机载光电稳定平台建模及动态特性分析

两轴两框架机载光电稳定平台以其机构简单、成本低、体积小的特点广泛应用于小型载机上。载机与光电平台之间、平台框架之间存在复杂的非线性耦合。本文根据运动学、动力学关系,采用机理建模的方法建立了包含内外框耦合力矩的数学模型,并进行了多种状态下的动态特性仿真。结果表明,当框架受扰时内框比外框更敏感,内框能更快恢复稳定。载机角速度扰动引起的光轴角速度变化比框架力矩扰动引起的光轴角速度变化小。载机三轴运动时内外框之间存在耦合力矩,耦合力矩的频率和载机运动速度的频率相同;载机三轴角运动时内框电机加入控制电压,内外框耦合力矩变大。     

偏轴反射镜平台视轴稳定技术及建模分析

常规反射镜平台采用方位/俯仰型两框架结构形式,探测器视轴平行于外框架旋转轴。区别于常规反射镜平台,偏轴反射镜平台不再遵循探测器视轴与外框架旋转轴平行的原则,其视轴角速度具有强耦合和非线性的特点。主要研究了这类偏轴反射镜平台的运动学、动力学建模和视轴稳定机理。首先,采用虚拟整体稳定平台技术推导平台运动学方程,并确定了虚拟平台框架类型的选取原则。在此基础上推导了完整的视轴坐标系动力学模型。然后,对载体运动耦合机制进行了分析并给出了控制框图。最后,对视轴运动特性进行仿真分析。仿真结果表明,该平台在视轴指向、力矩耦合等方面具有不同于常规反射镜平台的特性,且由视轴运动非线性引起的视轴交叉耦合力矩大于惯量耦合力矩。     

半捷联导引头机电平台观测器的角速率估计

为准确获取半捷联图像导引头视线角速率,构建了Kalman观测器对电机平台进行框架角速率估计。首先,根据半捷联导引头稳定跟踪原理,建立了以Kalman观测器为状态反馈的数学模型;其次,根据编码器误差特性,应用最优估计理论计算分析了估计精度与观测器参数之间的关系;再次,在保证稳定平台带宽的前提下,设计了两种不同采样率下的Kalman观测器;最后,进行了数字仿真实验验证。结果表明:在2 000 Hz采样率下,估计算法角速率精度为0.098 9 ()/s,优于200 Hz采样率下的0.301 3 ()/s;两种采样率下导引头带宽均为59.6 rad/s,平台隔离度为1.5%。提高导引头稳定系统采样率并与相应控制参数匹配,能有效提高平台角速率估计精度。     

小型惯性控制平台的设计

简述了小型惯性控制平台的组成和工作原理,运用动力学原理建立了台体结构模型.研究了各框架间台体平稳性和机械误差对平台的影响.通过采用小型捷联式/GPS组合航姿仪测量技术和控制技术,平台稳定和跟踪效果好,经测试负载能力3 kg,俯仰角摇摆范围-15°～+90°,方位角范围0～360°,水平姿态精度<0.2°,航向精度<0.3°.     

半捷联导引头光轴稳定性

为研究半捷联导引头光轴稳定性,对影响半捷联导引头光轴稳定的因素进行了分析。通过对半捷联稳定原理和传统速率陀螺稳定原理的分析和比较,揭示了半捷联稳定的实质。根据半捷联稳定方式下平台框架的惯性空间角速度表达式,分析了影响半捷联稳定的主要因素。针对影响半捷联稳定的弹体扰动和扰动力矩,采用了匹配滤波和扰动观测器的方法提高系统稳定精度。数值仿真结果表明,匹配滤波的方法有效地减小了弹体扰动对系统稳定的影响,平台对弹体扰动的解耦精度在1 Hz时提高了38 dB;扰动观测器有效抑制了扰动力矩对系统稳定的影响;采用高精度、低噪声的传感器是减小测速噪声对系统稳定影响的关键。综合仿真结果显示,在对3个主要因素补偿后,系统的稳定误差减小了近94%。     

光电稳定平台框架结构探讨

介绍了机载光电侦察稳定平台的几种框架形式,从稳定原理方面分析了各自的优缺点,并指出随着光电侦察技术及装备的发展,四框架两轴稳定平台系统是最佳的选择方案.     

