JP4214466B2 - Magnetic encoder and rotation angle calculation method thereof - Google Patents

Magnetic encoder and rotation angle calculation method thereof Download PDF

Info

Publication number
JP4214466B2
JP4214466B2 JP2003136157A JP2003136157A JP4214466B2 JP 4214466 B2 JP4214466 B2 JP 4214466B2 JP 2003136157 A JP2003136157 A JP 2003136157A JP 2003136157 A JP2003136157 A JP 2003136157A JP 4214466 B2 JP4214466 B2 JP 4214466B2
Authority
JP
Japan
Prior art keywords
temperature
detection element
magnetic field
output signal
phase
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
JP2003136157A
Other languages
Japanese (ja)
Other versions
JP2004340681A5 (en
JP2004340681A (en
Inventor
浩司 上村
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Yaskawa Electric Corp
Original Assignee
Yaskawa Electric Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Yaskawa Electric Corp filed Critical Yaskawa Electric Corp
Priority to JP2003136157A priority Critical patent/JP4214466B2/en
Publication of JP2004340681A publication Critical patent/JP2004340681A/en
Publication of JP2004340681A5 publication Critical patent/JP2004340681A5/ja
Application granted granted Critical
Publication of JP4214466B2 publication Critical patent/JP4214466B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Landscapes

  • Transmission And Conversion Of Sensor Element Output (AREA)

