基于PLC的同步电机新型智能励磁控制系统的设计

介绍基于PLC控制的同步电机智能励磁控制系统,利用触摸屏和PLC对同步电机励磁进行控制,可实现智能化及参数、故障记录的可视性,详细讲述了系统的工作原理、主要功能、硬件实现及软件流程.     

基于CC1020的高灵敏度低空探空接收机设计

针对当前低空探空接收机存在灵敏度低、便携性差、高功耗等多方面的缺点,本文介绍了一种新型接收机:以CC1020为核心收发芯片,可提高接收灵敏度至-118dBm,并采用C8051F320为控制芯片,完成数据处理、USB通信及供电。大大提高了系统的便携性及数据可靠性。文中对该接收机的工作原理和方式进行了分析,给出了设计思路和硬件电路。     

自动经纬仪的采集系统及目标自动检测算法实现

电视经纬仪中的图像采集和序列图像中目标的自动检测定位是跟踪的关键。本文用VC平台设计实现了基于VFW的经纬仪图像采集系统,在自定义回调函数中对图像序列进行了实时处理。并根据跟踪气象用气球的应用要求设计了基于特征的目标自动检测算法。然后通过VC平台实现了算法的模拟实验。实验结果表明,本文算法可实现具有特定特征目标的自动检测,在此基础上分析了算法的优缺点,为以后的跟踪测量打下良好的基础。     

基于无线传输且带USB接口的数据采集盒的设计

目前在数据采集系统中常常使用有线传输数据。这样很难在野外或者分散的厂房中保证采集和分析的数据的完整性和全面性,同时会导致更多的成本和人力消耗。本文提出了一种解决上述问题的方法并设计了一种新的智能化、应用范围广的基于无线传输且带USB接口的数据采集系统。接到主机的数据采集板采用Silabs公司生产的一种带USB接口的微控制器C8051F320作为核心芯片。完成后的数据采集系统具有精度高、功耗低、体积小、抗干扰能力强等特点。实现了较传统方式更经济有效灵活的数据采集,有着广泛的应用前景。     

人体平衡仪测试系统设计及软件实现

平衡功能障碍存在于大多数偏瘫患者中。平衡仪可以对人体的平衡机能进行定量、客观的评定,有效地协助医生对患者的平衡能力进行诊断。本文设计了一种集平衡测试与康复训练为一体的具有USB接口的平衡仪。论文对该系统的测量原理和设计、软件的具体实现进行了详细地介绍。测试实验结果表明:该系统运行稳定、具有良好的平衡测试及分析能力,同时采用基于虚拟现实技术的康复游戏进行康复训练,界面友好生动,激励患者训练的积极性。     

油管高效清洗装置的研制与应用

介绍一种高效油管清洗装置.该装置可以利用电能、天然气或原油加热,以热水作为清洗介质,采用全封闭箱式结构设计,集油管加热、清洗、传输和自动控制于一体.清洗装置内部采用中心轮盘驱动传输,传输精度高,故障率低;油管一站两次清洗,清洗效果较为理想.采取全封闭式设计,热能散失较小,比传统的清洗方式节能20%以上;清洗用水采取封闭式循环,不会造成环境污染,安全可靠.     

Dynamic Voltage Equalization for Series-Connected Ultracapacitors in EV/HEV Applications

Energy-storage systems (ESSs) play an important role in electric vehicle (EV) and hybrid EV (HEV) applications. In the system, an ultracapacitor is preferred for high power buffer and regenerative braking energy storage because it has the advantages of high power density, long life cycles, and high efficiency. While in the high-voltage application, the ultracapacitors are employed in series, and the voltage unbalance issue must be taken care of. This paper presents a novel circuit for equalizing a series ultracapacitor stack, which is based on a dc-dc converter. The proposed voltage-equalization circuit derives energy from the series ultracapacitor stack and transfers them to the weakest ultracapacitor cell. The equalizer balances the whole stack by sequentially compensating the weak ultracapacitor cells. Unlike previous methods for battery-storage systems, which include complex circuit detecting and comparing the voltages of capacitor cells, the novel equalizer can realize autonomic voltage equalization without voltage detection and comparison, and it is more efficient with the soft switching method, which is a benefit for high-power applications in EV/HEV. The simulation and experiment results validate the feasibility of the proposed equalization circuits.     

Highly Efficient and Green Oxidation of Nitrotoluenes with Dioxygen as Oxidant in a Novel Homogeneous and Recyclable Catalytic System

A novel homogeneous and recyclable catalytic system was applied in the oxidation of nitrotoluenes to nitrobenzoic acids with the isolated yield of 93%. In this method, the catalytic system could be easily separated from the aqueous phase by simple decantation and could be reused in subsequent runs without apparent change in activity.     

带悬臂梁段拼接的梁柱连接节点试验分析

通过对两个带悬臂梁段拼接的梁柱连接试件的设计和循环加载试验结果的对比分析 ,指出可以利用接触面的滑移和螺栓与孔壁的挤压来消耗能量 ,减少地震作用向梁柱焊缝的输入 ,提高连接的抗震性能。最后 ,根据分析结果提出了设计建议。     

Nondestructive determination of pear internal quality indices by visible and near-infrared spectrometry

The relationships between the nondestructive visible and near-infrared (Vis-NIR) measurements and the internal quality indices of pear fruit were established, and the potential of Vis-NIR spectrometry technique was investigated for its ability to nondestructively measure soluble solids content (SSC) and firmness of intact pear fruit. Intact pear fruit were measured by diffuse reflectance Vis-NIR in 350–1800 nm range. In this study, calibration models relating Vis-NIR spectra to SSC and firmness were developed based on multi-linear regression (MLR), principal component regression (PCR) and partial least squares regression (PLSR) with respect to the logarithms of the reflectance reciprocal log(1/R), its first derivative D₁ log(1/R) and second derivative D₂ log(1/R). The best combination, based on the robust models and the prediction results, was PLSR method with respect to log(1/R) at equatorial position of pear fruit. The PLSR models for prediction samples resulted correlation coefficient (r_p) of 0.912 and 0.854, and root mean standard error of prediction (RMSEP) of 0.662°Brix and 1.232 N for SSC and firmness, respectively. The results indicate that Vis-NIR spectrometry technique could provide an accurate, reliable and nondestructive method for assessing the internal quality indices of intact pear fruit.