{"id":4642,"date":"2019-10-24T15:49:00","date_gmt":"2019-10-24T13:49:00","guid":{"rendered":"https:\/\/garnet.it\/calibrazione-angolare-ad-alta-precisione-tamagawa\/"},"modified":"2020-10-29T16:56:25","modified_gmt":"2020-10-29T15:56:25","slug":"tamagawa-high-precision-angle-calibration","status":"publish","type":"post","link":"https:\/\/garnet.it\/en\/tamagawa-high-precision-angle-calibration\/","title":{"rendered":"Tamagawa high precision angle calibration"},"content":{"rendered":"\n

Industrial robots are indispensable in the automation and labor-saving of a plant. In order to accurately control their movements, it has become necessary to detect angles with high precision. How can the detecting of angles with high precision be evaluated? We will report on the devices born out of Tamagawa’s unrelenting commitment to angle accuracy.<\/strong>

Why Is the Accuracy of Angles Necessary?<\/strong>
The rotary encoder that is used for the angle sensors of servo motors and so on is a sensor that is indispensable for the control of industrial robots and semi-conductor manufacturing equipment. The demand for miniaturization and densi\ufb01cation of products requires manufacturing equipment to be capable of precision movements. The resolution of rotary encoders was 11 bits in the late 1990s (1 bit is about 0.18\u00b0 = resolution that divides 360\u00b0 into 0.18\u00b0 segments), and although this was the mainstream, in the early 2000s, resolution saw dramatic  improvements  to  17  bits  (1  bit  is  approximately  0.003\u00b0  = resolution that divides 360\u00b0 into 0.003\u00b0 segments).While resolution continues to improve, the need for calibration work to see whether the angles of angle sensors are correct and to evaluate the accuracy has also increased.

What Is the Calibration of Angles?<\/strong>
The calibration of angles refers to comparing the accuracy of an angle sensor with a reference to make an evaluation. However, as comparing with a standard stipulated by law each time is dif\ufb01cult, a device is used to carry out calibration work to evaluate measuring capability with a rotary encoder acknowledged as a secondary standard for national standard instruments.<\/p>\n\n\n\n

\"\"<\/figure><\/div>\n\n\n\n

Ensuring\u00a0 the\u00a0 connection\u00a0 between\u00a0 the\u00a0 user’s\u00a0 angle\u00a0 sensor\u00a0 and\u00a0 the national standard in this way is called\u00a0traceability, and is required by ISO9001 and IATF16949.International standards for length and weight (standard instruments) have been established for a long time, but there are no international standards\u00a0 for\u00a0 angle\u00a0 criteria.\u00a0 In Japan, standard instruments were stipulated in 2003, and a traceability system was put in place.

Angle calibration business of Tamagawa Seiki Co., Ltd.<\/strong>
While developing a general-purpose rotary encoder, Tamagawa also worked on the development of a special sensor such as the angle sensor for antenna rotation of the National Astronomical Observatory of Japan. In\u00a0 1999,\u00a0 their\u00a0 product\u00a0 was\u00a0 used\u00a0 for\u00a0 the\u00a0 angle\u00a0 sensor\u00a0 of\u00a0 the\u00a0\u00a0ALMA* telescope<\/strong>.<\/p>\n\n\n\n

However,\u00a0 at\u00a0 the\u00a0 time,\u00a0 as\u00a0 the\u00a0 required\u00a0 angle\u00a0 accuracy\u00a0 could\u00a0 not\u00a0 be measured in-house, consideration was given to whether there was a way of being able to do it in-house. This became the impetus for Tamagawa’s angle calibration business initiative. Then, in 2008, their angle calibration business, which started out as a private\u00a0 enterprise,\u00a0 was\u00a0 registered\u00a0 as\u00a0 a\u00a0 business\u00a0 with\u00a0 the\u00a0 Japan Calibration Service System (JCSS), and thus their calibration business for angle sensors was born.<\/p>\n\n\n\n

\"\"<\/figure><\/div>\n\n\n\n

High Precision\u00a0 Angle Calibrator:<\/strong><\/strong><\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

