JPH01305363A - Optical interference type angular velocity meter - Google Patents
Optical interference type angular velocity meterInfo
- Publication number
- JPH01305363A JPH01305363A JP63137781A JP13778188A JPH01305363A JP H01305363 A JPH01305363 A JP H01305363A JP 63137781 A JP63137781 A JP 63137781A JP 13778188 A JP13778188 A JP 13778188A JP H01305363 A JPH01305363 A JP H01305363A
- Authority
- JP
- Japan
- Prior art keywords
- detection means
- output
- synchronous detection
- phase
- signal
- 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.)
- Granted
Links
- 230000003287 optical effect Effects 0.000 title claims abstract description 41
- 238000001514 detection method Methods 0.000 claims abstract description 93
- 230000001360 synchronised effect Effects 0.000 claims abstract description 78
- 230000000644 propagated effect Effects 0.000 claims abstract 2
- 238000006243 chemical reaction Methods 0.000 claims description 6
- 230000002452 interceptive effect Effects 0.000 claims 1
- 239000012071 phase Substances 0.000 description 65
- 230000002441 reversible effect Effects 0.000 description 15
- 238000010586 diagram Methods 0.000 description 5
- 230000007613 environmental effect Effects 0.000 description 4
- 238000005259 measurement Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 239000008384 inner phase Substances 0.000 description 2
- 239000013307 optical fiber Substances 0.000 description 2
- 230000001902 propagating effect Effects 0.000 description 2
- RSWGJHLUYNHPMX-UHFFFAOYSA-N Abietic-Saeure Natural products C12CCC(C(C)C)=CC2=CCC2C1(C)CCCC2(C)C(O)=O RSWGJHLUYNHPMX-UHFFFAOYSA-N 0.000 description 1
- KHPCPRHQVVSZAH-HUOMCSJISA-N Rosin Natural products O(C/C=C/c1ccccc1)[C@H]1[C@H](O)[C@@H](O)[C@@H](O)[C@@H](CO)O1 KHPCPRHQVVSZAH-HUOMCSJISA-N 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- KHPCPRHQVVSZAH-UHFFFAOYSA-N trans-cinnamyl beta-D-glucopyranoside Natural products OC1C(O)C(O)C(CO)OC1OCC=CC1=CC=CC=C1 KHPCPRHQVVSZAH-UHFFFAOYSA-N 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
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Abstract
Description
【発明の詳細な説明】
「産業上の利用分野」
この発明は少なくとも一周する光学路の両端に右回り光
と左回り光とを通し、その光学路を通った右回り光、左
回り光を干渉させ、その干渉光から光学路に入力された
角速度を計測する光干渉角速度計に関する。Detailed Description of the Invention "Industrial Application Field" This invention passes clockwise light and counterclockwise light to both ends of an optical path that goes around at least once, and the clockwise light and counterclockwise light that have passed through the optical path. The present invention relates to an optical interference angular velocity meter that measures the angular velocity input to an optical path from the interference light.
「従来の技術」
第４図に従来の光干渉角速度計を示す。光ａ１１からの
出射光１８は光分配結合器１２、偏光子１３、光分配結
合器１４を順次径て少なくとも１周する光学路１６に反
対方向に伝搬する光１９．２０として分岐される。光分
配結合器１４と光学路１６の一端との間に継続的に位相
変調器１５が配される０発振器２７の出力が位相変調器
駆動回路２日を通して位相変調器１５へ供給され、光１
９．２０の位相が変調される。光学路１６を伝搬してき
た光１９．２０が光分配結合器１２で干渉され、その干
渉光２１が受光器１７へ供給される。この場合の干渉光
２１の強度■。は（１）式となる。"Prior Art" Figure 4 shows a conventional optical interference gyrometer. The emitted light 18 from the light a11 is branched as light 19.20 which propagates in the opposite direction to an optical path 16 that makes at least one circuit around the optical distribution coupler 12, the polarizer 13, and the optical distribution coupler 14 in this order. A phase modulator 15 is continuously disposed between the optical distribution coupler 14 and one end of the optical path 16. The output of the 0 oscillator 27 is supplied to the phase modulator 15 throughout the phase modulator drive circuit 2, and the optical
9.20 phase is modulated. Light beams 19 and 20 propagating through the optical path 16 are interfered by the optical splitting coupler 12, and the interference light beam 21 is supplied to the light receiver 17. The intensity ■ of the interference light 21 in this case. is the formula (1).