速率陀螺式稳定平台陀螺解耦的一种算法

速率陀螺式稳定平台由于框架结构在加工和装配过程中的误差,会造成陀螺彼此耦合,从而给输出视线角速度带来误差。给出了二自由度速率陀螺式稳定平台陀螺解耦的一种算法,该算法可以将处理器采集到的陀螺数据直接进行解耦计算,获取视线角速度。     

机载稳定跟踪平台速率回路的内模H∞控制

在机载四框架二轴稳定跟踪平台机理分析的基础上,对其速率回路的校正器设计问题进行了机理研究.针对传统的PI校正抗干扰性能差的缺陷,在内模控制与日柚控制结合的基础上,提出一种新的内模日.控制器设计方法.该方法不仅保留了内模控制方法所有的特征,而且结合日.控制方法对整个闭环系统进行设计;推广了日.控制的实用性和应用性,可用于...     

两轴四环架光电平台的多变量H∞控制方法

高精度光电稳定平台采用两轴四环架的结构形式扩展其跟踪范围,但增加了环架闻的耦合和系统的复杂度.提高稳定精度是控制系统设计的核心指标.以平台系统的动力学方程为基础,导出状态空间模型.针对内、外环架间的耦合特性,提出将内、外环架分系统作为多入多出对象进行多变量控制设计.采用H∞控制设计方法,根据平台系统对稳定性能和随动性能...     

基于角速度补偿的捷联天线稳定系统设计

研究了半捷联末制导系统中捷联天线稳定系统的设计原理和控制算法。首先分析了捷联稳定和陀螺稳定的本质区别与联系;然后基于弹体、导引头、天线的三维运动关系,提出了一种新型捷联天线稳定系统控制方案。使用框架角测量和惯导信息重构天线的绝对空间运动信息,并采用角速度补偿方法和数学稳定平台实现导引头天线的间接稳定,能够解决导引头在纯稳定和目标跟踪两种工作模式下的天线控制问题。最后通过数学仿真验证了所提方法的有效性。     

Optimal Synchronization Control of High-Precision Motion Systems

Recently, in the motion control area, one of the most challenging problems has been synchronization control of multiple motion axes or drivers. Unfortunately, the majority of the previous approaches have not fully addressed the synchronization problem when the system performs a complex motion. In this paper, a novel synchronized design of the high-precision motion control system is presented. The basic idea is to introduce the coupling and synchronization factors into the definition of the synchronization error. Then, a new quadratic performance index incorporating the synchronization errors of the multiple motion axes is introduced so that the resulting control law generates the cross-coupling control action, and as a consequence, improved tracking and synchronization performance can be obtained. The key to the success of the new design is to ensure that each motor tracks its desired trajectory while synchronizing motion with others. Computer simulations and real-time experiments on a servo system with two permanent-magnet linear motors demonstrate the effectiveness of the method.     

一种红外导引头小型快速伺服稳定平台

红外导引头是肩扛式反坦克导弹的重要分系统,其主要作用是通过瞄准具人工操作瞄准线运动,锁定目标并对目标进行跟踪。本文采用了速率陀螺稳定平台式随动系统,俯仰+偏航的双框架式结构。通过装在框架内的速率陀螺和角位置传感器分别提供速度和位置信号,利用DSP和FPGA构建随动控制电路,采用电流、速度和位置三环串级闭环PID设计控制框架电机实现目标扫描和跟踪。此方案快速跟踪能力强、跟踪精度高、抗干扰性强、易实现大范围扫描。     

基于ESO的导引头稳定平台双积分滑模控制

为了提高导引头稳定平台抗扰性及速度稳态跟踪性能,提出了一种基于扩张状态观测器（Extended State Observer,ESO）的双积分滑模控制器（Double Integral Sliding Mode Controller,DISMC）。首先,采用二阶扩张状态观测器对系统的未知扰动进行估计;然后,采用了双积分滑模控制器实现了系统的低稳态误差跟踪,同时采用了改进的幂次趋近律来削弱控制系统的抖振影响;最后,采用导引头稳定平台进行目标跟踪实验和隔离度性能测试。实验结果表明,与传统基于扰动观测器（Disturbance Observer,DOB）的PI控制方法相比,跟踪3（）/s的梯形波时,在提出的控制器作用下速度跟踪快速性提高了48 ms,跟踪误差标准差提高了0.0131（）/s。同时用转台模拟弹体扰动分别为sin（t）、3sin（5t）、7sin（2t）时,系统的隔离度分别提高了2.91%、0.45%、0.7%,表明基于扩张状态观测器的双积分滑模控制器对导引头稳定平台具有较强的抗扰性和较好的跟踪性能。     

