Underwater Robots - Gianluca Antonelli.pdf
Underwater Robots - Gianluca Antonelli.pdf
Underwater Robots - Gianluca Antonelli.pdf
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7.5 Non-regressor-Based Adaptive Control 149<br />
the manipulator’s motion. For this reason the additional control action ∆ τ � v<br />
is required. In[67], arobust control isdeveloped for the vehicle in order to<br />
counteract the coupling effects.<br />
Simulations are carried out considering a dry weight of 150 kg and a<br />
length of 1m for the vehicle and adry weight of40kgand alength of 1m<br />
for the manipulator. Moreover, the natural frequencies have been chosen as<br />
ω 0 v = 1. 5rad/s and ω 0 q = 15rad/s leading toavalue of ε = 0. 1.<br />
7.5 Non-regressor-Based Adaptive Control<br />
In 1999 reference [185, 252] extend to UVMSs the non-regressor-based<br />
adaptive control developed by J. Yuh [316] and experimentally validated<br />
in [83, 216, 320, 323] with respect to AUVs. In [322], this controller is integrated<br />
with adisturbance observer to improve its tracking performance<br />
and simulated on a1-DOF vehicle carrying a2-DOF manipulator.<br />
The main idea is to consider the vehicle subsystem separate from the manipulator<br />
subsystem and to develop two controllers with different bandwidth,<br />
independent one from the other. Itisworth noticing that the controller has<br />
been developed together with akinematic control approach (see Chapter 6).<br />
The vehicle generalized force τ � v ,thus, can be computed by considering<br />
the controller<br />
τ � v = K 1 ,v ¨η d + K 2 ,v ˙η + K 3 ,v + K 4 ,v ˙˜η + K 5 ,v ˜η =<br />
already defined and discussed in Section 3.3.<br />
The manipulator iscontrolled with the following<br />
τ q = K 1 ,q¨q d + K 2 ,q ˙q + K 3 ,q + K 4 ,q ˙˜q + K 5 ,q˜q =<br />
5�<br />
K i,vφ i,v ,<br />
i =1<br />
5�<br />
K i,qφ i,q ,<br />
i =1<br />
where ˜q = q d − q ,the gains K i,q ∈ IR n × n are computed as<br />
where<br />
� s q � � �<br />
� φ �<br />
i,q<br />
K i,q = ˆγ i,qs q φ T i,q<br />
s q = ˙˜q + σ ˜q with σ>0 ,<br />
i =1,...,5 ,<br />
and the factors ˆγ i,q’s are updated by<br />
˙ˆγ i,q = f i,q � s q � � �<br />
� φ �<br />
i,q with f i,q > 0 i =1,...,5 .