１ｏ −Ｃ（１＋ｃｏｓΔφ（Ｊｅ（ｘ）＋２Σ（１）
Ｊｚａ（ｘ）・ｃｏｓ２ｎ（ωｔ＋θ））０り
−ｓｉｎΔφ（２Σ（−１）’ −Ｊ 、、、、（ｘ）
・ｃｏｓ（２ｎ＋ １ ）（ａ＋ ｔ＋θ） １ ）
・（１）Ｃ：定数
ｘ ： ２ Ａｓ１ｎ１ｃｆ ｓｒ
Ａ：光位相変調の振幅
τ：光学路１６を通る光の伝搬時間
ω：位相変調器１５の駆動周波数
（ω−２π「、）
Δφ：光学路１６を互に逆方向に伝搬した両光間４πＲ
Ｌ
Ｒ；光学路１６の半径
Ｌ：ループ状に構成された光学路１６の長さＣ：光速
λ：光の波長
Ω：ルーブ状に構成された光学路１６の円周方向に印加
された角速度
６８位相変調器１５に印加される駆動電圧■□＝Ａｓｔ
ｎωｔとの位相差
（１）式から明らかなように干渉光２１の強度■。には
ｃｏｓΔ、φに比例する項とｓｉｎΔφに比例する項と
が含まれている。特開昭６２−９２１４号公報に示され
ているように、Δφが±ｍπ（ｍ＝０．１．２゜・・・
）に対し約±π／４の範囲で高感度化するため、受光器
１７の出力の内ｓｉｎΔφに比例する成分が同期検波回
路２２により取出される。この時同期検波回路２２にお
ける参照信号■１１．を・・・（２）
θ、二位相変調器１５に印加される駆動電圧Ｖｐ、＝Ａ
ｓｉｎωｔとの位相差
とすると、同期検波回路２２の出力Ｖ ＋ｉはＶ ３．
＝ Ｋ＋ Ｊ ＋（ｘ）ｓｉｎΔφＣ０８（θ−θｒ＞
・（３）Ｋ、：定数
となる。更にΔφが士（２ｍ＋１）・−（ｍ−０，１，
２，・・・）に対し約±π／４の範囲で高感度化するた
め受光器１７の出力の内ｃｏｓΔφに比例する成分が同
期検波回路２３により取出される。1o −C(1+cosΔφ(Je(x)+2Σ(1)
Jza(x)・cos2n(ωt+θ))0ri−sinΔφ(2Σ(−1)′ −J , ,,,(x)
・cos(2n+1)(a+t+θ)1)
・(1) C: Constant x: 2 As1n1cf sr A: Amplitude of optical phase modulation τ: Propagation time of light passing through optical path 16 ω: Driving frequency of phase modulator 15 (ω-2π'',) Δφ: Optical path 4πR between both lights propagating in opposite directions through 16
L R: Radius of the optical path 16 L: Length of the optical path 16 configured in a loop shape C: Speed of light λ: Wavelength of light Ω: Angular velocity applied in the circumferential direction of the optical path 16 configured in a loop shape 68 Drive voltage applied to phase modulator 15 = Ast
Phase difference with nωt As is clear from equation (1), the intensity of the interference light 21 is ■. includes a term proportional to cosΔ, φ and a term proportional to sin Δφ. As shown in Japanese Patent Application Laid-Open No. 62-9214, Δφ is ±mπ (m=0.1.2°...
), a component proportional to sin Δφ of the output of the light receiver 17 is extracted by the synchronous detection circuit 22. At this time, the reference signal in the synchronous detection circuit 22 ■11. (2) θ, drive voltage Vp applied to the two-phase modulator 15, = A
Assuming the phase difference with sinωt, the output V +i of the synchronous detection circuit 22 is V3.
= K+ J + (x) sinΔφC08(θ−θr>
・(3) K: Becomes a constant. Furthermore, Δφ is (2m+1)・−(m−0,1,
2, . . .), a component proportional to cosΔφ is extracted by the synchronous detection circuit 23 out of the output of the photodetector 17.
