共查询到17条相似文献,搜索用时 171 毫秒
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本文针对四旋翼无人机研究了鲁棒反步姿态控制策略.由于四旋翼无人机结构复杂,其非线性数学模型难以精确建立,因此在控制器设计过程中需要综合考虑模型不确定性、未知外部干扰、输入饱和以及姿态受限等因素.针对模型中的不确定项,使用神经网络进行逼近;对于外部未知干扰,使用非线性干扰观测器进行补偿;使用双曲正切函数逼近饱和函数,解决输入饱和问题;同时使用界限Lyapunov函数设计控制器,确保姿态满足限制条件.最后,设计四旋翼无人机反步姿态控制器,并根据Lyapunov稳定性定理证明了闭环控制系统的有界稳定.仿真结果表明了所研究控制方法的有效性. 相似文献
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四旋翼无人机轨迹稳定跟踪控制 总被引:1,自引:0,他引:1
针对四旋翼无人机轨迹稳定跟踪控制问题,为抑制外界扰动和参数不确定性的影响,设计一种双环鲁棒控制系统.首先,基于动态面内模法设计输出调节器进行位置控制,可解决系统的渐近跟踪及干扰抑制问题;其次,利用高阶滑模设计姿态控制器,可实现全局有限时间收敛,消除系统抖振和相对阶的限制;再次,为进一步提高控制精度,采用一种鲁棒精确微分器对姿态角指令信号进行精确求导;最后,对系统稳定性进行严格的数学证明,并与PID控制和传统滑模控制进行仿真对比,结果验证了所提出控制策略的优越性和鲁棒性. 相似文献
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为解决四旋翼无人机在饱和输入下的轨迹跟踪控制问题,同时兼顾系统存在的参数不确定性和外部风力扰动影响,设计了一种改进的抗干扰自适应鲁棒滑模控制方法;基于六自由度架构,设计四旋翼无人机简化的系统模型,进而降低控制器设计的复杂程度;引入带有误差信号的滑模函数,设计带有误差信号的饱和补偿自适应控制律,同时增加鲁棒控制项,降低由于饱和输入问题带来的抖振影响,并减小参数不确定和外部风力扰动对系统稳定性的影响;系统模型与抗干扰自适应控制律相结合,形成了改进的抗干扰自适应鲁棒滑模控制策略,实现四旋翼无人机的位置轨迹和姿态轨迹的稳定跟踪;最后通过数值仿真与传统PD控制算法进行仿真比较,验证控制方法的有效性和优越性。 相似文献
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针对高超声速飞行器无动力再入过程中具有强耦合、气动参数摄动及不确定性的非线性姿态模型,提出了飞行器姿态控制的一种非线性设计方法。首先基于时标分离原理分内外环设计非线性动态逆控制器,并利用Sigmoid函数分通道制定控制律。针对单纯使用动态逆控制鲁棒性弱的特点,引入基于扩张状态观测器(Extended State Observer,ESO)的自适应控制器对参数摄动和不确定性进行补偿,在参数拉偏和风干扰条件下仿真结果验证了设计控制器具有较强的鲁棒性。 相似文献
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针对四旋翼无人机姿态控制中模型不完整、部分参数和扰动不确定的问题,提出了一种基于神经网络的自适应控制方法,采用RBF神经网络对无人机姿态动力学模型中不确定和扰动部分进行学习,设计了以类反步法为基础,包含反馈控制和神经网络控制的自适应控制器,实现了对未知动态的准确逼近,解决了传统控制方法中过于依赖精确模型的问题。同时设计了神经网络的权值自适应律,实现了控制过程中的在线学习和调整,并且通过李雅普诺夫方法证明了闭环系统的稳定性。仿真结果表明,在存在较大扰动的情况下,上述控制器可得到很好的控制效果,可以实现误差的快速收敛,具有较好的鲁棒性和自适应性。 相似文献
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Modeling and Robust Backstepping Sliding Mode Control with Adaptive RBFNN for a Novel Coaxial Eight-rotor UAV
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Cheng Peng Yue Bai Xun Gong Qingjia Gao Changjun Zhao Yantao Tian 《IEEE/CAA Journal of Automatica Sinica》2015,2(1):56-64
This paper focuses on the robust attitude control of a novel coaxial eight-rotor unmanned aerial vehicles (UAV) which has higher drive capability as well as greater robustness against disturbances than quad-rotor UAV. The dynamical and kinematical model for the coaxial eight-rotor UAV is developed, which has never been proposed before. A robust backstepping sliding mode controller (BSMC) with adaptive radial basis function neural network (RBFNN) is proposed to control the attitude of the eightrotor UAV in the presence of model uncertainties and external disturbances. The combinative method of backstepping control and sliding mode control has improved robustness and simplified design procedure benefiting from the advantages of both controllers. The adaptive RBFNN as the uncertainty observer can effectively estimate the lumped uncertainties without the knowledge of their bounds for the eight-rotor UAV. Additionally, the adaptive learning algorithm, which can learn the parameters of RBFNN online and compensate the approximation error, is derived using Lyapunov stability theorem. And then the uniformly ultimate stability of the eight-rotor system is proved. Finally, simulation results demonstrate the validity of the proposed robust control method adopted in the novel coaxial eight-rotor UAV in the case of model uncertainties and external disturbances. 相似文献
