浮子式双油面控制器开启及燃油流动特性

飞机燃油系统具有储存燃油、将燃油输送到发动机以及调节飞机重心等功能,从储油箱供给发动机的燃油需经过消耗油箱,其中双油面控制器是消耗油箱中的 1种前导式阀门,能够控制输油的开启关闭,保证油箱基本满油。在使用过程中,发现双油面控制器会出现无法开启或提前关闭现象,给供输油安全带来极大影响。为了了解油面控制器工作异常的原因,并获取阀门内部燃油流动特性,文章采用动力学建模仿真的方法,获得大小活门不同工况下的运动轨迹,发现活门油压方向对开启过程具有明显影响;采用 CFD仿真方法,获取阀门燃油流动特性,发现随阀门开度和入口压力增大,出口燃油由“涌出”变为“喷出”,越过挡油板进入浮子腔的燃油占比增多,可能导致输油的提前关闭。     

基于PID控制的垂直发射控制技术

基于对PID控制的垂直发射控制技术的研究,针对导弹的垂直发射问题,文章阐述了：①建立了气动舵,推力矢量复合控制的模型;②提出了一种能够实现垂直发射快速转弯的程序弹道指令设计方法,并设计了导弹3个通道的PID控制器;③通过对弹道进行6DOF仿真分析,验证了指令和控制器设计的正确性和有效性。     

Fixed-time adaptive model reference sliding mode control for an air-to-ground missile

This paper addresses the fixed-time adaptive model reference sliding mode control for an air-to-ground missile associated with large speed ranges, mismatched disturbances and un-modeled dynamics. Firstly, a sliding mode surface is developed by the tracking error of the state equation and the model reference state equation with respect to the air-to-ground missile. More specifically,a novel fixed-time adaptive reaching law is presented. Subsequently, the mismatched disturbances and the un-modeled dynamics are treated as the model errors of the state equation. These model errors are estimated by means of a fixed-time disturbance observer, and they are also utilized to compensate the proposed controller. Therefore, the fixed-time controller is obtained by an adaptive reaching law and a fixed-time disturbance observer. Closed-loop stability of the proposed controller is established. Finally, simulation results including Monte Carlo simulations, nonlinear six-DegreeOf-Freedom(6-DOF) simulations and different ranges are presented to demonstrate the efficacy of the proposed control scheme.     

高精度非接触磁浮机构电磁干扰特性分析

针对因双超平台姿态控制引入非接触磁浮机构这一关键执行机构,而可能引起的卫星平台新的电磁兼容问题,开展了非接触磁浮机构的电磁干扰特性研究。首先,介绍了非接触磁浮机构及其驱动器的工作原理;其次,分别对非接触磁浮机构驱动器的脉冲宽度调制(PWM)控制信号高频干扰特性和传导电磁干扰特性进行了理论和仿真分析,并将其频率特性与星上其他典型单机的工作频率进行了比对。对比分析结果表明:非接触磁浮机构的电磁干扰频率与星上其他典型单机之间间隔较大,其相互之间产生的电磁干扰可忽略,磁浮机构的引入不会产生新的电磁兼容问题。     

Finite-time relative orbit-attitude tracking control for multi-spacecraft with collision avoidance and changing network topologies

This paper addresses the relative position tracking and attitude synchronization control problem for spacecraft formation flying (SFF). Based on the derived relative coupled six-degree-of-freedom dynamics, a robust adaptive finite-time fast terminal sliding mode controller is proposed to achieve the desired formation in the presence of model uncertainties and external disturbances. It is shown that the designed controller is effective for changing information exchange topology making it robust to node failure. Then, the artificial potential function method is employed to generate collision avoidance schemes to modify the controller such that inter-agent collision avoidance can be ensured during the formation maneuver, which is critical for practical missions. The stability of the overall closed-loop system is proved by using Lyapunov theory. Finally, numerical examples for a given SFF scenario are presented to illustrate the performance of the controller.     

Design of tracking mount and controller for mobile satellite laser ranging system

In this study, we have proposed and implemented a design for the tracking mount and controller of the ARGO-M (Accurate Ranging system for Geodetic Observation - Mobile) which is a mobile satellite laser ranging (SLR) system developed by the Korea Astronomy and Space Science Institute (KASI) and Korea Institute of Machinery and Materials (KIMM). The tracking mount comprises a few core components such as bearings, driving motors and encoders. These components were selected as per the technical specifications for the tracking mount of the ARGO-M. A three-dimensional model of the tracking mount was designed. The frequency analysis of the model predicted that the first natural frequency of the designed tracking mount was high enough. The tracking controller is simulated using MATLAB/xPC Target to achieve the required pointing and tracking accuracy. In order to evaluate the system repeatability and tracking accuracy of the tracking mount, a prototype of the ARGO-M was fabricated, and repeatability tests were carried out using a laser interferometer. Tracking tests were conducted using the trajectories of low earth orbit (LEO) and high earth orbit (HEO) satellites. Based on the test results, it was confirmed that the prototype of the tracking mount and controller of the ARGO-M could achieve the required repeatability along with a tracking accuracy of less than 1 arcsec.     

Start-up current adaptive control for sensorless high-speed brushless DC motors based on inverse system method and internal mode controller

The start-up current control of the high-speed brushless DC (HS-BLDC) motor is a chal-lenging research topic. To effectively control the start-up current of the sensorless HS-BLDC motor, an adaptive control method is proposed based on the adaptive neural network (ANN) inverse system and the two degrees of freedom (2-DOF) internal model controller (IMC). The HS-BLDC motor is identified by the online least squares support vector machine (OLS-SVM) algo-rithm to regulate the ANN inverse controller parameters in real time. A pseudo linear system is developed by introducing the constructed real-time inverse system into the original HS-BLDC motor system. Based on the characteristics of the pseudo linear system, an extra closed-loop feed-back control strategy based on the 2-DOF IMC is proposed to improve the transient response per-formance and enhance the stability of the control system. The simulation and experimental results show that the proposed control method is effective and perfect start-up current tracking perfor-mance is achieved.     

运输机超低空空投抗侧风控制器设计

为使运输机能在较强侧风下仍能完成空投任务,需设计抗侧风控制器减缓其对空投过程的影响。分别设计了经典的PD控制器和离散论域的模糊控制器。仿真结果表明,两者均能有效抑制侧风干扰。与PD控制器相比,模糊控制器具有更高的控制精度和较强的鲁棒性。     

基于变质心/RCS复合方式的再入飞行器控制系统设计方法研究

再入飞行器采用变质心控制不但可以保持较好的气动外形,还可以降低能量消耗以增大载荷能力,但该控制对气动力的依赖较大,在气动力不足时需要与其他控制方式复合以实现系统响应指标.本文提出一种基于变质心控制性能分析的全空域高动态特性再入飞行变质心/RCS复合控制模式,以动压和攻角偏差为逻辑判断变量,并设计了虚拟控制器与力矩分配控...     

利用VB设计动态模拟MCS51中断系统的仿真平台

用VB编程软件设计——仿真单片机8051中断系统的响应过程，采用动态教学方法，实验演示和动手相结合，使教学变得活灵活现，栩栩如生。