この時、同期検波回路２３における参照信号ｖ、２１と
すると、同期検波回路２３の出力Ｖ−はＶｔｍ＝ａＫ２
Ｊ ｚ（ｘ）ｃｏｓΔφｃｏｓ２ （θ−θｒ） ”
・（５）Ｋ２：定数
となる。同期検波回路２２．２３の各出力は低域通過ろ
波器２４，２５をそれぞれ通じて出力■１．。At this time, if the reference signal v in the synchronous detection circuit 23 is 21, the output V- of the synchronous detection circuit 23 is Vtm=aK2
J z(x)cosΔφcos2 (θ−θr)”
・(5) K2: Becomes a constant. Each output of the synchronous detection circuits 22 and 23 passes through the low-pass filters 24 and 25, respectively, and outputs ■1. .
Ｖｉｍが得られ、端子２９．３０へそれぞれ出力される
。発振器２７の出力は参照信号Ｖ 、、ｅｍとして同期
検波回路２３へ供給されると共に、ロジンク回路２６を
通じて参照信号Ｖ ｒ ＋ ａとして同期検波回路２２
へ供給される。Vim is obtained and output to terminals 29 and 30, respectively. The output of the oscillator 27 is supplied to the synchronous detection circuit 23 as a reference signal V , , em, and is also supplied to the synchronous detection circuit 22 as a reference signal V r + a through a rosin circuit 26 .
supplied to
ここで光干渉角速廣計のダイナミックレンジを拡大する
ために±ｍπ（ｍ＝０、１，２．・・・）に対し±π／
４の範囲では同期検波出力■−を出力π
■。とじて取出すと共に、±（２ｍ＋１）−（ｍ−０，
１，２，・・・）に対し±π／４の範囲では同期検波出
力ＶＺｍを出力■。として取出し、同期検波出力■、と
Ｖｔｍとの切替え回数ｍを係数することによって角速度
情報Ω、を（６）式より求める。Here, in order to expand the dynamic range of the optical interference angular velocity meter, ±π/
In the range of 4, the synchronous detection output ■- is output π ■. Close it and take it out, ±(2m+1)-(m-0,
1, 2, ...), the synchronous detection output VZm is output in the range of ±π/4. The angular velocity information Ω is obtained from equation (6) by taking out the synchronous detection output ■ and multiplying the number m of switching between Vtm and Vtm as a coefficient.
４πＲＬ ２
Ｋ （ｒａｄ／Ｖ） ：変換利得
すなわち第５図において端子２９には、ｓｉｎΔφに比
例する成分（第６口慣号７２）が入力され端子３０には
、ｃｏｓΔφに比例する成分（第６図における信号７３
）が入力される。ｓｉｎΔφに比例する信号とｃｏｓΔ
φに比例する信号は、スイッチ６１において可逆カウン
タ７０の２°の重み付けされた端子からのＤ出力によっ
て切替えられる。4πRL 2 K (rad/V): Conversion gain, that is, in FIG. Signal 73 in the figure
) is input. A signal proportional to sinΔφ and cosΔ
The signal proportional to φ is switched in switch 61 by the D output from the 2° weighted terminal of reversible counter 70.
スイッチ６１の出力は、スイッチ６２において可逆カウ
ンタ７０の２１の重み付けされた端子の出力Ｅによって
極性反転された後リニアライザ６４を通してジャイロ出
力端子６５に出力される。スイッチ６２の出力は、比較
器６６．６７の非反転入力側、反転入力側へそれぞれ供
給され、それぞれ基準電ｆＡ６８．６９の基準電圧＋Ｖ
、、−Ｖ。The output of the switch 61 is inverted in polarity by the output E of the 21 weighted terminals of the reversible counter 70 at the switch 62, and then outputted to the gyro output terminal 65 through the linearizer 64. The output of the switch 62 is supplied to the non-inverting input side and the inverting input side of the comparator 66.67, respectively, and the reference voltage +V of the reference voltage fA68.69 is respectively supplied.
,,-V.