What Do You Mean the Top Measuring Capability Is \u201c0.062 Seconds?\u201d<\/strong>
This angle calibrator, for receiving certi\ufb01cation by Tamagawa as a calibration business, began development with the goal of \u201cbeing a device that can measure the calibration accuracy of angle sensors in 0.1 seconds.\u201dIn order to measure accuracy in 0.1 second, the calculation error of 1\/10\u00a0 (0.01\u00a0 second)\u00a0 must\u00a0 be\u00a0 known,\u00a0 and\u00a0 the\u00a0 resolution\u00a0 required\u00a0 to understand the error is a precision of 0.001 second, which is 1\/10 of the calculation error.However, the top measuring capability of their completed angle calibra- tor\u00a0 is\u00a0 0.062\u00a0 seconds,\u00a0 which\u00a0 is\u00a0 dramatically\u00a0 better\u00a0 than Tamagawa target value. This means that the device has an accuracy of 1\/100 their original goal.<\/p>\n\n\n\n

\"\"<\/figure><\/div>\n\n\n\n

How Is Precision Measured?<\/strong>
If it is a rotary angle sensor, angle calibration can be done with a rotary encoder, resolver, or synchro
The  precision of an angle is evaluated by using the following two methods. In consideration of the mounting calculation error, the device checks reproducibility  (whether  the  same  calculation  error  is  produced)  by changing the position of the installation multiple times.<\/p>\n\n\n\n

  1. Phase difference time conversion method.<\/li><\/ol>\n\n\n\n

    The number of measurement clock pulses between the output pulse signals of the reference sensor that rotates at a constant speed and the calibrated angle sensor is calculated, and then this time is converted into an angle to measure the variation in the angle accuracy.<\/p>\n\n\n\n

    1. Method for dividing equally<\/li><\/ol>\n\n\n\n

      The  reference  sensor  and  the  angle  sensor  to  be  calibrated  are divided into 5 equal parts, comparative measurements are repeatedly taken while changing the mounting position, and then the 5 comparative data items are added and averaged to obtain the deviation of the calibrated angle sensor. This  method  enables  the  deviation  of  the  reference  sensor  and  the calibrated angle sensor to be completely separated, and the deviation of the calibrated angle sensor can be extracted.<\/p>\n\n\n\n

      <\/p>\n\n\n\n

      \"\"<\/figure><\/div>\n\n\n\n

      <\/p>\n\n\n\n

      Contents from “Tamagawa News” magazine\u00a0 n. 23.<\/em><\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

      Industrial robots are indispensable in the automation and labor-saving of a plant. In order to accurately control their movements, it has become necessary to detect angles with high precision. How can the detecting of angles with high precision be evaluated? We will report on the devices born out of Tamagawa’s unrelenting commitment to angle accuracy. […]<\/p>\n","protected":false},"author":2,"featured_media":4644,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1023],"tags":[1368],"class_list":["post-4642","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-motion-control-en","tag-tamagawa-en"],"acf":[],"_links":{"self":[{"href":"https:\/\/garnet.it\/en\/wp-json\/wp\/v2\/posts\/4642","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/garnet.it\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/garnet.it\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/garnet.it\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/garnet.it\/en\/wp-json\/wp\/v2\/comments?post=4642"}],"version-history":[{"count":2,"href":"https:\/\/garnet.it\/en\/wp-json\/wp\/v2\/posts\/4642\/revisions"}],"predecessor-version":[{"id":4655,"href":"https:\/\/garnet.it\/en\/wp-json\/wp\/v2\/posts\/4642\/revisions\/4655"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/garnet.it\/en\/wp-json\/wp\/v2\/media\/4644"}],"wp:attachment":[{"href":"https:\/\/garnet.it\/en\/wp-json\/wp\/v2\/media?parent=4642"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/garnet.it\/en\/wp-json\/wp\/v2\/categories?post=4642"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/garnet.it\/en\/wp-json\/wp\/v2\/tags?post=4642"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}