201009303 九、發明說明： 【發明所屬之技術領域】 本發明係有關於-種絕對式編媽器及其操作方法，特 別是有關於-種利用增量式編碼器架構之絕對式編碼器及 其操作方法。 【先前技術】 φ 習知交流伺服馬達通常内含一個光學編碼器，該光學 編碼器提供轉子的角度以獲知一馬達轉速資訊，該轉速資 訊可回授至相關速度控制單元以精確控制馬達轉速。 第一圖為-習知交流伺服馬達控制系統之方塊圖，馬 達1〇之轉子的角度位置係由一光學編碼器12摘測並經一訊 號處理單元20處理以得到一角度資訊。該角度資訊送至一 控制器14處理以得到一馬達估計轉速，然後一速 3〇接收該馬達估計轉速及—速度命令，藉讀制-控制器 φ f組32及-絕緣柵雙極電晶體（igbt)模組別產生控制馬達 轉速訊號，以精確控制馬達10轉速。 更明確而言’在飼服驅動馬達中’鎖附在馬 的位置感測器便异#基始_址u u t ^ 飼服馬達的定位精度取 析度高低，光學編碼器（或稱旋轉編碼 器J又/刀為增量型編碼器和絕對型編碼器。 2量型編碼器只能提供位置相對於前—位置的資訊， ，以，源中斷後，位置的資訊變化必須重新歸零才可確 Γ道目=後再重新上電的瞬間，增量型編碼器無法立即 知道目則機構所在位置。絕對型的位置編碼器，能隨時輸 5 201009303 出軸角度（位置）的絕對值且；1 町值立不會因為電源中斷而喪失位201009303 IX. Description of the invention: [Technical field of the invention] The present invention relates to an absolute type of knitting device and an operating method thereof, and more particularly to an absolute encoder using an incremental encoder architecture and Method of operation. [Prior Art] The φ conventional AC servo motor usually includes an optical encoder that provides the angle of the rotor to know a motor speed information that can be fed back to the associated speed control unit to precisely control the motor speed. The first figure is a block diagram of a conventional AC servo motor control system. The angular position of the rotor of the motor is measured by an optical encoder 12 and processed by a signal processing unit 20 to obtain an angle information. The angle information is sent to a controller 14 for processing to obtain a motor estimated speed, and then the motor is estimated to receive the motor speed and speed command at a speed of 3 ,, and the controller φ f group 32 and the insulated gate bipolar transistor are read. The (igbt) module generates control motor speed signals to precisely control the motor 10 speed. More specifically, 'in the feeding drive motor' is attached to the position sensor of the horse. The base position_location uut ^ The positioning accuracy of the feeding motor is high and low, and the optical encoder (or rotary encoder) J/tool is an incremental encoder and an absolute encoder. 2 The encoder can only provide information about the position relative to the front position, so that after the source is interrupted, the information change of the position must be reset to zero. After confirming the channel = then re-powering, the incremental encoder can't immediately know the location of the target mechanism. The absolute position encoder can input the absolute value of the output angle (position) of 201009303 at any time; 1 The value of the town will not be lost due to power interruption.
置的資訊，因此斷電再t雷％ & A 电丹上冤後無需進行歸零程序，簡化了 控制系統的運作。 參見第二圖’為光學式編碼器的基本構造，一光源 260發出的光線經過一旋轉碼盤細及一個固定不動的副 編碼片220到達一光感測元件24〇，光感測元件⑽接收 到的光線強度隨著旋轉碼盤2〇〇位置不同而有不同的強度 變化’透過光感測元件24〇上的訊號變化便可檢知位置訊 ，息。 參見第二圖，為一絕對型編碼器之旋轉碼盤300之示 意圖，其中該旋轉碼盤3〇〇為一 ό位元（6bit)二進位碼的 碼盤設計。該旋轉碼盤3〇〇包含一圓形主體3〇2及多數之 光柵304。該光栅3〇4包含在最内圈編碼軌道且佔有 圓周之1個第一光柵3〇4A、在内侧第二圈編碼軌道且各佔 有1/4圓周之2個第二光栅304B··及在最外側編碼軌道且 各佔有1/64圓周之32個光栅3〇4F。因此沿著輻射（radiai)方 向可以產生不同的明暗訊號，並可沿著圓周方向達成=64 的解析度。然而在如圖所示之絕對型編碼器架構，解析度 每增加一個位元（bit)碼盤便必須增加一圈的編碼軌道，解 析度越高編碼軌道數便越多，編碼器的體積就越大。在一 些有體積限制的場合，絕對式編碼器的精度便有所限制 了。 參見第四A圖，為一增量式編碼器之一旋轉碼盤4〇〇 不意圖’該旋轉碼盤400包含一圓形主體402及多數之光 6 201009303 栅。