传动钢带弹性对惯性稳定平台的稳定精度影响仿真分析

针对反射镜稳定方式下的某型惯性稳定平台,考虑基座扰动、摩擦力矩、传动钢带的弹性和预紧力等影响因素,推导了系统的动力学方程,并在ADAMS中建立了系统的动力学模型。用Matlab/Simulink进行机电联合仿真,重点分析并得到了钢带在不同刚度和预紧力下对稳定精度的影响。研究结果为惯性稳定平台的设计提供了依据。     

惯性稳定平台自适应前馈控制

结合反馈控制提出了一种自适应前馈控制方法来提高惯性稳定平台稳定控制的指令跟踪性能。应用子空间辨识算法,由输入输出数据辨识稳定平台动态模型的状态空间描述;采用频域回路成型方法设计反馈回路控制器,用于抑制外部扰动。应用递推最小二乘(RLS)自适应滤波器构建反馈控制回路逆模型,构造指令信号的全通特性,提高指令跟踪能力。针对不同的指令信号进行跟踪实验,验证了自适应前馈控制方法的有效性。实验结果表明:提出的自适应前馈方法对阶跃指令响应快,超调量可由反馈控制的30%降低至4.5%,对30 Hz正弦信号的响应幅值无衰减,相位滞后由反馈控制的90°降低至54°。得到的结果显著提高了系统的暂态性能,控制性能优于单独的反馈控制回路。     

航空遥感惯性稳定平台模糊/PID复合控制

为提高航空遥感惯性稳定平台控制系统稳定精度和扰动抑制能力,在常规PID控制的基础上设计了一种模糊控制与PID相结合的复合控制算法,分别应用于稳定平台横滚框及俯仰框系统进行实验验证。在三环控制系统位置环中将模糊控制与PID控制方法结合使用,并引入变论域思想,建立模糊/PID复合控制器,满足输出偏差变化不同时刻对PID参数整定的要求。通过模糊控制器实时调整PID参数,使系统具有良好的动、静态特性,实现多源扰动下惯性稳定平台的高稳定精度控制。分别通过仿真和静动态实验对方法进行分析和验证。实验结果表明:与常规PID控制及单纯模糊控制相比,模糊/PID复合控制器具有优越的扰动抑制能力和高稳定精度。相对传统PID控制,横滚框和俯仰框的静态均方根误差(RMS)值分别下降51%和73%、动态RMS值分别下降约20%和30%。     

惯性稳定平台载体扰动抑制算法研究

为了减小载体扰动对机载光电设备的影响,需要设计保证惯性稳定平台稳定的控制算法。以某型号惯性稳定平台为研究对象,通过建立其机电系统的动态模型,分析了影响平台稳像精度的扰动因素,在此基础上设计了扰动观测器。此外,为有效抑制载体的周期性扰动作用,针对性地设计了重复控制算法。仿真结果表明,所提出的扰动观测器与重复控制相结合的复合控制算法能够有效地抑制载体扰动,提高系统稳像精度。     

一种结合扰动观测器的惯性稳定平台稳定回路设计

介绍了大型重力测量惯性稳定平台的典型陀螺稳定回路设计,在此基础上以稳定回路闭环传递函数为被控对象设计了扰动观测器,实现了扰动观测器与陀螺稳定回路的结合。进行了没有扰动观测器和带有扰动观测器的稳定回路控制仿真对比,仿真结果表明,结合扰动观测器的稳定回路,具有更好的抗低频干扰力矩和高频陀螺测量噪声的能力。     

惯性平台台体组件的有限元模态分析

用ANSYS软件通过在轴承滚珠和滚道面间建立接触单元,较好地处理了台体组件中的轴承连接问题。通过对某型号惯性平台组件进行有限元模态分析和研究,给出了台体组件前6阶固有频率和振型。根据计算结果,对如何改善台体组件的动态特性提出了建议,为进一步进行台体组件的动力学分析奠定了基础。     

惯性平台基座结构的动态特性分析

采用有限元分析法,对某型号平台基座结构的固有频率、振型等模态参数以及动力响应(包括动态位移和动应力)等动态特性参数进行了计算分析和实验验证,由此判断其动特性是否满足要求,为基座结构的动力修改提供依据。     

惯性平台热分析与热变形试验研究

从温度场角度，就温度变化对平台装配精度、轴承预紧等方面所产生的影响进行了分析，并对平台结构系统进行了热分析及热变形试验，为平台动态测试参数超差问题的解决提供了一定的依据。     

