激光陀螺读出信号高速采集系统

介绍了激光陀螺（RLG）读出信号高速采集系统的设计和实现方案。该系统包括板卡和相应的应用软件,提供两路最高60MHz采样频率、14位精度的数据采集通道,能够同时对RLG两路光强拍频信号进行高速高精度数据采集,为RLG特性分析提供重要依据。该系统通过上位机软件控制板卡的工作状态、设置和切换采样模式。板卡利用FPGA接收计算机指令并协调控制模数转换器、SDRAM和USB接口芯片,完成RLG输出拍频信号的采集、缓存和传输。FP—GA设计中结合了硬件逻辑高速灵活的优点和NIOSⅡ软核处理器在控制方面的优势。SDRAM完成海量数据缓存,USB接口芯片工作在SlaveFIFO模式下,实现板卡与计算机的通信。实验证明该系统工作稳定,在RLG测试和性能分析中具有很好的实用性。     

激光陀螺克服高、低温冲击的技术研究

分析了激光陀螺在经历外部环境温度变化时光强和性能发生变化的原因,提出了利用新型腔长角度控制镜(光路程长控制镜)的角度控制元件作为驱动器件,应用类似小抖动稳频的原理对激光陀螺环形光路进行闭环控制,并通过对各光路控制单元采取分时控制的办法解决了光路稳定过程中的调制信号的冲突,使激光陀螺在环境变化时始终保持其光程长和光路相对位置的稳定从而保证其性能的稳定。实验结果表明,对原来在全使用温区(-40℃~ 60℃)光强变化达30%甚至只要有光的,通过光路稳定措施可将光强稳定在±3%以内,对于有些在高低温时不能出光的,也可以达到可使用的光强稳定水平。较好地解决了许多激光陀螺难以克服的耐高、低温冲击问题。     

自适应陷波器在机抖激光陀螺信号处理中的应用

首先利用极零点受限自适应陷波器对二频机械抖动激光陀螺输出信号利用预处理,然后再进行低通滤波器处理的方法,不仅有效地消除了抖动输出,而且减小了由FIR滤波器引起的时间延迟。     

CHAOS, CHAOS CONTROL AND SYNCHRONIZATION OF A GYROSTAT SYSTEM

The dynamic behavior of a gyrostat system subjected to external disturbance is studied in this paper. By applying numerical results, phase diagrams, power spectrum, period-T maps, and Lyapunov exponents are presented to observe periodic and choatic motions. The effect of the parameters changed in the system can be found in the bifurcation and parametric diagrams. For global analysis, the basins of attraction of each attractor of the system are located by employing the modified interpolated cell mapping (MICM) method. Several methods, the delayed feedback control, the addition of constant torque, the addition of periodic force, the addition of periodic impulse torque, injection of dither signal control, adaptive control algorithm (ACA) control and bang-bang control are used to control chaos effectively. Finally, synchronization of chaos in the gyrostat system is studied.     

延迟-非线性反馈控制混沌

提出了基于稳定性准则的延迟非线性反馈控制混沌的方法，即SC延迟非线性反馈控制法. 通过对混沌系统的适当分离，得到一个特殊的非线性函数，并利用混沌输出信号与其延迟信号的非线性函数的差，构造了连续反馈输入干扰，以控制混沌轨到某一期望的不稳周期轨上. 该方法继承了延迟反馈控制方法的优点，实现了自-控制过程. 另外由于该方法基于线性系统的稳定性准则，保证了控制的有效性. 控制过程可随时开始，具有简便、灵活性. 给出耦合Duffing振子的例子，数值模拟结果显示了SC延迟反馈方法控制的有效性. 关键词： 稳定性准则 混沌控制 延迟反馈 干扰     

半周期延迟-非线性反馈控制混沌

提出了基于稳定性准则的半周期延迟-非线性反馈控制混沌的方法，即SC(stability criterion)半周期延迟非线性反馈控制法.通过对混沌系统的适当分离，得到一个特殊的非线性函数，并利用混沌输出信号与其半周期延迟信号的非线性函数之和，构造了连续反馈输入干扰.该方法继承了延迟反馈控制方法及稳定性准则控制方法的优点，实现了有效的自控制过程；并克服了延迟反馈方法的限制，能将嵌入混沌吸引子中的自对称直接不稳周期轨稳定.控制过程可随时开始，具有简便、灵活性.数值模拟结果显示了SC半周期延迟-非线性反馈方法控制的有效性. 关键词： 稳定性准则 混沌控制 半周期延迟 非线性反馈     

