采用干扰观测器的水下滑翔蛇形机器人纵倾运动控制  

Control for Pitch Motion of Underwater Gliding Snake-Like Robot Based on Disturbance Observer

作　　者：陈恩志 常健[2,3] 李斌 张国伟[2,3] 刘春[2,3] CHEN Enzhi;CHANG Jian;LI Bin;ZHANG Guowei;LIU Chun(College of Information Science and Engineering,Northeastern University,Shenyang 110819,China;State Key Laboratory of Robotics,Shenyang Institute of Automation,Chinese Academy of Sciences,Shenyang 110016,China;Institutes for Robotics and Intelligent Manufacturing,Chinese Academy of Sciences,Shenyang 110169,China)

机构地区：[1]东北大学信息科学与工程学院,沈阳110819 [2]中国科学院沈阳自动化研究所机器人学国家重点实验室,沈阳110016 [3]中国科学院机器人与智能制造创新研究院,沈阳110169

出　　处：《西安交通大学学报》2020年第1期184-192,共9页Journal of Xi'an Jiaotong University

基　　金：国家重点研发计划资助项目(2017YFB1300103);国家自然科学基金资助项目(61803365)

摘　　要：针对水下滑翔蛇形机器人在实现滑翔运动时存在控制输入受限和外界未知干扰的问题,提出了一种基于Nussbaum函数和非线性干扰观测器的反步控制策略。通过对欠驱动水下滑翔蛇形机器人的垂直面运动进行分析和有条件的简化,得到了对应运动学及动力学方程组。采用Nussbaum函数与双曲正切函数相结合的方式处理系统控制输入饱和,避免了双曲正切函数存在的控制器奇异值,通过非线性干扰观测器实现对外界复合扰动的有效观测并进行补偿。设计了纵倾运动跟踪的反步控制器,针对反步法中虚拟项引发的计算膨胀,采用动态面方法来消除。基于Lyapunov稳定性理论设计了控制器,保证系统能够实现速度与位置信号量的全局一致稳定性。研究结果表明:所提方案相对传统反步法,在响应时间与误差收敛速度方面都有一定程度提高,且非线性干扰观测器对于复合扰动量观测性能良好;所设计的控制器可以有效实现机器人在外界未知干扰下纵倾运动的稳定跟踪,且具有较强的鲁棒性。Aiming at the problem that the underwater gliding snake-like robot has input constraints and unknown external disturbance during implementing gliding,the backstepping control method based on Nussbaum function and nonlinear disturbance observer is proposed to improve its pitching motion tracking performance.The vertical plane motion of the under-actuated underwater gliding snake-like robot is analyzed and conditionally simplified,and the corresponding kinematics and dynamic equations are obtained.Nussbaum function and hyperbolic tangent function are combined to deal with the problem of system control input saturations,which avoids the controller singularity of the latter,and the nonlinear disturbance observer is used to effectively observe and compensate the external complex disturbance.The backstepping controller is designed for pitching motion tracking,where the computational expansion caused by the virtual item in the backstepping method is eliminated by the dynamic surface method.The controller designed following Lyapunov stability theory ensures that the system can achieve global uniform stability of velocity and position semaphore.The results show that compared with the traditional backstepping method,the proposed scheme can improve the response time and error convergence rate to some extent,and the nonlinear disturbance observer has a good performance for observation of complex disturbances.The designed controller can effectively track the longitudinal motion of the robot under the unknown disturbance with strong robustness.

关 键 词：水下滑翔蛇形机器人 纵倾运动 干扰观测器 输入受限 反步控制 

分 类 号：TP242.3[自动化与计算机技术—检测技术与自动化装置]