{"id":1585,"date":"2020-01-18T13:21:46","date_gmt":"2020-01-18T13:21:46","guid":{"rendered":"https:\/\/www.admotec.com\/?p=1585"},"modified":"2020-03-08T15:44:09","modified_gmt":"2020-03-08T15:44:09","slug":"high-performance-motion-control","status":"publish","type":"post","link":"https:\/\/stage.admotec.com\/stage_mai23\/high-performance-motion-control\/","title":{"rendered":"High Performance Motion Control"},"content":{"rendered":"\n<div class=\"wp-block-columns has-2-columns is-layout-flex wp-container-core-columns-is-layout-1 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<p><strong>Content:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\"><li><a href=\"#Absolute-Angle\">Absolute Angle <\/a><\/li><li><a href=\"#Resolution\">Resolution<\/a><\/li><li><a href=\"#Increment\">Increment<\/a><\/li><li><a href=\"#Accuracy\">Accuracy<\/a><\/li><li><a href=\"#Electric-Motor-Commutation\">Electric Motor<\/a><a href=\"https:\/\/stage.admotec.com\/stage_mai23\/wp-admin\/post.php?post=1585&amp;action=edit&amp;lang=en#Electric-Motor-Commutation\"> <\/a><a href=\"#Electric-Motor-Commutation\">Commutation<\/a><\/li><li><a href=\"#speed-control\">Speed Control<\/a><\/li><li><a href=\"#Position-Control\">Position Control<\/a><\/li><\/ul>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-image\"><img decoding=\"async\" width=\"279\" height=\"272\" src=\"https:\/\/stage.admotec.com\/stage_mai23\/wp-content\/uploads\/2020\/01\/resolver-hp-motion-control-1.jpg\" alt=\"High Performace Resolver\" class=\"wp-image-1599\"\/><figcaption>High Performace Resolver Motion Control<\/figcaption><\/figure>\n<\/div>\n<\/div>\n\n\n\n<p>Rotary sensors are the key component to achieve best performance for demanding motion controls which require the best step response, high accuracy and high resolution without oscillations and ripple. Resolvers in particular are very robust sensors with infinite resolution. They allow keeping the electronics away from the \u201chot\u201d area.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"Absolute-Angle\"><strong>Absolute Angle<\/strong><\/h2>\n\n\n\n<div class=\"wp-block-columns has-2-columns is-layout-flex wp-container-core-columns-is-layout-2 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<p><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\"><\/div>\n<\/div>\n\n\n\n<p>A single\npole pair (p=1) resolver gives an absolute signal over 360\u00b0 mechanical\nrotation. The electric zero (E.Z.) is defined as the unique angle for Usin=0\nand Ucos = 1. <\/p>\n\n\n\n<p>To measure the angle of a move it is necessary first to define the zero position of the machine. To adjust the E.Z. to the zero position of the machine, the resolver has to be rotated manually and blocked with the three griffons in the servo groove.<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter is-resized\"><img decoding=\"async\" src=\"https:\/\/stage.admotec.com\/stage_mai23\/wp-content\/uploads\/2020\/01\/ref-cos-syn.jpg\" alt=\"Functionality Ref Cos Sin\" class=\"wp-image-1603\" width=\"441\" height=\"270\"\/><figcaption>Functionality Ref Cos Sin<\/figcaption><\/figure><\/div>\n\n\n\n<p>At power on the resolver gives the rotation angle of the rotor relative to the stator. The single speed resolver is the ideal sensor for measuring position of moves which do not exceed 360\u00b0. As a rudder control for example.<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter is-resized\"><img decoding=\"async\" src=\"https:\/\/stage.admotec.com\/stage_mai23\/wp-content\/uploads\/2020\/01\/resolver-rotation-angle.jpg\" alt=\"Resolver Rotation Angle\" class=\"wp-image-1606\" width=\"450\" height=\"215\"\/><figcaption>Resolver Rotation Angle<\/figcaption><\/figure><\/div>\n\n\n\n<p>Multipole\nresolvers have many electrical zeros. There is an E.Z. for every pole pair.\nThey give an absolute signal within an electrical period (360\u00b0\/p). Multipole\nresolvers have a higher accuracy and resolution than single pole pair resolvers.