と比較される。比較器６６．６７の出力は、それぞれ可
逆カウンタ７０のアップカウント端子ＵＰ、ダウンカウ
ント端子ＤＯＷＮへ供給されそれぞれア・ツブカウント
、ダウンカウントされる。可逆カウンタ７０の重みが２
°の出力端子の出力りは、スイッチ６１に切替え制御信
号として供給され、重みが２１の出力端子の出力Ｅは、
スイッチ６２に切替え制御信号として供給される。スイ
ッチ６１゜６２は、それぞれ初期状態（切替え制御信号
が論理゛０°゛）で端子ＮＣ側に切替えられ、切替え制
御信号が論理“ビでそれぞれ端子ＮＯ側に切替えられる
。可逆カウンタ７０の計数値は端子７１から取り出すこ
とができる。compared to The outputs of the comparators 66 and 67 are supplied to the up-count terminal UP and the down-count terminal DOWN of the reversible counter 70, respectively, and are counted up and down, respectively. The weight of the reversible counter 70 is 2
The output of the output terminal with a weight of 21 is supplied to the switch 61 as a switching control signal, and the output of the output terminal with a weight of 21 is
The signal is supplied to the switch 62 as a switching control signal. The switches 61 and 62 are respectively switched to the terminal NC side in the initial state (switching control signal is logic "0"), and are respectively switched to the terminal NO side when the switching control signal is logic "bi".The count value of the reversible counter 70 can be taken out from the terminal 71.
端子２９の出力は先に述べたようにｓｉｎΔφに比例し
第６図Ａの曲線７２に示すように右回り光と左回り光と
の位相差Δφに対しＳｉｎΔφで変化する。端子３０の
出力は、第６図Ａの曲線７３に示すように位相差Δφに
対しｃｏｓΔφに比例したものになる。位相差Δφが０
±π／４の範囲にあれば、スイッチ６１．６２は、第５
図に示した状態にあって端子２９よりのｓｉｎΔφに比
例した出力がリニナライザ６４によって直線補正された
後ジャイロ出力端子６５に出力される。比較器６６にお
いてその入力、つまりスイッチ６２の出力が基準電圧ｖ
Ｐを越えると第６図Ｂに示すようにパルスが発生する。As mentioned above, the output of the terminal 29 is proportional to sin Δφ, and changes by sin Δφ with respect to the phase difference Δφ between the clockwise light and the counterclockwise light, as shown by the curve 72 in FIG. 6A. The output of the terminal 30 is proportional to cos Δφ with respect to the phase difference Δφ, as shown by curve 73 in FIG. 6A. Phase difference Δφ is 0
If it is in the range of ±π/4, the switch 61.62
In the state shown in the figure, an output proportional to sin Δφ from the terminal 29 is linearly corrected by the linearizer 64 and then output to the gyro output terminal 65. In the comparator 66, its input, that is, the output of the switch 62, is the reference voltage v.
When P is exceeded, a pulse is generated as shown in FIG. 6B.
このパルスは、可逆カウンタ７０によって加算カウント
される。This pulse is added and counted by a reversible counter 70.
一方スイッチ６２の出力が一■、より負方向に大きくな
ると比較器６７より第６図Ｃに示すようなパルスが発生
し、これは可逆カウンタ７０で減算カウントされる。可
逆カウンタ７０の重みが２゜の出力は、第６図りに示す
ように変化し重みが２１の出力は、第６図Ｅに示すよう
に変化する。可逆カウンタ７０の重みが２°の出力が高
レベル（論理“１”）の時スイッチ６１が切替えられ、
端子３０の信号、即ちｃｏｓΔφに比例した出力が直線
補正されジャイロ出力端子６５に出力される。逆にスイ
ッチ６２の出力が基準電圧−■、より負方向に大きくな
ると比較器６７よりパルスが得られ、可逆カウンタ７０
が減算カウントされて、それにより重みが２°の出力が
高レベルとなり、スイッチ６１が作動して先の場合と同
様に端子３０の信号、即ちｃｏｓΔφに比例した出力が
直線補正された後ジャイロ出力端子６５に出力される。On the other hand, when the output of the switch 62 becomes larger in the negative direction, the comparator 67 generates a pulse as shown in FIG. 6C, which is counted by the reversible counter 70. The output of the reversible counter 70 with a weight of 2 degrees changes as shown in Figure 6, and the output with a weight of 21 changes as shown in Figure 6E. When the output of the reversible counter 70 with a weight of 2° is at a high level (logic "1"), the switch 61 is switched,
The signal at the terminal 30, ie, the output proportional to cosΔφ, is linearly corrected and output to the gyro output terminal 65. Conversely, when the output of the switch 62 becomes greater than the reference voltage -■ in the negative direction, a pulse is obtained from the comparator 67, and the reversible counter 70
is subtracted and counted, so that the output with a weight of 2° becomes a high level, the switch 61 is activated, and as in the previous case, the signal at the terminal 30, that is, the output proportional to cos Δφ, is linearly corrected and then becomes the gyro output. It is output to terminal 65.