該些光柵包含主光栅404A、第一副光柵404B及第二副 光栅404C，該第一副光栅404B及第二副光栅404C係在主光 柵404A兩侧，且在圓形主體402特定位置上。參見第四B 圖，為副編碼盤420之示意圖；該副編碼盤420包含四排 光栅420A。 參見第四C圖，為光感測元件440之示意圖，該光感 測元件440包含對應於主光栅404A之主感測單元442A， 444A，442B，444B (亦即標示為A+/B+/A-/B-之區域）。當旋轉 φ 碼盤400旋轉時，在光感測元件440的四個單元 (A+/B+/A-/B-)會產生類似弦波的訊號。這四個弦波的相位 分別為0/90/180/270度，取0/180訊號（A+/A-)作差動放大 後可得到消除共模雜訊（common mode noise)的正弦訊號A ; 同樣的取90/270訊號（B+/B-)作差動放大後可得到消除共模 雜訊的餘弦訊號B，AB兩個訊號的相位差90度，可以用 來判斷正轉或反轉。 增量式編碼器基本上只須AB訊號就可以檢知位置訊 ⑩ 息，但由於此位置訊息只提供相對於前一位置的資訊，因 此還需另外設置原點訊號感測單元446人44犯(Z+/Z-)，在每 次系統上電時先回原點歸零後才可得到絕對位置訊息。增 量式編竭器的優點是只需六個訊號便可得到南解析度 置訊息，其缺點則是每次開機上電都須執行回原點動作 不但浪費時間且在某些不容許回原點程序的應用場人 増 量式編蝎器就無法符合需求而需增設使用絕對式編碼器 【發明内容】 7 201009303 之絕的即在於提供一種增量式編碼器架構 I絕對式編碼器及其操作方法。 為了達成上述目的，本發明提供—種絕對式編碼器及 測絕對位置之方法，該編碼ϋ包含-光編碼輪，且該光 :碼輪包含一主光栅單元及兩個副光栅單元；該兩個副光 、单几分職在主光栅單元兩側且光柵數目比主光拇單元 少-個^在該編碼器做絕對位置_時，可以轉動編碼輪 以找出副光栅單元的檢光訊號零點，並找出主光栅單元 應該零點之數值，藉此即可推算絕對位置。由於該編碼器 可以同時提供增量位置及絕對位置計算，因此可以增加使 用彈性。 【實施方式】 目前絕對型編碼ϋ大都採用實體的位置編碼方式來提 供絕對位置m㈣編财式有mVBi卿c〇de) 及格雷碼（GmyCode)兩種方式，不論是二進位碼或格雷 碼，編碼器的解析精度取決於感測元件的數量，感測元件 的數量越多編碼器的體積越大成本也就越高。本專利的主 要目的是利用增量式編碼器的架構來達到絕對式編碼器的 ^能，只需在增量式編碼器原有的碼盤中增加一組調制訊 號（modulatingsignal)，便可產生週期36〇度的一組正弦及餘 弦訊號，對此組正弦及餘弦訊號便可内插出任一時刻的絕 對位置訊息。 參見第五A圖，為依據本發明之絕對式編碼器之一旋 轉碼盤100示意圖，該旋轉碼盤10〇包含一圓形主體1〇2 8 201009303 及多數之光栅104。該些光柵104包含位在主訊號軌道之 主光栅單元104A，位在至少一個調制軌道（圖示為兩個） 之第一副光栅單元104B及第二副光栅單元104C，其中第一 副光柵單元104B及第二副光柵單元104C之光栅數目比該主 光栅單元104A數目少1個。例如該主光栅單元104A之光柵 數目可以為2500個，則第一副光柵104B單元及第二副光柵 單元104C之光柵數目皆為2499個。 參見第五B圖，為副編碼盤120之示意圖；該副編碼 ❹ 盤120包含四排分別對應於光感測元件（容後詳述）之光 栅120A。參見第五C圖，為光感測元件14〇之示意圖，該 光感測元件140包含對應於主光柵單元104八之主感測單元 142A，144A，142B，144B (亦即標示為 A+/B+/A-/B-之區域）。 再者該光感測元件140亦包含對應於第一副光栅單元ι〇4Β 及第二副光栅單元104C之調制軌道感測單元H6A及146B。 本發明的主要目的為在增量式編碼器的精簡架構下達 成絕對定位的功能，參考第五A圖所示的碼盤設計，利用 ® 增量Sz+/z-的區域設置了比A+/A-/B+/B-主訊號執道少一光 柵的調制執道（M+/M-)。爲方便圖示起見，此處假設主光 栅單元104A具有16個光柵，而第一副光栅單元ι〇4Β及第二 副光柵單元104C具有15個光栅。參見第六圖，主訊號軌道 轉一圈在A+/A-光感測單元（主感測單元142A及142B )上 差動產生16個正弦波’用調制軌道感測元件146八及146B (M+/M-)所差動出來的訊號做取樣可以得到周期360度的 正弦訊號。如第六圖所示’若一控制器（未圖示，可利用 9 201009303 如第一圖之示之控制器14 )推動該旋轉碼盤loo移動一個 光栅之旋轉量（對應於2 角度變換），則可找出對應於 調制軌道感測單元146A及146B訊號為零點（A點）時之 A+/A-光感測單元之數值（對應於圓圈點之數值）。因為 利用調制轨道感測單元146A及146B訊號為零點取樣之 A+/A-光感測元件之數值為一個周期36〇度的正弦訊號， 因此可以利用該A點對應之數值找出該旋轉碼盤1〇〇之絕 對位置。 ❹ 上述說明係以具有16個光柵之主光栅單元i〇4A舉例說 明，如果主光柵單元104A之光柵數目越多，則一個光柵之 旋轉量就越小。 同樣的B+/B-光感測單元（主感測單元144入及144B ) 產生16個餘弦波與調制軌道的訊號（μ)做取樣可以得到周 期360度的餘弦訊號，利用正餘弦訊號便可内插出絕對位 置訊號，此新的架構由於仍然保留個光栅的增量式訊 號，内插出來的絕對位置仍保有增量式的基本精度，同時 如果原始正與餘弦訊號的高階諧波分量夠小的話，内插絕 對位置精度還可向上提升。 本發明之優點可以概述如下： 1. 以增量式編碼器的執道數達到輸出絕對位置的功 能。 2. 絕對式編碼器可以交互使用增量訊號與内插絕對 位置訊號以提升位置精確度。 3. 主訊號與調制訊號採差動放大方式消除共模雜 201009303 訊。 本專利的說明例冑然以光學式編碼器的架構為例，但 所k出的絕對疋位方式適用於以其他物理原理如電磁電容 等訊號方式的編碼器。 紅上所述，當知本發明已具有產業利用性、新穎性與 進步性，又本發明之構造亦未曾見於同類產品及公開使 用，完全符合發明專利申請要件，爰依專利法提出申請。 【圖式簡單說明】 ❹ 第一圖為一習知交流伺服馬達控制系統之方塊圖》 第二圖為光學式編碼器的基本構造。 第二圖為一習知絕對型編碼器之旋轉碼盤之示意圖。 第四A圖為一習知增量型編碼器之旋轉碼盤之示意 圖。 第四B圖為一習知副編碼盤之示意圖。 第四C圖為一習知光感測元件之示意圖。 第五A圖為本發明編碼器之旋轉碼盤之示意圖。 ❿ 第五B圖為本發明副編碼盤之示意圖。 第五C圖為本發明光感測元件之示意圖。 第六圖為說明主訊號執道及調制軌道感測單元之檢光 訊號。 