Drift angle compensation-based adaptive line-of-sight path following for autonomous underwater vehicle

The invention provides an aquaculture online monitoring system capable of automatically cruising. The aquaculture online monitoring system comprises an online monitoring ship, a hand-held remote control terminal and a remote monitoring platform. The online monitoring ship comprises a hull, an automatic ship control part, an environment and ecology online monitoring part, a wireless communication module, a hybrid power supply system and an automatic sleeping module, wherein the automatic ship control part is partially installed on the hull; the environment and ecology online monitoring part is used for monitoring the aquaculture environment and ecology and giving an early warning when environmental and ecological indicators exceed a set threshold range; the wireless communication module is connected with the automatic ship control part and the environment and ecology online monitoring part; the hybrid power supply system is installed on the hull; the automatic sleeping module is installed on the hull and used for automatically sleeping when the monitoring ship does not need to perform monitoring or sailing; the hand-held remote control terminal and the remote monitoring platform are both connected with the wireless communication module; the hull is made of aluminum alloy. The aquaculture online monitoring system has the advantages of being capable of automatically cruising, performing online monitoring and regulation on the environment and ecology and performing remote platform control.

Aquaculture online monitoring system capable of automatically cruising

Three-dimensional Path Following Control for an Underactuated UUV Based on Nonlinear Iterative Sliding Mode

The article proposes a new feedback control model which is suited for path following in a 3 Dimensional Cartesian space. Differently from other methods in literature, the method proposed neither requires to compute a projection of the robot's position on the path, nor it needs considering a moving virtual target. In spite of this: i) it guarantees asymptotic stability for every 3D curve which can be represented through a couple of intersecting surfaces f1(X, Y,Z) = 0, f2(X, Y,Z) = 0; ii) it does not put any bounds on the initial position of the vehicle depending on the path's curvature.

3D path following with no bounds on the path curvature through surface intersection

In this paper, an output-feedback fuzzy adaptive dynamic surface controller (FADSC) based on fuzzy adaptive extended state observer (FAESO) is proposed for autonomous underwater vehicle (AUV) systems in the presence of external disturbances, parameter uncertainties, measurement noises and actuator faults. The fuzzy logic system is incorporated into both the observers and controllers to improve the adaptability of the entire system. The dynamics of the AUV system is established first, considering the external disturbances and parameter uncertainties. Based on the dynamic models, the ESO, combined with a fuzzy logic system tuning the observer bandwidth, is developed to not only adaptively estimate both system states and the lumped disturbances for the controller, but also reduce the impact of measurement noises. Then, the DSC, together with fuzzy logic system tuning the time constant of the low-pass filter, is designed using estimations from the FAESO for the AUV system. The asymptotic stability of the entire system is analyzed through Lyapunov's direct method in the time domain. Comparative simulations are implemented to verify the effectiveness and advantages of the proposed method compared with other observers and controllers considering external disturbances, parameter uncertainties and measurement noises and even the actuator faults that are not considered in the design process. The results show that the proposed method outperforms others in terms of tracking accuracy, robustness and energy consumption.

https://www.mdpi.com/1424-8220/20/24/7084/pdf

Antidisturbance Control for AUV Trajectory Tracking Based on Fuzzy Adaptive Extended State Observer.

This paper derives a control law to steer the dynamic model of an underactuated autonomous underwater vehicle (AUV) along a predefined path. We describe the path to be followed by the movement of a virtual AUV and drive the actual AUV on the desired path through following this virtual AUV. Furthermore, it overcomes a singular point that are presented in a number of path following control strategies described in the literature. Controller design builds on Lyapunov theory and backstepping techniques. The resulting control law yields convergence of the path following error trajectories to zero. Simulations illustrate the performance of the proposed controller.

Backstepping-based path following control of an underactuated autonomous underwater vehicle

The invention provides an experimental control structure of an unmanned surface vessel, which comprises a shore module, a ship module, a navigation sensor and a ship body propelling and steering mechanism. A data collecting and receiving module collects movement parameter information of a ship body measured by the navigation sensor according to a set control cycle; a ship communication module transfers the movement parameter information of the ship body to a shore communication module; a navigational parameter display module displays the movement parameter information of the ship body; a movement control module carries out movement control resolving according to the movement parameter information of the ship body to obtain a drive instruction of movement of the ship body; and the shore communication module transfers the drive instruction to the ship communication module, and the ship communication module transfers an execution mechanism drive module and controls the ship body propelling and steering mechanism to drive the ship body to move according to the control requirement. According to the experimental control structure, modifying and validating of a movement control algorithm can be finished just by modifying shore control software in an experimental process without modifying ship control software, and a research of a movement control experiment of the unmanned surface vessel is conveniently carried out.

