JP2004053444A - Steering angle sensor - Google Patents

Steering angle sensor Download PDF

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Publication number
JP2004053444A
JP2004053444A JP2002212101A JP2002212101A JP2004053444A JP 2004053444 A JP2004053444 A JP 2004053444A JP 2002212101 A JP2002212101 A JP 2002212101A JP 2002212101 A JP2002212101 A JP 2002212101A JP 2004053444 A JP2004053444 A JP 2004053444A
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Japan
Prior art keywords
signal
reference signal
rotating body
cos
sin
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JP2002212101A
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Japanese (ja)
Inventor
Katsunori Matsubara
松原　克憲
Makoto Inoue
井上　眞
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Panasonic Holdings Corp
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Matsushita Electric Industrial Co Ltd
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Priority to JP2002212101A priority Critical patent/JP2004053444A/en
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
    • G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
    • G01D5/142—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices
    • G01D5/145—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices influenced by the relative movement between the Hall device and magnetic fields
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D2205/00—Indexing scheme relating to details of means for transferring or converting the output of a sensing member
    • G01D2205/20—Detecting rotary movement
    • G01D2205/26—Details of encoders or position sensors specially adapted to detect rotation beyond a full turn of 360°, e.g. multi-rotation
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D2205/00—Indexing scheme relating to details of means for transferring or converting the output of a sensing member
    • G01D2205/20—Detecting rotary movement
    • G01D2205/28—The target being driven in rotation by additional gears

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
  • Power Steering Mechanism (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a prescribed output signal from a detecting means without being affected by the lapse of time and temperature change. <P>SOLUTION: In this sensor, an output reference signal of the detecting means 6 is stored in a volatile memory 8 or a non-volatile memory 9, and an output signal value is updated when the output reference signal value is changed by the the lapse of time and the temperature change. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、自動車の車体制御システムなどに用いられる舵角センサに関するものである。
