AUV (autonomous underwater vehicle) three-dimension curve path tracking control method based on iteration

Abstract

The invention provides an AUV (autonomous underwater vehicle) three-dimension curve path tracking control method based on iteration. The method comprises the following steps that 1, initialization is carried out; 2, the relative tracking error of the current AUV position and the virtual guide point on an expected path in an AUV carrier coordinate system at the initial moment is calculated; 3, the expected moving speed of the virtual guide point on the expected path and the AUV kinematics tracking control law are calculated; 4, the iteration is adopted on the basis of the kinematics equivalent control law, and the kinematics equivalent control law of the underactuated AUV three-dimension path tracking is deduced; and 5, the distance between the current AUV position Eta<n>=(x, y, z) and the demarcated steering point WPk=(xk, yk, zk) is calculated, when the distance is smaller than the set track switching radius R, the result shows that the current specified path tracking task is completed, the navigation is stopped, or the track is switched to a next expected track, and otherwise, the second step is continuously carried out. The AUV three-dimension curve path tracking control method has the advantage that the AUV path tracking precision can be improved.

Description

technical field [0001] The invention relates to the technical field of three-dimensional space motion control of an underactuated autonomous underwater vehicle. Background technique [0002] The exploration and mapping of seabed terrain is of great significance to the development of deep sea resources. The underactuated autonomous underwater vehicle AUV (Autonomous Underwater Vehicle) plays an important role in ocean exploration and development due to its good maneuverability and endurance. With the continuous deepening of the application of AUV in the field of ocean engineering, new challenges have been proposed for the research on the motion control technology of AUV in three-dimensional underwater space. Considering the constraints of navigation economy or load capacity, the actuator is usually configured as a longitudinal tail Thrusters, horizontal rudders and vertical elevators, most AUVs are not equipped with lateral and vertical auxiliary propellers, so that the dimen...

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Problems solved by technology

"Underactuated UUV 3D Track Tracking Control Based on Nonlinear Iterative Sliding Mode" (Acta Automation, 2012, Vol. 38, No. 2) Design a nonlinear iterative sliding mode track tracking controller based on the idea of ​​engineering controller decoupling, Since the controlled object model is a six-degree-of-freedom coupled motion model, decoupling controllers designed separately for longitudinal velocity, heading control, and pitch control can only suppress the coupling effect in the model through robust terms. When the coupling effect between them is obvious, the controller can only eliminate the coupling effect at the cost of outputting a higher controller gain, causing the controller to output a saturated signal, and the decoupled controller can only ensure the gradual transition of the three independent control subsystems. However, the asymptotic stability of the entire control system cannot be guaranteed, while the three-dimensional track tracking controller proposed in this patent can guarantee the global asymptotic stability of the entire system; "Neural Network for Three-dimensional Path Tracking of Autonomous Underwater Vehicle h ∞ Robust Adaptive Control Method" (Control Theory and Application, 2012, Volume 29, Issue 3) to establish the AUV three-dimensional path tracking error equation based on the orthogonal projection Serret-Frenet coordinate system, using H ∞ The controller is designed with the idea of ​​robust control, and the uncertainty of the neural network compensation model is introduced at the same time. However, since there are singular value points in the AUV three-dimensional path tracking error model based on the orthogonal projection Serret-Frenet coordinate system, there are constraints on the initial conditions of the AUV. That is, the initial position of the AUV must be within the minimum radius of curvature of the tracking curve, so the global convergence of AUV tracking cannot be achieved. However, the 3D tracking error model expressed in the AUV carrier coordinate system in this patent does not have the singular value problem, so it can guarantee AUV tracking The global convergence of the error, in addition, this patent uses an iterative method to design the controller different from H ∞ Robust Control Design Thought

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