以上の状態から更に位相差Δφが絶対量として増加し、
ｃｏｓΔφに比例した出力が基準電圧＋■１又は−■、
よりも絶対値で大きくなると比較器６６゜６７よりパル
スが得られて可逆カウンタ７０が加算あるいは減算しス
イッチ６１が復帰して端子２９の信号、即ちｓｉｎΔφ
に比例した出力が直線性補正後ジャイロ出力端子６５に
得られるようになる。From the above state, the phase difference Δφ further increases as an absolute amount,
The output proportional to cosΔφ is the reference voltage +■1 or -■,
When the absolute value becomes larger than , a pulse is obtained from the comparators 66 and 67, the reversible counter 70 adds or subtracts, and the switch 61 is reset to return the signal at the terminal 29, that is, sin Δφ.
An output proportional to is obtained at the gyro output terminal 65 after linearity correction.
これとともにｓｉｎΔφとＣＯＳΔφに比例する出力が
位相差Δφに対し正の特性となるように可逆カウンタ７
０の重みが２１の出力によって信号極性反転指令（切替
え制御信号）が出力され、スイッチ６２がインバークロ
３側に切替えられる。上述において位相差Δφがπ／４
におけるｓｉｎΔφとｃｏｓΔφに比例するスイッチ６
２の出力電圧が基準電圧＋Ｖ、、−Ｖ、より絶対値で僅
かに少な目に設定しておくと、第６図Ｇに示すように鋸
歯状の出力として得ることができかつｓｉｎΔφとｃｏ
ｓΔφに比例する信号の切替えにヒステリシスを持たせ
ることができ安定に動作させることができる。このよう
にして位相差Δφが±ｍπに対し約±π／４の範囲にあ
る場合は、ｓｊｎΔφ成分をジャイロ出力として取り出
され±（２ｍ＋１）・−に対し約±π／４の範囲にある
場合は、ｃｏｓΔφ成分がジャイロ出力として取り出さ
れ、全範囲にわたって直線性が最も好ましい状態で出力
が得られる。この出力より角速度は、（６）式で求める
ことができる。At the same time, the reversible counter 7
A signal polarity reversal command (switching control signal) is output by the output of 21 with a weight of 0, and the switch 62 is switched to the inverter black 3 side. In the above, the phase difference Δφ is π/4
Switch 6 proportional to sinΔφ and cosΔφ in
If the output voltage of 2 is set to be slightly smaller in absolute value than the reference voltages +V, -V, it is possible to obtain a sawtooth output as shown in Fig. 6G, and sin Δφ and co
It is possible to provide hysteresis to the switching of the signal proportional to sΔφ and to operate stably. In this way, if the phase difference Δφ is in the range of about ±π/4 with respect to ±mπ, the sjnΔφ component is extracted as the gyro output, and if it is in the range of about ±π/4 with respect to ±(2m+1)・- The cosΔφ component is extracted as a gyro output, and the output is obtained with the most preferable linearity over the entire range. From this output, the angular velocity can be determined using equation (6).
（６）式中の■。はジャイロ出力端子６５の電圧、ｍは
可逆カウンタ７０における加算パルスの総数と減算パル
スの総数の差つまり可逆カウンタ７０の計数値であって
、これは端子７１から取り出される。(6) ■ in the formula. is the voltage of the gyro output terminal 65, and m is the difference between the total number of addition pulses and the total number of subtraction pulses in the reversible counter 70, that is, the count value of the reversible counter 70, which is taken out from the terminal 71.
「発明が解決しようとする課題」
受光器１７によって光電変換信号の中からｓｉｎΔφ成
分及びｃｏｓΔφ成分を適切に取り出すためには同期検
波回路における被同期検波信号と参照信号とが実質的に
同相であることが必要である。"Problem to be Solved by the Invention" In order to appropriately extract the sin Δφ component and the cos Δφ component from the photoelectric conversion signal by the photoreceiver 17, the synchronously detected signal and the reference signal in the synchronous detection circuit must be substantially in phase. It is necessary.