惯性稳定平台变置信度优化平滑CMAC复合控制

提出了一种基于变置信度(MC)及优化平滑算法(OS)的改进型小脑模型关节控制器(CMAC)复合控制方法,用于提高航空遥感惯性稳定平台控制系统指向精度及稳定性。首先,以CMAC学习过程中存储单元被激活的次数为依据,对存储单元设置不同的置信程度,提高了CMAC控制器的学习效率与控制精度,避免了系统动态跟踪中过学习发散现象而导致的控制系统精度下降甚至崩溃;其次,针对常规CMAC算法系统输出波动较大问题,加入优化权值算法,改善系统输出平滑性,提高了CMAC控制器的稳定性,避免了系统输出波动对电机及传动系统损害;最后对提出方法进行了仿真分析并利用实验室某三轴惯性稳定平台进行实验验证。实验结果表明:采用基于MCOS的改进型CMAC复合控制方法后,稳定平台系统控制精度、响应速度及输出平滑稳定性均得到有效提高,动基座推车实验框架角位置水平跟踪误差RMS值为0.021 6°,相对PID与常规CMAC控制方法分别降低了55.09%和30.55%。     

Characteristics of spherical hydrostatic supporting system for floated inertial platform

This paper presents a novel method to evaluate the characteristics of the spherical hydrostatic supporting system for the floated inertial platform in dynamic environments. This hydrostatic supporting system consists of eight suspension pads fixed on the inner sphere. The force model for each single suspension pad is established. The dynamic equations for the inner sphere are also derived from the geometrical configuration. The stable time and stable deviation of the inner sphere in different dynamic environments are calculated. The results show that the hydrostatic supporting system can make the inner sphere resistant to the vehicle acceleration effectively and omnidirectionally.     

On The Dynamic and Thermal Performance of a Zero Clearance Auxiliary Bearing(zcab) for a Magnetic Bearing System

Structural and thermal analysis of a zero clearance auxiliary bearing (ZCAB) for magnetic bearing systems is presented. The ZCAB consists a series of rollers whose centers are initially placed on a circle. At the open condition all rollers have an initial clearance about the rotating shaft. As the shaft drops on the ZCAB rollers, either due to failure of the magnetic bearing system or a transient shock, the centers of the rollers move circumferentially along a curve path and after eliminate the initial clearance by closing around the shaft and re-centering it. This is known as the closed condition. The overall stiffness of the ZCAB will then depend on the stiffness of each single roller and the initial clearance between the rollers and the shaft. This is affected by the number of rollers that will touch the shaft which will also vary the load applied on the rollers. The low shaft-rollers traction coefficient and overall dynamic support characteristics obviate the possibility of backward whirl, however this traction and the generated heat in the rolling element embedded in the rollers are sources of heat generation. This paper presents the results of a transient analysis for the ZCAB structural stiffness. A preliminary thermal model of the ZCAB and comparison between the predictions and test results are also discussed. Some design guidelines are presented to help improve the performance of the ZCAB in the case of high temperature working conditions.     

电磁轴承辅助设计系统研究

电磁轴承辅助设计系统是电磁轴承设计中的重要手段 ,根据电磁轴承设计的现状 ,分析轴承辅助设计系统的需求 ,进而对系统的数据组成以及轴承数据表示方法进行了研究 ,在此基础上设计了系统的用例模型 ,最后给出了系统的主要功能     

Auto-Eliminating Clearance Auxiliary Bearing Device for Active Magnetic Bearing Systems

An auto-eliminating clearance auxiliary bearing device (ACABD) for active magnetic bearings (AMBs) has recently been designed and a prototype system was tested in this study. ACABD mainly consists of a series of connected tilting supports. In this design, a ball bearing is directly mounted on a rotor as the auxiliary bearing in an AMB system. The outer race of this ball bearing is surrounded by these supports. In the open position, there exists an initial protective clearance between the outer race of the ball bearing and the tilting supports. When the bearing-mounted rotor drops on these supports due to an AMB failure, the friction between the outer race of the ball bearing and the tilting support rotates these supports to eliminate the clearance and recenter the rotor. Due to elimination of the clearance, the possibility of backward whirl of the rotor is eliminated. The movement mechanism of this device is analyzed kinematically. The rotation of these supports, elimination of the protective clearance, as well as the rotor rotating stability after the clearance elimination are discussed from the perspective of statics. Furthermore, a preliminary prototype experimental rig was developed to demonstrate the feasibility of the ACABD after AMB system failure. Experimental results show that, after the AMB system failed, the ACABD immediately eliminated the clearance between the outer race of the ball bearing and the supports and pushed the rotor center close to the initial position.     

