In the semi-physical simulation of aeroengines,using the pneumatic pressure servo control technology to provide realistic pneumatic excitation to the sensors and electronic controller can improve the confidence of the...In the semi-physical simulation of aeroengines,using the pneumatic pressure servo control technology to provide realistic pneumatic excitation to the sensors and electronic controller can improve the confidence of the simulation and reduce the test cost and risk.However,the existing methods could not satisfy the precise simulation of large-amplitude and high-frequency pulsating pressure during aeroengine surge.In this paper,a pneumatic pressure control system with asymmetric groups of the High-Speed on–off Valve(HSV)is designed,and an Improved Nonlinear Model Predictive Control(INMPC)method is proposed.First,the volumetric flow characteristics of HSV are tested and analyzed with Pulse Width Modulation(PWM)signal input.Then,a simplified HSV model with the volume flow characteristic correction is developed.Based on these,an integrated model for the whole system is further established and used as the prediction model in INMPC.To improve the computational speed of the rolling optimization process,the mapping scheme from control signal to PWM duty cycle of HSVs and the objective function with exterior penalty function are designed.Finally,the random step,sinusoidal and real engine surge data are set as the reference pressure in multiple comparative experiments to verify the effectiveness of the pressure tracking system.展开更多
An intuitive method is proposed to solve the diffcult problem for the initialization of group tracking. In order to initialize the group tracks. the reports obtained from the every moment must be separated as several ...An intuitive method is proposed to solve the diffcult problem for the initialization of group tracking. In order to initialize the group tracks. the reports obtained from the every moment must be separated as several groups at first. Then. each group in the first moment is associated with each group in the second moment. At last. group velocity vector must be estimated. In order to obtain accurate estimates meanwhile not to make the computation amount more heavier. different algorithms must be selected according to the target's number of the group in the first moment.展开更多
在随机有限集框架下给出了当杂波和漏检存在时,群目标联合检测与估计(Joint detection and estimation,JDE)误差界的递推形式.首先,将多个群目标运动过程建模为一个多Bernoulli过程,并采用连续个体目标数假设建模群目标观测似然函数;其...在随机有限集框架下给出了当杂波和漏检存在时,群目标联合检测与估计(Joint detection and estimation,JDE)误差界的递推形式.首先,将多个群目标运动过程建模为一个多Bernoulli过程,并采用连续个体目标数假设建模群目标观测似然函数;其次,采用最优子模式分配距离定义群目标JDE误差;最终,利用信息不等式推导获得了建议的误差界.仿真实验在不同杂波密度和检测概率场景下利用群势概率假设密度和群势平衡多目标多Bernoulli滤波器对该误差界的有效性进行了验证.展开更多
以多样成像模式对挠性敏捷卫星姿态的快速机动控制为需求,本文针对金字塔构型控制力矩陀螺(control moment gyroscope, CMG)群为执行机构的挠性卫星,提出基于三段式正弦角加速度的姿态路径规划方法及具有滚动优化思想的跟踪控制算法.在...以多样成像模式对挠性敏捷卫星姿态的快速机动控制为需求,本文针对金字塔构型控制力矩陀螺(control moment gyroscope, CMG)群为执行机构的挠性卫星,提出基于三段式正弦角加速度的姿态路径规划方法及具有滚动优化思想的跟踪控制算法.在姿态机动路径规划方法设计中,融合谱分析及非线性优化方法,设计了兼顾卫星姿态机动快速性及抑制挠性附件振动性能的姿态轨迹;为实现对规划姿态轨迹的高精度跟踪,综合加权优化指标及奇异性、执行机构能力等约束,设计了金字塔构型CMG群框架角速度的非线性模型预测(nonlinear model predictive control, NMPC)跟踪控制律.在转动惯量存在测量误差及空间干扰情况下,多种姿态机动仿真表明,本文提出的控制方法是有效的,且表现出较强的鲁棒性.展开更多
When a mass of individual targets move closely, it is unpractical or unnecessary to localize and track every specific target in wireless sensor networks (WSN). However, they can be tracked as a whole by view of group ...When a mass of individual targets move closely, it is unpractical or unnecessary to localize and track every specific target in wireless sensor networks (WSN). However, they can be tracked as a whole by view of group target. In order to decrease the amount of energy spent on active sensing and communications, a flexible boundary detecting model for group target tracking in WSN is proposed, in which, the number of sensors involved in target tracking is adjustable. Unlike traditional one or multiple individual targets, the group target usually occupies a large area. To obtain global estimated position of group target, a divide-merge algorithm using convex hull is designed. In this algorithm, group target’s boundary is divided into several small pieces, and each one is enclosed by a convex hull which is constructed by a cluster of boundary sensors. Then, the information of these small convex hulls is sent back to a sink. Finally, big convex hull merged from these small ones is considered as the group target’s contour. According to our metric of precision evaluation, the simulation experiments confirm the efficiency and accuracy of this algorithm.展开更多
联合概率数据关联粒子滤波(joint probabilistic data association-particle filter,JPDA-PF)算法常被用来解决群目标跟踪中的数据关联和非线性滤波问题.针对算法的数据关联时间较长以及样本枯竭问题,本文阐述了一种利用模糊聚类和拟蒙...联合概率数据关联粒子滤波(joint probabilistic data association-particle filter,JPDA-PF)算法常被用来解决群目标跟踪中的数据关联和非线性滤波问题.针对算法的数据关联时间较长以及样本枯竭问题,本文阐述了一种利用模糊聚类和拟蒙特卡罗重采样的群目标跟踪算法.首先,在群演化网络模型的基础上,采用最大熵模糊聚类法来完成群内个体目标和量测之间的数据关联,利用模糊隶属度来构建互联概率矩阵.其次,在目标状态样本的重采样的过程中,利用随机化拟蒙特卡罗序列映射到拟复制样本的子空间上,提高样本的多样性,抑制样本枯竭的出现.仿真实验结果表明,与JPDA-PF算法相比,本文算法能有效估计群内目标状态和群结构,并具有更优的估计性能.展开更多
基金co-supported by the National Natural Science Foundation of China(No.51976089)the Natural Science Foundation of Fujian Province of China(No.2021J05113).