【主要元件符號說明】 【習知】 馬達10 光學編碼器12 控制器14訊號處理單元2〇 11 201009303 速度控制器30 控制器模組32 絕緣栅雙極電晶體（IGBT)模組34 旋轉碼盤200,300,400 副編碼片220,420The information is set, so the power is turned off and then the Thunder & A electric Dan has no need to carry out the zeroing procedure, which simplifies the operation of the control system. Referring to the second figure 'for the basic structure of the optical encoder, the light emitted by a light source 260 passes through a rotating code wheel and a fixed sub-code sheet 220 reaches a light sensing element 24, and the light sensing element (10) receives The intensity of the light reaches a different intensity change depending on the position of the rotating code wheel 2'. The position signal can be detected by the signal change on the light sensing element 24. Referring to the second figure, the schematic diagram of a rotary encoder 300 of an absolute type encoder is a code wheel design of a bit (6 bit) binary code. The rotary code wheel 3 includes a circular body 3〇2 and a plurality of gratings 304. The grating 3〇4 includes one first grating 3〇4A occupying the innermost circumference coding track and occupying the circumference, and two second gratings 304B·· occupying the track on the inner second circumference and occupying 1/4 circumference each The outermost coded tracks each occupy 32 gratings 3〇4F of 1/64 circumference. Therefore, different light and dark signals can be generated along the radial direction and a resolution of =64 can be achieved along the circumferential direction. However, in the absolute encoder architecture shown in the figure, the encoding track must be increased by one revolution for each bit of the resolution. The higher the resolution, the more the number of encoded tracks, and the volume of the encoder. The bigger. In some cases where there is a volume limitation, the accuracy of the absolute encoder is limited. Referring to Figure 4A, one of the incremental encoders rotates the code wheel 4 〇〇. It is not intended that the rotary code wheel 400 includes a circular body 402 and a plurality of light 6 201009303 grids. The gratings include a main grating 404A, a first sub-grating 404B, and a second sub-grating 404C. The first sub-grating 404B and the second sub-grating 404C are flanked by the main grating 404A and at a specific position of the circular body 402. Referring to Figure 4B, there is a schematic diagram of a sub-coded disc 420; the sub-code disc 420 includes four rows of gratings 420A. Referring to FIG. 4C, which is a schematic diagram of a light sensing component 440, the light sensing component 440 includes primary sensing units 442A, 444A, 442B, 444B corresponding to the primary grating 404A (also labeled as A+/B+/A- /B- area). When the rotary φ disk 400 is rotated, a signal similar to a sine wave is generated in the four units (A+/B+/A-/B-) of the light sensing element 440. The four sine waves have a phase of 0/90/180/270 degrees, and a 0/180 signal (A+/A-) is used for differential amplification to obtain a sinusoidal signal A that eliminates common mode noise. The same 90/270 signal (B+/B-) is used for differential amplification to obtain the cosine signal B for canceling common mode noise. The phase difference between the two signals of AB is 90 degrees, which can be used to judge forward or reverse. . The incremental encoder basically only needs the AB signal to detect the position information. However, since