基于多标签联合定位的自主视觉着陆技术研究

旋翼无人机着陆场景较为复杂,且 GPS 信号经常被干扰,同时着陆平台非固定,通常需要采用合作标签引导无人机着陆。由于存在阴影、反光等特点,在室外环境下,单一的合作标签往往存在定位误差较大,漏识别较多的问题,严重影响无人机着陆稳定性。为解决这一问题, 本文将现有的单合作标签定位方法进行改进,在传统的单标签 pnp 定位解算的基础上,采用多个合作 Apriltag 标签进行联合定位的方法,以提升无人机定位精度和识别帧率,实现着陆过程精确的视觉导航功能。通过静态定位实验与无人机动态着陆实验,验证了该方法的有效性,提升了旋翼无人机自主着陆系统的鲁棒性。     

黑蒜抗氧化活性研究

研究黑蒜的抗氧化活性.对144只老龄小鼠随机分为空白组、模型组、阳性对照组(Vc组)、黑蒜低剂量组(65mg/kg)、黑蒜中剂量组(260mg/kg)、黑蒜高剂量组(650mg/kg)、白蒜低剂量组(65mg/kg)、白蒜中剂量组(260mg/kg)、白蒜高剂量(650mg/kg)组等9组,干预30d后,以溴化幕油灌喂小鼠,制造氧化损伤模型后,分别测定小鼠血液、肝脏组织中丙二醛(MDA)含量和超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GsH-Px)的活性.黑蒜可以显著降低血液和肝脏组织中丙二醛的含量,提高组织中抗氧化酶的活性,黑蒜降低丙二醛含量和提高GSH-Px活性的作用明显好于大蒜和阳性对照.结论:黑蒜具有较强的抗氧化活性,抗氧化作用明显好于白蒜.     

具有增益失配校正的I/Q双通道数模转换器设计

This paper presents a two-channel 12-bit current-steering digital-to-analog converter(DAC) for I and Q signal paths in a wireless transmitter.The proposed DAC has a full-scale output current with an adjusting range of 2 to 10 mA.A gain matching circuit is proposed to reduce gain mismatch between the I and Q channels.The tuning range is±24%of full scale and the minimum resolution is 1/16 LSB.To further improve its dynamic performance, the switch driver and current cell are optimized to minimize glitch energy.The chip has been processed in a standard 0.13μm CMOS technology.Gain mismatch between a 1-channel DAC and a Q-channel DAC is measured to be approximately 0.13%.At 120-MSPS sample rate for 1 MHz sinusoidal signal,the spurious free dynamic range (SFDR) is 75 dB.The total power dissipation is 62 mW and has an active area of 1.08 mm2.     

A power-efficient 12-bit analog-to-digital converter with a novel constant-resistance CMOS input sampling switch

Apower-efficient 12-bit40-MS/spipelineanalog-to-digitalconverter（ADC）implementedina0.13 μm CMOS technology is presented. A novel CMOS bootstrapping switch, which offers a constant on-resistance over the entire input signal range, is used at the sample-and-hold front-end to enhance the dynamic performance of the pipelined ADC. By implementing with 2.5-bit-per-stage and a simplified amplifier sharing architecture between two successive pipeline stages, a very competitive power consumption and small die area can be achieved. Meanwhile, the substrate-biasing-effect attenuated T-type switches are introduced to reduce the crosstalk between the two op- amp sharing successive stages. Moreover, a two-stage gain boosted recycling folded cascode （RFC） amplifier with hybrid frequency compensation is developed to further reduce the power consumption and maintain the ADC＇s performance simultaneously. The measured results imply that the ADC achieves a spurious-free dynamic range （SFDR） of 75.7 dB and a signal-to-noise-plus-distortion ratio （SNDR） of 62.74 dB with a 4.3 MHz input signal; the SNDR maintains over 58.25 dB for input signals up to 19.3MHz. The measured differential nonlinearity （DNL） and integral nonlinearity （INL） are -0.43 to ＋0.48 LSB and -1.62 to ＋ 1.89 LSB respectively. The prototype ADC consumes 28.4 mW under a 1.2-V nominal power supply and 40 MHz sampling rate, transferring to a figure- of-merit （FOM） of 0.63 pJ per conversion-step.     

基于Android的餐饮点单系统的设计与实现

为了打破餐饮行业传统的手工点单方式,本文阐述了一种采用Android客户端通过WIFI网络进行远程下单的方法,该方法实现了点单、下单、备货、出货等一系列操作,并能通过PC机客户端实现统计功能。     

自适应机械结构的机械手控制软件设计与实现

固定自由度机械手控制软件往往只能应用于某一固定产品,在机械结构扩展方面具有明显的缺陷。根据以往的工作经验,将机械手的机械结构进行抽象,采用计算机持久化存储方式实现自定义关节节点,可以在实际操作中拓展机械手控制软件的使用范围。本文以无锡职业技术学院机器人研究所开发的五自由度机械手为依托,设计了一种可以自适应机械结构的机械手控制软件,并在.net环境下实现。     

基于C#环境的单片机（89C51）与PC的串行通信

主要论述PC机与单片机之间实现异步串行通讯需要解决的问题以及如何利用C