Description

【０００１】
【発明の属する技術分野】
本発明は、例えば、産業用ロボット、ＮＣ工作機械等に用いられるモータの回転位置を検出する磁気式エンコーダとその回転角度算出方法に関する。
【０００２】
【従来の技術】
図３は、従来の磁気式エンコーダであって、（ａ）はその構成図、（ｂ）は磁界検出素子から出力される各相信号を処理する信号処理回路のブロック図である（例えば特許文献１参照）。
【０００３】
【特許文献１】
国際公開番号ＷＯ９９／１３２９６ （明細書第６頁〜７頁、図１〜図２）
【０００４】
図３（ａ）において、１は回転機械、１Ａは回転機械１の回転軸、２は回転軸１Ａの端部に固定された円板状の発磁体を構成する永久磁石で、永久磁石２の表面は回転軸１Ａに垂直な一方向に磁化されている。３は永久磁石２の外周側に設けられたリング状の固定体、７は回転機械１の回転中心に対し同心円状にして設けられ、且つ、固定体３の周方向に互いに等間隔に設置された磁界検出素子であって、４個の磁界検出素子７１、７２、７３、７４から構成されている。この各磁界検出素子は、永久磁石２の外周面に対して空隙を介して対向し、且つ、互いに機械角で９０度位相をずらしてＡ1相検出素子７１とＢ1相検出素子７３を設け、さらにＡ1相検出素子７１に対して機械角で１８０度位相をずらしてＡ2相検出素子７２を、Ｂ1相検出素子７３に対して機械角で１８０度位相をずらしてＢ2相検出素子７４を設けている。なお、回転軸１Ａの偏心量が極めて小さい場合は、磁界検出素子７を互いに周方向に機械角で９０度位相をずらして固定されたＡ1相検出素子７１と、Ｂ1相検出素子７３の、２個の検出信号だけを得るようにしてもよい。
次に、磁界検出素子から出力される各相信号を処理する信号処理回路について説明する。
図３（ｂ）において、８は信号処理回路であって、Ａ1相検出素子７１の出力信号 Ｖ71とＡ2相検出素子７２の出力信号 Ｖ72の差動信号Ｖaを出力する差動増幅器８１と、Ｂ1相検出素子７３の出力信号 Ｖ73とＢ2相検出素子７４の出力信号Ｖ74の差動信号Ｖbを出力する差動増幅器８２と、差動信号ＶaとＶbとから
ａｒｃｔａｎ（Ｖa／Ｖb）・・・（１）
の演算を行って回転角度を算出する角度演算回路８３とを設けている。
Ａ1 相検出素子７１とＢ1 相検出素子７３の２個の検出信号だけを用いる場合は、差動増幅器８１および差動増幅器８２は差動構成ではなく増幅器とし、Ａ1 相検出素子７１とＢ1 相検出素子７３の２個の検出信号の増幅信号Ｖa とＶbとから、同様に（１）の演算および回転角度の算出が角度演算回路８３で行なわれる。
【０００５】
【発明が解決しようとする課題】
ところが、このような従来の磁気式エンコーダでは、磁界検出素子の出力は、感度やオフセット値の温度変動により変動していた。すなわち、永久磁石２の磁束密度や、磁界検出素子７の感度の温度変動量は、前記の信号Ｖa およびＶbに対し同じ比率で発生するため、角度演算時の式（１）において相殺される。しかしながら、磁界検出素子７のオフセット値の温度変動量は素子によりばらつきがあるため、温度変動により回転角度の算出に誤差が発生する。そこで、磁界検出素子を選別することによりオフセット値の温度変動量の低減を図っていたが、磁界検出素子の選別工程が増えるという問題があった。
さらに、温度変動によるオフセット値の変動量を、あらかじめ記憶し、温度を計測して補正することが考えられる。しかしながら、温度計測のため温度検出素子を磁界検出素子近傍に配置することは、デバイス点数が多くなるため高価になり、大型化する、配線数が増えるなどの問題があり、磁気式エンコーダの適用範囲を狭めていた。
本発明は上記課題を解決するためになされたものであり、磁界検出素子の選別や温度検出装置を取り付けることなく、温度変動による磁気式エンコーダの回転角度の算出誤差を低減することができる磁気式エンコーダの回転角度算出方法を提供することを目的とする。
【０００６】
【課題を解決するための手段】
上記問題を解決するため、本発明に係る磁気式エンコーダは、回転機械１に固定された回転軸１Ａと、垂直方向の一方向に磁化され、前記回転軸１Ａに固定された永久磁石２と、前記永久磁石２に空隙を介して対向し、固定体３に少なくとも２つ取り付けられた磁界検出素子７と、前記磁界検出素子７から出力される信号を処理する信号処理回路を備えた磁気式エンコーダにおいて、前記磁界検出素子７から取得される少なくとも２つの出力信号Ｖａ、Ｖｂから振幅の正規化及び位相補正を行うための演算を実施し、前記位相補正された出力信号を用いて、Ｒ＝（Ｖａ ２＋Ｖｂ ２）１／２の演算を実施し、前記演算により求めたＲ値を用いて、予め記憶しているＲ値に対する温度の比較表に基づいて温度を推定し、前記推定した温度を用いて、予め記憶している温度に対する前記出力信号のオフセット補正値の比較表に基づいてオフセット補正値を推定し、前記推定したオフセット補正値を前記位相補正された出力信号に加える演算を実施し、前記推定オフセット補正値を加えた出力信号を用いて回転角度を算出するようにしたものである。
【０００７】
【発明の実施の形態】
以下、本発明の実施例を図に基づいて説明する。
図１は本発明の実施例を示す磁気式エンコーダの角度算出に係るフローチャートである。なお、磁気式エンコーダの構成要素及び信号処理回路は前述の図３と同じである。
本発明では、はじめにステップＳＴ１にて、少なくとも２つの磁界検出素子７から温度Ｔ0における少なくとも２つの出力信号Ｖa（Ｔ0）、Ｖb（Ｔ0）を取得する。次にステップＳＴ２にて、（２）式を用いて一方の出力で振幅の正規化と（３）式を用いて位相補正を行う。
Ｖax＝Ｖa、Ｖbx＝Ｖa／Ｖb・・・（２）
Ｖay＝Ｖax＋Ｖbx、Ｖby＝Ｖax−Ｖbx・・・（３）
次にステップＳＴ３にて、
Ｒ（Ｔ）＝（Ｖa（Ｔ）2＋Ｖb（Ｔ）2）1/2
を用いてＲ（Ｔ0）を算出し、ステップＳＴ４にて、予め記憶しているＲ（Ｔ）値に対する温度Ｔの比較表（表１）に基づいて温度Ｔ0を推定する。このときＲ（Ｔ0）に等しいＲ（Ｔ）値がない場合は、もっとも近い２つのＲ（Ｔ）値より、比例配分で推定温度Ｔｎを求めればよい。
【０００８】
【表１】

