【作者】 潘立鑫；

【导师】 金鸿章；

【作者基本信息】 哈尔滨工程大学 ， 控制理论与控制工程， 2010， 博士

【摘要】 由于人类社会对海洋开发利用意识的不断增强,作为复杂海洋环境下工作的载体,水下机器人的研究受到日益关注。近年来,随着海洋科学和海洋工程的发展,人们广泛展开对近海面大气、海洋气候、水雷布置、水下排障以及潜艇对抗等方面的研究。因此,研究和设计工作于水面或近水面的水下机器人成为海洋机器人发展的一种新趋势。当水下机器人在近水面作业时,由于受到海浪扰动的作用,其运动姿态会有明显的变化。剧烈的横摇和纵摇运动将严重影响水下机器人的正常作业,甚至还会影响到其安全性。为此,人们一直在寻求减小水下机器人近水面作业时的摇荡运动和控制近水面机器人姿态平衡的方法。另外,对于水下机器人来说,一次下潜所携带的能源通常是有限的。如何有效利用能源在完成规定作业任务的同时,实现姿态平衡也是水下机器人研究的重要问题之一。姿态控制与能耗问题的研究对提高水下机器人的智能化水平具有重要的理论研究意义和实际应用价值。针对水下机器人在近水面低航速作业时的姿态控制问题,本文首先从分析水下机器人近水面运动的数学模型入手,通过对近水面波浪干扰力、力矩的数值计算,发现水下机器人在航速很低时,按照普通减摇鳍的工作模式,很难产生足够升力对抗波浪干扰,实现横摇的有效控制。为此,需要引入一种新的减摇鳍翼面工作模式,以提高减摇鳍在零航速或低航速下产生的升力。为解决这一问题,本文采用基于Weis-Fogh机构的零航速减摇鳍装置对横摇姿态进行控制。利用势流理论和旋涡作用力理论对零航速减摇鳍的升力产生情况进行了分析,建立了零航速减摇鳍的升力模型。由于本文研究水下机器人低航速作业时的姿态控制,因而在使用零航速减摇鳍时,还考虑了低速水流经过鳍翼面时对升力产生的影响。本文研究的重点在于,分别针对水下机器人近水面运动模型具有的不确定性、非线性和强耦合特点,采用变结构控制、自抗扰控制、反馈线性化H∞控制、解耦控制和广义预测控制等多种先进控制策略设计姿态控制器,解决由于运动模型复杂性带来的问题。通过对基于零航速减摇鳍的水下机器人近水面姿态控制系统进行仿真,验证了每种控制策略设计和改进的有效性。为实现能源优化利用,本文建立了以减摇效果与驱动能耗优化为目标的综合性能指标,经过推导得到了零航速减摇鳍的最优控制规律。仿真和数值计算的结果说明基于能量优化的水下机器人姿态控制具有一定的理论意义和工程实现价值。更多还原

【Abstract】 AUV (Autonomous Underwater Vehicle) working in complex sea environment attracts increasing attention due to strengthened awareness of ocean exploitation and ocean utilization. With developing of ocean science and engineering in recent years, people make more wide research on atmosphere near sea surface, sea climate, torpedo arrangement, underwater fault-removing and submarine fight. Consequently, it becomes a new trend of sea robot developing to study and design AUV working on or near sea surface.Motion attitude of AUV working near sea surface often changes obviously under the influence of ocean wave. Intense roll and pitch will have a very negative effect on normal working and even safety of AUV. Therefore, the methods to control AUV’s attitude and reduce roll and pitch near sea surface are always needed eagerly. In addition, energy which is carried on AUV for submergence is usually limited, so it comes to be one of the most important issues in AUV research that how to finish specified tasks and aquire balanced AUV attitude with limited energy effectively. Attitude control and energy consumption issues have both the important theoretical and practical values in promoting intelligent levels of AUV.In allusion to the attitude control problem of AUV working near sea surface with low navigating speed, AUV motion model is firstly analyzed in this paper. Through numerical calculation of wave force and wave moment near sea surface, it is found that traditional fin stabilizer is hard to generate enough lift for counteracting wave disturbance when AUV is navigating with low speed. Consequently roll motion is very difficult to control effectively at the moment. Then a new pattern of fin stabilizer working is required to increase lift force in zero-speed or low-speed navigation.In order to solve the above problem, zero-speed fin stabilizer based on Weis-Fogh device is used to control roll attitude in this paper. Lift force generated on zero-speed fin stabilizer is analyzed by using potential theory and vortex action theory. Through relevant deduction, model of lift on zero-speed fin stabilizer is obtained. Because the problem discussed in this paper is attitude control of AUV with low navigating speed, it is necessary to consider additional effect of water flow on the lift while sea water flows through fin surface with relative flow speed.Considering uncertainty, nonlinearity and strong coupling of AUV motion model respectively, research emphasis in this paper focuses on applying corresponding advanced control strategy (e.g. variable structure control, active disturbances rejection control, Hoo control based on feedback linearization, decoupling control and general predictive control) in attitude controller design for solving problems induced by complexity of AUV motion model. Effectiveness of each control strategy in system design and modification is verified by simulation on attitude control system based on zero-speed fin stabilizer of AUV near sea surface.In order to optimize utilization of energy resource, a synthetical performance index is raised, which is based on roll stabilizing performance and energy consumption used for driving fin stabilizer. Through relevant deduction, optimal control law of zero-speed fin stabilizer is obtained. Simulation and numerical calculation results show theoretical significance and practical engineering value in the research of AUV attitude control based on energy optimization.更多还原