未知时变扰动和输入饱和下的智能船舶鲁棒非线性控制

复杂海况下环境多变并且船舶具有多耦合、强非线性的特点,针对智能船舶定位控制问题,考虑在未知时变扰动和输入饱和约束之下船舶的定位控制问题,结合非线性扰动观测器提出一种带辅助动态系统的鲁棒非线性控制算法。通过Lyapunov理论证明了所提出的非线性扰动观测器与控制器结合后闭环系统的稳定性和信号的一致最终有界性。利用非线性扰动观测器对环境中存在的海浪扰动进行有效的估计处理。最后,通过仿真验证了所提出的控制算法不仅能保证船舶期望的位置和艏向,而且提高了控制速度,具有较好的控制性能。     

一种基于跟踪变结构控制的鱼雷制导律设计方法

利用变结构控制对干扰和参数摄动的“完全自适应性”,设计出了一种基于运动跟踪变结构控制的鱼地律,并将其于被动方式的水下目标跟踪问题中,结果表明,该制导律可以令相对视线角速度按照给定的运动规律变化,从而大大增强了被动跟踪问题的可观性评估的 且对干扰和参数摄动具有较强的鲁棒性,易于工程化问题的处理     

舵阻摇H∞控制器的设计

舵阻摇的效果对船舶水动力参数敏感,Ｈ_∞控制器对模型不确定性具有良好的适应性。本文设计了一种基于并联控制模式的舵阻摇Ｈ_∞控制器。模拟海上航行条件的计算机仿真表明该控制器具有良好的鲁棒特性。     

Technical Note: Force Control in Electrohydraulic Active Suspensions Revisited

The inner loop control for the actuator force can be quite simply compensated by means of a correction term to the desired force signal at the input. The correction requires only a measurement of the actuator piston velocity and is employed to cancel the loop disturbance caused by the oil flow to the actuator. Although an additional time constant is introduced by the integration in the inner loop force control, the overall performance is nevertheless quite close to that of an ideal optimal system.     

离散型闭环增益成形算法及其应用

将闭环增益成形算法推广到离散系统中去。分别用Z变换、差分反演法和双线性变换给出一阶、二阶和三阶闭环增益成形算法的离散形式，然后针对船舶航向保持问题，在Matlab环境中进行了仿真研究。仿真结果表明，航向保持的跟踪速度快、没有超调，当模型参数改变时，控制器具有一定的鲁棒性，说明离散型闭环增益成形算法是有效的。     

Robust Spectral Estimation of Track Irregularity

Because the existing spectral estimation methods for railway track irregularity analysis are very sensitive to outliers, a robust spectral estimation method is presented to process track irregularity signals. The proposed robust method is verified using 100 groups of clean/contaminated data reflecting he vertical profile irregularity taken from Bejing-Guangzhou railway with a sampling frequency of 33 data every 10 m, and compared with the Auto Regressive (AR) model. The experimental results show that the proposed robust estimation is resistible to noise and insensitive to outliers, and is superior to the AR model in terms of efficiency,, stability and reliability.     

Robust control and actuator dynamics compensation for railway vehicles

A robust controller is designed for active steering of a high speed train bogie with solid axle wheel sets to reduce track irregularity effects on the vehicle’s dynamics and improve stability and curving performance. A half-car railway vehicle model with seven degrees of freedom equipped with practical accelerometers and angular velocity sensors is considered for the H_∞ control design. The controller is robust against the wheel/rail contact parameter variations. Field measurement data are used as the track irregularities in simulations. The control force is applied to the vehicle model via ball-screw electromechanical actuators. To compensate the actuator dynamics, the time delay is identified online and is used in a second-order polynomial extrapolation carried out to predict and modify the control command to the actuator. The performance of the proposed controller and actuator dynamics compensation technique are examined on a one-car railway vehicle model with realistic structural parameters and nonlinear wheel and rail profiles. The results showed that for the case of nonlinear wheel and rail profiles significant improvements in the active control performance can be achieved using the proposed compensation technique.     

非正态分布的汽车半轴凸缘的可靠性稳健设计

将可靠性优化设计理论、可靠性灵敏度分析技术与稳健设计方法相结合,讨论了随机参数服从非正态分布汽车半轴凸缘的可靠性稳健设计问题,提出了可靠性稳健优化设计的计算方法。把可靠性灵敏度溶入可靠性优化设计模型之中,将可靠性稳健设计归结为满足可靠性要求的多目标优化问题。     

灰色建模中数据缺失值处理方法探讨

为解决在利用灰色理论建模中,出现的数据缺失问题,本文提出综合利用SPSS软件的缺失值处理模块和稳健估计模块,针对数据的缺失机制进行处理的方法。使用该方法对缺失数据进行处理,以保证模型能够正常进行数据拟合。本文还利用了SPSS软件对某一实例中的缺失值进行了估计,并对缺失值填充后的结果进行了评价。     

Achieving sustainable development of supply chain by incorporating various carbon regulatory mechanisms

Nowadays, sustainability issues have received considerable attention in supply chain management because of the governmental requirements as well as expectations of the people. This paper introduces a novel supply chain network design problem to cover three dimensions of sustainability, namely economic, environmental, and social. The advantage of the presented model stems from considering the booming development aligned with reduction in environmental impact. In this paper, to achieve the mentioned benefits and to derive a more sustainable supply chain, a novel model in the presence of the most commonly used carbon policies is proposed. This paper, addresses sustainable development through imposing proper carbon regulatory mechanisms. Main contribution of this study is to consider the effect of imposing carbon policies on environmental advantages as well as improving the regional development level in a supply chain network design problem. Moreover, the shipment consolidation decisions are utilized to reduce cost as well as environmental impact. In addition, a novel mixed uncertainty approach is proposed to capture the uncertain emission parameters. The numerical examples and a case study are analyzed to evaluate the performance of the proposed models. It is concluded that, a high-growth economy with low-carbon can be made and also almost global well-being of people is ensured by applying the proposed model. Some managerial insights are provided for the enterprises of supply chains to make the most appropriate sustainable decisions. Finally, proper carbon emission policies are suggested based on the region sustainability characteristics.