【０００２】
【従来の技術】
従来、自動車用ハンドルなどのように１回転以上に有限で回転する回転体の回転角度を検出する舵角センサとしては、特表平１１−５００８２８号公報等に記載されたものが知られている。以下、従来の舵角センサの構成について説明する。図７（ａ）は従来の回転角度検出装置の平面図、図７（ｂ）は斜視図、図８はこの舵角センサにおける出力信号を示した特性図である。
【０００３】
図７（ａ），（ｂ）において、軸３１の外周に歯車３２が設置され、この歯車３２に接するように歯車３３，３４が設置されている。さらに歯車３３，３４にはそれぞれ磁石３５，３６が取り付けられている。この構成において、軸３１が回転することにより歯車３２，３３，３４がそれぞれ回転し、この回転に伴い磁石３５，３６が回転するため、磁界方向も回転する。そしてこの磁界方向の回転角に対してｓｉｎ信号４１およびｃｏｓ信号４２を検出手段によって出力し、この出力した信号によって軸３１の回転角度を検出する。
【０００４】
【発明が解決しようとする課題】
上記の構成において、温度等の変化により、舵角センサにおける検出手段の特性も変化するため、図８に示すように、例えば温度が２５℃から８５℃に変化した場合、ｓｉｎ信号４１が４３に、ｃｏｓ信号４２が４４にそれぞれ変化する。これに伴い基準信号値４５が４６に変化し、このため検出手段から出力される信号値も変化する。また、この装置では、この変化した信号値を補正することができないので、軸３１の回転角度を正しく検出することができなくなり、その結果自動車のハンドルの回転を、車体に正確に伝達することができなくなるおそれがあった。
【０００５】
そこで、本発明は上記の課題を解決するものであり、センサ単体で検出手段の所定の出力信号を得ることができ、自動車のハンドルの回転角度を常時正しく検出することができる舵角センサを提供することを目的とするものである。
【０００６】
【課題を解決するための手段】
そして、この目的を達成するために、本発明の請求項１に記載の発明は、特に、歯を備えた第１の回転体と、この第１の回転体の歯に係合される歯車、およびこの歯車に設けた磁石とを備えた第２の回転体と、この第２の回転体の回転角度を検出する検出手段と、前記磁石の回転により発信されるｓｉｎ信号およびｃｏｓ信号から算出される各々の基準信号値を記憶する機能を備えた不揮発性メモリと、電源投入時毎にこの不揮発性メモリに記憶された前記基準信号値を呼び出して記憶する機能を備えた揮発性メモリとを有し、前記電源投入時毎にこの揮発性メモリに記憶した前記基準信号値に対応するｓｉｎ信号とｃｏｓ信号を創出し、この創出したｓｉｎ信号とｃｏｓ信号によりｔａｎ信号を算出し、このｔａｎ信号により前記第１の回転体の回転角度を検出することを特徴とする舵角センサであり、この構成により、自動車の電源投入時毎における検出手段から出力される信号値の変化の影響を抑えることができ、自動車のハンドルの回転角度を正しく検出することが可能になるという効果を有する。
【０００７】
本発明の請求項２に記載の発明は、特に、自動車の走行中における温度変化で発生するｓｉｎ信号およびｃｏｓ信号の基準信号値の変化に対して、この変化後のｓｉｎ信号およびｃｏｓ信号の基準信号値を算出し、揮発性メモリに記憶されている各々の基準信号値を更新する請求項１記載の舵角センサであり、この構成により、短時間の温度変化による検出手段から出力される信号値の変化の影響を抑えることができ、自動車のハンドルの回転角度を正しく検出することが可能になるという効果を有する。
【０００８】
本発明の請求項３に記載の発明は、特に、自動車の時間経過、または使用環境による温度変化で発生するｓｉｎ信号およびｃｏｓ信号の基準信号値の変化に対して、この変化後のｓｉｎ信号およびｃｏｓ信号の基準信号値を算出し、不揮発性メモリに記憶されている各々の基準信号値を更新する請求項１記載の舵角センサであり、この構成により、長時間の温度変化による検出手段から出力される信号値の変化の影響を抑えることができ、自動車のハンドルの回転角度を、正しく検出することが可能になるという効果を有する。
【０００９】
【発明の実施の形態】
（実施の形態１）
以下本発明の実施の形態を用いて、図面を参照しながら説明する。本発明の実施の形態１における舵角センサを示す構成図を図１に、図１における第２の回転体と磁気検出手段の斜視図を図２に示す。
【００１０】
図１において、自動車のハンドルの軸の外周に接し、固定されるように第１の回転体１が配置され、この第１の回転体１の外周にある歯２と、第２の回転体３の外周にある歯４が係合する構成になっている。よって、自動車のハンドルが回転すると第１の回転体１が回転し、さらに第２の回転体３も回転する。このときの第１の回転体１の歯の歯数をａ、第２の回転体３の歯の歯数をｂとすると、第２の回転体３は第１の回転体１に対してａ／ｂ倍の速さで回転する。すなわち、第１の回転体１が１回転すると第２の回転体３はａ／ｂ回転する。例えば、歯数比ａ：ｂを３：１とすると、第１の回転体１が１回転した場合、第２の回転体３は３回転する。すなわち第１の回転体１が６０ｄｅｇ回転すると、第２の回転体３は１８０ｄｅｇ回転する。
