Robust Attitude Control Design for the BIOMASS Satellite (Earth Explorer Core Mission Candidate)

Abstract

The purpose of this paper is to describe the current activities, results to date, and future activities of the European Space Agency (ESA) Robust AOCS technology program in support to the Phase A of BIOMASS, candidate as Earth Explorer Core Mission 7. Due to the specificity of the chosen BIOMASS configuration this activity is driven by the expected interaction between the large flexible reflector antenna structure and its attitude control system. Currently ESA has developed a technology program to enable the capabilities of integrating the structural sizing and control system design in order to avoid interactions problems. The objective is the development of an Integrated Modeling, Control and Analysis framework IMCA: it incorporates uncertainty modeling via LFT's, robustness analysis via the Structured Singular Value µ and various robust control synthesis techniques such as H ∞ and µ methods. This framework results as natural multivariable extensions of the classical Bode frequency domain techniques. It shall be integrated with a structural design loop into an unified computational framework to exploit control structures interactions in order to increase the spacecraft capabilities, such as better pointing stability, and to improve the overall design when compared to the traditional approach. In the execution of this program two parallel activities will be presented, respectively one by Astrium Limited, UK, and the other by ThalesAlenia Space (TAS), Italy.

Uncertainty impact on micro-vibration control of an orbiting large adaptive space structure

“…The number of ON-mode devices and the required total average power are listed in Table 8. If the gains of the six actuators are increased by a factor 3 10 , no significant improvement in damping the vibration amplitude is noticed as depicted in Figure 21, even if the total power consumption reaches 72 Watts. We can deduce that by using all the optimized gains the system is able to cope with elastic vibrations better than by having some of them switched off, allowing a lower power consumption in addition.…”

“…The most widely used techniques are single loop frequency design methods, in particular a PID control for the rigid platform coupled with filters to eliminate resonant peaks of predominant elastic modes. 3 The shortage of available techniques stems mainly from scarcity of comprehensive understanding and implementation in the design phase of the aforementioned interaction problem. It is therefore fundamental the design process is considered at an integrated system level.…”

A Study on Structural Health Monitoring of a Large Space Antenna via Distributed Sensors and Deep Learning

“…In particular, accelerometers are selected as the sensing technology to acquire structural nodal acceleration time histories, as they are space qualified, easily installable, and have a low cost/mass impact, as demonstrated by the Honeywell, InnaLabs, and PCB catalogues [ 19 ]. Additionally, the presence of a distributed set of sensors, e.g., accelerometers and piezoelectrics, is of particular interest as being crucial to pave the road to another key technology, such as active structural control for spacecraft [ 20 , 21 , 22 ], especially in terms of failure-tolerant strategies.…”

End-to-end design of a robust attitude control and vibration suppression system for large space smart structures

“…However, currently, most of the wide space structures are sustained by passive materials, without putting into effect intelligent systems able to counteract external disturbances generated by the motion of the rigid base of the spacecraft and by environmental disturbances, as solar radiation pressure, gravity gradient torques and thermal gradients. In this context, research has been carried out to validate such an approach, by recurring to three distinct methods: independent attitude controllers, minimizing disturbance originated by the flexible parts (such as classical PID feedback with filters [4], Robust controllers [5]), vibration controllers, working in parallel to platform actuators (Direct Velocity Feedback methods [7], Positive Position Feedback [8], Pole/Zero Assignment [9], Machine Learning-based [10] among others) and combined controllers (as Synergetic methods [11] and wave-based controllers [6]), less often seen in literature.…”