Analysis of one dimensional and two dimensional fuzzy controllers

The analytical structures and the corresponding mathematical properties of the one dimensional and two dimensional fuzzy controllers are first investigated in detail. The nature of these two kinds of fuzzy controllers is next probed from the perspective of control engineering. For the one dimensional fuzzy controller, it is concluded that this controller is a combination of a saturation element and a nonlinear proportional controller, and the system that employs the one dimensional fuzzy controller is the combination of an open-loop control system and a closedloop control system. For the latter case, it is concluded that it is a hybrid controller, which comprises the saturation part, zero-output part, nonlinear derivative part, nonlinear proportional part, as well as nonlinear proportional-derivative part, and the two dimensional fuzzy controller-based control system is a loop-varying system with varying number of control loops.

Vibration Control of the Rail Grinding Vehicle with Abrasive Belt Based on Structural Optimization and Lightweight Design

As a new grinding and maintenance technology,rail belt grinding shows significant advantages in many applications The dynamic characteristics of the rail belt grinding vehicle largely determines its grinding performance and service life.In order to explore the vibration control method of the rail grinding vehicle with abrasive belt,the vibration response changes in structural optimization and lightweight design are respectively analyzed through transient response and random vibration simulations in this paper.Firstly,the transient response simulation analysis of the rail grinding vehicle with abrasive belt is carried out under operating conditions and non-operating conditions.Secondly,the vibration control of the grinding vehicle is implemented by setting vibration isolation elements,optimizing the structure,and increasing damping.Thirdly,in order to further explore the dynamic characteristics of the rail grinding vehicle,the random vibration simulation analysis of the grinding vehicle is carried out under the condition of the horizontal irregularity of the American AAR6 track.Finally,by replacing the Q235 steel frame material with 7075 aluminum alloy and LA43M magnesium alloy,both vibration control and lightweight design can be achieved simultaneously.The results of transient dynamic response analysis show that the acceleration of most positions in the two working conditions exceeds the standard value in GB/T 17426-1998 standard.By optimizing the structure of the grinding vehicle in three ways,the average vibration acceleration of the whole car is reduced by about 55.1%from 15.6 m/s^(2) to 7.0 m/s^(2).The results of random vibration analysis show that the grinding vehicle with Q235 steel frame does not meet the safety conditions of 3σ.By changing frame material,the maximum vibration stress of the vehicle can be reduced from 240.7 MPa to 160.0 MPa and the weight of the grinding vehicle is reduced by about 21.7%from 1500 kg to 1175 kg.The modal analysis results indicate that the vibration control of the grinding vehicle can be realized by optimizing the structure and replacing the materials with lower stiffness under the premise of ensuring the overall strength.The study provides the basis for the development of lightweight,diversified and efficient rail grinding equipment.

Structure analysis of a class of fuzzy controllers using pseudo trapezoid shaped membership functions

An output expression of a class of dual-input single-output fuzzy controllers using pseudo trapezoid shaped membership function is given. By structure analysis it is proved that this class of fuzzy controllers is the sum of a global two-dimensional multi-level relay and a local linear or nonlinear proportional-integral or proportional-differential controller. And the output of this class of fuzzy controllers is a continuous, non-decreasing function of its input variables. These and other meaningful results derived from structure analysis based on the output expressions can guide the design of fuzzy controllers.

A Hyper-redundant Elephant’s Trunk Robot with an Open Structure:Design,Kinematics,Control and Prototype

As for the complex operational tasks in the unstructured environment with narrow workspace and numerous obstacles,the traditional robots cannot accomplish these mentioned complex operational tasks and meet the dexterity demands.The hyper-redundant bionic robots can complete complex tasks in the unstructured environments by simulating the motion characteristics of the elephant’s trunk and octopus tentacles.Compared with traditional robots,the hyper-redundant bionic robots can accomplish complex tasks because of their flexible structure.A hyper-redundant elephant’s trunk robot(HRETR)with an open structure is developed in this paper.The content includes mechanical structure design,kinematic analysis,virtual prototype simulation,control system design,and prototype building.This design is inspired by the flexible motion of an elephant’s trunk,which is expansible and is composed of six unit modules,namely,3UPS-PS parallel in series.First,the mechanical design of the HRETR is completed according to the motion characteristics of an elephant’s trunk and based on the principle of mechanical bionic design.After that,the backbone mode method is used to establish the kinematic model of the robot.The simulation software SolidWorks and ADAMS are combined to analyze the kinematic characteristics when the trajectory of the end moving platform of the robot is assigned.With the help of ANSYS,the static stiffness of each component and the whole robot is analyzed.On this basis,the materials of the weak parts of the mechanical structure and the hardware are selected reasonably.Next,the extensible structures of software and hardware control system are constructed according to the modular and hierarchical design criteria.Finally,the prototype is built and its performance is tested.The proposed research provides a method for the design and development for the hyper-redundant bionic robot.

