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1.
The purpose of this study is to develop maneuvering models and systems of a simulator to improve the motion performance of autonomous underwater vehicles (AUVs) at the preliminary design stages in advance. The AUVs simulation systems based on the standard submarine equations of motion in six-degree-of-freedom (6-DOF) integrated with the Euler-Rodriguez quaternion method for representing singularity-free AUV attitude and time-saving calculation, and with a nonlinear control model for maneuvering and depth control simulations, time-marching in the fourth-order Runge-Kutta scheme. For validation of the simulation codes, results of the ISiMI AUV open-loop tests including turning test and zigzag test as well as an AUV simulator on the basis of Euler-angle method were used to compare with the quaternion-based AUV simulator. The computational results from the proposed simulator agree well with those from both the ISiMI AUV experiments and the Euler-angle based simulations. Additionally, a new maneuvering procedure, namely "put-out" was implemented to test directional stability for a large-scale AUV in the proposed AUV simulator that can be considered for vehicles in space as well as in constrained planes.  相似文献   

2.
This paper presents a method for identification of the hydrodynamic coefficients of the dive plane of an autonomous underwater vehicle. The proposed identification method uses the governing equations of motion to estimate the coefficients of the linear damping, added mass and inertia, cross flow drag and control. Parts of data required by the proposed identification method are not measured by the onboard instruments. Hence, an optimal fusion algorithm is devised which estimates the required data accurately with a high sampling rate. To excite the dive plane dynamics and obtain the required measurements, diving maneuvers should be performed. Hence, a reliable controller with satisfactory performance and stability is needed. A cascaded controller is designed based on the coefficients obtained using a semi-empirical method and its robustness to the uncertainties is verified by the μ-analysis method. The performance and accuracy of the identification and fusion algorithms are investigated through 6-DOF numerical simulations of a realistic autonomous underwater vehicle.  相似文献   

3.
Hybrid-driven underwater glider is a new type of unmanned underwater vehicle, which combines the advantages of autonomous underwater vehicles and traditional underwater gliders. The autonomous underwater vehicles have good maneuverability and can travel with a high speed, while the traditional underwater gliders are highlighted by low power consumption, long voyage, long endurance and good stealth characteristics. The hybrid-driven underwater gliders can realize variable motion profiles by their own buoyancy-driven and propeller propulsion systems. Stability of the mechanical system determines the performance of the system. In this paper, the Petrel-Ⅱ hybrid-driven underwater glider developed by Tianjin University is selected as the research object and the stability of hybrid-driven underwater glider unitedly controlled by buoyancy and propeller has been targeted and evidenced. The dimensionless equations of the hybrid-driven underwater glider are obtained when the propeller is working. Then, the steady speed and steady glide path angle under steady-state motion have also been achieved. The steady-state operating conditions can be calculated when the hybrid-driven underwater glider reaches the desired steady-state motion. And the steady-state operating conditions are relatively conservative at the lower bound of the velocity range compared with the range of the velocity derived from the method of the composite Lyapunov function. By calculating the hydrodynamic coefficients of the Petrel-Ⅱ hybrid-driven underwater glider, the simulation analysis has been conducted. In addition, the results of the field trials conducted in the South China Sea and the Danjiangkou Reservoir of China have been presented to illustrate the validity of the analysis and simulation, and to show the feasibility of the method of the composite Lyapunov function which verifies the stability of the Petrel-Ⅱ hybrid-driven underwater glider.  相似文献   

4.
Depth-trim mapping control of underwater vehicle with fins   总被引:1,自引:1,他引:0  
Underwater vehicle plays an important role in ocean engineering.Depth control by fin is one of the difficulties for underwater vehicle in motion control.Depth control is indirect due to the freedom coupling between trim and axial motion.It includes the method of dynamic analysis and lift-resistance-coefficient experiment and theory algorithm.By considering the current speed and depth deviation,comprehensive interpretation is used in object-planning instruction.Expected depth is transformed into expected trim.Dynamic output fluctuation can be avoided,which is caused by linear mapping of deviation.It is steady and accurate for the motion of controlled underwater vehicles.The feasibility and efficiency of the control method are testified in the pool and natural area for experiments.  相似文献   

5.
In this paper,the underwater vehicle,sling and the mother ship are considered as a single de-gree of freedom system connected by a spring.Through the analysis of this system,a physical model is es-tablished,which describes the motion of the vehicle caused by the ship motion and wave motion.Furthermore,a mathematical model based on this physical model is obtained,and a numerical solutionprogram is made.As an example,a practical launch and recovery system for an underwater robot is calcu-lated by use of the program.and the motion track of the robot is obtained.  相似文献   