Modeling and Analysis of Novel Integrated Radial Hybrid Magnetic Bearing for Magnetic Bearing Reaction Wheel

Conventional ball bearing reaction wheel used to control the attitude of spacecraft can't absorb the centrifugal force caused by imbalance of the wheel rotor,and there will be a torque spike at zero speed,which seriously influences the accuracy and stability of spacecraft attitude control.Compared with traditional ball-bearing wheel,noncontact and no lubrication are the remarkable features of the magnetic bearing reaction wheel,and which can solve the high precision problems of wheel.In general,two radial magnetic bearings are needed in magnetic bearing wheel,and the design results in a relatively large axial dimension and smaller momentum-to-mass ratios.In this paper,a new type of magnetic bearing reaction wheel(MBRW) is introduced for satellite attitude control,and a novel integrated radial hybrid magnetic bearing(RHMB) with permanent magnet bias is designed to reduce the mass and minimize the size of the MBRW,etc.The equivalent magnetic circuit model for the RHMB is presented and a solution is found.The stiffness model is also presented,including current stiffness,position negative stiffness,as well as tilting current stiffness,tilting angular position negative stiffness,force and moment equilibrium equations.The design parameters of the RHMB are given according to the requirement of the MBRW with angular momentum of 30 N ? m ? s when the rotation speed of rotor reaches to 5 kr/min.The nonlinearity of the RHMB is shown by using the characteristic curves of force-control current-position,current stiffness,position stiffness,moment-control current-angular displacement,tilting current stiffness and tilting angular position stiffness considering all the rotor position within the clearance space and the control current.The proposed research ensures the performance of the radial magnetic bearing with permanent magnet bias,and provides theory basis for design of the magnetic bearing wheel.     

用线性加速度计实现无陀螺平台稳定的理论研究

为实现加速度计在平台稳定控制中的应用,需要建立相关的理论基础.简述了线性加速度计在光电稳定平台装置中的应用研究;在证明刚体角运动与基点位置选择无关的理论基础上,提出了线性加速度计在稳定平台中可行的配置方案;解决了线性加速度计在实际应用中安装不便所带来的问题.     

用于电磁轴承的快速控制原型

对电磁轴承引入快速控制原型技术 ,并对控制方案设计、建模、仿真的软件环境以及运行、验证控制方案的硬件环境进行了较为深入的讨论 ,提出了实现快速控制原型 ,组建自己的实时控制系统设计与测试平台的方案。快速建设自己的实时快速控制开发系统 ,无疑会促进电磁轴承的数字化和产品化进程。     

磁悬浮飞轮用嵌环式永磁偏置径向磁轴承

为满足航天用扁平转子磁悬浮飞轮对低功耗磁轴承的需求,提出一类同极性嵌环式永磁偏置径向磁轴承(Radial permanent-magnet-biased magnetic bearing,RPMB),旋转损耗低,工作气隙径向内外双环、轴向同层分布,径向磁力为平面汇交力系,具有磁极轴向短、可灵活设计的独特优势.根据全主动、主被动两类磁悬浮飞轮的不同需求,采用磁路分析与有限元仿真的方法,对磁极对齐型、磁极交错型、磁极偏置型三种嵌环式RPMB进行了有针对性的分析与设计,所设计的全主动磁悬浮飞轮,具有轴向长度短、质量小、精度高的优点;所设计的两轴主动磁悬浮飞轮,经优化设计,具有高被动刚度、高电流刚度、电流刚度高稳定性的优点.     

动力磁悬浮轴承的特点及关键技术

基于普通的径向磁悬浮轴承 ,提出了一种新型的机电一体化零件———具有电机机能的动力磁悬浮轴承 ,分析其小形、超高速、大扭矩的应用特点和工作原理 ,并指出了动力磁悬浮轴承理论研究的关键技术。     

磁悬浮轴承连续式模糊控制系统

介绍了主动磁悬浮轴承的连续式模糊控制系统，主要由高精度气隙检测电路、PS－7483多功能综合板与PC机组成，系统具有较高控制精度，良好的动态特性和鲁棒性。