超磁致伸缩材料微位移驱动器的实验研究

针对超磁致伸缩材料微位移驱动器在精密定位控制中存在的迟滞和位移非线性等不足,对超磁致伸缩材料微位移驱动器进行实验研究,介绍了微位移驱动器中预紧机构和放大机构的设计理论、设计过程和研究方法。研究结果表明:微位移驱动器的控制精度高、重复性好且适用范围较大。     

平面2自由度冗余驱动并联机构最优控制

以平面2自由度冗余驱动并联机构为研究对象，推导了该对象的动力学模型，提出了基于该机构动力学模型的最优控制器，详细给出了最优控制器的设计过程。对机构在典型的PD控制器以及所提出的最优控制器下的点到点运动控制进行了仿真实验，同时以机构末端执行器的位王误差、速度误差为被控变量，对比分析了它们的控制精度。实验证明，最优控制能够进一步减小机构在运动中的位置误差和速度误差，提高机构运动精度，获得更好的位置、速度跟踪性能。     

空气炮清堵装置的研究与应用

介绍了空气炮清堵装置的工作原理、结构特点和设计分析，并根据其原理及特点简单介绍了在使用中的注意事项。     

一种用于主从控制的阻尼力可调关节模块机构设计

现有的力觉反馈设备,大多将驱动力直接作用于操作人员,具有操纵安全性和柔顺性上的缺陷。针对这个问题,设计了一种用于主从控制的阻尼力可调关节模块机构。该关节模块机构基于制动器原理设计,为被动力反馈系统,安全性好。驱动器使用一对膜片式气缸,采用驱动力转换为摩擦力方式,间接达到转动阻尼力调节的目的。文中论述了阻尼力可调关节模块的设计方案、阻尼力调控原理,并对制作的样机进行实验和数据分析。经过实验证明,阻尼力可调关节模块机构响应速度快、运动可靠、控制精度高,达到了主从控制的使用要求。     

磁流变传动机构的设计与研究

设计了一种磁流变传动机构的基本结构，分析其工作原理；并推导了磁路设计的理论计算公式，得出了磁路设计的一般方法；对机构所传递的力矩进行了实验测试和分析。为磁流变传动机构的应用与研究提供了参考和依据。     

高速平面6杆并联机器人运动学建模与误差分析

并联机器人具有负载能力强、运动速度快和刚度大等优点,弥补了串联机器人的不足,使得并联机构成为一个潜在的高速度、高精度运动平台。平面6杆并联机器人改善了经典平面5杆并联机构工作空间内存在较多的奇异性和承载能力差、刚度低的缺陷。基于高速平面6杆并联机器人结构,建立了运动学正向和逆向求解模型;针对机构存在的基座定位误差、驱动角误差和连杆加工误差对控制精度的影响进行了系统、深入地研究,为实现机器人结构的最优化设计和高速、高精度控制,奠定了理论基础。     

受生物启发的扑翼飞行器弹跳机构概念设计

针对扑翼飞行器自主起降能力缺失、严重影响其适用场景的问题，开展了仿生弹跳机构设计研究。对鸟类跳跃起飞过程中典型的运动状态进行分析，结合其各阶段的后肢骨骼结构、重心、力、速度等运动变化规律，对扑翼飞行器弹跳起飞动态过程进行了设计。基于鸟腿的骨骼解剖学结构，设计了闭链齿轮-五杆仿鸟腿弹跳机构，并基于D-H法推导出弹跳机构运动学方程，利用拉格朗日方程建立了弹跳机构起跳阶段的动力学方程。对弹跳机构进行了详细结构设计，采用ADAMS对简化的弹跳模型进行了仿真分析。仿真结果显示，借助该仿生弹跳机构，扑翼飞行器系统质心速度达到8.4 m/s，大于“信鸽”飞行器起飞所需的速度7.9 m/s，具备弹跳起飞的可能性。     

基于PLC的夹紧力在线调控系统

为了获得金属切削过程中的合理夹紧力,减少薄板件的铣削变形,将PLC技术应用到机床夹具的设计中,设计了夹紧力大小可动态调控的液压夹具系统(HFAC).HFAC系统包括夹紧机构、液压系统和控制机构,通过PLC闭环控制调节电液比例减压阀的出口压力,以使系统获得高精度夹紧力,并实现夹紧力的动态调控.实验结果表明,HFAC系统可实时调节机床夹具的夹紧力,其夹紧力控制精度为3％左右,即系统具有良好的稳定性以及较高的夹紧力控制精度.     