【００１１】
さらに、この第２の回転体３には磁石５が組み込まれており、この磁石５の上方もしくは下方に異方性磁気検出素子を含む検出手段６が配置されている。検出手段６からは増幅器を介して演算手段（例えば、マイクロコンピュータ）７が接続されており、さらに演算手段７には揮発性メモリ（例えば、ＲＡＭ）８が内蔵されている。また、演算手段７からは不揮発性メモリ（例えば、ＥＥＰＲＯＭ）９が接続されている。
【００１２】
次に、第２の回転体３に固定されている磁石５の回転を検出する検出手段６からの絶対角度算出方法について説明する。検出手段から出力される信号値を示す特性図をそれぞれ図３〜５に、検出手段から出力される信号値と角度換算値を示す特性図を図６に示す。図１の装置において、第２の回転体３の回転に伴い磁石５も回転するので、この磁石５の回転とともに磁界方向も回転し、この磁界方向を検出手段６で検出する。検出手段６からは前記磁界方向の回転角に対してｓｉｎ信号２１とｃｏｓ信号２２を出力する。これらの出力信号値は演算手段７に入力されるが、図３に示すように、通常時は、ｓｉｎ信号２１とｃｏｓ信号２２の（最大値＋最小値）／２で算出される基準信号値２４，２５が等しいので、ｓｉｎ信号２１とｃｏｓ信号２２の除算によりｔａｎ信号２３を算出することができ、このｔａｎ信号２３により絶対回転角度が精度良く検出される。
【００１３】
しかし図４に示すように、検出手段６の特性変化等でｓｉｎ信号２１の基準信号値２４とｃｏｓ信号２２の基準信号値２５とが等しくなくなり、これらの間に差が発生した場合、この差を補正せずにｔａｎ信号２３を算出しようとすると絶対回転角度を正確に検出することができない。そこで基準信号値２４，２５の変化時に、通信ラインを通してこれらの基準信号値２４，２５を算出するモードにするコードを演算手段７に送信し、第２の回転体３を１回転以上回転させることによりｓｉｎ信号２１およびｃｏｓ信号２２の最大値、最小値を検出し、さらにそれぞれの（最大値＋最小値）／２で算出した値を各々の基準信号値２４，２５として不揮発性メモリ９に記憶し、その後通信ラインを通して、この基準信号値２４，２５のずれ量を算出するモードから通常モードにするコードを演算手段７に送信する。そして自動車の電源投入時毎に不揮発性メモリ９に記憶されている基準信号値２４，２５を呼び出し、これらを演算手段７に内蔵される揮発性メモリ８に記憶し、これらの基準信号値２４，２５に対応するｓｉｎ信号２１、ｃｏｓ信号２２に補正してからｔａｎ信号２３を算出することによって、第１の回転体１の絶対回転角度を検出する。
【００１４】
一方、時間の経過や温度変化によって、基準信号値２４，２５は変化していく。図５に示すように、例えば温度が２５℃から８５℃に変化したとき、ｓｉｎ信号２１は２６、ｃｏｓ信号２２は２７に変化し、これに伴い基準信号値はそれぞれ２８，２９に変化する。このため不揮発性メモリ９に記憶されている基準信号値２４，２５を書き換える必要がある。これらを書き換えるため、第２の回転体３を１回転以上回転させることにより、この回転により発信されるｓｉｎ信号２１、ｃｏｓ信号２２の各々の最大値、最小値を確定する。例えば図６に示すように、ｓｉｎ信号２１およびｃｏｓ信号２２の変化に対応して変動する角度変換値３０の、第１の範囲でｓｉｎ信号２１の最大値取得、第２の範囲でｃｏｓ信号２２の最小値取得、第３の範囲でｓｉｎ信号２１の最小値取得、第４の範囲でｃｏｓ信号２２の最大値取得を行う。これらによってｓｉｎ信号２１、ｃｏｓ信号２２の最大値、最小値を確定し、ここから（最大値＋最小値）／２を求めることにより補正後の各々の基準信号値２４ａ，２５ａを算出し、不揮発性メモリ９に記憶されている基準信号値をそれぞれ書き換える。
【００１５】
ここで、自動車の走行等の短時間の温度変化の場合、この温度変化後の基準信号値２４ａ，２５ａを算出後、揮発性メモリ８に記憶されている基準信号値２４，２５を、それぞれ２４ａ，２５ａに更新するように書き換え、この書き換えられた基準信号値２４ａ，２５ａに対応するｓｉｎ信号２１、ｃｏｓ信号２２に補正してからｔａｎ信号２３を算出することによって、第１の回転体１の回転角度を検出する。
【００１６】
一方、自動車の経時および使用環境等による長時間の温度変化の場合、この温度変化後の基準信号値２４ａ，２５ａを算出後、不揮発性メモリ９に記憶されている基準信号値２４，２５を、それぞれ２４ａ，２５ａに更新するように書き換え、この書き換えられた基準信号値２４ａ，２５ａに対応するｓｉｎ信号２１、ｃｏｓ信号２２に補正してからｔａｎ信号２３を算出することによって、第１の回転体１の回転角度を検出する。
【００１７】
以上のように、本実施の形態によれば、時間の経過または温度変化等により変化した基準信号値を現在の設定値に更新することにより、第１の回転体１の回転角度を検出することができるので、検出手段から出力される信号値の変化の影響を抑えることができ、自動車のハンドルの回転角度を正しく検出することができるようになった。
【００１８】
【発明の効果】
以上のように、本発明によれば、経時および温度変化による影響を受けることなく、回転体の絶対回転角度を精度良く検出することができる舵角センサを実現でき、その結果自動車のハンドルの回転を正確に車体に伝達することができるという効果が得られる。
【図面の簡単な説明】
【図１】本発明の一実施の形態における舵角センサの構成図
【図２】同実施の形態における第２の回転体と検出手段の拡大斜視図
【図３】同実施の形態における第２の回転体の回転角と検出手段の出力信号を示す特性図