ところが位相変調器１５に印加される駆動電圧を■、と
干渉光の基本周波数成分との位相差θ（高調波成分にお
ける位相差は（１）式で示されるように次数倍した値を
取る）は位相変調器１５がさらされる環境条件、特に温
度によって変わる。位相変調器１５は例えば円筒状の電
歪振動子に光ファイバを巻き付けて作製されているため
本質的に環境条件によって入出力特性における位相特性
が変化し易い。加えるに位相変調器１５の共振点に位相
変調器の動作点を設定すると環境条件に対し著しく変化
し易くなる。なお一般に位相変調器１５の動作点は共振
点に合せられる。このため同期検波回路２２．２３にお
ける被同期検波信号と参照信号との位相が同相でなくな
り、（３）式、（５）式から明らかなように出力Ｖｌｉ
と出力Ｖｉａのスケールファクタに変動を来たす。これ
はとりもなおさずジャイロ出力■。の変動を示すもので
あり、（６）式で明らかなように入力範囲の拡大を計っ
た光干渉角速度計における角速度計測に誤差が生じる。However, when the drive voltage applied to the phase modulator 15 is set to ■, the phase difference θ between the fundamental frequency component of the interference light (the phase difference in the harmonic component takes the value multiplied by the order as shown in equation (1)) varies depending on the environmental conditions to which phase modulator 15 is exposed, particularly temperature. Since the phase modulator 15 is manufactured by winding an optical fiber around a cylindrical electrostrictive vibrator, for example, the phase characteristics in the input/output characteristics are essentially likely to change depending on the environmental conditions. In addition, if the operating point of the phase modulator 15 is set at the resonance point of the phase modulator 15, the operating point of the phase modulator 15 is likely to change significantly depending on environmental conditions. Note that the operating point of the phase modulator 15 is generally aligned with the resonance point. Therefore, the phases of the synchronously detected signal and the reference signal in the synchronous detection circuits 22 and 23 are no longer in phase, and as is clear from equations (3) and (5), the output Vli
This causes a change in the scale factor of the output Via. This is the gyro output■. As is clear from equation (6), an error occurs in the angular velocity measurement in the optical interference gyrometer designed to expand the input range.
この発明の目的は位相変調器の入出力位相特性が変動し
ても同期検波回路における被同期検波信号と参照信号と
を同相に保ち入力範囲全域に渡ってジャイロスケールフ
ァクタを安定に保つ光干渉角速度計を提供することにあ
る。The purpose of this invention is to develop an optical interference angular velocity that keeps the synchronously detected signal and the reference signal in the synchronous detection circuit in phase and keeps the gyro scale factor stable over the entire input range even if the input/output phase characteristics of the phase modulator vary. The objective is to provide a measurement system.
［課題を解決するための手段」
この発明によれば光学通路から出力された右回り光と左
回り光とを干渉させ、その干渉光を光電変換手段で電気
信号に変換し、その電気信号の内位相変調手段の変調周
波数の任意の奇数波成分を第１同期検波手段で同期検波
し、上記電気信号の内位相変調手段の変調周波数の任意
の偶数波成分を第２同期検波手段で同期検波すると共に
、更に上記電気信号を、第１同期検波手段の参照信号に
対して９０°位相差をもった参照信号により第３同期検
波手段で同期検波し、また上記電気信号を、第２同期検
波手段の参照信号に対して９０°位を目差をもった参照
信号により第４同月検波手段で同期検波する。第１同期
検波手段の出力と第３同期検波手段の出力とによって第
１位相検知手段で、第１同期検波手段に印加される参照
信号と入力として印加される信号の内被同期検波成分と
の位相差情報を出力する。また第２同期検波手段の出力
と第４同期検波手段の出力とによって第２位相検知手段
で第２同期検波手段に印加される参照信号と入力として
印加される信号の内被同期検波成分との位相差情報を出
力する。第１位相検知手段の出力と第２位相検知手段の
出力とから第１同期検波手段と第２同期検波手段とにお
ける参照信号と被同期検波信号との位相が常に同相とな
るように制御手段で制御する。[Means for Solving the Problems] According to the present invention, clockwise light and counterclockwise light outputted from an optical path are caused to interfere with each other, the interference light is converted into an electrical signal by a photoelectric conversion means, and the electrical signal is converted into an electrical signal. An arbitrary odd number wave component of the modulation frequency of the inner phase modulation means is synchronously detected by the first synchronous detection means, and an arbitrary even number wave component of the modulation frequency of the inner phase modulation means of the electric signal is synchronously detected by the second synchronous detection means. At the same time, the electric signal is further synchronously detected by a third synchronous detection means using a reference signal having a phase difference of 90° with respect to the reference signal of the first synchronous detection means, and the electric signal is synchronously detected by a second synchronous detection means. Synchronous detection is performed by the fourth same month detection means using a reference signal with a difference of about 90 degrees from the reference signal of the means. The first phase detection means uses the output of the first synchronous detection means and the output of the third synchronous detection means to detect the reference signal applied to the first synchronous detection means and the synchronously detected component of the signal applied as input. Output phase difference information. Further, the reference signal applied to the second synchronous detection means by the second phase detection means and the synchronously detected component of the signal applied as input are determined by the output of the second synchronous detection means and the output of the fourth synchronous detection means. Output phase difference information. The control means controls the output of the first phase detection means and the output of the second phase detection means so that the phases of the reference signal and the synchronously detected signal in the first synchronous detection means and the second synchronous detection means are always in phase. Control.
