【作者】 张杰；

【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， 硕士

【摘要】 水下机器人在近水面作业时,由于受到海浪、海风、海流等海洋环境扰动的作用,会产生横摇、纵摇等摇荡运动。水下机器人的剧烈摇荡将严重影响机器人的正常作业,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,并设计出多种近水面作业的水下机器人运动控制系统,比如含有PID控制器、模糊控制器、神经网络控制器和变结构控制器等的运动控制系统。在一定条件下,滑动模对于干扰与参数的变化具有不变性,这是具有滑动模的变结构系统的一个非常重要的特征。正是因为这一特征,这些年来,在解决十分复杂的非线性系统的综合问题时,变结构控制系统理论作为一种综合方法得到重视。因此本文选择变结构控制系统对近水面作业的水下机器人的运动进行控制。本文重点研究设计可控正则型的多输入非线性系统模型的变结构控制器,利用分散滑动模态控制的方法将可控正则型系统进行合理分解,分解成若干个子系统,再对各个子系统分别进行变结构控制器的设计,采用极点配置法设计切换函数,采用等速趋近率来削弱抖振。对于设计近水面作业的机器人系统的变结构控制器,先将原系统进行可控正则化后,再按照这一方法设计变结构控制器。在MATLAB SIMULINK软件环境下,对近水面作业的水下机器人控制系统进行仿真,仿真结果表明,本文所设计的控制系统综合减摇取得了较好的减摇效果,而且系统抖振较弱,动态性能较好,控制精度也高,控制器既具有理想滑模的优点,又避免了它的缺点。为变结构控制器控制近水面作业的机器人综合减摇的提供了一定的理论支持。更多还原

【Abstract】 The attitude and motion of the near-sea-surface robot will change obviously under the influence of ocean waves. Because the roll motion and the pitch motion will have a very negative effect on the near-sea-surface robot’s duty and safety, the methods to control the near-sea-surface robot’s attitude and reduce the roll and pitch motion are needed eagerly. And many methods have been found and already used to control the near-sea-surface robot, such as PID controller、fuzzy controller、neural network controller and variable structure controller.The most important characteristic of the variable structure controller is that under some condition, the sliding mode is insensitive to the external disturbance and parameter variations. Just because of this characteristic, the variable structure control has been widely used to solve complex non-linear system problems. So the variable structure control is chosen as the method to control the position and attitude of the near-sea-surface robot in this paper.In the paper, the method to design variable structure controller of the controllable regular multi-input nonlinear system is proposed. Firstly, the controllable regular multi-input nonlinear system is divided into some subsidiary systems by a decentralized control strategy. Secondly, the variable structure controller of the subsidiary system is designed correspondingly. The pole placement method is used to design the switching function and the constant ration strategy is used to reduce the chattering phenomenon. So the variable structure controller of the near-sea-surface robot can be designed by this method.The simulation of the near-sea-surface robot control system is carried out by MATLAB SIMULINK program. The simulation results show that, the control system designed in this paper do reduce the roll motion and pitch motion. And the system has satisfactory quality, much smaller chattering, the high performance dynamic characteristics and robustness. The design in this paper has provided that the variable structure controller is an effective measurement to control the motion of the near-sea-surface robot system and maintain the robot’s attitude effectively.更多还原