模糊控制型数字阀在流量控制中的应用研究

该文设计研究了一种新型数字阀控制器,该控制器基于模糊控制理论与脉宽调制控制技术相结合,并通过了实验验证。实践表明该控制器能解决高压气体微小流量的精确控制问题,其控制精度满足设计要求。     

仿鸟扑翼飞行机器人执行机构优化设计的研究

仿鸟扑翼飞行机器人结构多样,应用广泛。主要对仿鸟扑翼飞行机器人的扑翼飞行原理和执行机构进行了分析研究。在此基础上建立了以齿轮连杆机构作为执行机构的仿鸟扑翼飞行机器人的数学模型和三维模型,并采用黄金分割法结合MATLAB软件对执行机构进行了数值模拟和优化设计,得到了在最小传动角最大的情况下,满足扑翼飞行的最佳四杆机构。此外,研究过程中所建立的三维模型利用ADAMS软件进行了运动仿真模拟,得出分析结果与模型相符合,满足设计要求。所做的工作为仿鸟扑翼飞行机器人的理论研究和实际模型的建立提供了可靠的参照和引导。     

Three-body impact wear study on conventional and new P/M + HIPed wear resistant materials

A new hammer-mill type impact wear testing facility was built for impact wear testing and characterization. Tests with the hammer-mill impact wear device were carried out on conventional wear resistant materials such as Mn-steels of different compositions, white cast iron, and on new P/M+HIPed wear resistant materials. To verify the validity in using this laboratory wear testing apparatus, wear behavior and worn surfaces obtained on conventional and new Mn-steels generated from this device were compared with wear phenomena and worn surfaces developed in industrial applications, i.e. from certain types of rock crushers. The strain hardening effect in different Mn-steel grades was studied first. Second, the wear resistance of materials with different properties was studied using two different grades of abrasive. With silica sand (high hardness, low compressive strength), conventional Mn-steel and white cast iron perform in a manner comparable with the P/M+HIPed materials. With volcanite sand (low hardness, very high compressive strength), the P/M+HIPed wear resistant materials appear to have the best wear resistance.     

童车动击性能检测综合试验机的研制

为了获得精确的碰撞速度和撞击能量,在分析现存检测设备不足的基础上,研制了一台新型的童车动击性能检测综合试验机。针对现存设备存在的碰撞速度和撞击能量的可控性差、二次撞击现象、可重复性差、产生试验数据能力不足等诸多问题,采用了包括框架底座、引导装置、提升装置、防二次撞击装置、碰撞挡板及数据采集和处理系统等结构性的整体解决方案。突破了以往关于童车碰撞与冲击检测的相关设计思想,提升了检测过程的科学性和公正性。     

Control and evaluation of particle impact conditions in a sand erosion test facility

For the prediction of actual damage to plant component materials and for making the erosion mechanisms clear, it is important to control and to evaluate the particle impact conditions in a testing facility. A sand blast type erosion test rig, which can achieve the particle impact velocities up to 135 m s⁻¹ and a wide range of impact angles has been constructed. The key factors in particle impact conditions of particle flux, impact velocity and impact angle were examined. The relative distance between particles and particle size was discussed, as the particle flux affected erosion rate of material. A new method was proposed to determine particle velocities in this facility. The theoretical velocity of the particle calculated by the equations of particle motion was compared with the experimental results. The divergence of particles from a geometrical angle was evaluated by measuring surface roughness of the specimens. Although some spread of the particles were observed surrounding the central damage area of the specimen surface, the greatest amount of damage was concentrated in the center. As a result, it was found that particle impact conditions were well controlled in this testing unit.     

Pneumatic actuating device with nanopositioning ability utilizing PZT impact force coupled with differential pressure

This paper reports a new actuating method using piezoelectric (PZT) impact force coupled with differential pressure for the pneumatic positioning device. Fundamental experiments show that the sliding table can be actuated to move with precise step motions in both the forward and backward directions based on the proposed method. A two degree-of-freedom (DOF) analytic model is established and verified for expressing the impact actuation. Furthermore, a pulse width, which is equal to the period of second-mode vibration of the actuating device, is experimentally examined for the actuation of PZT actuator. Finally, position control based on a hybrid controller is implemented. The experimental result shows that the sliding table is successfully positioned from the reference origin to the target position of 4 mm in 0.924 s with the positioning accuracy of 5 μm due to the actuation of the pneumatic cylinder, and that the final positioning accuracy of 10 nm is obtained by the actuation of PZT impact force coupled with differential pressure. The total control time is 2.683 s. It is shown that the proposed method is capable of significantly improving the positioning performance of the pneumatic actuating device. It is expected that the proposed method will be widely applied in the precision industry using pneumatic cylinders.     