空间正交三轴激光陀螺的调腔技术

通过分析传统激光陀螺的调腔方式,提出了激光陀螺应在实际工作条件(具有增益能力状态)下进行调腔的观点,以及通过控制其腔长或光程长来控制反射镜的反射方向的调腔方法,并相应地设计了新的腔长控制镜结构。通过全面扫描的方式,找出了空间正交三轴激光陀螺的三腔在高质量运转时的最佳角度控制参数,解决了空间三轴激光陀螺高精度调腔的难题。     

Ultraviolet diode laser system based on the resonant optical feedback method with the capability of fast continuous sweep

An ultraviolet laser diode system stabilized to an external Fabry–Perot cavity by using the resonant optical feedback method is described. Both wide continuous sweep with fast response and drift compensation for long term operation are realized simultaneously by performing feedforward control along with feedback control of the system parameters. By utilizing the capability of synchronized sweep realized by the feedforward control, the modulation of the output frequency, due to dither for lock-in feedback control of the system parameters, is almost perfectly canceled. The method described here is useful for developing diode laser systems for practical use with such features as small short term fluctuation, long-term operability and fast continuous sweep. PACS 42.55.Px; 42.60.By; 32.80.Pj     

激光二极管相对于铯饱和吸收D2线的无调制扰动三次谐波锁频

将频率调制加在声光调制器上 ,用三次谐波探测法获得了铯原子D2 线的三阶微分饱和光谱。采用这种激光器无调制扰动方案结合三次谐波锁频技术 ,实现了 85 2nm的分布布拉格反射器半导体激光器相对于 6S1/2 F =4- 6P3 /2 F′ =5超精细跃线的频率锁定。由锁定后的频率误差信号估算 ,10s内激光频率起伏小于± 35 0kHz ,相对频率稳定度约 1× 10 -9。这种无调制扰动方案可以消除一般的饱和吸收稳频方法中由于直接对激光器进行频率调制而带来的额外频率噪声 ;三次谐波锁频技术的应用 ,还可有效地降低铯原子饱和吸收谱中剩余多普勒背景的影响     

激光陀螺腔长控制机构研究与改进

腔长控制机构在激光陀螺中通过控制腔长来保证激光陀螺工作光束的频率稳定,其对激光陀螺性能的提高有着重要意义。针对激光陀螺工作过程中,传统腔长控制机构的控制镜扭偏导致光束在腔中的位置偏移毛细孔的中心位置,引起腔内的散射、损耗发生变化从而影响陀螺性能及精度的问题,对激光陀螺腔长控制机构进行了研究,并设计了一种新的腔长控制机构以减小控制镜的扭偏对陀螺产生的影响。利用有限元分析法对新腔长控制机构进行了优化设计和仿真。试验表明,新的腔长控制机构减小了控制镜的扭偏,使得激光陀螺的零偏稳定性由0.7/h提高至0.3/h。     

A new control method based on the lattice hydrodynamic model considering the double flux difference

A new feedback control method is derived based on the lattice hydrodynamic model in a single lane. A signal based on the double flux difference is designed in the lattice hydrodynamic model to suppress the traffic jam. The stability of the model is analyzed by using the new control method. The advantage of the new model with and without the effect of double flux difference is explored by the numerical simulation. The numerical simulations demonstrate that the traffic jam can be alleviated by the control signal.     

利用分段回归拟合激光陀螺仪零偏测试的Allan方差

在介绍Allan方差方法的基础上,计算出了激光陀螺仪零偏测试数据的Allan方差。首次利用分段回归方法拟合Allan方差数据,得到了零偏测试中的各误差源系数。结果表明,该方法能有效地辨识出存在于激光陀螺仪零偏测试中的各种噪声,极大地降低了激光陀螺仪Allan方差数据处理的难度。指出了激光陀螺硬件中存在的误差,提出了激光陀螺仪的改进方案。     

Experimental and analytical study of dither signals in a class of chaotic systems

A method for controlling a class of chaotic systems by injecting another external input, called a dither signal, into the systems, just ahead of the nonlinearities is given. The method is robust to measurement noise due to no state being fed back and applicable to experimental situations in which the system parameters are unknown and unalterable. Two numerical examples and one experimental test are performed to demonstrate the feasibility of the method.     