the position information only provides information relative to the previous position, it is necessary to additionally set the origin signal sensing unit 446. (Z+/Z-), the absolute position message can be obtained after returning to the original zero point each time the system is powered on. The advantage of the incremental programmer is that it only needs six signals to get the south resolution message. The disadvantage is that it needs to perform the homing action every time the power is turned on, which is not only a waste of time but also does not allow the homing. The application of the point program can not meet the requirements and need to add absolute encoders. [Inventive content] 7 201009303 is to provide an incremental encoder architecture I absolute encoder and its operation method. In order to achieve the above object, the present invention provides an absolute encoder and a method for measuring absolute position, the code ϋ includes an optical encoder wheel, and the light: code wheel includes a main grating unit and two sub-grating units; A sub-light, a single sub-division on both sides of the main grating unit and the number of gratings is less than the main optical unit - when the encoder is in absolute position _, the encoder wheel can be rotated to find the photo-detection signal of the sub-grating unit Zero point, and find the value of the main grating unit should be zero, so that the absolute position can be estimated. Since the encoder can provide incremental position and absolute position calculations at the same time, the flexibility of use can be increased. [Embodiment] At present, most of the absolute type coding schemes use the position coding method of the entity to provide the absolute position m (four), the code type has mVBiqing c〇de) and Gray code (GmyCode), whether it is binary code or Gray code, The resolution accuracy of the encoder depends on the number of sensing elements. The more the number of sensing elements, the larger the volume of the encoder and the higher the cost. The main purpose of this patent is to use the architecture of the incremental encoder to achieve the absolute encoder, by adding a set of modulation signals to the original encoder of the incremental encoder. A set of sine and cosine signals with a period of 36 degrees, the set of sine and cosine signals can be inserted into the absolute position information at any moment. Referring to Figure 5A, there is shown a schematic diagram of a rotary encoder 100 in accordance with one of the absolute encoders of the present invention. The rotary encoder 10 includes a circular body 1〇2 8 201009303 and a plurality of gratings 104. The gratings 104 include a primary barrier unit 104A located in a primary signal track, a first secondary barrier unit 104B and a second secondary barrier unit 104C positioned in at least one modulation track (shown as two), wherein the first secondary barrier unit The number of gratings of the 104B and the second sub-grating unit 104C is one less than the number of the main grating unit 104A. For example, the number of gratings of the main grating unit 104A may be 