A discrete differential evolution algorithm combined with the branch and bound method is developed to solve the integer linear bilevel programming problems, in which both upper level and lower level variables are forc...A discrete differential evolution algorithm combined with the branch and bound method is developed to solve the integer linear bilevel programming problems, in which both upper level and lower level variables are forced to be integer. An integer coding for upper level variables is adopted, and then a discrete differential evolution algorithm with an improved feasibility-based comparison is developed to directly explore the integer solution at the upper level. For a given upper level integer variable, the lower level integer programming problem is solved by the existing branch and bound algorithm to obtain the optimal integer solution at the lower level. In the same framework of the algorithm, two other constraint handling methods, i.e. the penalty function method and the feasibility-based comparison method are also tested. The experimental results demonstrate that the discrete differential evolution algorithm with different constraint handling methods is effective in finding the global optimal integer solutions, but the improved constraint handling method performs better than two compared constraint handling methods.展开更多
针对X-Y平台中模型误差和扰动未知等问题,本文以夹胶玻璃自动切膜为应用背景,设计自动切膜恒力控制系统,并对系统中的交互力进行分析与建模。提出了一种改进线性自抗扰(linear active disturbance rejection controller,LADRC)力控制器...针对X-Y平台中模型误差和扰动未知等问题,本文以夹胶玻璃自动切膜为应用背景,设计自动切膜恒力控制系统,并对系统中的交互力进行分析与建模。提出了一种改进线性自抗扰(linear active disturbance rejection controller,LADRC)力控制器,将滑模控制嵌入到基于预报的线性跟踪微分器(tracking differentiator,TD)中,平衡滤波与相位滞后间的矛盾,利用分数阶比例微分(fractional order proportion differentiation,FOPD)快速响应跟踪力误差,并通过Lyapunov函数对改进线性跟踪微分器进行稳定性证明。通过与线性自抗扰进行比较,对所设计的控制器进行了仿真分析与实验验证。实验结果表明,当玻璃位置等参数发生变化时,基于改进跟踪微分器的线性自抗扰控制系统仍能较好地实现对切刀的交互力控制,有效保证切膜效果,证明了提出方法的有效性与实用性。展开更多
四旋翼无人机系统具有参数不确定性及强耦合性的特点,其飞行性能容易受到外部干扰而下降.为了保证四旋翼无人机飞行的稳定性,本文提出了一种基于改进线性扩张状态观测器(Linear Extended State Observer,LESO)的模糊线性自抗扰控制方法...四旋翼无人机系统具有参数不确定性及强耦合性的特点,其飞行性能容易受到外部干扰而下降.为了保证四旋翼无人机飞行的稳定性,本文提出了一种基于改进线性扩张状态观测器(Linear Extended State Observer,LESO)的模糊线性自抗扰控制方法.通过模糊算法自适应调节线性自抗扰控制器的参数,基于Levant跟踪微分器跟踪四旋翼无人机位置及姿态角的二阶微分信号进而提取四旋翼无人机系统的总扰动,使用总扰动偏差及偏差的微分作为输入的模糊控制器来优化LESO对总扰动的估计精度.此外,分析了LESO的收敛性及闭环系统的稳定性.最后通过对比仿真验证了所提控制策略的有效性,并从系统的控制信号,动态响应能力和抗干扰能力等方面对控制方案的性能进行了定量分析.展开更多
基金supported by the Natural Science Basic Research Plan in Shaanxi Province of China(2013JM1022)the Fundamental Research Funds for the Central Universities(K50511700004)
文摘A discrete differential evolution algorithm combined with the branch and bound method is developed to solve the integer linear bilevel programming problems, in which both upper level and lower level variables are forced to be integer. An integer coding for upper level variables is adopted, and then a discrete differential evolution algorithm with an improved feasibility-based comparison is developed to directly explore the integer solution at the upper level. For a given upper level integer variable, the lower level integer programming problem is solved by the existing branch and bound algorithm to obtain the optimal integer solution at the lower level. In the same framework of the algorithm, two other constraint handling methods, i.e. the penalty function method and the feasibility-based comparison method are also tested. The experimental results demonstrate that the discrete differential evolution algorithm with different constraint handling methods is effective in finding the global optimal integer solutions, but the improved constraint handling method performs better than two compared constraint handling methods.
文摘针对X-Y平台中模型误差和扰动未知等问题,本文以夹胶玻璃自动切膜为应用背景,设计自动切膜恒力控制系统,并对系统中的交互力进行分析与建模。提出了一种改进线性自抗扰(linear active disturbance rejection controller,LADRC)力控制器,将滑模控制嵌入到基于预报的线性跟踪微分器(tracking differentiator,TD)中,平衡滤波与相位滞后间的矛盾,利用分数阶比例微分(fractional order proportion differentiation,FOPD)快速响应跟踪力误差,并通过Lyapunov函数对改进线性跟踪微分器进行稳定性证明。通过与线性自抗扰进行比较,对所设计的控制器进行了仿真分析与实验验证。实验结果表明,当玻璃位置等参数发生变化时,基于改进跟踪微分器的线性自抗扰控制系统仍能较好地实现对切刀的交互力控制,有效保证切膜效果,证明了提出方法的有效性与实用性。
基金Supported by National Basic Research Program of China （973 Program） （2007CB814904）, National Natural Science Foundation of China （10671112, 10701050）, and Natural Science Foundation of Shandong Province （Z2006A01）
文摘采用自主水下航行器(Autonomous Underwater Vehicle,AUV)磁测平台可开展海洋地磁场测量、水下磁性目标探测和识别等工作,AUV磁测平台具有广阔的应用前景,但目前AUV载体磁干扰补偿技术研究尚不成熟,制约着水下航行器测磁精度。基于磁测平台抗磁干扰基本原理,提出一种基于线性种群规模缩减和成功历史的参数自适应差分进化(Success History-based Adaptive Differential Evolution with Linear Population Size Reduction,L-SHADE)算法的AUV载体磁干扰参数辨识的数值模拟方法。用磁偶极子和旋转椭球壳混合模型来等效模拟AUV载体磁干扰,通过模拟航行获得多组磁测数据,据此建立磁干扰参数辨识模型,并采用L-SHADE算法求解。通过数值模拟实验定量分析研究磁测平台测磁精度随磁传感器、平台姿态及航向等误差的传播规律。研究结果表明:当磁传感器测量精度为10 nT、姿态测量精度为0.01°、航向测量精度为0.1°时,测磁误差可小于100 nT。设计的AUV磁测平台抗干扰试验表明,地磁场总量最大相对误差为1.07%。
文摘四旋翼无人机系统具有参数不确定性及强耦合性的特点,其飞行性能容易受到外部干扰而下降.为了保证四旋翼无人机飞行的稳定性,本文提出了一种基于改进线性扩张状态观测器(Linear Extended State Observer,LESO)的模糊线性自抗扰控制方法.通过模糊算法自适应调节线性自抗扰控制器的参数,基于Levant跟踪微分器跟踪四旋翼无人机位置及姿态角的二阶微分信号进而提取四旋翼无人机系统的总扰动,使用总扰动偏差及偏差的微分作为输入的模糊控制器来优化LESO对总扰动的估计精度.此外,分析了LESO的收敛性及闭环系统的稳定性.最后通过对比仿真验证了所提控制策略的有效性,并从系统的控制信号,动态响应能力和抗干扰能力等方面对控制方案的性能进行了定量分析.
