一类非自治单种群模型的持久性

在这篇文章里,我们利用微分方程比较原理以及一些精细的分析方法,研究了具有无限时滞和反馈控制的非自治单种群模型的持久性,得到了一些新的结论。     

火控系统故障诊断与性能检测设备研究

从设备主要功能、设备硬件设计、检测软件及故障诊断软件设计等方面,系统地分析了检测设备的总体设计方案,功能特点,信号采集、处理与控制等。设计过程突出了理论与实践相结合的设计理念,针对某型火控系统的特点,结合实际研制过程,该方法具有较好的应用推广价值。     

四元数在火控中的应用

介绍了四元数的定义、代数运算、三角形式和指数形式以及球面表示形式;综述了四元数在刚体姿态控制,计算机三维图像旋转,彩色图像处理和信号处理分析等实际应用中表示的物理含义,着重探讨了四元数理论在火控领域中应用方法,并对比传统欧拉角火控模型,分析了应用四元数火控模型的优点。最后从理论上得出,四元数理论方法在常规兵器火控系统有广阔的应用前景。     

一种基于二分法的无线传感器网络拓扑控制算法

文中针对传感器节点分布不均和拓扑建立时间长的问题,提出了一种基于二分法的拓扑控制算法,每个节点自适应选择发射功率以获得预设的度。仿真显示,与基于均匀功率增量的算法相比,基于二分法的拓扑控制算法大大减少了功率切换次数且形成的拓扑简单,减少了网络拓扑形成时间和平均发射功率。     

基于多层授权体制的档案全文检索系统设计与实现

档案资料不同于普通的信息资源,其在保密性和专属性上有较高的要求。研 究了在网络环境下建设数字档案全文检索系统时遇到的问题,分析了原有授权体制存在的 弊端,提出了一种基于角色、用户分离的多层授权体制,并在实际系统建设中应用此授权体 制,实现了高效的全文检索和安全、可靠、灵活的访问控制。     

Dual-steering mode based on direct yaw moment control for multi-wheel hub motor driven vehicles:Theoretical design and experimental assessment

One of the main challenges for multi-wheel hub motor driven vehicles is the coordination of individual drivetrains to improve mobility and stability in the steering process.This paper proposes a dual-steering mode based on direct yaw moment control for enhancing vehicle steering ability in complex environ-ments.The control system is designed as a hierarchical structure,with a yaw moment decision layer and a driving force distribution layer.In the higher-level layer,the objective optimization function is con-structed to obtain the slip steering ratio,which represents the degree of vehicle slip steering in the dual-steering mode.A yaw moment controller using active disturbance rejection control theory is designed for continuous yaw rate control.When the actual yaw rate of the vehicle deviates from the reference yaw rate obtained by the vehicle reference model and the slip steering ratio,the yaw moment controller is actuated to determine the yaw moment demand for vehicle steering.In the lower-level layer,there is a torque distribution controller based on distribution rules,which meets the requirement of yaw moment demand without affecting the total longitudinal driving force of the vehicle.For verifying the validity and feasibility of the dual-steering mode,simulations were conducted on the hardware-in-loop real-time simulation platform.Additionally,corresponding real vehicle tests were carried out on an eight-wheel prototype vehicle.Test results were generally consistent with the simulation results,thereby demon-strating that the proposed dual-steering mode reduces steering radius and enhances the steering per-formance of the vehicle.     

基于经典控制理论的制导系统校正方法研究

针对空空导弹抗目标大机动时,制导系统持续增加的快速性需求,利用反馈/前馈控制信号可提高瞬态和频率响应的经典控制思想,以及在制导算法中引入导弹的实际加速度补偿量以改善制导回路性能的方法,设计了制导系统校正算法.然后,通过线性化模型对制导系统校正算法的性能进行了数字仿真,仿真结果表明系统校正算法能够降低目标机动时所产生的脱...     

二语熟练度及语言使用特征对双语者抑制控制能力的影响

本文考察双语者二语熟练程度及不同语言使用特征对其抑制控制能力影响的差异。根据二语的熟练程度将被试分为熟练双语者组和不熟练双语者组,在熟练组和不熟练组中根据不同的语言使用特征划分为以口语为主和以阅读为主的两个被试组。所有被试都参与Stroop任务、Simon任务和Flanker任务。结果发现:熟练度高的双语者在三种任务中均表现出了优势反应。说明二语熟练程度对双语者的抑制控制能力有着促进作用;在不同语言使用特征组中,两组被试在simon任务与stroop任务中表现无显著差异,但表现出明显的CA效应。表明二语熟练度影响双语者的抑制控制能力;语言使用特征的不同对双语者的抑制控制能力无显著影响。     

Barrier Lyapunov functions-based dynamic surface control with tracking error constraints for ammunition manipulator electro-hydraulic system

This paper focuses on the dynamic tracking control of ammunition manipulator system. A standard state space model for the ammunition manipulator electro-hydraulic system (AMEHS) with inherent non-linearities and uncertainties considered was established. To simultaneously suppress the violation of tracking error constraints and the complexity of differential explosion, a barrier Lyapunov functions-based dynamic surface control (BLF-DSC) method was proposed for the position tracking control of the ammunition manipulator. Theoretical analysis prove the stability of the closed-loop overall system and the tracking error converges to a prescribed neighborhood asymptotically. The effectiveness and dynamic tracking performance of the proposed control strategy is validated via simulation and experi-mental results.     

Finite-time tracking control and vibration suppression based on the concept of virtual control force for flexible two-link space robot

The dynamic modeling, finite-time trajectory tracking control and vibration suppression of a flexible two-link space robot are studied. Firstly, the dynamic model of the system is established by combining Lagrange method with assumed mode method. In order to ensure that the base attitude and the joints of space robot can reach the desired positions within a limited time, a non-singular fast terminal sliding mode (NFTSM) controller is designed, which realizes the finite-time convergence of the trajectory tracking errors. Subsequently, for the sake of suppressing the vibrations of flexible links, a hybrid tra-jectory based on the concept of the virtual control force is developed, which can reflect the flexible modes and the trajectory tracking errors simultaneously. By modifying the original control scheme, a NFTSM hybrid controller is proposed. The hybrid control scheme can not only realized attitude stabili-zation and trajectory tracking of joints in finite time, but also provide a new method of vibration sup-pression. The simulation results verify the effectiveness of the designed hybrid control strategy.