Stabilization of Euler-Bernoulli beam with a nonlinear locally distributed feedback control

This paper studies the stabilization problem of uniform Euler-Bernoulli beam with a nonlinear locally distributed feedback control. By virtue of nonlinear semigroup theory, energy-perturbed approach and polynomial multiplier skill, the authors show that, corresponding to the different values of the parameters involved in the nonlinear locally distributed feedback control, the energy of the beam under the proposed feedback decays exponentially or in negative power of time t as t → ∞.     

Pose Synchronization of Multiple Rigid Bodies Under Average Dwell Time Condition

This paper considers the pose synchronization problem of a group of moving rigid bodies under switching topologies where the dwell time of each topology may has no nonzero lower bound. The authors introduce an average dwell time condition to characterize the length of time intervals in which the graphs are connected. By designing distributed control laws of angular velocity and linear velocity, the closed-loop dynamics of multiple rigid bodies with switching topologies can be converted into a hybrid dynamical system. The authors employ the Lyapunov stability theorem, and show that the pose synchronization can be reached under the average dwell time condition. Moreover, the authors investigate the pose synchronization problem of the leader-following model under a similar average dwell time condition. Simulation examples are given to illustrate the results.     

基于磁悬浮转子微框架能力的航天器姿态二自由度测控一体化控制方法

提出一种基于磁悬浮转子微框架能力的航天器姿态二自由度测控一体化控制方法,在磁悬浮控制力矩陀螺框架不动的条件下,通过实时检测磁轴承控制电流、磁悬浮转子位移求解出航天器的滚动、偏航轴姿态角速度,建立磁悬浮转子控制的航天器姿态动力学方程,利用已测得的姿态角速度,设计姿态解耦控制律,控制磁悬浮转子的旋转主轴在磁间隙范围内以一定角速度偏转,产生所需的径向二自由度输出力矩,调节航天器的滚动、偏航轴姿态,仿真表明,该方法能够实现航天器的二自由度姿态调节,微框架力矩具有高精度的优点,能够完成航天器机动段末端小角度的姿态控制。     

Stabilization of an Euler-Bernoulli beam with a tip mass under the unknown boundary external disturbances

This paper studies the stabilization problem of an Euler-Bernoulli beam with a tip mass, which undergoes unknown but uniform bounded disturbance at tip mass. Here the nonlinear feedback control law is used to cancel the effects of the external disturbances. For the controlled nonlinear system, the authors prove the well-posedness by the maximal monotone operator theory and the variational principle. Further the authors prove that the controlled nonlinear system is exponential stable by constructing a suitable Lyapunov function. Finally, some numerical simulations are given to support these results.     

基于MSCMG金字塔构型的航天器姿态测控一体化控制方法

提出一种基于磁悬浮控制力矩陀螺(magnetically suspended control moment gyroscope,MSCMG)金字塔构型的航天器姿态测控一体化控制方法,利用姿控回路中的执行机构,既进行航天器姿态测量,又进行航天器姿态控制,改变了传统姿控系统由姿态敏感器、控制器、执行机构的组成方式。首先建立磁悬浮转子径向力矩模型,通过实时检测磁悬浮控制力矩陀螺中的磁轴承电流、磁悬浮转子位移、框架角速度,联立金字塔构型中的3个径向力矩模型求解出航天器的姿态角速度,再设计相应的姿态控制律和框架操纵律,实现航天器的姿态调节,仿真结果证明了该方法的正确性和有效性。     

Adaptive set stabilization of the attitude of a rigid spacecraft without angular velocity measurements

The global adaptive set stabilization problem of the attitude of a rigid spacecraft is addressed in this paper. Two different cases are considered. First, by using adaptive backstepping method, the authors design a global adaptive control law for the attitude control system with unknown inertia matrix such that the attitude and the angular velocities can be globally asymptotically stabilized to a set consisting of two equilibria. And then, based on the obtained backstepping adaptive law, the authors consider the case that the angular velocities are not measurable. By introducing an auxiliary state, a semi-global adaptive set stabilization law without angular velocity measurements is also designed. It is rigorously proved that, for the two cases, both of the closed loop systems satisfy the set stability. The effectiveness of the proposed methods is verified by simulation results.     