Figure 0004214466
【０００９】
図２はＲ（Ｔ）値より求めた推定温度Ｔｎと計測温度Ｔとの関係を示すグラフである。図２の縦軸は推定温度Ｔｎを、横軸は計測温度Ｔを示しており、両者はほぼ等しいことがわかる。その理由は、磁界検出素子７から得られる回転角度に応じたそれぞれの正弦波信号の振幅値は、温度に対し均一な比率で変動するため、前記のそれぞれの正弦波信号のベクトルの大きさを算出することにより、温度を推定する事ができるからである。
なお、磁界検出素子が１つだけの場合は、回転機械の回転軸の位置により出力の大きさが変動するのでこのような処理は不可能である。
次にステップＳＴ５にて、前記推定した温度Ｔｎを用いて、予め記憶している温度に対する前記出力信号のオフセット補正値の比較表（表１）に基づいてオフセット補正値Ｖaoff（Ｔn）、Ｖboff（Ｔn）を推定する。
次にステップＳＴ６にて、式
Ｖaz＝Ｖay（Ｔ）＋Ｖaoff（Ｔn）
Ｖbz＝Ｖby（Ｔ）＋Ｖboff（Ｔn）
よりＶaz、Ｖbzを導出する。
最後にステップＳＴ７にて、前記ステップＳＴ６で求めた前記推定オフセット補正値を加えた出力信号Ｖaz、Ｖbzを式（１）に代入し補正された回転角度θ（Ｔ0）を算出する。
【００１０】
補正の効果を検証するため、本発明と従来例の回転角度算出方式を用いた磁気式エンコーダを各１０ヶ準備した。表２に本発明、及び従来の実施例の絶対角度誤差の結果を示す。
【００１１】
【表２】
Figure 0004214466
【００１２】
温度を室温時と８５℃、−２０℃にしたときの各々の１回転における絶対角度誤差を求めた。永久磁石には希土類磁石を用い、磁界検出素子にはＧａＡｓからなるホール素子を用いた。その結果、従来例では絶対角度誤差が最小のものでも±０．８％であったが、本発明では絶対角度誤差が最大のもので±０．０２％であり、本発明が高精度な磁気式エンコーダになりうることがわかった。
したがって、本発明の実施例に係る磁気式エンコーダの回転角度算出方法は、回転機械１に固定された回転軸１Ａと、垂直方向の一方向に磁化され、前記回転軸１Ａに固定された永久磁石２と、前記永久磁石２に空隙を介して対向し、固定体３に少なくとも２つ取り付けられた磁界検出素子７と、前記磁界検出素子７から出力される信号を処理する信号処理回路を備えた磁気式エンコーダにおいて、前記磁界検出素子７から取得される少なくとも２つの出力信号Ｖa、Ｖbから振幅の正規化及び位相補正を行うための演算を実施し、前記位相補正された出力信号を用いて、Ｒ＝（Ｖa 2＋Ｖb 2）1/2の演算を実施し、前記演算により求めたＲ値を用いて、予め記憶しているＲ値に対する温度の比較表に基づいて温度を推定し、前記推定した温度を用いて、予め記憶している温度に対する前記出力信号のオフセット補正値の比較表に基づいてオフセット補正値を推定し、前記推定したオフセット補正値を前記位相補正された出力信号に加える演算を実施し、前記推定オフセット補正値を加えた出力信号を用いて回転角度を算出するようにしているため、磁界検出素子の選別や温度検出装置を取り付けることなく、温度変動による磁気式エンコーダの回転角度の算出誤差を低減することができる。
【００１３】
【発明の効果】
以上述べたように、本発明の磁気式エンコーダ及びその回転角度算出方法によれば、回転機械１に固定された回転軸１Ａと、垂直方向の一方向に磁化され、前記回転軸１Ａに固定された永久磁石２と、前記永久磁石２に空隙を介して対向し、固定体３に少なくとも２つ取り付けられた磁界検出素子７と、前記磁界検出素子７から出力される信号を処理する信号処理回路を備えた磁気式エンコーダにおいて、前記磁界検出素子７から取得される少なくとも２つの出力信号Ｖａ、Ｖｂから振幅の正規化及び位相補正を行うための演算を実施し、前記位相補正された出力信号を用いて、Ｒ＝（Ｖａ ２＋Ｖｂ ２）１／２の演算を実施し、前記演算により求めたＲ値を用いて、予め記憶しているＲ値に対する温度の比較表に基づいて温度を推定し、前記推定した温度を用いて、予め記憶している温度に対する前記出力信号のオフセット補正値の比較表に基づいてオフセット補正値を推定し、前記推定したオフセット補正値を前記位相補正された出力信号に加える演算を実施し、前記推定オフセット補正値を加えた出力信号を用いて回転角度を算出するようにしているため、磁界検出素子の選別や温度検出装置を取り付けることなく、温度変動による磁気式エンコーダの回転角度の算出誤差を低減することができる。
【図面の簡単な説明】
【図１】本発明の実施例を示す磁気式エンコーダの角度算出に係るフローチャートである。
【図２】Ｒ（Ｔ）値より求めた推定温度Ｔｎと計測温度Ｔとの関係を示すグラフである。
【図３】従来の磁気式エンコーダであって、（ａ）はその構成図、（ｂ）は磁界検出素子から出力される各相信号を処理する信号処理回路のブロック図である。
【符号の説明】
１ 回転機械
１Ａ 回転軸
２ 永久磁石
３ 固定体
７、７１、７２、７３、７４ 磁界検出素子
８ 信号処理回路
８１、８２ 差動増幅器
８３ 角度演算回路[0001]
BACKGROUND OF THE INVENTION
The present invention is, for example, an industrial robot, related to the rotation angle calculating method of a magnetic encoder and its for detecting the rotational position of the motor used in NC machine tools or the like.
[0002]
[Prior art]
3A and 3B show a conventional magnetic encoder, in which FIG. 3A is a configuration diagram thereof, and FIG. 3B is a block diagram of a signal processing circuit that processes each phase signal output from a magnetic field detection element (for example, Patent Documents). 1).
[0003]
[Patent Document 1]
International Publication Number WO99 / 13296 (Specifications, pages 6-7, FIGS. 1-2)
[0004]
In FIG. 3 (a), 1 is a rotating machine, 1A is a rotating shaft of the rotating machine 1, 2 is a permanent magnet constituting a disc-shaped magnet generator fixed to the end of the rotating shaft 1A, The surface is magnetized in one direction perpendicular to the rotation axis 1A. 3 is a ring-shaped fixed body provided on the outer peripheral side of the permanent magnet 2, 7 is provided concentrically with the rotation center of the rotary machine 1, and is installed at equal intervals in the circumferential direction of the fixed body 3. The magnetic field detection element includes four magnetic field detection elements 71, 72, 73, and 74. Each of the magnetic field detection elements faces the outer peripheral surface of the permanent magnet 2 via a gap, and is provided with an A 1 phase detection element 71 and a B 1 phase detection element 73 with a mechanical angle shifted by 90 degrees from each other. , further a 2-phase detecting element 72 by shifting the phase by 180 degrees in mechanical angle with respect to a 1 phase detection element 71, B 1 phase detection element 73 mechanical angle 180 degrees out of phase B 2 phase detection for An element 74 is provided. When the amount of eccentricity of the rotating shaft 1A is extremely small, the magnetic field detecting element 7 includes an A 1 phase detecting element 71 and a B 1 phase detecting element 73, which are fixed with a mechanical angle shifted by 90 degrees in the circumferential direction. Only two detection signals may be obtained.