【図４】同実施の形態における第２の回転体の回転角と検出手段の出力信号を示す特性図
【図５】同実施の形態における第２の回転体の回転角と検出手段の出力信号を示す特性図
【図６】同実施の形態における第２の回転体の回転角と検出手段の出力信号と角度換算値を示す特性図
【図７】（ａ）（ｂ）はそれぞれ従来の例を示す平面図、斜視図
【図８】従来の例を示す特性図
【符号の説明】
１　第１の回転体
２　第１の回転体の歯
３　第２の回転体
４　第２の回転体の歯
５　磁石
６　検出手段
７　演算手段
８　揮発性メモリ
９　不揮発性メモリ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a steering angle sensor used for a vehicle body control system of an automobile and the like.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a steering angle sensor that detects a rotation angle of a rotating body that rotates finitely more than one rotation such as a steering wheel for an automobile, a steering angle sensor described in Japanese Patent Application Laid-Open No. 11-500828 is known. . Hereinafter, the configuration of a conventional steering angle sensor will be described. FIG. 7A is a plan view of a conventional rotation angle detecting device, FIG. 7B is a perspective view, and FIG. 8 is a characteristic diagram showing an output signal of the steering angle sensor.
[0003]
7A and 7B, a gear 32 is provided on the outer periphery of a shaft 31, and gears 33 and 34 are provided so as to be in contact with the gear 32. Further, magnets 35 and 36 are attached to the gears 33 and 34, respectively. In this configuration, the rotation of the shaft 31 causes the gears 32, 33, and 34 to rotate, and the magnets 35 and 36 rotate with this rotation, so that the direction of the magnetic field also rotates. Then, a sin signal 41 and a cos signal 42 are output by the detecting means for the rotation angle in the direction of the magnetic field, and the rotation angle of the shaft 31 is detected based on the output signal.
[0004]
[Problems to be solved by the invention]
In the above configuration, the characteristics of the detecting means in the steering angle sensor also change due to a change in temperature or the like. For example, when the temperature changes from 25 ° C. to 85 ° C., as shown in FIG. , Cos signal 42 changes to 44, respectively. Accordingly, the reference signal value 45 changes to 46, and the signal value output from the detecting means also changes. Further, in this device, since the changed signal value cannot be corrected, the rotation angle of the shaft 31 cannot be correctly detected, and as a result, the rotation of the steering wheel of the automobile can be accurately transmitted to the vehicle body. There was a possibility that it would not be possible.
