基于负载观测的伺服系统抗扰研究

当负载变化时，按线性二次型状态反馈(LQSF)所设计的最优闭环控制系统是有静差的，为了减小和消除扰动静差，文中引入负载观测器实施对扰动负载的观测，并将其引入到电流调节器的输入端，作为速度调节器前馈补偿的控制输入，从而使系统具有优良的抗扰性能。文中给出了伺服系统负载观测的存在条件，负载观测器的构成方法，并在有或无负载观测结果参与控制的情况下，对实际系统做对比研究。系统的仿真和实验均证实了负载观测器参与系统控制的有效性。     

一种基于小波变换的数字图像自动聚焦算法

由傅立叶光学理论可知 ,图像高频能量值可以反映聚焦程度 .在传统图像灰度方差评价函数的基础上 ,利用小波多分辨率分析 ,提出了一种新的自动聚焦算法 .清晰度评价函数通过舍去图像低频概貌信号 ,突出了高频能量 ,具有更好的尖锐性 .并分析了分解层数对评价函数性能的影响 .通过改进的变步长爬山算法实验表明 ,该算法与传统灰度方差算法相比具有更好的聚焦精确度 .     

三轴转台中框双马达驱动控制技术研究

在对同步技术及同步误差产生原因分析的基础上，提出了共反馈同步误差模糊校正系统方案，并对模糊控制器进行了设计及修正。着重分析了仿真转台电液位置伺服系统控制策略，最后通过实验来验证所采用的控制策略是提高控制精度及减小同步误差的有效方法。     

高密度光盘径向动态特性测量方法研究

分析了现有光盘径向动态特性测量方法的特点，深入研究了一种适用于高密度光盘径向动态特性的基于过道波形信号连续测量方法及其具体实现。比较了该方法与国际标准推荐的测量方法的测量精度，结果表明该方法精度更高，更能适应未来高密度光盘的测试要求。     

FANUC RAM轴在数控伺服冲床上的应用

在FANUC Oi PD数控系统的基础上,把RAM轴功能应用在数控伺服冲床上,通过模拟伺服适配器控制第三方驱动器和电机,选择M信号来指定冲压轴所处的动作模式,控制冲头上下移动的形式、速度,降低冲压噪声,提高效率。     

液压伺服阀故障分析及处理

介绍了牡丹江恒丰纸业有限公司10~#纸机的压榨、雕印、施胶系统的液压伺服阀控制原理,并结合实际应用阐述MOOG伺服阀D633系列的维护经验和故障处理方法。     

Die quenching limit of AA2024 aluminum alloy billet on servo press

Die quenching of AA2024 aluminum alloy billets was carried out on a servo press with ram-motion control of WC-20 mass%Co dies directly after solution heat treatment (SHT). To clarify the dependence on billet size for die quenching, two billets with a height of h₀ = 8 mm or 16 mm and with the same diameter of 16 mm were prepared. The cylindrical billets were heated in an electric furnace at 823 K and transferred to the press. Then the billets were uniaxially compressed with a reduction in height (Δh/h₀) of 2% or 5%, and further held between the dies. The sandwiching duration by dies (t_d.q.) was varied from 0 to 8 s. Based a measured temperature change, hardness and TG–DTA analysis, it is found that die quenching is successfully carried out without precipitation hardening only in the case of the billet with a height of 8 mm and t_d.q. > 6 s. The reduction in height is limited less than 5% by intergranular fracture on side surface of billet during the die quenching process.     

基于气压传动和触摸屏的智能烫印机研发

针对当前烫印机采用薄膜轻触面板型人机界面交互性差、无网络功能、信息化和自动化水平低等问题,设计开发了一种新型智能烫印机。采用基于T5内核的串口电容触摸屏,实现了烫印工艺多模式交叉配置,提升了设备适应当前小批量定制化生产需求的能力。基于T5触摸屏集成的网络接口,实现了远程监控、算法升级、网络化生产管理。嵌入式控制系统以STM32F10系列32位高性能微控制器为核心,集成了烫印胶头温度测控模块和伺服电机驱动模块。采用UL2068达林顿管全数字化驱动气缸,高速全自动完成移印过程。实践应用表明:所开发的烫印机性能稳定,实现了烫印工艺、烫头恒温、伺服电机、高速气缸高性能一体化全自动控制。该烫印机集成度高,触摸屏显示界面友好,能够实现网络化控制与管理,具有广阔的工程应用前景。     

Discrete-time setpoint-triggered reset integrator design with guaranteed performance and stability

According to Bode's gain-phase relationship, in linear time-invariant controllers, introducing an integral action to eliminate the steady-state error has an adverse effect of increased phase delay and overshoot, leading to performance deterioration. Moreover, increasing the bandwidth of the closed-loop system to enhance the low-frequency disturbance rejection invariably amplifies the sensitivity to high-frequency disturbances. Hence, the performance of the linear controllers is always limited due to these fundamental frequency- and time-domain limitations. Motivated by the desire to address the fundamental limitations of linear controllers and improve the time-varying closed-loop performance, we put forward a novel setpoint-triggered reset integrator strategy that varies the integrator cut-off frequency based on the setpoint information. Particularly, to tackle the time-varying disturbances and setpoint profiles, the proposed controller consists of a nominal linear controller and a variable-gain reset integrator. We show the global asymptotic stability of the proposed methodology using positive-real lemma along with the LaSalle's invariance principle and experimentally validate using measured frequency response function. Moreover, the efficacy of the proposed technique compared to that of the linear controller is experimentally demonstrated on a benchmark rotary servo system. Experimental results assessed using the tracking error and cumulative power spectral density substantiate that the proposed control strategy can not only improve the low-frequency disturbance rejection but also augment the high-frequency trajectory tracking performance.     

一种钢卷车随降液压系统在带尾卷取中的应用

介绍了为某厚规格、高强度的不锈钢热轧酸洗退火机组设计的一种钢卷车随降液压系统的原理、调试要点及实际使用情况。该系统满足了机组的生产工艺需要,即在带尾卷取时,通过该随降液压系统,使钢卷车对带尾提供足够压力,同时随着卷取机芯轴上钢卷卷径的增加压力同步下降,从而既保证了带尾卷取的紧实度,又有效保证了关键设备的安全。