Adaptative high-gain extended Kalman filter and applications

tel-00559107, version 1 - 24 Jan 2011
4.2 Simulation
In the second scenario, we notice that at some unexpected moments the adaptive highgain
observer has the same behavior as that of the non high-gain observer (e.g. Figure 4.15).
When we take a look at Figure 4.18, we see that θ didn’t actually increase for t ∈ [40; 80] and
t ∈ [100; 160]. The explanation lies in Figure 4.12. The sudden change in the torque load
wasn’t sufficient enough to have a significant effect on the output signal.
As in the previous scenario, the adaptive observer presents two advantages with respect
to the two other filters, namely that of improved noise rejection and that of increased speed
of convergence in the event of perturbations.
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Figure 4.15: Scenario 3: Estimation of the rotation speed.
We conclude this section with Figure 4.19, which shows the estimation obtained from a
adaptive high-gain observer with a poorly chosen value for m2. Since it is too small, θ is
increasing when it is not needed. The corresponding innovation plot is provided in Figure
4.20.
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