2,500, and the number of gratings of the first sub-grating 104B unit and the second sub-grating unit 104C is 2499. Referring to FIG. 5B, a schematic diagram of the sub-coded disc 120; the sub-coded disc 120 includes four rows of gratings 120A respectively corresponding to the photo-sensing elements (described in detail later). Referring to FIG. 5C, which is a schematic diagram of the light sensing element 140, the light sensing element 140 includes a main sensing unit 142A, 144A, 142B, 144B corresponding to the main grating unit 104 (also labeled as A+/B+). /A-/B- area). Furthermore, the light sensing element 140 also includes modulation track sensing units H6A and 146B corresponding to the first sub-grating unit ι4 and the second sub-grating unit 104C. The main purpose of the present invention is to achieve the absolute positioning function under the reduced architecture of the incremental encoder. Referring to the code wheel design shown in Figure 5A, the area of the ® incremental Sz+/z- is set to A+/A. -/B+/B- The main signal is executed by one less grating (M+/M-). For convenience of illustration, it is assumed here that the main grating unit 104A has 16 gratings, and the first sub-grating unit ι4 and the second sub-grating unit 104C have 15 gratings. Referring to the sixth figure, the main signal track is rotated one turn to generate 16 sine waves on the A+/A-light sensing unit (the main sensing units 142A and 142B). The modulated track sensing elements 146 and 146B (M+ /M-) The signal sent by the differential can be sampled to obtain a sinusoidal signal with a period of 360 degrees. As shown in the sixth figure, if a controller (not shown, 9 201009303 can be used as the controller 14 shown in the first figure), the rotation of the rotary code wheel loo is shifted by one grating (corresponding to the 2 angle transformation). Then, the value of the A+/A-light sensing unit corresponding to the zero point (point A) of the modulated track sensing unit 146A and 146B (corresponding to the value of the circle point) can be found. Because the value of the A+/A-light sensing component that uses the modulated track sensing unit 146A and 146B to sample the zero point is a sinusoidal signal with a period of 36 degrees, the value corresponding to the point A can be used to find the rotating code wheel. The absolute position of 1〇〇. ❹ The above description is exemplified by a main grating unit i〇4A having 16 gratings. If the number of gratings of the main grating unit 104A is larger, the amount of rotation of one grating is smaller. The same B+/B-light sensing unit (main sensing unit 144 and 144B) generates 16 cosine waves and modulated track signals (μ) for sampling to obtain a cosine signal with a period of 360 degrees, which can be obtained by using a sine and cosine signal. The absolute position signal is interpolated. Since the new architecture still retains the incremental signal of the grating, the absolute position of the interpolation still maintains the incremental basic accuracy, and if the original high-order harmonic components of the cosine signal are sufficient In small cases, the absolute positional accuracy of the interpolation can also be increased upwards. The advantages of the present invention can be summarized as follows: 1. The function of the absolute position of the output is achieved by the number of lanes of the incremental encoder. 