「実施例」
第１図にこの発明の実施例の要部を示し、第４図と対応
する部分には同一符号を付けである。この発明において
は同期検波回路３２．３４が設けられる。ロジック回路
４３．４４において、同期検波回路２２．２３の参照信
号Ｖｒ＋ａｌＶｒ２Ｍに対しそれぞれ位相が９０°ずれ
た信号Ｖ ｒ＋ｔ＋ ｌ Ｖｒｔｂが作られ、これら信
号Ｖｒｌｂ ｌ Ｖｒｔｂが同期検波回路３２．３４
へ参照信号として供給され、受光器１７の出力■、がそ
れぞれ同期検波される。同期検波回路３２．３４の各出
力は低域通過ろ波器３６．３Ｂへそれぞれ供給される。Embodiment FIG. 1 shows the main parts of an embodiment of the present invention, and parts corresponding to those in FIG. 4 are given the same reference numerals. In this invention, synchronous detection circuits 32 and 34 are provided. In the logic circuits 43.44, signals V r+t+ l Vrtb whose phases are shifted by 90 degrees from the reference signals Vr+alVr2M of the synchronous detection circuit 22.23 are created, and these signals Vrlb l Vrtb are sent to the synchronous detection circuit 32.34.
The outputs (1) and (2) of the photoreceiver 17 are each synchronously detected. Each output of the synchronous detection circuit 32.34 is supplied to a low pass filter 36.3B.
低域通過ろ波器３６．３Ｂの各出力■＋ｂ＋ ■Ｚｂ
はそれぞれＶ、、＝Ｖ、・■、１゜
＝ Ｋ、、 ・Ｊ ＋（ｘ） ・ｓｉｎΔφ５ｉｎ（θ
−θｆ）・・・（７）
■Ｚｂ＝ Ｖ ｌ ’ Ｖｒｔｂ
”” Ｋｚｂ−Ｊ ｚ（ｘ） ・ｃｏｓΔφ５ｉｎ２（
θ−θ、）・・・（８）
Ｋ＋ｂ、 Ｋｚｂ：定数
となる。低域通過ろ波器２４．３６の各出力Ｖ ｌ ｍ
＋Ｖｌｋは位相検知手段としての乗算手段３９へ供給
され、また低域通過ろ波器２５．３８の各出力■２．。Each output of low-pass filter 36.3B ■+b+ ■Zb
are respectively V,,=V,・■,1゜=K,,・J+(x)・sinΔφ5in(θ
-θf)...(7) ■Zb= V l' Vrtb ”” Kzb-J z(x) ・cosΔφ5in2(
θ−θ, )...(8) K+b, Kzb: Constant. Each output V l m of the low-pass filter 24.36
+Vlk is supplied to the multiplication means 39 as a phase detection means, and each output of the low-pass filter 25.38 2. .
Ｖ２ｂは位相検知手段としての乗算手段４０へ供給され
る。乗算手段３９．４０の各出力■。＋ ｒ ■＊ ｔ
は
（ＫＩｓｉｎΔφ）２
Ｌ＋””Ｖｌｌｌ’ ■、、＝ −
・５ｉｎ２（θ−θｆ ） ・・・
（９）（Ｋ、ｃｏｓΔφ）２
Ｖ＊ｚ＝Ｖｔｍ・ ■２、・・・
・５ｉｎ４（θ−θ、 ）・Ｏｏ）
ココでに、＝に、、−Ｊ、（ｘ）＝に＋ｂ’ 、Ｌ（ｘ
）Ｋｚ ”Ｋｔ−・Ｊｚ（ｘ）＝Ｋｚｂ・Ｊｚ（ｘ）
となる。即ち乗算手段３９．４０の各出力はｓｉｎΔφ
、 ｃｏｓΔφはそれぞれ自乗されているため、必ず正
となり、出力極性は位相差（θ−θｔ）の正弦出力に対
応したものとなり、入力角速度の極性、即ち光学路１６
の左回り光、右回り光間の位相差Δφに対応したｓｉｎ
Δφ成分、ｃｏｓΔφ成分の極性に影響されない。V2b is supplied to multiplication means 40 as phase detection means. Each output of multiplication means 39.40 ■. + r ■* t
is (KIsinΔφ)2 L+””Vllll' ■,, = −
・5in2(θ-θf)...