[0005]
Therefore, the present invention is to solve the above-mentioned problem, and provides a steering angle sensor that can obtain a predetermined output signal of a detection unit by a sensor alone and can always correctly detect a rotation angle of a steering wheel of an automobile. It is intended to do so.
[0006]
[Means for Solving the Problems]
In order to achieve this object, the invention according to claim 1 of the present invention provides, in particular, a first rotating body having teeth, a gear engaged with the teeth of the first rotating body, A second rotator having a magnet provided on the gear, a detecting means for detecting a rotation angle of the second rotator, and a sine signal and a cos signal transmitted by rotation of the magnet. A nonvolatile memory having a function of storing each of the reference signal values, and a volatile memory having a function of recalling and storing the reference signal value stored in the nonvolatile memory each time the power is turned on. Then, each time the power is turned on, a sine signal and a cos signal corresponding to the reference signal value stored in the volatile memory are created, and a tan signal is calculated based on the created sine signal and the cos signal. The first time A steering angle sensor characterized by detecting a rotation angle of a body. With this configuration, it is possible to suppress an influence of a change in a signal value output from a detection unit each time the vehicle is powered on, and to reduce a steering wheel of the vehicle. There is an effect that it becomes possible to correctly detect the rotation angle of.
[0007]
The invention according to claim 2 of the present invention is particularly applicable to a change in the reference signal values of the sin signal and the cos signal caused by a temperature change during the running of the automobile, and the reference of the sin signal and the cos signal after the change. 2. The steering angle sensor according to claim 1, wherein the signal value is calculated, and each of the reference signal values stored in the volatile memory is updated. The effect of changing the value can be suppressed, and the rotation angle of the steering wheel of the automobile can be correctly detected.
[0008]
The invention according to claim 3 of the present invention is particularly suitable for a change in the reference signal value of the sin signal and the reference signal value of the cos signal caused by a change in temperature due to the passage of time of the automobile or a use environment. 2. The steering angle sensor according to claim 1, wherein a reference signal value of the cos signal is calculated, and each of the reference signal values stored in the nonvolatile memory is updated. The effect of the change in the output signal value can be suppressed, and the rotation angle of the steering wheel of the automobile can be correctly detected.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
(Embodiment 1)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing a steering angle sensor according to Embodiment 1 of the present invention, and FIG. 2 is a perspective view of a second rotating body and a magnetic detection unit in FIG.
[0010]
In FIG. 1, a first rotating body 1 is disposed so as to be in contact with and fixed to an outer periphery of a shaft of a steering wheel of an automobile, and a tooth 2 on an outer periphery of the first rotating body 1 and a second rotating body 3 Are configured to engage with the teeth 4 on the outer periphery of the outer ring. Therefore, when the steering wheel of the automobile rotates, the first rotating body 1 rotates, and the second rotating body 3 also rotates. Assuming that the number of teeth of the first rotating body 1 at this time is a and the number of teeth of the second rotating body 3 is b, the second rotating body 3 is a with respect to the first rotating body 1. / B times faster. That is, when the first rotating body 1 makes one rotation, the second rotating body 3 rotates a / b. For example, if the gear ratio a: b is 3: 1 and the first rotating body 1 makes one rotation, the second rotating body 3 makes three rotations. That is, when the first rotating body 1 rotates 60 degrees, the second rotating body 3 rotates 180 degrees.
[0011]
Further, a magnet 5 is incorporated in the second rotating body 3, and a detecting means 6 including an anisotropic magnetic detecting element is disposed above or below the magnet 5. The detecting means 6 is connected to a calculating means (for example, a microcomputer) 7 via an amplifier, and the calculating means 7 has a built-in volatile memory (for example, RAM) 8. Further, a non-volatile memory (for example, an EEPROM) 9 is connected to the arithmetic unit 7.