DSP based fuzzy controller for series parallel resonant converter

In this paper, digital signal processor （DSP） based fuzzy controller for series parallel resonant converter （SPRC） has been estimated, and the performance of the converter is analyzed by using state space model. The method to predict the steady-state and dynamic perfor-mance of the converter with load independent operation has been presented. The proposed converter has been analyzed with the closed-loop and open-loop conditions. The simple form of transfer function for SPRC is developed, and it is used to analyze the stability of the converter with closed-loop operation. The stability analy-sis of the converter is carried out by using frequency response plan. The fuzzy controller regulates the output voltage with change supply voltage and load disturbance. The controller performance of inductance capacitance inductance - T network （LCL-T） SPRC is compared with inductance inductance capacitance - T network （LLC-T） SPRC through simulation TMS320F2407 processor. and experimental studies using

Structural design, analysis and performance evaluation of a novel planar parallel robot： theory and experiment

The structural design, analysis and experimental verification of a novel planar parallel robot that includes parallelogram linkages are reported in this paper. A design methodology combining finite element analysis （FEA） and flexible dynamics is employed in the analysis. The appropriate natural frequencies of robot throughout workspaee are predicted, and the effects of payload, flexibility of joints, cross section and orientations of robot on the natural frequency are analyzed by simulation. Extensive structural vibration experiments with the completed manipulator confirm the predicted structural vibration characteristics throughout the workspace. The experiment also proves the robot＇s performance under a fuzzy self-tuning PI controller.

下肢战伤康复轮足外骨骼设计与步态试验

针对脑部和脊柱战伤士兵的术后康复训练、战时转移、生活代步需求,设计了一种下肢战伤康复轮足外骨骼,通过共用结构和驱动系统进行不同的组装来实现不同工作模式,提高装备的集成度和减轻整体质量;建立轮足外骨骼单腿摆动期的二连杆模型并推导其动力学模型;利用动力学模型和轮足外骨骼的虚拟样机模型分别获得髋、膝关节的理论计算和虚拟仿真力矩;建立基于位置阻抗的轮足外骨骼主动康复训练控制策略,搭建轮足外骨骼实物样机,获得样机的关节运动轨迹与人机交互力。理论计算、虚拟仿真及摆动腿试验测试3种方法的关节力矩曲线走势基本一致,说明理论计算和虚拟仿真模型的正确性;基于步态试验所获得的数据表明其轨迹误差和交互力均较小,满足设计要求,验证了轮足外骨骼设计的合理性与可行性。

水下控制模块安装工具结构设计与对接精度分析

水下控制模块是水下生产系统的关键部件,针对水下控制模块在水下如何精准、高效、安全地实现回收和再安装工作的问题,本文设计了一种水下控制模块安装工具。对此安装工具进行了机械结构的设计,将安装工具各部分结构在工作过程中的作用进行了介绍。针对安装工具能够顺利完成水下控制模块的安装,基于安装工具各部分结构对接精度关系分析,通过数学建模与仿真分析,得到影响水下控制模块安装精度的原因,设计合理的安装精度参数。将仿真分析得到的数据与设计参数相比较,可证明水下控制模块的结构设计能满足水下控制模块的对接定位精度要求。结果表明:各精度参数满足水下控制模块安装工具设计要求,在此设计参数下安装工具能够完成水下控制模块的精确安装。

混合基础隔震体系优化设计及性能

为解决基础隔震结构中隔震层位移需求过大的问题,提出了一种基础隔震结构(Base Isolated Structure,BIS)+串并联调谐质量阻尼器惯容器(Tuned Tandem Mass Damper-Inerter, TTMDI)的混合隔震体系。采用Bouc-Wen滞回模型模拟隔震层的非线性力-变形行为,基于随机等效线性化和模式搜索优化算法并考虑地震动模型,在频域内建立了BIS+TTMDI体系的优化设计框架。分别从鲁棒性、有效性、刚度和阻尼系数、冲程及对地震频率敏感性方面对BIS+TTMDI体系的性能进行评估,并与BIS+调谐质量阻尼器(Tuned Mass Damper, TMD)、串并联调谐质量阻尼器(TunedTandemMassDamper,TTMD)和调谐质量阻尼器惯容器(TunedMass Damper-Inerter, TMDI)进行比较。通过对近场地震动下某七层混合基础隔震结构(包括BIS+TTMDI和BIS+TMDI体系)的动力弹塑性分析,评价了其减/隔震性能。结果表明:BIS+TTMDI体系具有最好的减/隔震性能和强鲁棒性;而且在BIS+TTMDI体系中TTMDI的总阻尼需求不到BIS+TMDI体系中TMDI的一半,因而更为经济实用。