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"Resolution\"><strong>Resolution<\/strong><\/h2>\n\n\n\n<p>Considering\na resolver-RDC system. It is easy to analyse the performance\n \n \n  \n  \n  \n  \n  \n  \n  \n  \n  \n  \n  \n  \n \n \n \n\n \n \n. Resolvers\nare analogue sensors which require an RDC (Resolver Digital Converter) giving a\nspeed and a position output. <\/p>\n\n\n\n<p>An RDC is\na chip containing an oscillator in the frequency range 1 to 10 kHz feeding the\nprimary coil of the resolver and a converter calculating the arctangent of the\nangle from sine and cosine signals coming from the resolver.<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter is-resized\"><img decoding=\"async\" src=\"https:\/\/stage.admotec.com\/stage_mai23\/wp-content\/uploads\/2020\/01\/resolver-rdc.jpg\" alt=\"Resolver RDC\" class=\"wp-image-1611\" width=\"450\" height=\"154\"\/><figcaption>Resolver RDC<\/figcaption><\/figure><\/div>\n\n\n\n<div class=\"wp-block-columns has-2-columns is-layout-flex wp-container-core-columns-is-layout-3 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<p><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<p><\/p>\n<\/div>\n<\/div>\n\n\n\n<p>The RDC\nconverts the angle of an electrical period into 10, 12, 14, 16 bits or more. <\/p>\n\n\n\n<p>The\nresolution for 1 mechanical turn is the product of number of pole pairs and the\nresolution of the RDC<\/p>\n\n\n\n<div class=\"wp-block-columns has-2-columns is-layout-flex wp-container-core-columns-is-layout-4 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<p class=\"has-small-font-size\">R = Resolution<br>p = Number of pole pairs<br>RRDC = RDC Resolution<\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<p style=\"background-color:#9cc3ec;text-align:center\" class=\"has-background has-medium-font-size\">R = p * R<sub>RDC<\/sub><\/p>\n<\/div>\n<\/div>\n\n\n\n<p>Resolution\nmeans that this is the number of steps or increments the system gives for 1\nmechanical revolution.<\/p>\n\n\n\n<div style=\"height:20px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter is-resized\"><img decoding=\"async\" src=\"https:\/\/stage.admotec.com\/stage_mai23\/wp-content\/uploads\/2020\/01\/increment-per-turn.jpg\" alt=\"Increments per turn\" class=\"wp-image-1617\" width=\"450\" height=\"220\"\/><\/figure><\/div>\n\n\n\n<div style=\"height:20px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p>This\nshows an extreme high number of steps per turn which gives a broad choice <\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"Increment\"><strong>Increment<\/strong><\/h2>\n\n\n\n<div class=\"wp-block-columns has-2-columns is-layout-flex wp-container-core-columns-is-layout-5 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<p>An\nincrement is the length of 1 step. <\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<p style=\"background-color:#9cc3ec;text-align:center\" class=\"has-background has-medium-font-size\">I = 360\u00b0 \/ R<sub>RDC<\/sub> * p<\/p>\n<\/div>\n<\/div>\n\n\n\n<p>As the resolution is very high, it is a good rule to choose an increment ten times smaller than the desired accuracy. <\/p>\n\n\n\n<div style=\"height:20px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter is-resized\"><img decoding=\"async\" src=\"https:\/\/stage.admotec.com\/stage_mai23\/wp-content\/uploads\/2020\/01\/increment-size.jpg\" alt=\"Increment Size\" class=\"wp-image-1622\" width=\"450\" height=\"203\"\/><\/figure><\/div>\n\n\n\n<div style=\"height:20px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"Accuracy\"><strong>Accuracy<\/strong><\/h2>\n\n\n\n<p>Position accuracy of a resolver RDC system depends essentially of the accuracy of the resolver. In fact, we have to add the error of the resolver to the error of the RDC:<\/p>\n\n\n\n<div class=\"wp-block-columns has-2-columns is-layout-flex wp-container-core-columns-is-layout-6 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<ul class=\"wp-block-list\"><li> \u03b5 = Total Error <\/li><li> \u03b5 RDC= Resolver Digital Converter Error <\/li><li> \u03b5 R= Resolver Error <\/li><\/ul>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\np =\nnumber of pole pairs\n\n\n\n<\/p>\n<\/div>\n<\/div>\n\n\n\n<p style=\"background-color:#9cc3ec;text-align:center\" class=\"has-background has-medium-font-size\"> \u03b5 = \u03b5<sub>R<\/sub> + \u03b5<sub>RDC<\/sub> \/ p<\/p>\n\n\n\n<p>The higher\nthe number of pole pairs the lower the total error of the resolver-RDC\nsystem.