6.
An optimal interpolation assimilation model for satellite altimetry data is developed based on Princeton Ocean Model (POM), which is applied in a quasi-global domain, by the method of isotropic correlation between sea level anomaly (SLA) and sea temperature anomaly. The perfor- mance of this assimilation model is validated by the modeled results of SLA and the current patterns. Comparisons between modeling and satellite data show that both the magnitudes and distribution patterns of the simulated SLA are improved by assimilation. The most signiˉcant improvement is that meso-scale systems, e.g., eddies, are well reconstructed. The evolution of an eddy located in the northwest Paciˉc Ocean is traced by using the assimilation model. Model results show that during three months the eddy migrated southwestward for about 6 degrees before merging into the Kuroshio. The three dimensional structure of this eddy on 12 August 2001 is further analyzed. The strength of this warm, cyclonic eddy decreases with the increase of depth. The eddy shows di?erent horizontal patterns at di?erent layers, and the SLA and temperature ˉelds agree with each other well. This study suggests that this kind of data assimilation is economic and reliable for eddy reconstruction, and can be used as a promising technique in further studies of ocean eddies as well as other ˉne circulation structures.  相似文献   

7.
A hybrid underwater glider Petrel-II has been developed and field tested. It is equipped with an active buoyancy unit and a compact propeller unit. Its working modes have been expanded to buoyancy driven gliding and propeller driven level-flight, which can make the glider work in strong currents, as well as many other complicated ocean environments. Its maximal gliding speed reaches 1 knot and the propelling speed is up to 3 knots. In this paper, a 3D dynamic model of Petrel-II is derived using linear momentum and angular momentum equations. According to the dynamic model, the spiral motion in the underwater space is simulated for the gliding mode. Similarly the cycle motion on water surface and the depth-keeping motion underwater are simulated for the level-flight mode. These simulations are important to the performance analysis and parameter optimization for the Petrel-II underwater glider. The simulation results show a good agreement with field trials.  相似文献   

8.
The wave period probability densities in non-Gaussian mixed sea states are calculated by utilizing a transformed Gaussian process method. The transformation relating the non-Gaussian process and the original Gaussian process is obtained based on the equivalence of the level up-crossing rates of the two processes. A saddle point approximation procedure is applied for calculating the level up-crossing rates in this study. The accuracy and efficiency of the transformed Gaussian process method are validated by comparing the results predicted by using the method with those predicted by the Monte Carlo simulation method.  相似文献   

9.
The The Great-West Dyke with a length of 6.7 km, the largest sea wall in China, was completed in June, 1994. This paper introduces structure options of nibble mound sea wall on soft foundation and a new type of armour block-hexagon multihole block (HMB) and a new method of treatment for soft foundation by using underwater explosion. Construction practice of some projects in China shows that by using this method good effect of treatment and marked economic benefit can be achieved by using this method.  相似文献   

10.
The finite volume method (FVM) has many advantages in 2-D shallow water numerical simulation. In this study, the finite volume method is used with unstructured triangular grids to simulate the tidal currents. The Roe scheme is applied in the calculation of the intercell numerical flux, and the MUSCL method is introduced to improve its accuracy. The time integral is a two-step scheme of forecast and revision. For the verification of the present method, the Stoker's problem is calculated and the result is compared with the mathematically analytic solutions. The comparison indicates that the method is feasible. A sea area of a port is used as an example to test the method established here. The result shows that the present computational method is satisfactory, and it could be applied to the engineering fields.  相似文献   

11.
无舵翼水下机器人路径跟踪控制研究   总被引:1,自引:0,他引:1  
针对无舵翼水下机器人的各种不同任务要求下的路径跟踪控制进行研究。通过模拟人的运动行为,建立了虚拟避碰声纳模型。根据地形跟踪的方法提出基于虚拟声纳的路径跟踪控制方法,并通过考虑纵向速度对于其他各个自由度运动的影响设计了运动控制器。通过海上试验验证了所提出的路径跟踪控制方法对于无舵翼水下机器人是可以满足实际需要的。  相似文献   

12.
研究了用于维护和检修中国渤海海域输油管道的浅海管道检测艇的操纵性和运动仿真,提出了浅海海底管道检测艇的水动力学方程。为了更好地了解在配置上与一般潜器不同的浅海海底管线检测艇的动力学性能,通过水动力系数分析,研究了浅海海底管线检测艇的操纵性。最后根据运动方程建立了仿真系统,并通过仿真试验结果验证了仿真试验平台的可行性和可靠性。  相似文献   

13.
针对现有拖曳式水下潜器控制机构复杂、航向与姿态不容易稳定的缺陷,提出和设计了一种具有航向与姿态稳定的多自由度可控制拖曳式水下潜器样机。该样机主要由鱼雷状浮体、固定水平主翼、转角可控制襟翼、立式翼型主体等部分组成,潜器的深度控制通过控制襟翼的偏转来诱导固定水平主翼攻角的改变来实现;潜器的横荡运动操纵以通过控制两个作为转艏控制器的导管螺旋桨的转向与转速、诱导立式翼型主体产生诱导力矩使其产生横向偏转来进行。文中所提出和设计的样机具有运动过程中自我稳定能力强、航向稳定性好、控制机构简单并具有较高实用价值的特点。  相似文献   