Experimental control structure of unmanned surface vessel

The invention relates to an AUV (Autonomous Underwater Vehicle) underwater acoustic locating method based on double mobile beacons, which is characterized in that the double mobile beacons are realized by two USVs, a differential GPS (Global Positioning System), a course and course angular velocity sensor and an acoustic locating and communication sonar are respectively installed on the two USVs, and course, navigational speed and course angular velocity sensors and an acoustic locating and communication sonar are installed on the AUV. The acoustic locating and communication sonars on the two USVs periodically send acoustic locating signals and send the self positions to the AUV. When the AUV receives the acoustic locating signal and position coordinate of the USV, the AUV performs underwater locating through an extended Kalman filter; and meanwhile, the AUV sends the measuring and locating result to the two USVs through the acoustic locating and communication sonar to drive the two USVs to move with the AUV in a grouping manner with the AUV as navigator and stabilize the distance between the AUV to minimal safe distance and stabilize the included angle between the AUV connecting line to pi/2.

AUV (Autonomous Underwater Vehicle) underwater acoustic locating method based on double mobile beacons

The invention relates to an AUV back-to-the-dock guidance system and an AUV back-to-the-dock guidance method based on a dipole potential field. The AUV back-to-the-dock guidance system and the AUV back-to-the-dock guidance method are characterized in that the head of an AUV is equipped with a USBL transceiver, and two USBL transponders are installed at the two sides of a recycling station; the AUV can use the transceiver to measure the distances and the azimuths of the transponders in an AUV body coordinate system xBoByB; the coordinates of the AUV in a recycling coordinate system xoy can be calculated according to the distances and the azimuths, and an AUV back-to-the-dock expected course angle instruction can be obtained based on the principle of dipole potential field; and the AUV controls the AUV to sail at an expected course angle by an adaptive nonsingular terminal sliding mode control method to realize back-to-the-dock guidance. By adopting the method, the coordinates of the AUV in the recycling coordinate system xoy can be calculated directly. Then, the AUV is guided by an established dipole potential field to enter the recycling station along the central axis of the recycling station. The method is simple, only needs a small amount of calculation, makes the error between the actual course angle and the course angle specified by the instruction in the back-to-the-dock process very small, and has a better back-to-the-dock effect than other back-to-the-dock algorithms.

AUV back-to-dock guidance system and AUV back-to-the-dock guidance method based on dipole potential field

The invention discloses a water surface automatic tracking and monitoring system for an underwater vehicle. The water surface automatic tracking and monitoring system comprises a shore-based display and control center, a wireless network communication system, an unmanned ship tracking platform and an underwater acoustic positioning system, wherein the shore-based display and control center performs two-way communication with an unmanned ship platform through a wireless network; an unmanned ship obtains a relative position of the autonomous underwater vehicle through the ultra-short base line underwater acoustic positioning system, and the autonomous underwater vehicle is tracked by operating a controller; meanwhile, status information of the underwater vehicle is transmitted to the shore-based display and control center, and further tracking type monitoring of the autonomous underwater vehicle is realized. According to the water surface automatic tracking and monitoring system disclosed by the invention, positioning and tracking control of the unmanned ship to the underwater vehicle are realized by combined use of wireless network communication, the ultra-short base line positioning system and a satellite positioning system, and tracking data are transmitted to workers on a shore, so that high-precision real-time tracking and on-shore remote monitoring of the underwater vehicleare realized.

Wang Yintao

Papers

Backstepping-based path following control of an underactuated autonomous underwater vehicle

Experimental control structure of unmanned surface vessel

AUV (Autonomous Underwater Vehicle) underwater acoustic locating method based on double mobile beacons

AUV back-to-dock guidance system and AUV back-to-the-dock guidance method based on dipole potential field

Water surface automatic tracking and monitoring system for underwater vehicle