文摘In the semi-physical simulation of aeroengines,using the pneumatic pressure servo control technology to provide realistic pneumatic excitation to the sensors and electronic controller can improve the confidence of the simulation and reduce the test cost and risk.However,the existing methods could not satisfy the precise simulation of large-amplitude and high-frequency pulsating pressure during aeroengine surge.In this paper,a pneumatic pressure control system with asymmetric groups of the High-Speed on–off Valve(HSV)is designed,and an Improved Nonlinear Model Predictive Control(INMPC)method is proposed.First,the volumetric flow characteristics of HSV are tested and analyzed with Pulse Width Modulation(PWM)signal input.Then,a simplified HSV model with the volume flow characteristic correction is developed.Based on these,an integrated model for the whole system is further established and used as the prediction model in INMPC.To improve the computational speed of the rolling optimization process,the mapping scheme from control signal to PWM duty cycle of HSVs and the objective function with exterior penalty function are designed.Finally,the random step,sinusoidal and real engine surge data are set as the reference pressure in multiple comparative experiments to verify the effectiveness of the pressure tracking system.
文摘An intuitive method is proposed to solve the diffcult problem for the initialization of group tracking. In order to initialize the group tracks. the reports obtained from the every moment must be separated as several groups at first. Then. each group in the first moment is associated with each group in the second moment. At last. group velocity vector must be estimated. In order to obtain accurate estimates meanwhile not to make the computation amount more heavier. different algorithms must be selected according to the target's number of the group in the first moment.
文摘在随机有限集框架下给出了当杂波和漏检存在时,群目标联合检测与估计(Joint detection and estimation,JDE)误差界的递推形式.首先,将多个群目标运动过程建模为一个多Bernoulli过程,并采用连续个体目标数假设建模群目标观测似然函数;其次,采用最优子模式分配距离定义群目标JDE误差;最终,利用信息不等式推导获得了建议的误差界.仿真实验在不同杂波密度和检测概率场景下利用群势概率假设密度和群势平衡多目标多Bernoulli滤波器对该误差界的有效性进行了验证.
文摘以多样成像模式对挠性敏捷卫星姿态的快速机动控制为需求,本文针对金字塔构型控制力矩陀螺(control moment gyroscope, CMG)群为执行机构的挠性卫星,提出基于三段式正弦角加速度的姿态路径规划方法及具有滚动优化思想的跟踪控制算法.在姿态机动路径规划方法设计中,融合谱分析及非线性优化方法,设计了兼顾卫星姿态机动快速性及抑制挠性附件振动性能的姿态轨迹;为实现对规划姿态轨迹的高精度跟踪,综合加权优化指标及奇异性、执行机构能力等约束,设计了金字塔构型CMG群框架角速度的非线性模型预测(nonlinear model predictive control, NMPC)跟踪控制律.在转动惯量存在测量误差及空间干扰情况下,多种姿态机动仿真表明,本文提出的控制方法是有效的,且表现出较强的鲁棒性.
文摘When a mass of individual targets move closely, it is unpractical or unnecessary to localize and track every specific target in wireless sensor networks (WSN). However, they can be tracked as a whole by view of group target. In order to decrease the amount of energy spent on active sensing and communications, a flexible boundary detecting model for group target tracking in WSN is proposed, in which, the number of sensors involved in target tracking is adjustable. Unlike traditional one or multiple individual targets, the group target usually occupies a large area. To obtain global estimated position of group target, a divide-merge algorithm using convex hull is designed. In this algorithm, group target’s boundary is divided into several small pieces, and each one is enclosed by a convex hull which is constructed by a cluster of boundary sensors. Then, the information of these small convex hulls is sent back to a sink. Finally, big convex hull merged from these small ones is considered as the group target’s contour. According to our metric of precision evaluation, the simulation experiments confirm the efficiency and accuracy of this algorithm.
文摘联合概率数据关联粒子滤波(joint probabilistic data association-particle filter,JPDA-PF)算法常被用来解决群目标跟踪中的数据关联和非线性滤波问题.针对算法的数据关联时间较长以及样本枯竭问题,本文阐述了一种利用模糊聚类和拟蒙特卡罗重采样的群目标跟踪算法.首先,在群演化网络模型的基础上,采用最大熵模糊聚类法来完成群内个体目标和量测之间的数据关联,利用模糊隶属度来构建互联概率矩阵.其次,在目标状态样本的重采样的过程中,利用随机化拟蒙特卡罗序列映射到拟复制样本的子空间上,提高样本的多样性,抑制样本枯竭的出现.仿真实验结果表明,与JPDA-PF算法相比,本文算法能有效估计群内目标状态和群结构,并具有更优的估计性能.