[0012]
Next, a method of calculating an absolute angle from the detecting means 6 for detecting the rotation of the magnet 5 fixed to the second rotating body 3 will be described. 3 to 5 are characteristic diagrams showing signal values output from the detecting means, and FIG. 6 is a characteristic diagram showing signal values output from the detecting means and angle conversion values. In the apparatus shown in FIG. 1, since the magnet 5 also rotates with the rotation of the second rotating body 3, the direction of the magnetic field also rotates with the rotation of the magnet 5, and the direction of the magnetic field is detected by the detecting unit 6. The detection means 6 outputs a sin signal 21 and a cos signal 22 for the rotation angle in the magnetic field direction. These output signal values are input to the calculating means 7, but as shown in FIG. 3, in normal times, the reference signal value calculated by (maximum value + minimum value) / 2 of the sin signal 21 and the cos signal 22 Since 24 and 25 are equal, the tan signal 23 can be calculated by dividing the sin signal 21 and the cos signal 22, and the absolute rotation angle can be accurately detected by the tan signal 23.
[0013]
However, as shown in FIG. 4, when the reference signal value 24 of the sine signal 21 and the reference signal value 25 of the cos signal 22 become unequal due to a change in the characteristics of the detection means 6 and the like, and a difference occurs between them, If it is attempted to calculate the tan signal 23 without correcting the absolute rotation angle, the absolute rotation angle cannot be accurately detected. Therefore, when the reference signal values 24 and 25 change, a code for setting the mode for calculating these reference signal values 24 and 25 is transmitted to the arithmetic means 7 through the communication line, and the second rotating body 3 is rotated by one or more rotations. , The maximum value and the minimum value of the sin signal 21 and the cos signal 22 are detected, and the values calculated by (maximum value + minimum value) / 2 are stored as the respective reference signal values 24 and 25 in the nonvolatile memory 9. After that, a code for changing the mode of calculating the shift amount of the reference signal values 24 and 25 from the normal mode to the normal mode is transmitted to the arithmetic unit 7 through the communication line. Each time the vehicle is powered on, the reference signal values 24 and 25 stored in the non-volatile memory 9 are called out, and these are stored in the volatile memory 8 built in the calculating means 7. The absolute rotation angle of the first rotator 1 is detected by calculating the tan signal 23 after correcting the sin signal 21 and the cos signal 22 corresponding to 25.
[0014]
On the other hand, the reference signal values 24 and 25 change with the passage of time and a change in temperature. As shown in FIG. 5, for example, when the temperature changes from 25 ° C. to 85 ° C., the sin signal 21 changes to 26 and the cos signal 22 changes to 27, and the reference signal value changes to 28 and 29 accordingly. Therefore, it is necessary to rewrite the reference signal values 24 and 25 stored in the nonvolatile memory 9. In order to rewrite these, the second rotator 3 is rotated by one or more rotations, thereby determining the maximum value and the minimum value of the sin signal 21 and the cos signal 22 transmitted by this rotation. For example, as shown in FIG. 6, the maximum value of the sin signal 21 is obtained in the first range and the cos signal 22 is obtained in the second range of the angle conversion value 30 that fluctuates in response to changes in the sin signal 21 and the cos signal 22. , The minimum value of the sin signal 21 in the third range, and the maximum value of the cos signal 22 in the fourth range. From these, the maximum value and the minimum value of the sin signal 21 and the cos signal 22 are determined, and (maximum value + minimum value) / 2 is calculated therefrom to calculate the corrected reference signal values 24a and 25a. The reference signal values stored in the memory 9 are rewritten.
[0015]
Here, in the case of a short-term temperature change such as a running of an automobile, after calculating the reference signal values 24a and 25a after the temperature change, the reference signal values 24 and 25 stored in the volatile memory 8 are respectively converted to 24a. , 25a, and the tan signal 23 is calculated after correcting the sine signal 21 and the cos signal 22 corresponding to the rewritten reference signal values 24a, 25a. Detect the rotation angle.
