Soft Computing Based Control Algorithm on AUV
A0014 H. H. Chen Shenyang Institute of Automation, Chinese Academy of Sciences
A0012 Z. W. Xing Shenyang Institute of Automation, Chinese Academy of Sciences
A0025 Y. Zhang Shenyang Institute of Automation, Chinese Academy of Sciences
A0013 X. S. Feng Shenyang Institute of Automation, Chinese Academy of Sciences
Currently, most of AUVs are survey research vehicles, and have
performed in ocean environment surveys, oceanographic sections and
hydrographic samples, subsea resources surveys. However, AUVs are
limited by some key technologies such as energy, acoustic
communications, sensors, navigation and positioning, control and
artificial intelligence, it is difficult for to AUVs perform
complicated subsea tasks such as pipeline survey, subsea oil field
inspection and intervention, undewater connection and recovery. AUVs
of highly accuracy dynamical position and target tracking is one of
the keys of performing above tasks. Due to the poor control precision
of common control method, a new control method must be adapted.
Affected by the hydrodynamics and the environment disturbance,
dynamics of AUVs are highly nonlinear, multi-freedom coupled, and time
varying. Due to the uncertainty of the hydrodynamics and the
complexity of ocean environment, it is difficult to establish highly
accurate dynamics of AUVs. Usually, approximate hydrodynamics model
of AUVs is obtained by experience and experiment.
The environmental disturbance of the ocean includes wave, ocean
current and imbalance force . The imbalance force is brought from the
imbalance of vehicle structure and hydrodynamics, the imbalance force
model and the ocean current model both are 1st-order and showly-vary
ing disturbance. Wave forces can be divided into 1st-order wave
disturbance and 2st-order wave drift force. In this paper, we
supposed the environmental disturbance of the ocean as the combination
of fundamental harmonic, 1st-order harmonic and 2nd-order harmonic.
Usually, we use singleton to fuzzize input variable of fuzzy logic
controller, but in the situation with serious disturbance, this
traditional fuzzy logic controller can't work well.
Considering the problems mentioned above, a novel control algorithm
based on Soft Computing is proposed in this paper. The main idea of
the algorithm is that, firstly, we fuzzize input by Gauss function,
and choose Gauss function as membership function, and choose center-
average defuzzier, then we can build a neural-net based on fuzzy logic
control, and some optimization method has been applied to the neural-
net. By studying we draw the conclusion that the control system
resorting to this algorithm is of perfect even in the environment of
In this paper, this control law is applied to horizontal and vertical
closed-loop control of AUV CR-02. We made some computer simulations,
and compared with traditional PID controller and sliding controller,
the performance has obviously been improved on accuracy of dynamic
positioning and target tracking, especially under serious disturbance..
Based on simulation, we will carry out a pool test of AUV CR-02.
Authors:H.H. Chen, Z.W. Xing ,Y.Zhang, X.S. Feng