关键词: 自主水下机器人, 变深控制, 反步法, 神经网络, 自适应方法

Abstract:

In order to implement precise diving control of the autonomous underwater vehicle (AUV), according tothe kinematic and nonlinear dynamic model of AUV, an adaptive iterative backstepping method based on neuralnetwork is proposed, and a kinematic and dynamic controller is designed. In the investigation, considering theexistence of attack angle and the uncertainties of hydrodynamic damping parameters of the nonlinear model of AUV,a neural network-based controller is designed to on-line estimate the nonlinear hydrodynamic damping terms existingin the pitch motion together with external ocean current disturbances. Then, the adaptive law of the network weightsis presented based on the Lyapunov stability theory to guarantee the uniform ultimate bounding of all signals in theclosed-loop system. Finally, two groups of simulation experiments are carried out to compare the system response ofthe designed controller at a certain control gain and the diving control performance in the presence of disturbances.The results show that the designed controller is of smaller static error and higher tracking precision.

Key words: autonomous underwater vehicle, diving control, backstepping method, neural network, adaptivemethod