基于攻角预测模型的航空发动机高稳定性控制

研究了发动机稳定性控制问题.作战飞机在超机动飞行时,发动机进口流场畸变严重,采用常规控制并不能保证其稳定工作.针对上述问题,提出了基于攻角预测的发动机超机动飞行高稳定性控制器:首先建立了进气道攻角预测模型,以实时估计发动机进口流场畸变,并在此基础上用增广线性二次型调节器(augmented linear quadratic regulator,简称ALQR)方法设计了高稳定性控制器,最后在发动机/三自由度飞机综合模型平台上模拟大攻角飞行任务进行了数字仿真验证.数字仿真结果验证了提出的控制思想的合理性和可行性.

机械式光栅拼接稳定性全闭环控制技术研究

激光惯性约束聚变对机械式拼接光栅的稳定性提出更高的要求,采用全闭环控制技术实现光栅拼接的高稳定性。为提高光栅装置的拼接精度,分析柔性机构的运动性能,从理论上推导精确的拼接机构运动控制算法;以电容微位移传感器作为反馈元件,研究动光栅位姿监测算法,实现动光栅位姿的实时监测。综合应用拼接机构运动控制算法和光栅位姿监测算法,实现光栅拼接稳定性的单神经元自校正PID全闭环控制;设计了光学检测系统,进行光栅拼接试验,并测试拼接装置的运动精度和稳定性,评估光栅拼接稳定性全闭环控制技术的可行性。试验结果表明拼接机构定位精度为0.2μrad/步(转动)、10 nm/步(平动),转动稳定精度小于1.2μrad/30 min、平动小于24 nm/30 min(平动),满足光栅拼接任务的要求。

高稳定性发动机控制飞行试验结果

由刘易斯研究中心出资并管理的高稳定性发动机控制（HISTEC）计划的目的，是发展和飞行验证一种先进的高稳定性一体化发动机控制系统。这种系统是用实时测量方式来预估进行道压力畸变，以增强发动机的稳定性。飞行验证的在德赖登飞行试验研究中心的一体化先进控制技术研究机（ACTIVE）F15上进行。飞行试验的构型研究目标的详情以及为达到这些目标而运用的飞行试验矩阵将在本文中阐述。飞行试验结果表明，这套设计方法可以精确地估计畸变并能对发动机调节进行实时控制。

发动机进气总压畸变流场中压力脉动分析

总压脉动强度和涡旋尺度是描述发动机进气总压畸变流场脉动强度和大小的主要参数,对于发动机的稳定裕度有着较大的影响,了解它们在畸变流场中的变化趋势及其关系将有助于发动机稳定性控制研究。本文分析了总压脉动强度和涡旋尺度在进气总压畸变流场中随湍流发展的一些变化趋势及其相互关系。

Trajectory tracking and formation control based on consensus in high-dimensional multi-agent systems

This paper discusses consensus problems for high-dimensional networked multi-agent systems with fixed topology. The communication topology of multi-agent systems is represented by a digraph. A new consensus protocol is proposed, and consensus convergence of multigent systems is analyzed based on the Lyapunov stability theory. The consensus problem can be formulated into solving a feasible problem with bilinear matrix inequality （BMI） constrains. Furthermore, the consensus protocol is extended to achieving tracking and formation control. By introducing the formation structure set, each agent can gain its individual desired trajectory. Finally, numerical simulations are provided to show the effectiveness of our strategies. The results show that agents from arbitrary initial states can asymptotically reach a consensus. In addition, agents with high-dimensional can track any target trajectory, and maintain desired formation during movement by selecting appropriate structure set.

High stable power control of alaser diode

In this paper,the low and the high frequency noises of a laser diode have been analyzed. Based on the analysis a novel scheme that adapts analog and digital hybrid techniques is proposed to stabilize the output power of a laser diode. With the hybrid controller,the low and the high frequency noises of a laser diode are conspicuously reduced.By accurate calculation,the short-term stability of the output power of laser diode reaches ±0.55‰, and the long-term stability is ±0.7‰.

The Availability Improvement of Uninterruptible Power Supply by Stabilizing Node Application at Control Part

The UPS （uninterruptible power supplies） are essential power infrastructure components of systems designed for critical application, including data centers. High availability achievement is a very important factor related to UPS performance, consequently to proper critical application functionality. Generally, UPS have a limited input voltage window, referring to the nominal input voltage value. Goal of this paper is to prove larger voltage window, without affecting normal UPS operation. Larger window will result on less commutation, backup and normal mode reduction, and consequently duty time of batteries reduction, too. Thus, under these conditions, it is to be expected availability improvement. The stabilizing node model, applied at UPS＇s control part through this paper is presented. UPS＇s behavior with an implemented stabilizing node is observed at few sites. In order to analyze and conclude about UPS＇s performance under these technical conditions, simulation results are further presented.

STATE-FEEDBACK ADAPTIVE STABILIZING CONTROL DESIGN FOR A CLASS OF HIGH-ORDER NONLINEAR SYSTEMS WITH UNKNOWN CONTROL COEFFICIENTS

In this paper, a new approach is successfully addressed to design the state-feedback adaptive stabilizing control law for a class of high-order nonlinear systems in triangular form and with unknown and nonidentical control coefficients, whose stabilizing control has been investigated recently under the knowledge that the lower bounds of the control coefficients are exactly known. In the present paper, without any knowledge of the lower bounds of the control coefficients, based on the adaptive technique and appropriately choosing design parameters, we give the recursive design procedure of the stabilizing control law by utilizing the approach of adding a power integrator together with tuning functions. The state-feedback adaptive control law designed not only preserves the equilibrium at the origin, but also guarantees the global asymptotic stability of the closed-loop states and the uniform boundedness of all the other closed-loop signals.

Robust adaptive cross-coupling position control of biaxial motion system

The stability and synchronous performance are usually hard to be improved simultaneously in the biaxial cross-coupling position motion control system.Based on analyzing the characteristics of the cross-coupling control system,a robust adaptive cross-coupling control strategy is proposed.To restrict influences of destabilizing factors and improve both of stability and synchronous performance,the strategy forces dual axes to track the same reference model using Narendra adaptive control theory.And then,a robust parameters adaptive law is proposed.The stability analysis of the proposed strategy is conducted by applying Lyapunov stability theory.Related simulations and experiments indicate that the proposed strategy can improve synchronous performance and stability simultaneously.

A modified structure internal model robust control method for the integration of active front steering and direct yaw moment control

Taking into account the nonlinearity of vehicle dynamics and the variations of vehicle parameters,the integrated control strategy for active front steering(AFS)and direct yaw control(DYC)that can maintain the performance and robustness is a key issue to be researched.Currently,the H∞method is widely applied to the integrated control of chassis dynamics,but it always sacrifices the performance in order to enhance the stability.The modified structure internal model robust control(MSIMC)obtained by modifying internal model control(IMC)structure is proposed for the integrated control of AFS and DYC to surmount the conflict between performance and robustness.Double lane change(DLC)simulation is developed to compare the performance and the stability of the MSIMC strategy,the PID controller based on the reference vehicle model and the H∞controller.Simulation results show that the PID controller may oscillate and go into instability in severe driving conditions because of large variations of tire parameters,the H∞controller sacrifices the performance in order to enhance the stability,and only the MSIMC controller can both ensure the robustness and the high performance of the integrated control of AFS and DYC.