Huazhong University of Science and Technology

Shaolong Yang

Xianbo Xiang

Gong Xiang

Qin Zhang

Yan Wang

Donglei Dong

Yu Duan

Jinjiang Li

Chuan Liu

Jialei Zhang

Guohua Xu

Chaicheng Jiang

Xinyang Xiong

Zhao Wang

This disclosure provides an adaptive STSMC hierarchical control method for depth tracking of an underwater vehicle. The method includes: using an adaptive line-of-sight guidance algorithm to estimate the vehicle's angle of attack in real time and obtain an expected pitch angle; employing a nonlinear interference observer based on a sliding mode surface error to detect unknown interference; and applying an STSMC controller with adaptive saturation compensation to determine the expected control rudder angle from the sliding mode surface error, the expected pitch angle, and the observed interference. The adaptive saturation compensation corrects the rudder angle based on the saturation deviation, which is determined by the previously calculated expected control rudder angle and the actual output rudder angle at the previous moment. By introducing an adaptive saturation compensator in the dynamic control layer, the issue of rudder angle saturation is mitigated, thereby enhancing both control performance and stability.

Adaptive STSMC hierarchical control method for depth tracking oriented to underwater vehicle

A method and device for docking control of an underwater vehicle based on sonar imaging, belonging to the field of vehicle automatic control technology. Decomposes docking control of the underwater vehicle into depth tracking control and horizontal plane docking control, designs corresponding reinforcement learning cost functions to train deep network-based depth tracking controller and servo docking controller, designs nonlinear weight to balance position error and field of view in the cost function, and uses reinforcement learning to make the controller learn optimized control strategy, quickly eliminate position error and maintain recovery device features in the imaging sonar field of view. The device may effectively avoid docking failure caused by loss of target features and improve docking success rate.

Method and device for docking control of underwater vehicles based on imaging sonar

A method and a system for ship stability prediction by weighted fusion of RBFNN and random forest based on GD are provided. Firstly, input characteristics when predicting failure probabilities under different failure modes are determined through prior knowledge. Secondly, a mean square error of k-fold cross-validation is used as performance evaluation criterion of the RBFNN and the RF to search for model capacities of the RBFNN and the RF. Then, network parameters of the RBFNN are updated. Multiple random sample sets are generated using a bootstrap sampling method and are parallelly trained to generate multiple regression trees. A Gini index is used as an attribute division index, and a prediction result of the random forest is obtained. Finally, weight coefficients are introduced for weighted fusion of prediction results of the RBFNN and the RF. The weight coefficient is obtained by solving through iterative optimization of the gradient descent.

Method and system for ship stability prediction by weighted fusion of radial basis function neural network and random forest based on gradient descent

The invention discloses an integrated detection method of electromagnetic searching, locating and tracking for subsea cables. After being launched into water, the cable-tracking AUV carries out primary Z-shaped reciprocating sailing to search the electromagnetic signal of the target subsea cable, when the electromagnetic signal reaches a preset threshold value, the AUV executes the cable-tracking detection. In the tracking process, if the target electromagnetic signal intensity is lower than the preset threshold, it is determined that subsea cable tracking is lost. At this time, the secondary Z-shaped cable-researching route planning and tracking are performed based on the lost point. In the process that the AUV autonomously tracks and detects the subsea cable, relative locating between AUV and subsea cable is performed based on the electromagnetic signal radiated by the subsea cable, and autonomous tracking control under the guidance of the electromagnetic locating signal is performed.

Integrated detection method of electromagnetic searching, locating and tracking for subsea cables

The disclosure provides a method and system for hierarchical disturbance rejection depth tracking control of an underactuated underwater vehicle, and the depth tracking of the underactuated underwater vehicle is divided into kinematic layer guidance and dynamic layer pitch tracking. Adaptive line of sight guidance is used in the kinematic layer to convert a depth error into a desired pitch angle and to estimate and compensate an angle of attack to reject disturbance introduced by an unmeasurable true angle of attack. Based on the above, in the dynamic layer, the active disturbance rejection sliding mode pitch tracking method is used to observe a composite disturbance including an unknown dynamic model and an environmental disturbance by using the active disturbance rejection framework. The model is compensated as a unified integral series type, a sliding mode control law is finally designed to resist an observation error, and a control elevator angle is calculated.

Method and system for hierarchical disturbance rejection depth tracking control of underactuated underwater vehicle

Disclosed are a non-singular finite-time control method and system for prescribed performance dynamic positioning of unmanned boat, which belong to the field of automatic control of unmanned boats. The method includes obtaining a difference between the actual measured position and the desired position of the unmanned boat to obtain a position error of the unmanned boat; performing prescribed performance transformation on the unmanned boat position error; constructing a non-singular finite-time virtual velocity law as a reference velocity for unmanned boats; obtaining the difference between the reference speed and the actual measured speed to obtain the speed tracking error; calculating the fuzzy supervisory saturation compensated law and adaptive fuzzy approximation term; constructing a non-singular finite-time dynamical controller to output control commands; applying a force or moment to the unmanned boat to adjust the propeller speed of the unmanned boat, thereby realizing positioning of the unmanned boat.

Non-singular finite-time control method and system for dynamic positioning of unmanned boat with prescribed performance

The disclosure discloses a trajectory optimization method and device for accurately deploying marine sensors under water. The method includes the following steps. 1. Randomly select N sets of initial control variables within a range. 2. Input all of N sets of xto the sensor's underwater glide kinematics and dynamics models, and calculate the smallest distance between N actual deployment positions and target deployment positions. 3. Determine whether the number of iterative operations is less than the preset value, if yes, perform global random walk and local random walk on N sets of x, obtain N sets of xagain, and return to step 2; otherwise, go to step 4. 4. Output the control variable xcorresponding to &#x394;s(x)and the corresponding trajectory as the optimal control variable and optimal trajectory. The disclosure can improve the accuracy of prediction on the underwater three-dimensional trajectory of the marine sensor.

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Hubei, China

Shaolong Yang