[0016]
On the other hand, in the case of a long-term temperature change due to the aging of the automobile and the use environment, etc., after calculating the reference signal values 24a and 25a after the temperature change, the reference signal values 24 and 25 stored in the non-volatile memory 9 are used. The first rotator is rewritten so as to be updated to 24a and 25a, respectively, and corrected to the sine signal 21 and the cos signal 22 corresponding to the rewritten reference signal values 24a and 25a, and then calculating the tan signal 23. 1 is detected.
[0017]
As described above, according to the present embodiment, the rotation angle of the first rotating body 1 is detected by updating the reference signal value changed due to the passage of time or a temperature change to the current set value. Therefore, the influence of the change in the signal value output from the detection means can be suppressed, and the rotation angle of the steering wheel of the automobile can be correctly detected.
[0018]
【The invention's effect】
As described above, according to the present invention, it is possible to realize a steering angle sensor that can accurately detect the absolute rotation angle of a rotating body without being affected by aging and temperature changes, and as a result, the rotation of a steering wheel of an automobile can be realized. Can be accurately transmitted to the vehicle body.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a steering angle sensor according to an embodiment of the present invention; FIG. 2 is an enlarged perspective view of a second rotating body and a detecting unit according to the embodiment; FIG. FIG. 4 is a characteristic diagram showing the rotation angle of the rotating body and the output signal of the detection means. FIG. 4 is a characteristic chart showing the rotation angle of the second rotating body and the output signal of the detection means in the embodiment. FIG. 6 is a characteristic diagram showing a rotation angle of a second rotator and an output signal of a detection unit in the embodiment. FIG. 6 is a graph showing a rotation angle of the second rotator, an output signal of the detection unit, and an angle conversion value in the embodiment. FIGS. 7 (a) and 7 (b) are a plan view and a perspective view, respectively, showing a conventional example. FIG. 8 is a characteristic diagram showing a conventional example.
DESCRIPTION OF SYMBOLS 1 1st rotating body 2 1st rotating body tooth 3 2nd rotating body 4 2nd rotating body tooth 5 Magnet 6 Detecting means 7 Calculation means 8 Volatile memory 9 Nonvolatile memory

Claims (3)

歯を備えた第１の回転体と、この第１の回転体の歯に係合される歯車、およびこの歯車に設けた磁石とを備えた第２の回転体と、この第２の回転体の回転角度を検出する検出手段と、前記磁石の回転により発信されるｓｉｎ信号およびｃｏｓ信号から算出される各々の基準信号値を記憶する機能を備えた不揮発性メモリと、電源投入時毎にこの不揮発性メモリに記憶された前記基準信号値を呼び出して記憶する機能を備えた揮発性メモリとを有し、前記電源投入時毎にこの揮発性メモリに記憶した前記基準信号値に対応するｓｉｎ信号とｃｏｓ信号を創出し、このｓｉｎ信号とｃｏｓ信号によりｔａｎ信号を算出し、このｔａｎ信号により前記第１の回転体の回転角度を検出することを特徴とする舵角センサ。A second rotating body including a first rotating body having teeth, a gear engaged with the teeth of the first rotating body, and a magnet provided on the gear, and the second rotating body. A non-volatile memory having a function of storing respective reference signal values calculated from a sin signal and a cos signal transmitted by the rotation of the magnet, A volatile memory having a function of retrieving and storing the reference signal value stored in the nonvolatile memory, and a sin signal corresponding to the reference signal value stored in the volatile memory every time the power is turned on. And a cos signal, a tan signal is calculated from the sin signal and the cos signal, and a rotation angle of the first rotating body is detected from the tan signal. 自動車の走行中における温度変化で発生するｓｉｎ信号およびｃｏｓ信号の基準信号値の変化に対して、この変化後のｓｉｎ信号およびｃｏｓ信号の基準信号値を算出し、揮発性メモリに記憶されている各々の基準信号を更新する請求項１記載の舵角センサ。With respect to a change in the reference signal value of the sin signal and the reference signal value of the cos signal generated by the temperature change during the running of the automobile, the reference signal value of the sin signal and the cos signal after the change is calculated and stored in the volatile memory. The steering angle sensor according to claim 1, wherein each reference signal is updated. 自動車の時間経過、または使用環境による温度変化で発生するｓｉｎ信号およびｃｏｓ信号の基準信号値の変化に対して、この変化後のｓｉｎ信号およびｃｏｓ信号の基準信号値を算出し、不揮発性メモリに記憶されている各々の基準信号値を更新する請求項１記載の舵角センサ。With respect to the change in the reference signal values of the sin signal and the cos signal generated due to the time change of the vehicle due to the passage of time or the use environment, the reference signal values of the sin signal and the cos signal after the change are calculated and stored in the nonvolatile memory. The steering angle sensor according to claim 1, wherein each stored reference signal value is updated.
