红外与激光工程
紅外與激光工程
홍외여격광공정
INFRARED AND LASER ENGINEERING
2014年
2期
497-501
,共5页
门涛%杨悦%徐蓉%刘长海%温昌礼
門濤%楊悅%徐蓉%劉長海%溫昌禮
문도%양열%서용%류장해%온창례
轴角编码器%零点漂移%球谐函数%指向精度
軸角編碼器%零點漂移%毬諧函數%指嚮精度
축각편마기%영점표이%구해함수%지향정도
incremental angular encoder%reference mark excursion%spherical function%pointing precision
介绍了增量式光电轴角编码器的工作原理及其在空间目标测量领域的应用。分析了轴角编码器零点漂移的原因,推导了基于轴系和球谐函数的望远镜系统误差修正模型。提出了采用外复核方法解算望远镜指向精度,即用前两天测星解算出来的系统球谐函数误差模型系数修正并复核当天的测星误差。设计了零点标定实验对轴角编码器零位进行标定,进行了连续11个晴天夜晚的观测实验,在零点标定前后观测在视场内均匀分布的30颗恒星,分别解算得到望远镜指向误差,确认了轴角编码器的零点漂移现象。采集GPS卫星数据进行了精度鉴定,望远镜方位和俯仰的轴系误差均值由13.99″、11.50″分别降至5.94″、-3.49″,验证了零点标定方法消除零位漂移并提高望远镜测量精度的可行性。
介紹瞭增量式光電軸角編碼器的工作原理及其在空間目標測量領域的應用。分析瞭軸角編碼器零點漂移的原因,推導瞭基于軸繫和毬諧函數的望遠鏡繫統誤差脩正模型。提齣瞭採用外複覈方法解算望遠鏡指嚮精度,即用前兩天測星解算齣來的繫統毬諧函數誤差模型繫數脩正併複覈噹天的測星誤差。設計瞭零點標定實驗對軸角編碼器零位進行標定,進行瞭連續11箇晴天夜晚的觀測實驗,在零點標定前後觀測在視場內均勻分佈的30顆恆星,分彆解算得到望遠鏡指嚮誤差,確認瞭軸角編碼器的零點漂移現象。採集GPS衛星數據進行瞭精度鑒定,望遠鏡方位和俯仰的軸繫誤差均值由13.99″、11.50″分彆降至5.94″、-3.49″,驗證瞭零點標定方法消除零位漂移併提高望遠鏡測量精度的可行性。
개소료증량식광전축각편마기적공작원리급기재공간목표측량영역적응용。분석료축각편마기영점표이적원인,추도료기우축계화구해함수적망원경계통오차수정모형。제출료채용외복핵방법해산망원경지향정도,즉용전량천측성해산출래적계통구해함수오차모형계수수정병복핵당천적측성오차。설계료영점표정실험대축각편마기령위진행표정,진행료련속11개청천야만적관측실험,재영점표정전후관측재시장내균균분포적30과항성,분별해산득도망원경지향오차,학인료축각편마기적영점표이현상。채집GPS위성수거진행료정도감정,망원경방위화부앙적축계오차균치유13.99″、11.50″분별강지5.94″、-3.49″,험증료영점표정방법소제령위표이병제고망원경측량정도적가행성。
The operational principle and characteristic of incremental photoelectric angular encoder were summarized and discussed. And the reasons of reference mark excursion for incremental photoelectric angular encoder were analyzed. In order to validate reference mark excursion, a pointing function, which defined in the spherical coordinate of level mounting telescope, was expanded into series by spherical function. Then the spherical function model of pointing error was obtained. 30 stars scattered in sky space uniformly were selected to observe, through which the discrete value of 30 stars′ pointing error were gained in longitude dimension and latitude dimension respectively. A new technique called external checking method, which used observing data two days ago to check intraday pointing error, was tested to validate the phenomenon of reference mark excursion. An experiment measuring pointing error before and after reference mark calibration by observing Polaris last 11 days. The results showed reference mark excursion caused pointing error of telescope becoming greater than the technical index designed. And after calibration the reference mark became fixed all night. To evaluate the effect of reference mark calibration, orbital position of a GPS satellite was measured by optoelectronic telescope. Pointing error of the telescope was gained compared with precision orbital position of GPS satellite. The results show that before reference mark calibration the mean azimuth and elevation error was 13.99″, 11.50″. And after calibration the mean azimuth and elevation error decreased to 5.94″, -3.49″ respectively. The experiment of GPS star observation showed that the reference mark calibration was available to eliminate reference mark excursion and to improve observation precision.