Next, a signal processing circuit that processes each phase signal output from the magnetic field detection element will be described.
In FIG. 3 (b), 8 is a signal processing circuit, and outputs a differential signal V a of the output signal V 72 of the output signal V 71 and the A 2 phase detection element 72 of the A 1 phase detection element 71 Differential an amplifier 81, a differential amplifier 82 for outputting a differential signal V b of the output signal V 74 of the output signal V 73 and the B 2 phase detection element 74 B 1 phase detection element 73, a differential signal V a and V b Arctan (V a / V b ) (1)
And an angle calculation circuit 83 for calculating the rotation angle.
In the case of using only two detection signals of the A 1 phase detection element 71 and B 1 phase detection element 73, a differential amplifier 81 and the differential amplifier 82 is an amplifier rather than a differential configuration, the A 1 phase detection element 71 From the amplified signals V a and V b of the two detection signals of the B 1 phase detection element 73, the calculation of (1) and the calculation of the rotation angle are similarly performed by the angle calculation circuit 83.
[0005]
[Problems to be solved by the invention]
However, in such a conventional magnetic encoder, the output of the magnetic field detecting element fluctuates due to temperature fluctuations in sensitivity and offset value. That is, since the magnetic flux density of the permanent magnet 2 and the temperature fluctuation amount of the sensitivity of the magnetic field detection element 7 are generated at the same ratio with respect to the signals V a and V b, they are canceled in the equation (1) at the time of angle calculation. The However, since the temperature fluctuation amount of the offset value of the magnetic field detection element 7 varies depending on the element, an error occurs in the calculation of the rotation angle due to the temperature fluctuation. Therefore, although the amount of temperature variation of the offset value is reduced by selecting the magnetic field detection elements, there is a problem that the number of steps for selecting the magnetic field detection elements increases.
Furthermore, it is conceivable that the amount of change in the offset value due to temperature variation is stored in advance, and the temperature is measured and corrected. However, disposing the temperature detection element in the vicinity of the magnetic field detection element for temperature measurement is expensive due to the increased number of devices, resulting in problems such as an increase in size and an increase in the number of wires. Was narrowing.
The present invention has been made to solve the above problems, and can reduce a calculation error of a rotation angle of a magnetic encoder due to a temperature change without selecting a magnetic field detection element or attaching a temperature detection device. An object of the present invention is to provide a method for calculating the rotation angle of an encoder.
[0006]
[Means for Solving the Problems]
In order to solve the above problem, a magnetic encoder according to the present invention includes a rotating shaft 1A fixed to the rotating machine 1, a permanent magnet 2 magnetized in one vertical direction and fixed to the rotating shaft 1A, A magnetic encoder comprising a magnetic field detection element 7 opposed to the permanent magnet 2 with a gap and attached to the fixed body 3, and a signal processing circuit for processing a signal output from the magnetic field detection element 7. 