bold in the above list. Interested candidates are highly encouraged to visit the ESA website www.esa.int Fields of activitiesresearch Experimental validation of advanced active microvibration mitigation strategies. Attaining high pointing stability performance is a critical objective for many current and future space missions. As lineofsight stability requirements get tighter, mechanical vibrations become one of the key performance limiting factors. Commonly termed microvibrations, these lowamplitude disturbances span a wide frequency range from few Hz up to 1 kHz and are produced by a variety of mechanical and electrical spacecraft systems. Microvibrations can propagate, through the structure of the spacecraft, towards the various optical or communication systems severely degrading their performance. It is critical for mission success to design adequate vibration isolation systems that can minimize their impact. Pure passive isolators, such as the ones based on elastomeric materials, are the current baseline for microvibration mitigation to dampen highfrequency perturbations. Yet, passive isolation methods are limited in the lower part of the microvibration range and can be insufficient in terms of isolation performance. In order to overcome the frequency limitations of a purely passive approach and achieve broadband vibration isolation, the proposed research will focus on the design of a complementary active control strategy that primarly targets the lower range of the frequency perturbations such as the ones introduced by reaction wheels. In order to precisely tune these control strategies and guarantee both compliance with the mission pointing stability requirements and also safeguard against potential uncertainties or faults, accurate dynamic models of the endtoend system must be obtained. Mathematical models that reflect both the driving physical phenomena as well as uncertainties present in the system will be established and validated along the project. These models will supplement nonlinear simulations and capture the complex dynamic interactions between the microvibration sources, the isolation system, the spacecraft structural dynamics and the optical payload system. With this knowledge, a second objective of the study is to demonstrate the capabilities of a common unified framework in which system design, robust controller synthesis, parametric sensitivity and worstcase analysis can be rigorously performed using a common set of wellestablished mathematical tools. These analytical tools provide strong stability and endtoend performance guarantees in the face of uncertainty without relying on timeconsuming Monte Carlo simulations. In a natural way, adaptive control solutions with guaranteed stability and performance margins will be obtained by design. Finally, the project will lead to the development of an advanced experimental testbed that will serve as a validation platform for future microvibration control and high pointing stability research activities. Research Programme Specifics The Research Fellowship programme of work would be the following YEAR 1. Detailed problem Formulation, Requirements Capture, Model Identification and Setup of the Simulation and Experimental Platforms, Preliminary Controller Synthesis a Development of the simulation environment SimMechanics capturing the relevant dynamics of the experimental platform b From the physical high fidelity E2E model perform the derivation of adequate analysis and synthesis models that capture model uncertainties using a linear fractional representation c Model identification, validation and uncertainty quantification based on experimental results shall be performed via an experimental system identification campaign d Definition of performance and robustness objectives based on the physical limitations of the system. e Setup of the IQC robust analysis framework to validate and verify a given control law. f Baseline controller synthesis, experimental validation and comparative analysis of a series of classical vibration control algorithms. YEAR 2. Advanced Controller Synthesis and Fault Tolerant Design a development of modern robust control design methodology in order to synthesize a family of adaptive highperformance controllers for different levels of uncertainty b experimental demonstration and validation of the robust control laws for the plant subjected to different parametric variations. c Addition of Fault tolerant capabilities to the system. Implementation of FDI and reconfiguration mechanisms. Technical competencies Ability to conduct research autonomously Breadth of exposure coming from past andor current researchactivities Researchpublication record Knowledge relevant to the field of research Interest in space and space research Ability to gather and share relevant information Behavioural competencies Innovation Creativity Continuous Learning Self Motivation Communication Problem Solving Relationship Management CrossCultural Sensitivity Education Applicants must have recently completed, or be close to completion of a PhD in a related technical or scientific discipline, preferably Control Engineering. Preference will be given to applications submitted by candidates within five years of receiving their PhD. Additional requirements Applicants should have good analytical skills and be able to work in a multicultural environment in an autonomous manner. Applicants should have a methodical approach to their work and the ability to clearly document their work and results. The working languages of the Agency are English and French. A good knowledge of one of these is required. Knowledge of another Member State language would be an asset. Other information For behavioural competencies expected from ESA staff in general, please refer to the ESA Competency Framework. The Agency may require applicants to undergo selection tests. The closing date for applications is 18 October 2017. In addition to your CV and your motivation letter, please add your proposal of no more than 5 pages outlining your proposed research. Candidates must also arrange for three letters of reference to be sent by email, before the deadline, to temp.htresa.int. The letters must be sent by the referees themselves. The candidates name must be mentioned in the subject of the email. If you require support with your application due to a disability, please email contact.human.resourcesesa.int. Please note that applications are only considered from nationals of one of the following States Austria, Belgium, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Luxembourg, the Netherlands, Norway, Poland, Portugal, Romania, Spain, Sweden, Switzerland, the United Kingdom and Canada and Slovenia as well as Bulgaria, Cyprus, Latvia, Lithuania, Slovakia as European Cooperating States ECS. Priority will first be given to candidates from underrepresented Member States. In accordance with the European Space Agencys security procedures and as part of the selection process, successful candidates will be required to undergo basic screening before appointment Apply HERE
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