Distributed High-Gain Attitude Synchronization Using Rotation Vectors

This paper addresses attitude synchronization problems for systems of multiple rigid-body agents with directed interconnection topologies.Two scenarios which differ in available information are considered.In the first scenario the agents can obtain their rotations and angular velocities relative to an inertial reference frame and transmit these information to their neighbors,while in the second scenario the agents can only obtain their own angular velocities and measure the relative rotations and relative angular velocities of their neighbors.By using rotation vectors and the high gain control,the authors provide torque control laws asymptotically synchronizing the rotations of the system almost globally for the first scenario and with initial rotations of the agents contained in a convex ball of SO(3)for the second scenario.An illustrative example is provided to show the synchronization results for both scenarios.     

基于逻辑控制的双输入运动体感算法研究

针对飞行模拟器中的双输入经典洗出算法存在感知角速度信号丢失、相位误差、逼真度不足等问题.提出一种逻辑控制洗出算法:依据前庭系统理论改进经典洗出算法高通角速度通道结构,设计逻辑控制器和角位移连续发生器优化高通角速度通道和倾斜协调通道中的耦合角速度并稳定跳跃变化时洗出角位移,使改进率法更符合人体感知模型.在Matlab/S...     

X-Y式光电跟踪系统虚拟样机建模及仿真分析

结合动量定理和动量矩定理分析了X-Y式光电跟踪系统的动力学特性,建立了X-Y式光电跟踪系统的非线性模型,并用虚拟样机技术对其非线性模型进行仿真.理论分析与仿真结果表明,当X轴和Y轴均以较高的角速度或角加速度运动时,因非线性关系所导致的扰动力矩会严重影响系统的跟踪精度,当X-Y式光电跟踪系统的X轴相对其各惯性主轴的转动惯量相等时,可彻底解决X轴与Y轴之间的运动偶合关系.     

航天器非线性鲁棒自适应姿态机动控制律

针对存在未知转动惯量和外部干扰力矩的敏捷航天器快速大角度姿态机动问题,结合非线性反步法和Lyapunovo稳定性分析方法设计控制力矩和转动惯量估计值的非线性鲁棒自适应控制律。在控制力矩控制律中,加入非线性阻尼项对外部干扰力矩进行补偿,证明了系统的全局一致最终有界稳定性。引入非线性动系数增加系统的动态性能,提高了姿态快速机动后的快速稳定能力。在Maltlab/Simulink环境下进行航天器姿态机动控制仿真研究,仿真结果验证了所设计控制器的有效性和可行性。     

加权平均法在GFSINS角速度解算中的应用

针对积分法带来快速误差积累以及开方法存在大量开方运算和符号误判等问题,提出了将加权平均法应用到无陀螺捷联惯导系统(gyro free strapdown inertial navigation system, GFSINS)角速度解算中的新方法。基于一种改进的九加速度计配置方式,推导了两种传统角速度解算方法;采用基于多元统计理论的加权平均法,将积分法和开方法得到的两组角速度通过选择最优权数进行有效数据融合,得到一组误差更小的角速度。仿真结果表明,此方法不仅能消除迭代误差,而且其角速度解算精度比开方法提高了大约1.5倍。     

STABILIZATION OF NONUNIFORM TIMOSHENKOBEAM WITH COUPLED LOCALLY DISTRIBUTED FEEDBACKS

The stabilization problem of a nonuniform Timoshenko beam system With coupled locally distributed feedback controls is studied. First, by proving the uniqueness of the solution to the related ordinary differential equations, we establish the asymptotic decay of the energy corresponding to the closed loop system. Then, by virtue of piecewise multiplier method, we prove the exponential decay of the closed loop system.     