2, an operation for normalizing the amplitude and correcting the phase is performed from the at least two output signals V a and V b acquired from the magnetic field detection element 7, and using the output signal corrected in phase, R = (V a 2 + V b 2 ) 1/2 is calculated, and using the R value obtained by the calculation, the temperature is estimated based on a temperature comparison table with respect to the R value stored in advance, The estimated temperature The offset correction value is estimated based on a comparison table of offset correction values of the output signal with respect to the temperature stored in advance, and an operation for adding the estimated offset correction value to the phase-corrected output signal is performed. The rotation angle is calculated using the output signal to which the estimated offset correction value is added.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a flowchart relating to angle calculation of a magnetic encoder showing an embodiment of the present invention. The components and signal processing circuit of the magnetic encoder are the same as those in FIG.
In the present invention, first, in step ST1, at least two output signals V a (T 0 ) and V b (T 0 ) at temperature T 0 are obtained from at least two magnetic field detecting elements 7. Next, in step ST2, amplitude normalization is performed on one output using equation (2) and phase correction is performed using equation (3).
V ax = V a , V bx = V a / V b (2)
V ay = V ax + V bx , V by = V ax −V bx (3)
Next, in step ST3,
R (T) = (V a (T) 2 + V b (T) 2 ) 1/2
Is used to calculate R (T 0 ), and in step ST4, the temperature T 0 is estimated based on a comparison table (Table 1) of the temperature T with respect to the R (T) value stored in advance. At this time, if there is no R (T) value equal to R (T 0 ), the estimated temperature Tn may be obtained by proportional distribution from the two closest R (T) values.
[0008]
[Table 1]
Figure 0004214466
[0009]
FIG. 2 is a graph showing the relationship between the estimated temperature Tn obtained from the R (T) value and the measured temperature T. The vertical axis in FIG. 2 indicates the estimated temperature Tn, and the horizontal axis indicates the measured temperature T. It can be seen that both are substantially equal. The reason is that the amplitude value of each sine wave signal corresponding to the rotation angle obtained from the magnetic field detecting element 7 fluctuates at a uniform ratio with respect to the temperature. This is because the temperature can be estimated by calculating.
In the case where there is only one magnetic field detection element, such a process is not possible because the magnitude of the output varies depending on the position of the rotating shaft of the rotating machine.
Next, in step ST5, using the estimated temperature Tn, an offset correction value V aoff (T n ) based on a comparison table (Table 1) of offset correction values of the output signal with respect to the temperature stored in advance, Estimate V boff (T n ).
Next, in step ST6, the formula V az = V ay (T) + V aoff (T n )
V bz = V by (T) + V boff (T n )
Thus, V az and V bz are derived.
Finally, in step ST7, the corrected rotation angle θ (T 0 ) is calculated by substituting the output signals V az and V bz to which the estimated offset correction value obtained in step ST6 is added into the equation (1).
[0010]
In order to verify the effect of the correction, ten magnetic encoders using the present invention and the conventional rotation angle calculation method were prepared. Table 2 shows the absolute angle error results of the present invention and the conventional examples.
[0011]
[Table 2]
Figure 0004214466
[0012]
The absolute angle error in each rotation when the temperature was room temperature, 85 ° C., and −20 ° C. was obtained. A rare earth magnet was used as the permanent magnet, and a Hall element made of GaAs was used as the magnetic field detection element. As a result, in the conventional example, the absolute angle error is ± 0.8% even when the absolute value is minimum, but in the present invention, the absolute angle error is ± 0.02% when the absolute value is maximum. It turns out that it can be an expression encoder.