&nbsp; <\/p>\n\n\n\n<div class=\"wp-block-columns has-2-columns is-layout-flex wp-container-core-columns-is-layout-7 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\nTypical\nangular error curve of a resolver: \n\n\n\n<\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<p style=\"background-color:#9cc3ec;text-align:center\" class=\"has-background has-medium-font-size\">\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\u03b5<sub>R<\/sub> (\u03d5)\n\n\n\n<\/p>\n<\/div>\n<\/div>\n\n\n\n<div style=\"height:20px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter is-resized\"><img decoding=\"async\" src=\"https:\/\/stage.admotec.com\/stage_mai23\/wp-content\/uploads\/2020\/01\/angle-error.jpg\" alt=\"Angle Error\" class=\"wp-image-1627\" width=\"450\" height=\"189\"\/><\/figure><\/div>\n\n\n\n<div style=\"height:20px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-columns has-2-columns is-layout-flex wp-container-core-columns-is-layout-8 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\nResolver\nangular error:\n\n\n\n<\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<p style=\"background-color:#9cc3ec;text-align:center\" class=\"has-background has-medium-font-size\">\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\u03d5<sub>R<\/sub>&nbsp; =&nbsp; \u03d5 + \u03b5<sub>R<\/sub>\n\n\n\n<\/p>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-columns has-2-columns is-layout-flex wp-container-core-columns-is-layout-9 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<p> Slope of the resolver error curve:<\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<p style=\"background-color:#9cc3ec;text-align:center\" class=\"has-background has-medium-font-size\">\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\nd\u03b5<sub>R<\/sub>\/d\u03d5\n\n\n\n<\/p>\n<\/div>\n<\/div>\n\n\n\n<div style=\"height:20px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter is-resized\"><img decoding=\"async\" src=\"https:\/\/stage.admotec.com\/stage_mai23\/wp-content\/uploads\/2020\/01\/slope.jpg\" alt=\"\" class=\"wp-image-1631\" width=\"450\" height=\"167\"\/><\/figure><\/div>\n\n\n\n<div style=\"height:20px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-columns has-2-columns is-layout-flex wp-container-core-columns-is-layout-10 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\nResolver\nspeed error:&nbsp;&nbsp; \n\n\n\n<\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<p style=\"background-color:#9cc3ec;text-align:center\" class=\"has-background has-medium-font-size\"> d\u03d5<sub>R<\/sub>\/dt = \u03c9(1+d\u03b5<sub>R<\/sub>\/d\u03d5) <\/p>\n<\/div>\n<\/div>\n\n\n\n<p>In other terms a rotor\neccentricity gives typically a harmonic 1 error. If an eccentricity of 0.1 mm\nproduces for a given resolver an angle error of 30 arcmin the max slope will be\n1 %. This is a harmless example. Errors with higher harmonics (e.g. H4, H12\u2026)\nproduce much higher slopes. So, it\u2019s important for high speed applications to\nselect a resolver with a low speed error and to avoid any disturbances on the\nresolver lines.<\/p>\n\n\n\n<p>While the angular error\naffects the position accuracy of the motion, the speed error limits the gain of\nthe velocity loop which is important for the performance of motion control.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"Electric-Motor-Commutation\"><strong>Electric Motor Commutation<\/strong><\/h2>\n\n\n\n<p> Brushless synchronous motors or servomotors needs to synchronize the turning magnetic field with the rotor. Generally, one single resolver is used for three functions. <\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter is-resized\"><img decoding=\"async\" src=\"https:\/\/stage.admotec.com\/stage_mai23\/wp-content\/uploads\/2020\/01\/powerbridge.jpg\" alt=\"Power Bridge\" class=\"wp-image-1635\" width=\"300\" height=\"350\" srcset=\"https:\/\/stage.admotec.com\/stage_mai23\/wp-content\/uploads\/2020\/01\/powerbridge.jpg 600w, https:\/\/stage.admotec.com\/stage_mai23\/wp-content\/uploads\/2020\/01\/powerbridge-258x300.jpg 258w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><figcaption>Power Bridge<\/figcaption><\/figure><\/div>\n\n\n\n<ul class=\"wp-block-list\"><li>sensor for commutation<\/li><li>sensor for speed loop<\/li><li>sensor for position loop<\/li><\/ul>\n\n\n\n<p>For\ncommutation, single pole as well as multipole resolvers are used.