基于高速DSP的跳频通信系统设计

文章研究了跳频通信的实现方法,提出了一种基于高速DSP的跳频通信系统的硬件实现方案,详细给出了跳频控制模块的硬件设计、跳频同步方法、伪码的产生和部分电路设计。该系统可应用于短波和超短波跳频通信装备。     

Leveraging Bioinspired Structural Constraints for Tunable and Programmable Snapping Dynamics in High-Speed Soft Actuators

Creating high-speed soft actuators will have broad engineering and technological applications. Snapping provides a power-amplified mechanism to achieve rapid movements in soft actuators that typically show slow movements. However, precise control of snapping dynamics (e.g., speed and direction of launching or jumping) remains a daunting challenge. Here, a bioinspired design principle is presented that harnesses a reconfigurable constraint structure integrated into a photoactive liquid crystal elastomer actuator to enable tunable and programmable control over its snapping dynamics. By reconfiguring constrained fin-array-shaped structure, the snapping dynamics of the structured actuator, such as launching or jumping angle and height, motion speed, and release force can be on-demand tuned, thus enabling controllable catapult motion and programmable jumping. Moreover, the structured actuators exhibit a unique combination of ultrafast moving speed (up to 2.5 m s⁻¹ in launching and 0.22 m s⁻¹ in jumping), powerful ejection (long ejection distance of ≈20 cm, 35 mg ball), and high jumping height (≈8 cm, 40 times body lengths), which few other soft actuators can achieve. This study provides a new universal design paradigm for realizing controllable rapid movements and high-power motions in soft matter, which are useful for building high-performance soft robotics and actuation devices.     

一种高速高共模瞬态抗扰度电平位移电路

设计了一种适用于GaN栅驱动的高速、高共模瞬态抗扰度的电平位移电路。电路受PWM信号和短脉冲协同控制,利用短脉冲控制的加速电路提升了电平转换速度。在浮动电源轨高速切换和减幅振荡过程中,电路内部对地寄生电容的充放电会导致输出逻辑错误。针对此问题,采用一种高速、低功耗的交叉控制式噪声屏蔽电路,实现了极高的共模瞬态抗扰度。采用0.35μm高压CMOS工艺进行电路设计。仿真结果表明,在100 V电平转换情况下,该电平位移电路的平均传输延时为1.58 ns,延时失配小于100 ps,共模瞬态抗扰度达到200 V/ns。     

DSP图像处理系统与PC机高速通信电路设计

基于双口RAM,配合高速单片机、电平转换驱动器以及PCI数据采集卡,设计了一种能够实现DSP图像处理系统与上位PC机之间高速通信的应用电路。介绍了系统组成、接口电路的软硬件实现,以及高速PCI数据采集卡的使用。该电路已应用于某图像处理平台以及相应的测试设备中,通信效果良好。     

Novel direct designs for 3-input XOR function for low-power and high-speed applications

Novel direct designs for 3-input exclusive-OR (XOR) function at transistor level are proposed in this article. These designs are appropriate for low-power and high-speed applications. The critical path of the presented designs consists of only two pass-transistors, which causes low propagation delay. Neither complementary inputs, nor V _DD and ground exist in the basic structure of these designs. The proposed designs have low dynamic and short-circuit power consumptions and their internal nodes dissipate negligible leakage power, which leads to low average power consumption. Some effective approaches are presented for improving the performance, voltage levels, and the driving capability and lowering the number of transistors of the basic structure of the designs. All of the proposed designs and several classical and state-of-the-art 3-input XOR circuits are simulated in a realistic condition using HSPICE with 90 nm CMOS technology at six supply voltages, ranging from 1.3 V down to 0.8 V. The simulation results demonstrate that the proposed circuits are superior in terms of speed, power consumption and power-delay product (PDP) with respect to other designs.     

铁路隧道衬砌极限状态法设计验证研究

为了验证极限状态法在隧道衬砌设计中的可操作性,分别采用极限状态法和破损阶段法对铁路隧道衬砌进行了试设计,并对比分析了两种方法的试设计结果。研究结果表明:(1)当衬砌为素混凝土结构时,极限状态法的计算厚度均比破损阶段法计算厚度大,最大相差20 cm,需对极限状态法抗裂验算公式中的调整系数γ_d重新校核,校核后γ_d=1.55;(2)针对钢筋混凝土衬砌结构及明洞结构,极限状态法的设计结果与破损阶段法设计结果基本相同,钢筋混凝土结构的极限状态方程中相关分项系数及调整系数取值是合理的。(3)采用极限状态法(γ_d=1.55)与破损阶段法试设计工程投资相当,极限状态法较破损阶段法工程投资增加237万元,增加1%。     

高速钢激光重熔后的组织与性能

研究了W18Cr4V高速钢激光重熔后的组织与性能。结果表明，常规淬回火组织经激光重熔后其硬度、韧性都有提高，熔化层的残余应力为技应力；经640℃回火后；由于残余应力的消除及重熔组织中马氏体的二次硬化和残余奥氏体的二次淬火效应其耐磨性能有了进一步地提高。     

浅谈延迟焦化装置露天栈桥的设计

根据延迟焦化装置露天栈桥的工程设计实践,围绕一炉两塔(一个加热炉两个焦炭塔)的焦化装置,分析了露天栈桥设计中的要点及难点,对其在平面布置、基础安排和吊车梁选型等设计方面做一些介绍和论述。     

铁路信号电缆绝缘检测准确性优化方法

为提高铁路信号电缆在线绝缘检测准确性,提出具体优化方法。通过理论建模,分析铁路信号电缆在线绝缘检测不准确的原因,在此基础上提出优化方法。实践结果表明,该方法具备有效性。     

高速移动环境下基于深度学习的信道估计方法

针对高速移动环境下信道快时变、非平稳特性导致下行链路信道估计性能受限的问题,本文提出一种基于深度学习的信道估计网络,即ChanEstNet.ChanEstNet使用卷积神经网络（Convolutional Neural Network,CNN）提取信道响应特征矢量和循环神经网络（Recurrent Neural Network,RNN）进行信道估计.我们利用标准的高速信道数据对学习网络进行离线训练,充分挖掘训练样本中的信道信息,使其学习到高速移动环境下信道快时变和非平稳的特点,更好的跟踪高速环境下信道的变化特征.仿真结果表明,在高速移动环境下,与传统方法相比,所提信道估计方法计算复杂度低,性能提升明显.