Therefore, the rotation angle calculation method of the magnetic encoder according to the embodiment of the present invention includes a rotating shaft 1A fixed to the rotating machine 1, and a permanent magnet magnetized in one direction in the vertical direction and fixed to the rotating shaft 1A. 2, a magnetic field detection element 7 facing the permanent magnet 2 with a gap and attached to the fixed body 3, and a signal processing circuit for processing a signal output from the magnetic field detection element 7. In the magnetic encoder, an operation for normalizing the amplitude and correcting the phase is performed from at least two output signals V a and V b acquired from the magnetic field detecting element 7, and the phase-corrected output signal is used. Then, the calculation of R = (V a 2 + V b 2 ) 1/2 is performed, and the temperature is estimated based on the temperature comparison table for the stored R value using the R value obtained by the calculation. And the estimated temperature Is used to estimate an offset correction value based on a comparison table of offset correction values of the output signal with respect to a temperature stored in advance, and to perform an operation of adding the estimated offset correction value to the phase-corrected output signal Since the rotation angle is calculated using the output signal to which the estimated offset correction value is added, the rotation angle of the magnetic encoder due to temperature fluctuations can be reduced without selecting a magnetic field detection element or attaching a temperature detection device. Calculation error can be reduced.
[0013]
【The invention's effect】
As described above, according to the magnetic encoder and the rotation angle calculation method of the present invention, the rotary shaft 1A fixed to the rotary machine 1 is magnetized in one vertical direction and fixed to the rotary shaft 1A. The permanent magnet 2, the magnetic field detection element 7 facing the permanent magnet 2 with a gap and attached to the fixed body 3, and a signal processing circuit for processing a signal output from the magnetic field detection element 7 In the magnetic encoder provided with the above, the phase-corrected output is obtained by performing an operation for normalizing the amplitude and correcting the phase from at least two output signals V a and V b acquired from the magnetic field detecting element 7. Using the signal, R = (V a 2 + V b 2 ) 1/2 is calculated, and using the R value obtained by the above calculation, based on the temperature comparison table for the previously stored R value Estimate the temperature Using the estimated temperature, estimating an offset correction value based on a comparison table of offset correction values of the output signal with respect to a temperature stored in advance, and outputting the estimated offset correction value to the phase-corrected output signal The rotation angle is calculated using the output signal to which the estimated offset correction value is added, so that the magnetic type due to temperature fluctuations can be used without selecting a magnetic field detection element or attaching a temperature detection device. The calculation error of the rotation angle of the encoder can be reduced.
[Brief description of the drawings]
FIG. 1 is a flowchart relating to angle calculation of a magnetic encoder according to an embodiment of the present invention.
FIG. 2 is a graph showing a relationship between an estimated temperature Tn obtained from an R (T) value and a measured temperature T.
3A is a block diagram of a conventional magnetic encoder, and FIG. 3B is a block diagram of a signal processing circuit that processes each phase signal output from a magnetic field detection element.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Rotating machine 1A Rotating shaft 2 Permanent magnet 3 Fixed body 7, 71, 72, 73, 74 Magnetic field detection element 8 Signal processing circuit 81, 82 Differential amplifier 83 Angle calculation circuit