风速可调的地空一体化风力灭火遥控机结构设计与性能分析

风力灭火遥控机作为地面灭火装备的一种创新形式,具备机动性强、远程操作、快速响应等特点,能够在复杂的火情环境中灵活作业,大大提高了灭火效率和安全性。为探讨风力灭火遥控机在应对森林和草原地表火灾地空一体化监测系统中的角色与作用,对风力灭火遥控机进行结构设计,分析旋转开合结构的安装位置和开口大小对出口风速的影响。利用Fluent软件对风力灭火筒进行流体仿真,结合Design Expert软件对仿真数据进行处理,建立了位置S和开口大小d对出口平均风速和出口最大风速的响应曲面和二次模型。结果表明,安装位置和开口大小均为出口风速的重要影响因素,当风筒入口风速设定为70 m/s、旋转开合结构开口大小为30 mm且安装在位置5处时,出口平均风速和出口最大风速达到最大,分别为97.7551 m/s和290.001 m/s。相较于开口大小,安装位置对出口平均风速和出口最大风速的影响更大,且安装位置越靠近风筒出口处风力灭火机的灭火性能越好。

基于爪极式磁悬浮力矩马达的流量调节阀

传统流量调节阀存在结构复杂、质量大、输出流量小等缺点,不适用于航空航天等特殊领域。设计了一种新型流量调节阀,该阀为旋转直驱式,具有输出流量大、结构简单、质量轻等优点。利用UG软件建立三维模型,介绍了该流量调节阀的工作原理。基于Workbench和Fluent软件,分别建立流量阀的强度校核模型和流体域模型,进行阀芯、阀套变形量仿真及稳态流场仿真。加工实验样机,进行流量调节阀的静态特性测试。结果表明:该流量调节阀总质量为375.5 g,当入口压力为4 MPa,出口压力为3.5 MPa时,最大输出流量为25.99 L/min,满足质量轻、输出流量大的使用需求。

不同结构参数对高速开关阀液压力的影响研究

因其具有价格低廉、抗污染性强等优点,高速开关阀已被广泛运用到各种车辆的制动系统中,其动态性能直接影响到车辆的制动效果,而阀芯所受的液压力是决定高速开关阀动态特性优劣的关键参数。针对不同参数对高速开关阀液压力的影响,以及实际工程中阀芯液压力难以测量的问题,采用计算流体动力学(CFD)对高速开关阀进行了数值模拟。首先,基于有限体积法(FVM),建立了不同开度、压差、温度、以及结构参数(阀座节流孔直径和锥角)的三维仿真模型;然后,对比不同网格数量的仿真结果,排除了网格数量对于仿真结果的影响,并详细分析了各参数对液压力的影响,得出了高速开关阀液压力与各参数之间的变化规律;最后,采用响应面分析结合遗传算法对开关阀的结构参数进行了优化。研究结果表明:随着阀芯开度的增加,节流区域发生了转变;较大的压差会导致液压力产生较大幅度的变化;相较于高温,低温对液压力有着更加显著的影响;对结构参数进行优化后,最小开度的液压力提高了49.2%,提高了阀控制稳定性,为高速开关阀线性控制设计提供了理论基础。

考虑SSI效应时TMD的减震优化设计

土-结构相互作用(SSI)效应可能会对地震作用下调谐质量阻尼器(TMD)的有效性产生重要影响,因此本文研究了考虑SSI效应时TMD对高层建筑的抗震控制性能。针对一个质量分布均匀、层刚度随高度呈线性分布的40层benchmark结构,以结构顶层均方根位移最小为优化目标,采用改进粒子群算法对其在不同地基土条件以及地震波激励下的调谐质量阻尼器参数进行优化设计。优化结果表明,忽略SSI效应可能会造成地震激励下高层结构中TMD减震性能的不恰当估计,TMD的优化参数与地基土类型和地震波种类紧密相关。优化后的TMD可以有效降低结构顶层位移响应且不增加其峰值加速度,优化后的TMD耗散了绝大部分地震输入能量,并大大降低了结构能量。