2. Absolute encoders can use incremental signals and interpolate absolute position signals to improve positional accuracy. 3. The main signal and the modulation signal adopt the differential amplification method to eliminate the common mode miscellaneous 201009303. The illustrative example of this patent is exemplified by the architecture of the optical encoder, but the absolute clamping method is suitable for encoders with other physical principles such as electromagnetic capacitors. As described above, it is known that the present invention has industrial applicability, novelty, and advancement, and the structure of the present invention has not been found in similar products and public use, and fully complies with the requirements of the invention patent application, and is filed according to the patent law. [Simple diagram of the diagram] ❹ The first diagram is a block diagram of a conventional AC servo motor control system. The second diagram shows the basic structure of an optical encoder. The second figure is a schematic diagram of a conventional rotary encoder with an absolute encoder. Figure 4A is a schematic diagram of a conventional rotary encoder with an incremental encoder. Figure 4B is a schematic diagram of a conventional sub-coded disc. Figure 4C is a schematic diagram of a conventional light sensing element. Figure 5A is a schematic diagram of the rotary code wheel of the encoder of the present invention.第五 The fifth B diagram is a schematic diagram of the sub-coded disc of the present invention. The fifth C is a schematic view of the light sensing element of the present invention. The sixth picture shows the light detection signal of the main signal and the modulation track sensing unit. [Main component symbol description] [Practical] Motor 10 Optical encoder 12 Controller 14 Signal processing unit 2〇11 201009303 Speed controller 30 Controller module 32 Insulated gate bipolar transistor (IGBT) module 34 Rotary code wheel 200,300,400 sub-codes 220,420
光感測元件240,440 光源260 圓形主體302,402 第一光柵304A 第二光柵304B 第三光柵304C 第四光栅304D φ 第五光柵304E 第六光栅304FLight sensing element 240, 440 light source 260 circular body 302, 402 first grating 304A second grating 304B third grating 304C fourth grating 304D φ fifth grating 304E sixth grating 304F
主光柵404A 第一副光栅404B 第二副光栅404C 光柵420A 主感測單元 442A，444A，442B,444B 原點訊號感測單元446A，446B 【本發明】 旋轉碼盤100 ® 副編碼片120 光感測元件140Main grating 404A First sub-grating 404B Second sub-grating 404C Grating 420A Main sensing unit 442A, 444A, 442B, 444B Origin signal sensing unit 446A, 446B [Invention] Rotary code wheel 100 ® Sub-coded film 120 Light sense Measuring component 140
主光栅單元104A 第一副光柵單元104B 第二副光栅單元104C 主感測單元 142A, 144A，142B，144B 調制軌道感測單元146A, 146B 12Main grating unit 104A First sub-grating unit 104B Second sub-grating unit 104C Main sensing unit 142A, 144A, 142B, 144B Modulation track sensing unit 146A, 146B 12