This paper is concerned with the stabilization problem for a class of nonlinear systems with disturbance. The disturbance model is unknown and the first derivative of disturbance is bounded. Firstly, a general disturb...This paper is concerned with the stabilization problem for a class of nonlinear systems with disturbance. The disturbance model is unknown and the first derivative of disturbance is bounded. Firstly, a general disturbance observer is proposed to estimate disturbance approximatively. Secondly, since the bound of the disturbance observer error is unknown, an adaptive sliding mode controller is designed to guarantee that the state of system asymptotically converges to zero and the unknown bound can be adjusted by an adaptive law. Finally, an example is given to illustrate the effectiveness of the proposed method.展开更多
针对受外界海洋环境扰动的欠驱动船舶航向保持控制问题,设计一种基于鲁棒自适应扰动观测器的船舶航向保持控制算法。通过Lyapunov理论,证明设计的控制器半全局一致最终有界稳定(Semi-Global Uniform and Ultimately Bounded,SGUUB)。以...针对受外界海洋环境扰动的欠驱动船舶航向保持控制问题,设计一种基于鲁棒自适应扰动观测器的船舶航向保持控制算法。通过Lyapunov理论,证明设计的控制器半全局一致最终有界稳定(Semi-Global Uniform and Ultimately Bounded,SGUUB)。以“育鲲”轮为船舶模型,建立考虑外界干扰的非线性Nomoto数学模型,在4级海况下进行航向保持仿真试验,并且与已有的控制算法进行对比,仿真结果表明:在达到稳定之后,基于鲁棒自适应扰动观测器的船舶航向保持器能使舵机操舵频率明显下降,舵机损耗较低,进一步验证提出的控制器算法具有较好的控制效果和鲁棒性。展开更多
Underwater vehicles are being emphasized as highly integrated and intelligent devices for a significant number of oceanic operations. However, their precise operation is usually hindered by disturbances from a tether ...Underwater vehicles are being emphasized as highly integrated and intelligent devices for a significant number of oceanic operations. However, their precise operation is usually hindered by disturbances from a tether or manipulator because their propellers are unable to realize a stable suspension. A dynamic multi-body model-based adaptive controller was designed to allow the controller of the vehicle to observe and compensate for disturbances from a tether or manipulator. Disturbances, including those from a tether or manipulator, are deduced for the observation of the controller. An analysis of a tether disturbance covers the conditions of the surface, the underwater area, and the vehicle end point. Interactions between the vehicle and manipulator are mainly composed of coupling forces and restoring moments.To verify the robustness of the controller, path-following experiments on a streamlined autonomous underwater vehicle experiencing various disturbances were conducted in Song Hua Lake in China. Furthermore,path-following experiments for a tethered open frame remote operated vehicle were verified for accurate cruising with a controller and an observer, and vehicle and manipulator coordinate motion control during the simulation and experiments verified the effectiveness of the controller and observer for underwater operation. This study provides instructions for the control of an underwater vehicle experiencing disturbances from a tether or manipulator.展开更多
An adaptive sliding mode control(ASMC) method, based on fractional-order disturbance-observer(FODOB), is presented for a class of fractional-order nonlinear time-delay systems(FONTDS) with uncertainties to solve the t...An adaptive sliding mode control(ASMC) method, based on fractional-order disturbance-observer(FODOB), is presented for a class of fractional-order nonlinear time-delay systems(FONTDS) with uncertainties to solve the target output tracking problem.The external disturbances are estimated by FODOB, and the unknown internal perturbations of the system are adaptively estimated by sliding mode control(SMC). Furthermore, Gronwall's inequality approach is used to ensure that the output tracking error is uniformly bounded for FONTDS. Firstly, a fractional-order sliding mode control(FOSMC) based FODOB is proposed for a fractional-order linear time-delay system(FOLTDS). Secondly, combined with adaptive estimation, the ASMC of FONTDS is studied. Finally, a numerical example of FONTDS is used to verify the effectiveness of the proposed methods.展开更多
基金supported by National Natural Science Foundationof China (Nos.61074011 and 60904023)
文摘This paper is concerned with the stabilization problem for a class of nonlinear systems with disturbance. The disturbance model is unknown and the first derivative of disturbance is bounded. Firstly, a general disturbance observer is proposed to estimate disturbance approximatively. Secondly, since the bound of the disturbance observer error is unknown, an adaptive sliding mode controller is designed to guarantee that the state of system asymptotically converges to zero and the unknown bound can be adjusted by an adaptive law. Finally, an example is given to illustrate the effectiveness of the proposed method.
文摘针对受外界海洋环境扰动的欠驱动船舶航向保持控制问题,设计一种基于鲁棒自适应扰动观测器的船舶航向保持控制算法。通过Lyapunov理论,证明设计的控制器半全局一致最终有界稳定(Semi-Global Uniform and Ultimately Bounded,SGUUB)。以“育鲲”轮为船舶模型,建立考虑外界干扰的非线性Nomoto数学模型,在4级海况下进行航向保持仿真试验,并且与已有的控制算法进行对比,仿真结果表明:在达到稳定之后,基于鲁棒自适应扰动观测器的船舶航向保持器能使舵机操舵频率明显下降,舵机损耗较低,进一步验证提出的控制器算法具有较好的控制效果和鲁棒性。
基金Supported by National Natural Science Foundation of China(Grant Nos.5129050,51579053,61633009)Major National Science and Technology Project of China(Grant No.2015ZX01041101)Key Basic Research Project of "Shanghai Science and Technology Innovation Plan" of China (Grant No.15JC1403300)
文摘Underwater vehicles are being emphasized as highly integrated and intelligent devices for a significant number of oceanic operations. However, their precise operation is usually hindered by disturbances from a tether or manipulator because their propellers are unable to realize a stable suspension. A dynamic multi-body model-based adaptive controller was designed to allow the controller of the vehicle to observe and compensate for disturbances from a tether or manipulator. Disturbances, including those from a tether or manipulator, are deduced for the observation of the controller. An analysis of a tether disturbance covers the conditions of the surface, the underwater area, and the vehicle end point. Interactions between the vehicle and manipulator are mainly composed of coupling forces and restoring moments.To verify the robustness of the controller, path-following experiments on a streamlined autonomous underwater vehicle experiencing various disturbances were conducted in Song Hua Lake in China. Furthermore,path-following experiments for a tethered open frame remote operated vehicle were verified for accurate cruising with a controller and an observer, and vehicle and manipulator coordinate motion control during the simulation and experiments verified the effectiveness of the controller and observer for underwater operation. This study provides instructions for the control of an underwater vehicle experiencing disturbances from a tether or manipulator.
基金supported by the National Natural Science Foundation of China (Grant Nos. 61573008 and 61973199)the Post-Doctoral Applied Research Projects of Qingdao (Grant No. 2015122)。
文摘An adaptive sliding mode control(ASMC) method, based on fractional-order disturbance-observer(FODOB), is presented for a class of fractional-order nonlinear time-delay systems(FONTDS) with uncertainties to solve the target output tracking problem.The external disturbances are estimated by FODOB, and the unknown internal perturbations of the system are adaptively estimated by sliding mode control(SMC). Furthermore, Gronwall's inequality approach is used to ensure that the output tracking error is uniformly bounded for FONTDS. Firstly, a fractional-order sliding mode control(FOSMC) based FODOB is proposed for a fractional-order linear time-delay system(FOLTDS). Secondly, combined with adaptive estimation, the ASMC of FONTDS is studied. Finally, a numerical example of FONTDS is used to verify the effectiveness of the proposed methods.