Claims (2)

回転機械に固定された回転軸と、垂直方向の一方向に磁化され、前記回転軸に固定された永久磁石と、前記永久磁石に空隙を介して対向し、固定体に少なくとも２つ取り付けられた磁界検出素子と、前記磁界検出素子から出力される信号を処理する信号処理回路を備えた磁気式エンコーダにおいて、
前記磁界検出素子から取得される少なくとも２ つの出力信号Ｖａ、Ｖｂから振幅の正規化及び位相補正を行うための演算を実施し、
前記位相補正された出力信号を用いて、Ｒ＝（Ｖａ ２＋Ｖｂ ２）１／２の演算を実施し、
前記演算により求めたＲ値を用いて、予め記憶しているＲ値に対する温度の比較表に基づいて温度を推定し、
前記推定した温度を用いて、予め記憶している温度に対する前記出力信号のオフセット補正値の比較表に基づいてオフセット補正値を推定し、
前記推定したオフセット補正値を前記位相補正された出力信号に加える演算を実施し、前記推定オフセット補正値を加えた出力信号を用いて回転角度を算出するようにしたことを特徴とする磁気式エンコーダの回転角度算出方法。A rotating shaft fixed to the rotating machine, a permanent magnet magnetized in one direction in the vertical direction, fixed to the rotating shaft, and opposed to the permanent magnet through a gap, and attached to the fixed body. In a magnetic encoder comprising a magnetic field detection element and a signal processing circuit for processing a signal output from the magnetic field detection element,
Performing calculations for amplitude normalization and phase correction from at least two output signals V a and V b acquired from the magnetic field detection element;
Using the phase-corrected output signal, R = (V a 2 + V b 2 ) 1/2 is calculated,
Using the R value obtained by the above calculation, the temperature is estimated based on a temperature comparison table for the R value stored in advance,
Using the estimated temperature, the offset correction value is estimated based on a comparison table of offset correction values of the output signal with respect to the temperature stored in advance,
A magnetic encoder that performs an operation of adding the estimated offset correction value to the phase-corrected output signal and calculates a rotation angle using the output signal to which the estimated offset correction value is added. Rotation angle calculation method. 回転機械に固定された回転軸と、垂直方向の一方向に磁化され、前記回転軸に固定された永久磁石と、前記永久磁石に空隙を介して対向し、固定体に少なくとも２つ取り付けられた磁界検出素子と、前記磁界検出素子から出力される信号を処理する信号処理回路を備えた磁気式エンコーダにおいて、A rotating shaft fixed to the rotating machine, a permanent magnet magnetized in one direction in the vertical direction, fixed to the rotating shaft, and opposed to the permanent magnet through a gap, and attached to the fixed body. In a magnetic encoder including a magnetic field detection element and a signal processing circuit that processes a signal output from the magnetic field detection element,
前記磁界検出素子から取得される少なくとも２At least 2 obtained from the magnetic field detection element つの出力信号ＶOutput signal V ａa 、Ｖ, V ｂb から振幅の正規化及び位相補正を行うための演算を実施し、To perform normalization of amplitude and phase correction from
前記位相補正された出力信号を用いて、Ｒ＝（ＶUsing the phase corrected output signal, R = (V ａa ２2 ＋Ｖ+ V ｂb ２2 ）) １／２1/2 の演算を実施し、The operation of
前記演算により求めたＲ値を用いて、予め記憶しているＲ値に対する温度の比較表に基づいて温度を推定し、Using the R value obtained by the above calculation, the temperature is estimated based on the temperature comparison table for the R value stored in advance,
前記推定した温度を用いて、予め記憶している温度に対する前記出力信号のオフセット補正値の比較表に基づいてオフセット補正値を推定し、Using the estimated temperature, an offset correction value is estimated based on a comparison table of offset correction values of the output signal with respect to the temperature stored in advance,
前記推定したオフセット補正値を前記位相補正された出力信号に加える演算を実施し、前記推定オフセット補正値を加えた出力信号を用いて回転角度を算出するようにしたことを特徴とする磁気式エンコーダ。A magnetic encoder that performs an operation of adding the estimated offset correction value to the phase-corrected output signal, and calculates a rotation angle using the output signal to which the estimated offset correction value is added. .
JP2003136157A 2003-05-14 2003-05-14 Magnetic encoder and rotation angle calculation method thereof Expired - Fee Related JP4214466B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2003136157A JP4214466B2 (en) 2003-05-14 2003-05-14 Magnetic encoder and rotation angle calculation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2003136157A JP4214466B2 (en) 2003-05-14 2003-05-14 Magnetic encoder and rotation angle calculation method thereof