<\/p>\n\n\n\n<p>Another\nsolution is to use the E.Z. of a speed 1 resolver.<\/p>\n\n\n\n<p>If the\nnumber of pole pairs of the resolver is identical to that of the motor, the\ndrive (also called homopolar drive) can start at power on without needing a\nzeroing routine.<\/p>\n\n\n\n<p>In all other cases when a higher resolution or precision is required e.g. a zeroing routine is necessary. <\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"Speed-Control\"><strong>Speed Control<\/strong><\/h2>\n\n\n\n<p>This block diagram shows a typical speed control. It\u2019s easy to see that harmonic speed error directly effects the speed of the motor. The gain of the velocity controller at high speed is limited by the content of harmonics of the resolver signal. It gives the best performing velocity control. Speed control are used on E-mobility applications. It allows single pedal speed control: acceleration and deceleration with kinetic energy recuperation. <\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter is-resized\"><img decoding=\"async\" src=\"https:\/\/stage.admotec.com\/stage_mai23\/wp-content\/uploads\/2020\/01\/velocity-control.jpg\" alt=\"\" class=\"wp-image-1638\" width=\"150\" height=\"371\" srcset=\"https:\/\/stage.admotec.com\/stage_mai23\/wp-content\/uploads\/2020\/01\/velocity-control.jpg 300w, https:\/\/stage.admotec.com\/stage_mai23\/wp-content\/uploads\/2020\/01\/velocity-control-121x300.jpg 121w\" sizes=\"(max-width: 150px) 100vw, 150px\" \/><figcaption>Velocity Control<\/figcaption><\/figure><\/div>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"Position-Control\"><strong>Position Control<\/strong><\/h2>\n\n\n\n<p>The high\nresolution of a resolver-RDC systems allows very precise positioning of the driven\nmechanic.<\/p>\n\n\n\n<p>A high velocity loop gain stabilizes the position loop. To achieve it at high speed, it is necessary to use resolvers with low speed error.<\/p>\n\n\n\n<p>Positions\ncontrolled moves are used on machine tool, robots and precision actuators.<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter is-resized\"><img decoding=\"async\" src=\"https:\/\/stage.admotec.com\/stage_mai23\/wp-content\/uploads\/2020\/01\/position-control.jpg\" alt=\"Position Control\" class=\"wp-image-1641\" width=\"150\" height=\"486\" srcset=\"https:\/\/stage.admotec.com\/stage_mai23\/wp-content\/uploads\/2020\/01\/position-control.jpg 300w, https:\/\/stage.admotec.com\/stage_mai23\/wp-content\/uploads\/2020\/01\/position-control-93x300.jpg 93w\" sizes=\"(max-width: 150px) 100vw, 150px\" \/><figcaption>Postiion Control<\/figcaption><\/figure><\/div>\n\n\n\n<p>These application examples show how to implement resolvers in order to solve complex controlengineering problems. For more information please don\u2019t hesitate to contact Admotec Precision AG. <\/p>\n","protected":false},"excerpt":{"rendered":"<p>Rotary sensors are the key component to achieve best performance for demanding motion controls which require the best step response, high accuracy and high resolution without oscillations and ripple. Resolvers in particular are very robust sensors with infinite resolution. They allow keeping the electronics away from the \u201chot\u201d area.<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-1585","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/stage.admotec.com\/stage_mai23\/wp-json\/wp\/v2\/posts\/1585"}],"collection":[{"href":"https:\/\/stage.admotec.com\/stage_mai23\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/stage.admotec.com\/stage_mai23\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/stage.admotec.com\/stage_mai23\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/stage.admotec.com\/stage_mai23\/wp-json\/wp\/v2\/comments?post=1585"}],"version-history":[{"count":0,"href":"https:\/\/stage.admotec.com\/stage_mai23\/wp-json\/wp\/v2\/posts\/1585\/revisions"}],"wp:attachment":[{"href":"https:\/\/stage.admotec.com\/stage_mai23\/wp-json\/wp\/v2\/media?parent=1585"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/stage.admotec.com\/stage_mai23\/wp-json\/wp\/v2\/categories?post=1585"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/stage.admotec.com\/stage_mai23\/wp-json\/wp\/v2\/tags?post=1585"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}