Multiple User Variable Rate Coding for TASI and Packet Transmission Systems

In this paper we examine the use of variable rate coding concepts for TASI and packet speech transmission systems. The paper is divided into three major parts. In the first part, the theoretical performance of variable rate coding is analyzed for multiple user (TASI) applications. Potential gains are experimentally determined from twoparty telephone conversation data for up to 12 shared conversations on a channel. In the second part of the paper, the buffer control mechanism for a dynamic buffer scheme for coupling a variable rate coder to a fixed rate (or slowly varying rate) channel is analyzed. It is shown that the buffer control can be modeled as a second-order control system and, under adverse parameter settings, the system can be unstable. By an appropriate design and parameter setting, the buffer control can be stabilized, The insight developed from this particular buffer control mechanism may also lead to a better understanding of other buffer control problems in variable rate transmission or packet systems. In the third part of the paper, a practical method is analyzed for implementing a variable rate ADPCM system for multiple user applications. Examples of computer simulations of the system are presented.     

基于MEMS惯导的机载两轴稳定平台方案

动中通天线平台往往基于不同姿态数据输入的解算直接影响天线伺服控制系统的响应速度,最终影响天线系统最终的跟踪精度,惯导设备欧拉角、角速度的精度、输出频率、系统转发延迟等均对最终的跟踪精度有较大影响。文章针对卫星天线基于载机惯导的稳定模型分析,构建了基于自带惯导的基于MEMS陀螺的两轴稳定平台,并对稳定平台模型、控制进行分析,实验验证。     

Stabilization system on an office-based ear surgical device by force and vision feedback

An “office-based surgical device” is a kind of device which aims to shift the conventional surgical procedures from the operating room to the confines of the doctor’s/surgeon’s office as well as to assist the surgeons to carry out the surgeries on the patients automatically or semi-automatically. In this paper, an office-based surgical device suitable for patients with Otitis Media with Effusion (OME) is introduced. Due to the office-based design, it is not possible to subject the patient to general anesthesia, i.e., the patient is awake during the surgical treatment with the device. To ensure a high success rate and safety, it is very important that the relative motion and the contact force between the tool set of the device and the tympanic membrane (TM) can be stabilized. To this end, a control scheme using force and vision feedback is proposed. The force feedback controller is a PID-based (proportional-integral-derivative) controller, which is designed for force tracking. The vision feedback controller is a vision-based motion compensator, which is designed to measure and compensate the head motion since it is equivalent to TM motion. Furthermore, the control scheme is implemented and tested in a mock-up system. The experimental results show that the proposed composite controller can achieve much better performance in force tracking than a pure force feedback controller. The performance can at least improve by 20% after augmenting the motion compensator, which helps the system to stabilize the relative motion indirectly and maintain the contact force precisely.     

利用全景图的视频稳像算法

针对具有场景变换、景深变换较小的抖动视频,本文提出了一种利用全景图的视频稳像方法。不同于传统稳像方法,本文所提算法利用原始视频序列生成广角视图,通过后期抽取视频帧,以合成方式输出稳定视频。通过区域块的运动估计,获取相机的运动轨迹;在此基础上,为消除视频抖动导致的原始运动轨迹的非平滑问题,提出了一种基于运动矢量统计的相机运动模式判决方法,并以此选择相应的平滑方式。最后,通过平滑后的运动轨迹对全景图进行抽帧,合成平滑、稳定视频。实验结果表明,本文提出的稳像方法能有效去除较大抖动,同时避免了对视频宽度的裁剪等后处理,具有较好的稳像能力。      

A method for designing control parameters of a 3-DOF parallel tool head

The mechatronic system of a parallel tool head consists of the mechanical subsystem and the control subsystem, and appropriate control parameters have a significant effect on the performance of the parallel tool head. Thus, it is a core issue of how to make the right choice of the control parameters. However, due to the time-varying and coupling dynamic characteristics, there is still not an effective control parameters design method during industrial machining process. In this paper, by taking a 3-DOF parallel tool head with proportional control and velocity feedforward compensation as an object of study, a complete method for designing control parameters is investigated. First, a coupling variable is specified to reflect the dynamic properties between the mechanical subsystem and the control subsystem. Next, a novel dynamic index is proposed to evaluate the dynamic load of each driving shaft in the workspace, and the shaft with maximum dynamic load should be mainly pay attention. Then, based on the typical movement experiments, two design indices are proposed to ensure that the coupling variable has appropriate properties during the motion process. Finally, a parameters design experiment and a cutting experiment of an S-shaped test piece are performed, the results show that compared with the original control parameters used in industry, the tracking error of the driving shaft is much better when using the optimized control parameters, and the test piece meets the accuracy requirement. This design thought can also be applied to other parallel manipulators in industry.