人工鱼群算法在单轴旋转惯导系统轴向陀螺漂移辨识中的应用

在惯性导航系统中,采用单轴旋转技术可以调制垂直于旋转轴方向上的惯性器件误差,而对沿旋转轴方向的误差没有抑制作用,因此旋转轴方向上激光陀螺漂移成为影响惯性导航系统精度的主要因素之一。为精确地辨识旋转轴方向上激光陀螺漂移,提高激光陀螺单轴旋转惯导系统的精度,利用人工鱼群算法AFSA（artificial fish swarm algorithm）建立了单轴旋转惯导系统轴向陀螺漂移辨识模型,给出了AFSA 辨识的详细步骤和方法。实验结果表明:AFSA可以对轴向激光陀螺漂移进行精确建模,补偿后的激光陀螺零偏不稳定性达到0.000 4 /h。     

基于DSP的激光陀螺稳频回路设计及其参数整定

针对某小型化激光陀螺,对基于TMS320F2810数字信号处理芯片（DSP）的激光陀螺交流抖动稳频回路设计及其参数整定进行了理论分析、Matlab数值仿真和实验研究。TMS320F2810这款芯片具有集成度高、处理速度快、功耗低和性价比高等突出优点,有利于实现激光陀螺控制系统的小型化。基于这款DSP芯片实现了某小型化激光陀螺的交流抖动稳频回路的软、硬件设计,使用衰减曲线法得到了该型激光陀螺经优化后的PID控制参数（Kp=0.048,Ki=0.059,Kd=0.013）,并根据国军标对稳频回路进行了实验验证。实验结果表明,稳频控制回路经过PID参数整定后,该小型化激光陀螺的零偏稳定性从0.025/h降到0.014/h,该稳频控制回路在目标型号激光陀螺上满足预期的性能指标要求。     

机械抖动激光陀螺新型信号处理方法的研究

针对高速采样低通滤波的线性脉冲响应(FIR)滤波器在机械抖动激光陀螺(MDRLG)信号处理中存在着较大的时延,限制MDRLG在快速跟踪中的应用,基于相关滤波技术提出了一种新的信号处理方法。对这一方法的基本理论进行了分析,并基于Labview实现了仿真。相关滤波后,激光陀螺输出中的抖动信号衰减了约41dB,还不能达到激光陀螺应用的要求,可以适当加一低阶的FIR低通滤波器去除抖动剥除后剩余的抖动成分和高频噪声。在静态条件下用这三种信号处理方法分别对激光陀螺零偏进行了测试。相关滤波法所测得零偏稳定性(1σ00)比50阶FIR滤波器差了将近三倍,相关滤波后再经过22阶的FIR低通滤波测得的零偏稳定性比50阶FIR低通滤波器的测试结果大了不足0.001°/h,延迟时间却从4.9ms减小至2.1ms。     

Detection of nuclear resonance signals: modification of the receiver operating characteristics using feedback

The performance of a nuclear resonance detection system can be quantified using binary detection theory. Within this framework, signal averaging increases the probability of a correct detection and decreases the probability of a false alarm by reducing the variance of the noise in the average signal. In conjunction with signal averaging, we propose another method based on feedback control concepts that further improves detection performance. By maximizing the nuclear resonance signal amplitude, feedback raises the probability of correct detection. Furthermore, information generated by the feedback algorithm can be used to reduce the probability of false alarm. We discuss the advantages afforded by feedback that cannot be obtained using signal averaging. As an example, we show how this method is applicable to the detection of explosives using nuclear quadrupole resonance.     

剪切力模式近场扫描光学显微镜的恒幅反馈控制方法研究

剪切力模式近场扫描光学显微镜(Near-field Scanning Optical Microscopy,NSOM) 的音叉探针间距控制系统中,用相位反馈控制和检测剪切力,同时采用比例＋积分（PI）技术实现对音叉探针振幅的反馈控制,使探针振幅在扫描过程中保持为恒定值.用相位信号作为探针与样品间距控制信号,分别在无振幅反馈和有振幅反馈两种情况下,以不同速率扫描得到标准CD_RW光盘光栅的两组图像,并进行了比较分析.实验表明,恒振幅反馈电路的引入有助于提高探针系统的响应速度和灵敏度,改善所得图像的质量及分辨率.     

Suppressing nonlinear dynamics induced by external optical feedback in vertical-cavity surface-emitting lasers

A numerical study of using external optical injection to suppress the nonlinear dynamics introduced by external optical feedback in vertical-cavity surface-emitting lasers (VCSELs) has been undertaken. The model under consideration is a master–slave configuration where the master VCSEL provides the continuous wave to control the nonlinear behaviors arising in the slave VCSEL. Simulation results indicate that the feedback-induced nonlinear dynamics (e.g. chaotic, single-periodic, and multi-periodic oscillations), relative intensity noise (RIN) as well as the coherence collapse can be suppressed effectively as long as the injection is strong enough to overcome the nonlinear effects of the feedback.