共查询到20条相似文献，搜索用时 156 毫秒
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《天文研究与技术》2020,(2)
观测技术及仪器的进步推动了太阳物理的研究,步进电机是各类观测仪器精密结构调整部件中经常采用的驱动源,步进电机控制系统的性能直接影响太阳望远镜的数据精度和时间分辨率。介绍了一套怀柔太阳观测基地自主研制的多轴步进电机控制系统。该系统以现场可编程门阵列为核心控制器,利用中断处理机制及输入/输出寄存器产生多路晶体管-晶体管逻辑电平(TTL)方波信号,结合驱动器实现多轴步进电机控制;通过周期信号化简处理算法缩短电机调整时间;以霍尔器件作为位置传感器实现系统闭环控制,通过对霍尔信号的软、硬件滤波处理,提高信号识别的准确率;设计了板载存储电路,实时保存系统关键参数,大幅提高系统整体的可靠性。同时,该系统设计了丰富的输入/输出接口、通讯接口,提高系统的可集成性。目前该系统已在多台太阳望远镜中投入使用。 相似文献
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本文以北京天文台研制中的数字相关接收机为基础,介绍了这类数字接收机的工作过程,着重讨论了量化和采样所引起的损失,并通过与对应的模拟相关接收机比较,得到了数字接收机的相关损失与采样率的关系,同时推导了接收机输出信噪比的关系式,为进一步分析提供了基础。 相似文献
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汪沪生 《中国科学院上海天文台年刊》2002,(23):135-143
对中国科学院上海天台25m天线的驱动结构进行了分析。并对该天线的方位速度及使用更多电机同时驱动天线方面的问题进行了探讨。 相似文献
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波导极化器是射电天文接收机系统中的重要微波器件,其核心部分是差分移相器。通过对移相器的分析,详细研究了宽带波纹方波导差分移相器的特性。应用电磁仿真软件对32 GHz~48 GHz(7 mm波段)的波纹方波导移相器结构进行了设计与优化,在整个带宽范围内得到90°±7.5°的良好相移特性,驻波比仅仅为1.02。研制具备尺寸小、性能优和宽频特点的差分移相器满足射电天文接收机发展需求,可以改善接收机的性能,并有效提高对天文射电源相关特性等的观测能力。 相似文献
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针对昆明VLBI观测站终端设备(S3数据采集系统)的特殊性,设计在标准的终端控制计算机(Field System)上能够控制相应硬件设备的软件.S3数据采集系统包括SX接收机、中频分配器、视频转换器、时延计数器、噪声控制开关和气象数据自动采集仪.设计过程中,考虑到软件的可读性和可维护性,各种设备分别用相应的子函数来完成具体功能,各子函数由主程序调用.在完成程序安装后,经测试能与S3数据采集系统进行良好的通讯,达到控制各硬件设备的目的及满足实际测控工作的需要. 相似文献
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An open loop stepper motor controller has been designed specifically for the control of small telescopes. The stepper motor driver is controlled by an IBM-type PC with TURBO PASCAL being used to develop the control software. The software has been set up to be driven either by a mouse or the keyboard. A configuration file contains information specific to the geographical location of the telescope and the mechanical details of the telescope drive such as the type of stepper motors used and the gearing ratios on the two axes. This feature allows the system to be easily attached to a variety of telescopes. 相似文献
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《天文和天体物理学研究(英文版)》2016,(11)
This paper proposes a dual-motor configuration to enhance closed-loop performance of a telescope control system. Two identical motors are mounted on each side of a U-type frame to drive the telescope elevation axis instead of a single motor drive, which is usually used in a classical design. This new configuration and mechanism can reduce the motor to half the size used in the former design, and it also provides some other advantages. A master-slave current control mode is employed to synchronize the two motors. Acceleration feedback control is utilized to further enhance the servo performance. Extensive experiments are used to validate the effectiveness of the proposed control algorithm in synchronization, disturbance attenuation and low-velocity tracking. 相似文献
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A cross bow-tie dipole feed with cavity and symmetrical E and H plane pattern is presented for the Five hundred-meter Aperture Spherical radio Telescope(FAST).In this paper we describe the design,optimization and simulation results of a wide-band cross dipole feed with cavity covering the frequency range from 300 MHz to 600 MHz for FAST.The main goals of our design are to ensure that,(1)we cover the octave bandwidth,(2)the feed has symmetrical E and H plane pattern,and(3)the physical dimension is suitable for mounting it in the reserved position of the FAST feed cabin.The initial results indicate that we have met most of our design goals.This kind of feed had been equipped with the multi-beam receiver to carry out observation on the platform of FAST cabin. 相似文献
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Xin-Xin Zhang Ran Duan Xin-Ying Yu Di Li Ning-Yu Tang Tao-Chung Ching 《天文和天体物理学研究(英文版)》2020,(5):155-164
The Five-hundred-meter Aperture Spherical radio Telescope(FAST)was launched on 2016 September 25.From early 2017,we began to use the FAST wideband receiver,which was designed,constructed and installed on the FAST in Guizhou,China.The front end of the receiver is composed an uncooled Quad Ridge Flared Horn feed(QRFH)with the frequency range of 270 to 1620 MHz,and a cryostat operating at 10 K.We have cooperated with the Institute of Automation of the Chinese Academy of Sciences to develop the China Reconfigurable ANalog-digital backEnd(CRANE).The system covers the 3 GHz operating band of FAST.The hardware part of the backend includes an Analog Front-end Board,a wideband high precision Analog Digital Converter,and a FAST Digital Back-end.Analog circuit boards,field programmable gate arrays,and control computers form a set of hardware,software,and firmware platforms to achieve flexible bandwidth requirements through parameter changes.It is also suitable for the versatility of different astronomical observations,and can meet specific requirements.This paper briefly introduces the hardware and software of CRANE,as well as some observations of the system. 相似文献
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针对FAST的天文观测要求,对其天文观测软件进行了设计与开发。首先介绍了FAST天文观测的原理,对天文观测软件进行了需求分析。而后提出了馈源天文运动轨迹规划算法,并进行了仿真。针对其轨迹要求给出了控制方法,对天文观测控制软件进行了设计与实现。最后通过现场实地实验,验证了本文所提的算法与软件的可行性。 相似文献
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The absolute temperature of the cosmic microwave background (CMB) has been measured at a frequency of 1280 MHz. The observation was made with a modified version of the L-band receiver used in the Giant Metre wavelength Radio Telescope (GMRT): the feed horn was replaced by a corrugated plate and the receiver was placed on the ground, directed at zenith, and shielded from ground radiation by an aluminium screen with corrugated edges. Novel techniques have been adopted for ?reducing and cancelling unwanted contributions to the system temperature of the receiver and ?calibrating the contributions from the feed assembly and receiver. The thermodynamic temperature of the CMB is estimated to be 3.45 ± 0.78 K. 相似文献