结合建筑工程结构设计的工程造价应用分析

在工程建设项目前期关键的结构设计阶段,造价预测是衡量项目可行性的重要参考,为给项目决策者提供评估依据,结合建筑工程结构设计的工程造价应用进行分析。选取工程结构设计阶段造价影响指标,确立一套可以反映建筑工程结构特点的指标体系,挖掘并预处理建筑工程结构设计数据,将其作为模型输入,并基于BP神经网络构建工程造价预测模型。实例应用结果表明,本文设计的工程造价预测模型的均方根误差为10^(-4)、平均相对误差为1.82%,验证了该模型在建筑工程结构设计阶段的工程造价预测中具有良好的应用效果。

汽车轮毂轴承内、外圈自动送料装置的研制

为提高汽车轮毂轴承制造自动化水平,研制一种汽车轮毂轴承内、外圈的磨床自动送料装置。创新发明了储料料仓、取料送料机械手等组成机构,设计非标自动送料装置整体机械结构以及PLC电气控制系统。使用ANSYS Workbench对关键零部件进行模态分析,避免其在装置运行过程中产生共振而影响作业精度。经试用验证:该自动送料装置结构合理,运行正常,满足工程实际需求。

跨临港大道景观桥的结构设计与计算分析

异型拱桥因其姿态多变,在城市景观桥梁建设中应用较多。跨临港大道景观桥采用横向非对称、纵向偏态拱型式,主跨130 m,主梁为分体双箱弧形梁,中间以横梁联系。文章对其结构设计、施工控制和计算分析做全面介绍,总结了该类桥梁的结构特点和受力特性,并提出了改善其受力性能的方法,可为类似项目的设计提供有益的参考。

DECENTRALIZED ROBUST CONTROL FOR UNCERTAIN FLEXIBLE SPACE STATION

A decentralized variable-structure robust control technique for uncertain large-scale systems is proposed and using the proposed technique. a decentralized robust control system for uncertain flexible space station is designed. The designed robust control system can guarantee the stability and safe operation of space station in a wide range of system parameters variations and highly intensive external disturbances. In addition. because decentralized adaptation laws for the upper bounds of system uncertainties are introduced, the control technique is particularly applicable to the uncertain flexible space station with complex structure whose bounds of system uncertainties can not be determined or vary with time.

基于STPA-FCM模型的自主航行船舶功能系统分析

为探析自主航行船舶(MASS)功能系统之间的失效机制,提升航行安全,将系统理论过程分析(STPA)方法与模糊认知图(FCM)方法相结合,构建MASS功能系统失效特征分析模型。通过STPA方法对功能系统的控制/反馈关系建模,确定27个控制关系与43个反馈关系,分析潜在的不安全控制行为(UCA)及其产生的关键致因,在此基础上,运用FCM方法构建各功能系统之间的交互关系,并反演出最终稳态下的相对失效概率。结果表明:最为核心的功能模块为电力系统、虚拟船长系统、动力定位系统、避碰系统,其稳定值占比分别为7.66%,7.62%,7.47%,7.14%,应优先确保其可靠性、稳定性和安全性。

汽车动力总成磁流变悬置研究综述

磁流变悬置作为一种半主动悬置,被应用在汽车动力总成隔振系统中,其性能直接影响乘车的舒适性。从磁流变悬置的结构设计、控制算法和性能仿真分析方法3个方面进行阐述,介绍了不同结构下磁流变悬置的性能特点,并重点突出了结构设计与优化对其隔振性能的影响;对比分析了几种常用控制算法在控制效果上的优劣,指出了PID算法联合其他算法控制的磁流变悬置具有更好的隔振性能;比较了键合图理论分析法和有限元仿真分析法各自的优缺点;针对磁流变悬置研究现状进行归纳总结,指出单一模式结构与单一算法控制存在的不足以及性能仿真分析时遇到的几点问题,并结合当前研究现状对磁流变悬置的发展前景进行了展望。

一种流体驱动式管道机器人的结构设计与运动分析

基于流体力学理论和油气管道参数设计了一款模块化链式管道机器人,用于解决传统流体驱动式管道机器人周向体积庞大,摩擦阻力难于准确预测的问题。通过三维软件Solidworks建立机器人模型,依据机器人和管道几何形貌对管道机器人驱动力、摩擦力变化规律进行了分析。新设计的管道机器人摩擦阻力可实时检测,最大摩擦力相对于传统皮碗接触支承式管道机器人减小40%,适用最低管道流速为4 m/s。以此为理论依据给出了机器人在管道内的速度控制方案。利用Ansys Workbench软件对机器人压差调节效果进行仿真。以现役油气管道和市政供水管道最大流速为条件,对机器人驱动单元中不同结构的密封皮碗最大承载压力变形情况进行了分析,得出边沿变曲率倾角皮碗相对于传统直板皮碗在抵抗受压变形和密封性能方面均有所提高,更适合管道机器人驱动单元和管壁之间的保压和密封。