Modeling and Adaptive Sliding Mode Control of the

Authors: Min Xiao

Publish Date: 2014/05/20

Volume: 10, Issue: 3, Pages: 210-216

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Abstract

The mathematical model of a highspeed underwater vehicle getting catastrophe in the outofwater course and a nonlinear sliding mode control with the adaptive backstepping approach for the catastrophic course are proposed The speed change is large at the moment that the highspeed underwater vehicle launches out of the water to attack an air target It causes motion parameter uncertainties and affects the precision attack ability The trajectory angle dynamic characteristic is based on the description of the transformed statecoordinates the nonlinear sliding mode control is designed to track a linear reference model Furthermore the adaptive backstepping control approach is utilized to improve the robustness against the unknown parameter uncertainties With the proposed control of attitude tracking the controlled navigational control system possesses the advantages of good transient performance and robustness to parametric uncertainties These can be predicted and regulated through the design of a linear reference model that has the desired dynamic behavior for the trajectory of the highspeed underwater vehicle to attack its target Finally some digital simulation results show that the control system can be applied to a catastrophic course and that it illustrates great robustness against system parameter uncertainties and external disturbancesMin Xiao received her MSc and Ph D degrees in control science and engineering from Northwestern Polytechnical University China in 2006 and 2010 respectively Currently she is an associate professor in the College of Computer and Information Technology China Three Gorges University ChinaA highspeed underwater vehicle is a type of stratagem weapon that is essential for naval equipment as it can be used in deep water and control large areas of sea The motion of a moving body is a system with the property of unmodeled dynamics and input uncertainty12 It has a control system that meets the requirements of large distance runs and highprecision tactics but it is vulnerable to the impact of model input uncertaintyRecent studies about launched outofwater tasks give rise to challenging control problems involving crossmedia motion process hydrodynamic parameter uncertainties and external disturbances The control system should be able to learn and adapt to the changes in the dynamics of highspeed underwater vehicleIn the past for nonlinear models of an underwater vehicle with known dynamics control laws were designed using the Lyapunov stability theory and the pure backstepping design technique3 For the control of underwater vehicle models in the presence of uncertainties sliding mode control was considered45 Adaptive control laws were also designed for the control of underwater vehicles68 A discretetime adaptive sliding mode controller for an underwater vehicle with parameter uncertainties and external disturbance was presented8 From the performance evaluation of an exact feedbacklinearization controller it was seen that this method is very sensitive to variation of parameters9 The adaptive backstepping control approach in 9 10 11 is capable of keeping almost all the robustness properties of the unknown uncertaintiesHowever by means of these design methods38 the outputgenerated attitude of the highspeed underwater vehicle outofthewater trajectory has a nonlinear and coupled form and hydrodynamic coefficient1214 Therefore in order to obtain a linearly controlled attitude and keep the robustness of nonlinear sliding mode control a nonlinear sliding mode control with an adaptive backstepping approach was designed to achieve a high performance attitude tracking of catastrophic course

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