JP2002212101A 2002-07-22 2002-07-22 Steering angle sensor Pending JP2004053444A (en)

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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006080325A1 (en) 2005-01-25 2006-08-03 The Furukawa Electric Co., Ltd. Rotation sensor
WO2008050843A1 (en) 2006-10-25 2008-05-02 The Furukawa Electric Co., Ltd. Rotation angle detecting device
WO2008056792A1 (en) 2006-11-10 2008-05-15 The Furukawa Electric Co., Ltd. Rotation angle determining apparatus
WO2008056793A1 (en) 2006-11-10 2008-05-15 The Furukawa Electric Co., Ltd. Rotation angle determining apparatus
US7420363B2 (en) 2006-05-16 2008-09-02 Denso Corporation Rotation angle detection apparatus enabling measurement of degree of rotation of a shaft that exceeds 360°
JP2011053501A (en) * 2009-09-03 2011-03-17 Hitachi Metals Ltd Lens drive device
JP2013501486A (en) * 2009-07-31 2013-01-10 ローベルト ボツシユ ゲゼルシヤフト ミツト ベシユレンクテル ハフツング Electric drive device with commutator and control method of electric motor with commutator
JP2016151576A (en) * 2015-02-16 2016-08-22 ローベルト ボツシユ ゲゼルシヤフト ミツト ベシユレンクテル ハフツングＲｏｂｅｒｔ Ｂｏｓｃｈ Ｇｍｂｈ Sensor device for detecting rotation angle of rotation module in vehicle

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006080325A1 (en) 2005-01-25 2006-08-03 The Furukawa Electric Co., Ltd. Rotation sensor
US7420363B2 (en) 2006-05-16 2008-09-02 Denso Corporation Rotation angle detection apparatus enabling measurement of degree of rotation of a shaft that exceeds 360°
DE102007022196B4 (en) 2006-05-16 2018-10-31 Denso Corporation A rotation angle detecting device which enables measurement of degrees of rotation of a shaft exceeding 360 °
WO2008050843A1 (en) 2006-10-25 2008-05-02 The Furukawa Electric Co., Ltd. Rotation angle detecting device
WO2008056792A1 (en) 2006-11-10 2008-05-15 The Furukawa Electric Co., Ltd. Rotation angle determining apparatus
WO2008056793A1 (en) 2006-11-10 2008-05-15 The Furukawa Electric Co., Ltd. Rotation angle determining apparatus
JP2013501486A (en) * 2009-07-31 2013-01-10 ローベルト ボツシユ ゲゼルシヤフト ミツト ベシユレンクテル ハフツング Electric drive device with commutator and control method of electric motor with commutator
JP2011053501A (en) * 2009-09-03 2011-03-17 Hitachi Metals Ltd Lens drive device
JP2016151576A (en) * 2015-02-16 2016-08-22 ローベルト ボツシユ ゲゼルシヤフト ミツト ベシユレンクテル ハフツングＲｏｂｅｒｔ Ｂｏｓｃｈ Ｇｍｂｈ Sensor device for detecting rotation angle of rotation module in vehicle

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