基于转矩观测法的开关磁阻电机转矩脉动抑制

研究抑制开关磁阻电机(SRM)的振动和噪声是改善开关磁阻电动机调速系统(SRD)性能的重要课题之一。基于SRD的非线性动态仿真模型,研究了基于转矩观测法的转矩脉动抑制。针对SR电机的时变、非线性特性,对闭环系统的速度调节器采用自适应模糊PID控制器进行转速调节,仿真结果表明该系统具有良好的转矩脉动抑制效果。     

永磁同步电动机自适应反步控制的建模与仿真

设计了一种基于自适应反步控制的永磁同步电动机非残性速度控制器，采用二阶滤波环节平滑速度指令．在设计非线性速度控制器的同时，进行不确定参数及负载力矩的在线自适应估计。建立了采用该控制器的永磁同步电动机速度伺服系统仿真模型．仿真结果表明，所设计的非线性控制器保证了系统的全局一致稳定性，永磁同步电动机伺服系统获得了很好的跟踪效果，并且对参数不确定性及负载力矩扰动具有很好的鲁棒性。     

开关磁阻电机多种控制策略的仿真比较研究

针对开关磁阻电机非线性严重、变量耦合强烈、电磁关系难以分析的特点,采用了直接转矩控制方法。利用PI调节器分别对电机转矩和磁链进行控制,并且分别与滞环直接转矩控制和电流斩波控制进行了实验仿真的分析和对比,证明PI直接转矩控制系统准确的控制了磁链,减小了电流噪声,提高了响应速度,有效的抑制了转矩的脉动。     

考虑姿态禁忌约束的航天器安全姿态跟踪控制

针对航天器姿态跟踪过程中的姿态约束问题,提出了一种基于势函数的安全姿态机动控制算法。与姿态定点机动的姿态约束问题不同,引入误差四元数和误差角速度,建立了航天器姿态跟踪误差模型。采用四元数描述了姿态禁忌区域,并根据禁止姿态最小允许角构造了一种新的规避高斯势函数。利用规避势函数和吸引势函数得到安全姿态机动控制器,对于无扰动和有扰动的情况分别分析了闭环控制系统的Lyapunov稳定性。最后,对于有约束的姿态跟踪情况进行了计算机数值仿真。仿真结果表明,所提出的控制方法既能实现姿态跟踪的目的,又能确保航天器在机动过程中不会进入姿态禁忌区域。     

The Analysis and Numerical Simulation of Dynamical Functions of the Transpiration Cooling Control System with Surface Ablation

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一种用于九加速度计GFSINS的姿态角速度辅助算法

针对现有的一类无陀螺捷联惯导系统九加速度计配置方案解算载体姿态角速度时,存在需要开方及符号判断等不足,提出一种同时具有积分算法包含加速度计误差少、开方算法没有加速度计误差积累两种优点的姿态角速度辅助算法,彻底消除解算过程中开方及符号判断带来的误差,能够在一定程度上提高系统精度,同时降低导航系统的计算量、提高系统的实时性。     

提高无陀螺捷联惯导系统角速度解算精度的新方法

在无陀螺捷联惯导系统中，由于合弃陀螺而使系统具有很多优点，但角速度需从加速度计输出的信号中解算出来，且它的解算误差随时间而发散。所以，抑制角速度解算误差的发散，提高其解算精度是该项技术研发的关键。提出了一种在九加速度方案下提高角速度解算精度的新方法，它是一种利用冗余信息得到残余误差方程，再进行数值迭代的方法。该方法比建立噪声状态估计、利用卡尔曼滤波束修正姿态的方法简单而有效。仿真结果表明，利用此方法能明显提高系统角速度解算精度。     

高级分布式仿真中的数据收集技术研究

介绍了高级分布式仿真中数据收集的体系结构、存储方式以及事后分析等关键技术，并在此基础上设计了一个数据收集系统。该系统主要针对数据收集后在内存和磁盘中的组织，应用实时数据库技术来提高数据收集和数据导入磁盘的性能，并为数据的运行时使用提供了条件。对于数据收集后导入磁盘的算法以及分布式数据收集的体系结构，本文也作了初步探讨。