Abstract: 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.

Abstract: The present disclosure discloses a method for quantifying a bearing capacity of foundation containing shallow-hidden spherical cavities, comprising: in Step 1, constructing a spatial axisymmetric calculation model for stability analysis of the foundation containing shallow-hidden spherical cavities; in Step 2, solving the model to obtain a general solution which reflects the spatial stress distribution of surrounding rock containing shallow-hidden spherical cavities; in Step 3, obtain a mathematical expression by derivation for calculating the bearing capacity of the foundation containing shallow-hidden spherical cavities; and in Step 4: completing the determination of the foundation bearing capacity. Benefits: This method has many advantages such as comprehensive consideration, high accuracy and reliability of calculation results, and may provide the scientific basis for the development of prevention and control against the instability of the foundation containing shallow-hidden cavities.

Abstract: 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.

Abstract: 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.

Abstract: 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 xi to 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 xi, obtain N sets of xi again, and return to step 2; otherwise, go to step 4. 4. Output the control variable xi corresponding to ?s(x)nminmin 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.

Abstract: 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.

Abstract: 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 xi to 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 xi, obtain N sets of xi again, and return to step 2; otherwise, go to step 4. 4. Output the control variable xi corresponding to ?s(x)nminmin 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.