压电双晶片型2自由度精密驱动器的动态特性

研制以自由端带有集中质量的悬臂式压电双晶片为驱动单元的新型惯性冲击式2自由度精密驱动器.建立基于Karnopp摩擦模型的驱动器动力学模型,对驱动器动态特性进行仿真分析和试验对比研究.提出压电双晶片型惯性冲击式精密驱动器特定的定频调压驱动方法.仿真分析结果和试验结果吻合较好,表明该动力学模型符合驱动器的动态特性,可用于对压电双晶片型惯性冲击式2自由度精密驱动器的理论分析.     

Influence of tribological additives on friction and impact performance of injection moulded polyacetal

Tribological additives are used to improve frictional properties of injection moulded thermoplastics. The additives might however also affect the mechanical properties of the material. The influence of processing conditions on both frictional and mechanical properties is highly relevant in the development of tribologically modified grades. In the present study we investigate how two commonly used tribological additives, polydimethylsiloxane and polytetrafluoroethylene, affect friction and impact properties of polyacetal (polyoxymethylene). A new injection mould provides test specimens for both friction and impact testing. Friction is evaluated through ring-on-disc testing against polypropylene simulating use-conditions in a particular medical device. The impact testing is based on instrumented three-point bending of single-edge notched beams of component-realistic thickness. Both frictional and mechanical properties are benchmarked against those of the base polyacetal resin. High-speed video recording of the crack propagation during impact testing reveals potential differences in fracture mechanisms among the blends. Fractography by scanning electron microscopy is used for comparison of fracture surface characteristics. The tested concentration of the additives is found to effectively reduce friction, yet are not found critical with respect to the impact properties evaluated. A noticeable interaction with respect to friction is found between the additives speaking in favour of their use in combination.     

低温液化气体汽化保护控制装置的研究

低温容器在使用过程中,当液化气体汽化不充分时会使液态介质流入常温管道,从而导致材料的冲击韧性大幅降低。针对这种现状,分析了低温液化气体对人体和设备的危害,以水为介质进行了低温液化气体汽化保护控制试验,研究了介质在0~4℃温度区间内,温度变化和调节阀开度、液体泵转速的关系,得出一种新型的低温汽化保护控制装置。试验结果表明：该装置精密度高,数据准确稳定,对低温液化气体的使用安全起到保障作用。     

提高FMS有轨运输车定位精度及其可靠性研究试验──PDF控制器的研制和应用

叙述了一种新型的、具有很强鲁棒性的伪微分反馈（ＰＤＦ－Ｐｓｅｕｄｏ－ＤｅｒｉｖａｔｉｖｅＦｅｅｄ－ｂａｃｋ）控制器。作者将其用来控制ＦＭＳ有轨运输车模型，以提高运输车定位精度及其可靠性。介绍了研究试验中的设计、计算、调试以及实验结果。其中详细地阐述了模型运输车的机械结构与设计，驱动系统固有频率计算与控制，模型车数学模型的建立与参数识别，ＰＤＦ控制器设计与参数优化以及实验装置总体调试与定位精度测试。研究结果表明，实验装置的设计、分析计算以及试验是成功的，达到预期的目标，为工业试验提供了依据；采用ＰＤＦ控制器控制运输车具有调试方便，工作可靠以及能较大地提高运输车的定位精度等优点。     

航空发动机燃油计量装置的AMESim建模

现代航空发动机控制系统采用全权限数字电子控制,但液压机械控制装置——燃油计量装置作为一种精确控制燃油流量的执行机构,仍是控制系统必不可少的组成部分。本文基于AMESim软件建立了燃油计量装置的仿真模型,并通过物理试验验证了模型的精度。最后基于经校验的AMESim仿真模型,分析了计量装置的主要设计参数对燃油计量特性的影响,为燃油计量装置的设计提供了参考依据。     

AI808P调节器在熔融炉温控系统中的应用

从应用的角度出发,着重论述了国产AI808P型人工智能调节器和AIJK3型可控硅触发器在熔融炉温控系统中的应用.较为详细地阐述了温控系统的组成、调节器和触发器的性能和功能.该系统采用双向可控硅作为功率驱动器件,在武钢质检中心实际应用表明,系统温控精度高,稳定性好,主要性能指标完全能满足使用要求.