14.
In the paper, a hydrodynamic model including the characteristics of maneuvering and seakeeping is developed to simulate the six-degree of freedom motions of the underwater vehicle steering near the sea surface. The corresponding wave exciting forces on the underwater vehicle moving in waves are calculated by the strip theory, which is based on the source distribution method. With the hydrodynamic coefficients relevant to the maneuvering and seakeeping, the fourth-order Runge–Kutta numerical method is adopted to solve the equations of motions and six-degrees of freedom of the motions for the underwater vehicle steering near the free surface can be obtained. The wave effect on the corresponding motions of the underwater vehicle is investigated and some interesting phenomena with respect to different wave frequencies and headings are observed. The hydrodynamic numerical model developed here can be served as a valuable tool for analyzing the ascending and descending behaviors of the underwater vehicle near the sea surface.  相似文献   

15.
The paper addresses the problem of autonomous underwater vehicle (AUV) modelling and parameter estimation as a means to predict the dynamic performance of underwater vehicles and thus provide solid guidelines during their design phase. The use of analytical and semi-empirical (ASE) methods to estimate the hydrodynamic derivatives of a popular class of AUVs is discussed. A comparison is done with the results obtained by using computational fluid dynamics to evaluate the bare hull lift force distribution around a fully submerged body. An application is made to the estimation of the hydrodynamic derivatives of the MAYA AUV, an autonomous underwater vehicle developed under a joint Indian-Portuguese project. The estimates obtained were used to predict the turning diameter of the vehicle during sea trials.  相似文献   

16.
To achieve accurate positioning of autonomous underwater vehicles, an appropriate underwater terrain database storage format for underwater terrain-matching positioning is established using multi-beam data as underwater terrain-matching data. An underwater terrain interpolation error compensation method based on fractional Brownian motion is proposed for defects of normal terrain interpolation, and an underwater terrain-matching positioning method based on least squares estimation (LSE) is proposed for correlation analysis of topographic features. The Fisher method is introduced as a secondary criterion for pseudo localization appearing in a topographic features flat area, effectively reducing the impact of pseudo positioning points on matching accuracy and improving the positioning accuracy of terrain flat areas. Simulation experiments based on electronic chart and multi-beam sea trial data show that drift errors of an inertial navigation system can be corrected effectively using the proposed method. The positioning accuracy and practicality are high, satisfying the requirement of underwater accurate positioning.  相似文献   

17.
Energy-optimal trajectories for underwater vehicles be computed using a numerical solution of the optimal control problem. A performance index consisting of a weighted combination of energy and time consumption is proposed. Collision avoidance is solved by including path constraints. Control vector parameterization with direct single shooting is used in this study. The vehicle is modeled with six-dimensional nonlinear and coupled equations of motion. Optimal trajectories are computed for a vehicle controlled in all six degrees of freedom by dc-motor-driven thrusters. Good numerical results are achieved  相似文献   

18.
To achieve accurate positioning of autonomous underwater vehicles, an appropriate underwater terrain database storage format for underwater terrain-matching positioning is established using multi-beam data as underwater terrainmatching data. An underwater terrain interpolation error compensation method based on fractional Brownian motion is proposed for defects of normal terrain interpolation, and an underwater terrain-matching positioning method based on least squares estimation(LSE) is proposed for correlation analysis of topographic features. The Fisher method is introduced as a secondary criterion for pseudo localization appearing in a topographic features flat area, effectively reducing the impact of pseudo positioning points on matching accuracy and improving the positioning accuracy of terrain flat areas. Simulation experiments based on electronic chart and multi-beam sea trial data show that drift errors of an inertial navigation system can be corrected effectively using the proposed method. The positioning accuracy and practicality are high, satisfying the requirement of underwater accurate positioning.  相似文献   

19.
为明确高海况下海况等级对无人水下航行器横摇运动的影响,得出满足某型无人水下航行器安全回收的海况条件,对高海况下无人水下航行器的横摇运动进行分析。运用频率响应法,分别在4级、5级和6级海况下,根据海浪谱密度函数和该型航行器的横摇频率响应函数,求得其横摇运动谱密度函数。再运用公式推导,得到其横摇运动的时域函数。使用MATLAB仿真软件对该型航行器进行横摇运动仿真,得到3种海况条件下,其横摇运动的时域函数图像,并验证仿真结果的准确性。仿真结论:高海况下的海况等级对无人水下航行器的横摇幅度有较大影响,满足其安全回收的海况条件为5级海况。  相似文献   

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