Flexible Modes Control Using Sliding Mode Observers: Application to Ares I

Sensor fault tolerant control using a robust LPV based sliding mode observer

“…where P o ∈ IR nn×nn is a Lyapunov Matrix for the stable matrixà s 22 , and the scalar K(·) is any function satisfying K(·) ≥ a 21 z(t) + ∥CM ∥ √ r(·) 2 + b 2 ϕ + ∥A f ∥α(·) + η 0 (24) where a 21 is a scalar (which will be defined in the appendix), α(·) is the bound on the fault from (11), r(·) is a bound on the uncertainty from (7), b ϕ is a bound on the disturbance ϕ(t) from (12) and η 0 is a positive design scalar. Note that the modulation function in (24) is different from the one in [1] because of the difference in the uncertainty structure considered in this paper compared to [1].…”

“…There is significant literature which describes schemes (using sliding mode observers) to reconstruct unknown disturbance signals in the system and then uses this information as part of a dedicated controller to compensate the unwanted effect of the disturbance (see for example [4], [17]). In terms of aerospace applications, the work of [12], [11] estimates spacecraft flexible modes to compensate for low frequency oscillations with a dedicated control scheme. However, most of these applications require dedicated controller designs and use the unknown signal reconstruction to deal with input disturbances.…”

Sensor Fault Tolerant Control Using Sliding Mode Fault Reconstruction on an Aircraft Benchmark

“…The use of sliding mode observers to estimate unmeasurable quantities in a closed-loop system, and compensate for them, has also been considered in a different context in. 9,10 The work in 9, 10 uses a sliding mode observer to estimate the sloshing effect and exploits this estimate as part of the control feedback loop to mitigate the effects on the structure.…”

An adaptive sliding mode differentiator for actuator oscillatory failure case reconstruction

“…In this paper, the rod speed will be created using the adaptive sliding mode differentiator proposed in this paper. Sliding mode observers have previously been used to estimate the presence of oscillations in aerospace structures in [20]. The work in [20] uses a sliding mode observer to estimate the sloshing effect and exploits this estimate as part of the control feedback loop to mitigate the effects on the structure.…”

“…Sliding mode observers have previously been used to estimate the presence of oscillations in aerospace structures in [20]. The work in [20] uses a sliding mode observer to estimate the sloshing effect and exploits this estimate as part of the control feedback loop to mitigate the effects on the structure. The adaptive differentiator proposed in this paper is also different to the ones in [9,21,22], since the latter papers consider a control design problem and seek to ensure the gains are as small as possible to avoid chattering.…”