Publications (3)

Publication Number Publication Date
JP2004340681A JP2004340681A (en) 2004-12-02
JP2004340681A5 JP2004340681A5 (en) 2006-06-15
JP4214466B2 true JP4214466B2 (en) 2009-01-28

Family

ID=33526214

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2003136157A Expired - Fee Related JP4214466B2 (en) 2003-05-14 2003-05-14 Magnetic encoder and rotation angle calculation method thereof

Country Status (1)

Country Link
JP (1) JP4214466B2 (en)

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU2004264324B2 (en) * 2003-08-04 2011-03-03 Carefusion 203, Inc. Compressor control system for a portable ventilator
DE502006005526D1 (en) * 2005-07-26 2010-01-14 Ebm Papst St Georgen Gmbh & Co ELECTRIC MOTOR WITH AN ABSOLUTE VALVE TORQUE SENSOR, AND METHOD FOR GENERATING AN ANGLE ABSOLUTE VALUE
JP4706413B2 (en) * 2005-09-22 2011-06-22 株式会社安川電機 Magnetic encoder device, rotation angle calculation method and position detection method thereof
JP5128766B2 (en) * 2005-11-08 2013-01-23 東洋電装株式会社 Rudder angle sensor
US10845434B2 (en) 2012-01-06 2020-11-24 Allegro Microsystems, Llc Magnetic field sensor having a temperature compensated threshold on power up
US9395391B2 (en) * 2013-03-15 2016-07-19 Allegro Microsystems, Llc Magnetic field sensor and associated method that can store a measured threshold value in a memory device during a time when the magnetic field sensor is powered off
JP6131601B2 (en) * 2013-01-09 2017-05-24 株式会社デンソー Magnetic sensor
CN104748768B (en) * 2015-03-12 2017-07-25 常州大学 The detection method of angle position detection means
CN111505538B (en) * 2020-03-17 2022-12-09 天津中科华誉科技有限公司 Magnetic field direction sensor correction and calculation method, device, storage medium and equipment
CN116892960B (en) * 2023-09-06 2023-12-08 西安甘鑫科技股份有限公司 Angle rotary encoder suitable for ultralow temperature environment

Also Published As

Publication number Publication date
JP2004340681A (en) 2004-12-02

Similar Documents

Publication Publication Date Title
US8368392B2 (en) Magnetic encoder and method of detecting absolute rotational position
JP5613839B2 (en) Method and apparatus for absolute positioning of a moving object
US8471552B2 (en) Rotational angle-measurement apparatus and rotational speed-measurement apparatus
KR102195533B1 (en) Rotary encoder and angle correction method of rotary encoder
JP4900837B2 (en) Rotation angle detector and rotating machine
JP6779227B2 (en) Angle detector and electric power steering device
CN108426587B (en) Rotary encoder
US20020011814A1 (en) Pole position detector for motor
JP4214466B2 (en) Magnetic encoder and rotation angle calculation method thereof
US9742425B2 (en) Rotation detector and rotation detection method
EP2975364A1 (en) Position sensor device and method for providing a filtered position signal
CN113167598A (en) Angle sensor with a multipole magnet for a motor vehicle steering system
JP5176208B2 (en) Rotation angle detection method and rotation angle sensor
US11489470B2 (en) Sensor device for an electric machine, method for the operation of a sensor device
JP2018132357A (en) Rotary encoder
JP3693280B2 (en) Resolver assembly equipment
JP4224154B2 (en) Self-calibration type angle detection device and detection accuracy calibration method
Guyol AMR Angle Sensors
CN115900775A (en) Encoder, position compensation method and device thereof, and storage medium
JP6842943B2 (en) Rotary encoder
JP2006042537A (en) Brushless dc motor added with magnetic encoder and signal processing circuit
JP5193930B2 (en) Small angle detection sensor
WO2024143256A1 (en) Angle detecting device
JP7573973B2 (en) System for determining at least one rotational parameter of a rotating member - Patents.com
JP2020153980A (en) System for determining at least one rotation parameter of rotating member

Legal Events

Date Code Title Description
A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20060413

A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20060413

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20080905

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20081009

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20081022

R150 Certificate of patent or registration of utility model

Free format text: JAPANESE INTERMEDIATE CODE: R150

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20111114

Year of fee payment: 3

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20111114

Year of fee payment: 3

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20121114

Year of fee payment: 4

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20121114

Year of fee payment: 4

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20131114

Year of fee payment: 5

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20141114

Year of fee payment: 6

LAPS Cancellation because of no payment of annual fees