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Mojtaba Sharifi 《Advanced Robotics》2015,29(3):171-186
In this paper, a new nonlinear robust adaptive impedance controller is addressed for Unmanned Aerial Vehicles (UAVs) equipped with a robot manipulator that physically interacts with environment. A UAV equipped with a robot manipulator is a novel system that can perform different tasks instead of human being in dangerous and/or inaccessible environments. The objective of the proposed robust adaptive controller is control of the UAV and its robotic manipulator’s end-effector impedance in Cartesian space in order to have a stable physical interaction with environment. The proposed controller is robust against parametric uncertainties in the nonlinear dynamics model of the UAV and the robot manipulator. Moreover, the controller has robustness against the bounded force sensor inaccuracies and bounded unstructured modeling (nonparametric) uncertainties and/or disturbances in the system. Tracking performance and stability of the system are proved via Lyapunov stability theorem. Using simulations on a quadrotor UAV equipped with a three-DOF robot manipulator, the effectiveness of the proposed robust adaptive impedance controller is investigated in the presence of the force sensor error, and parametric and non-parametric uncertainties. 相似文献
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四旋翼无人飞行器的轨迹跟踪与滑模事件驱动控制 总被引:1,自引:0,他引:1
四旋翼飞行器作为一个典型的欠驱动的系统,具有强耦合、非线性等特性.针对飞行器外部干扰、和通信资源受限条件下的轨迹跟踪控制问题,进行滑模事件驱动控制方法的研究.首先,分析动力学特性,通过时间尺度分解方法将系统解耦成位置子系统和姿态子系统.其次,将位置子系统转化为严格反馈形式,设计反步滑模控制器,实现位置轨迹稳定跟踪;针对姿态子系统存在时变有界扰动及通信受限,设计滑模事件驱动控制律,在抑制干扰的同时实现对虚拟姿态跟踪指令的跟踪.根据Lyapunov分析方法证明了所设计控制器的稳定性,并通过理论分析证明闭环控制系统不会出现Zeno现象.最后,仿真结果验证了滑模事件驱动控制律在存在外部扰动和通信受限时四旋翼无人飞行器轨迹跟踪的鲁棒性. 相似文献
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In this paper, the control problem for a quadrotor helicopter which is subjected to modeling uncertainties and unknown external disturbance is investigated. A new nonlinear robust control strategy is proposed. First, a nonlinear complementary filter is developed to fuse the raw data from the onboard barometer and the accelerometer to decrease the negative effects from the noise associated with the low-cost onboard sensors Then the adaptive super-twisting methodology is combined with a backstepping method to formulate the nonlinear robust controller for the quadrotor''s attitude angles and the altitude position. Lyapunov based stability analysis shows that finite time convergence is ensured for the closed-loop operation of the quadrotor''s roll angle, pitch angle, row angle and the altitude position. Real-time flight experimental results, which are performed on a quadrotor flight testbed, are included to demonstrate the good control performance of the proposed control methodology. 相似文献