Jiancheng Yu

Motion Parameter Optimization and Sensor Scheduling for the Sea-Wing Underwater Glider

Underwater gliders adjust buoyancy to generate gliding motion through water columns using a pair of wings. Various types of underwater gliders have been developed and have been tested as efficient long-distance, long-duration ocean sampling platforms. We introduce the Chinese Sea-Wing underwater glider and develop methods to increase its gliding range by optimizing the steady motion parameters to save energy. The methods are based on a model that relates gliding range to steady gliding motion parameters as well as energy consumption. A sensor scheduling strategy accounts for the distributed features of vertical profiles so that the sampling resolution is adjusted to reduce energy consumption of sensing. The effect of the proposed methods to increase gliding range is evaluated on the Sea-Wing glider. The proposed methods may be applicable to other types of underwater gliders.

Marine Vehicle Sensor Network Architecture and Protocol Designs for Ocean Observation

The micro-scale and meso-scale ocean dynamic processes which are nonlinear and have large variability, have a significant impact on the fisheries, natural resources, and marine climatology. A rapid, refined and sophisticated observation system is therefore needed in marine scientific research. The maneuverability and controllability of mobile sensor platforms make them a preferred choice to establish ocean observing networks, compared to the static sensor observing platform. In this study, marine vehicles are utilized as the nodes of mobile sensor networks for coverage sampling of a regional ocean area and ocean feature tracking. A synoptic analysis about marine vehicle dynamic control, multi vehicles mission assignment and path planning methods, and ocean feature tracking and observing techniques is given. Combined with the observation plan in the South China Sea, we provide an overview of the mobile sensor networks established with marine vehicles, and the corresponding simulation results.

Steady three dimensional gliding motion of an underwater glider

Underwater Gliders have found broad applications in ocean sampling. In this paper, the nonlinear dynamic model of the glider developed by the Shenyang Institute of Automation, Chinese Academy of Sciences, is established. Based on this model, we solve for the parameters that characterize steady state spiraling motions of the glider. A set of nonlinear equations are simplified so that a recursive algorithm can be used to find the solutions.

Development of a Virtual Platform for Telepresence Control of an Underwater Manipulator Mounted on a Submersible Vehicle

This paper develops a virtual platform of an underwater manipulator mounted on a submersible vehicle via the three-dimensional simulator “Webots” for teleoperation through a replica master arm. The graphical, kinematic, and dynamic models of the manipulator refer to a master-slave servo hydraulic manipulator with seven functions, consisting of six degrees of freedom and a parallel gripper, while the “Jiaolong” deep-manned submersible vehicle, operating below the sea surface down to 7000 m, is chosen as the underwater manipulator carrier. This study uses the virtual platform for training an operator to telepresence control the virtual manipulator to complete basic tasks in subsea environments. When training the operator, one has to consider uncertain external disturbances and the visual impacts that stem from subsea environments. In order to demonstrate the feasibility and effectiveness of the virtual platform, one designs two typical underwater operational tasks: grasping a marine organism sample and reaching at a given position. This paper presents the comparative studies: 1) the performances demonstrated by remotely controlling the virtual manipulator and the real manipulator; 2) the operating performances delivered by three operators before and after training when using the platform.

Discrete-time quasi-sliding mode control of underwater vehicles

This paper presents a novel discrete-time quasi-sliding mode controller for the multiple-input multiple-output underwater vehicle system. First, according property of slow time-varying dynamics system, an on-line estimation method is used to eliminate the uncertainties of the underwater vehicle systems. Second, combined with the constant term and uncertainties estimation in the dynamics model, the discrete-time quasi-sliding mode control law is designed. And third, the chattering terms in the designed controller are eliminated by using the sliding surface exponential convergence method. Computer simulation is performed for a numerical model of an underwater vehicle in surge, sway, and yaw degrees of freedom. Results show the effectiveness of the proposed control law in the presence of system uncertainties and external disturbances without any predictive control techniques or intelligent control methods.

Design of a wheel-propeller-leg integrated amphibious robot

The operation capabilities of robot in the amphibious environments (such as shallow water fields, surf zones, and beaches) are critical for military and civilian. In this paper, we introduce a novel amphibious robot with wheel-propeller-leg integrated driving devices, developed by Shenyang Institute of Automation, which can realize both crawling locomotion on the ground and swimming locomotion in the water without changing its driving devices. This paper describes the design of the overall robot structure, the design of the novel driving devices, and the design of the embedded control system, respectively. All the driving devices of the robot are driven by independent motor, thus the amphibious robot can conveniently switch its locomotion modes according to the operational environments. The embedded control system is a distributed control system based on CAN bus, which makes it is easy to expend sensors and devices for the robot in the future. Finally, the hydrodynamic performances of the wheel-propeller device are analyzed by using CFX hydrodynamic calculation software, and some primary experiments have been done for verifying the fundamental locomotion functions of the robot.

Surrogate Models for Shape Optimization of Underwater Glider

Design of experiments and surrogate models method facilitating much of today’s engineering design and optimization. In this paper we systematically compare several experimental design types and surrogate modeling techniques in terms of their capability to generate accurate approximations for the shape optimization of underwater gliders. The parametric geometry construction, mesh generation and computation fluid dynamics were integrated as an automatic analysis process. Procedures of surrogate model construction were presented and the characteristics and applicability of response surface model and radial basis function model were discussed. A fast design exploration and multi-objective optimization was implemented. At last, the optimal plane shape of the Underwater Glider was found out based on the surrogate model.

Dynamics analysis of wave-driven unmanned surface vehicle in longitudinal profile

Wave-driven unmanned surface vehicle (WUSV) is a great success of application of solar and wave energy in the ocean robot. In this paper, the nonlinear dynamic model of WUSV in two dimension is established based on the analysis of its driving principle in the longitudinal profile. Then, we calculate the wave and driving force, and determine hydrodynamic coefficients according to the empirical data and experimental platform of WUSV. Finally, we simplify the nonlinear equations and present the simulation results of the model.

From simulation to validation: Moth-inspired chemical plume tracing with an autonomous underwater vehicle

Chemical plume tracing capability is important for autonomous underwater vehicles (AUVs) to perform a variety of ocean exploration and exploitation missions. For studying and validating moth-inspired chemical plume tracing algorithms, Shenyang Institute of Automation, Chinese Academy of Sciences developed an AUV equipped with multiple sensors, including an underwater fluorometer and a Doppler velocity log (DVL). Based on the AUVs dynamics and its path-following capability, a path-following based algorithm implementation of the moth-inspired chemical plume tracing strategy was developed. To validate the algorithm, computer simulation and field experiments were conducted. This paper presents the path-following based algorithm of the moth-inspired chemical plume tracing strategy and the systematic study on the algorithm, from computer simulation via proper numerical plumes, to field experiments with the AUV and Rhodamine dye plumes performed at Dalian Bay, China in 2010.

A practical path tracking method for autonomous underwater gilders using iterative algorithm

This paper proposes a path tracking method to solve the engineering problem that how to keep gliders travelling along predetermined routes automatically without using ocean current information. The path tracking method is low cost in computational and without additional sensors on gliders. In the first half year of 2015, two sea trials of glides with different purposes were implemented, in which the path tracking is in use to reduce the cost of manual observation. The final trajectory of gliders and other related results show that the path tracking method is practical and effective.