(9) (K, cosΔφ)2 V*z=Vtm・ ■2,... ・5in4(θ−θ, )・Oo) Here, = to, , -J, (x) = to +b' , L(x
)Kz ”Kt-・Jz(x)=Kzb・Jz(x)
becomes. That is, each output of the multiplication means 39 and 40 is sinΔφ
, cosΔφ are squared, so they are always positive, and the output polarity corresponds to the sine output of the phase difference (θ−θt), and the polarity of the input angular velocity, that is, the optical path 16
sin corresponding to the phase difference Δφ between the counterclockwise and clockwise lights of
It is not affected by the polarity of the Δφ component and the cosΔφ component.
従って乗算手段３９．４０の各出力でロジック回路４３
．４４の手段に配置した自動位相調整器４５を制御し位
相差θに対応しθ、を変えれば位相差（θ−θｆ）を常
に零に保つことができる。Therefore, at each output of the multiplication means 39 and 40, the logic circuit 43
．． By controlling the automatic phase adjuster 45 disposed in the means 44 and changing θ in accordance with the phase difference θ, the phase difference (θ−θf) can always be kept at zero.
自動位相調整器４５の代りに位相変調駆動回路２８の前
段に自動位相調整器５３を配置し、同期検波回路２２，
２３．３２．３４の参照信号に対する位相変調器１５に
印加する信号■Ｐ７の位相関係を制御することによって
も同様な効果が得られる。Instead of the automatic phase adjuster 45, an automatic phase adjuster 53 is arranged before the phase modulation drive circuit 28, and the synchronous detection circuit 22,
A similar effect can be obtained by controlling the phase relationship of the signal P7 applied to the phase modulator 15 with respect to the reference signal of 23.32.34.
第１図では乗算手段３９．４０の各出力Ｖ １１１ ＋
ｖｅｘを加算手段４１で加算し、その出力■。を電気ろ
波器を含む増幅器４２に入力し、増幅器４２の出力を自
動位相調整器４５の制御信号として使用しているが、第
２図に示すように乗算手段３９゜４０の各出力Ｖ、、、
Ｖ、アをスイッチ手段４８によって切替えて増幅器４２
に入力し、その出力を制御信号として使用してもよい。In FIG. 1, each output V 111 + of the multiplication means 39.40
vex is added by the addition means 41, and its output is ■. is input to an amplifier 42 including an electric filter, and the output of the amplifier 42 is used as a control signal for the automatic phase adjuster 45. As shown in FIG. ,,
V and A are switched by the switch means 48 to the amplifier 42.
and its output may be used as a control signal.
この場合、スイッチ手段４８はΔφが±ｍπ（ｍ＝０、
ｉ ２．・・・）に対し約±π／４の範囲では信号と
して十分大きい値を示している乗算出力■１に切替え、
Δφがπ
±（２ｍ＋１） ・ （ｍ＝０．１，２、・・
・）に対して約±π／４の範囲では同様に十分大きい値
を示す乗算手段３９からの出力■１に切替えて増幅器４
２に出力する。つまり第５図中の可逆カウンタ７０の重
みが２°の出力りによりスイッチ手段４８を制御すれば
よい。In this case, the switch means 48 has a Δφ of ±mπ (m=0,
i2. ), switch to multiplication output ■1 which shows a sufficiently large value as a signal in the range of approximately ±π/4,
Δφ is π ±(2m+1) ・ (m=0.1,2,...
), the output from the multiplier 39 is switched to ■1 which similarly shows a sufficiently large value in the range of approximately ±π/4, and the amplifier 4
Output to 2. That is, the switching means 48 may be controlled by the output of the reversible counter 70 in FIG. 5 whose weight is 2 degrees.
第３図は他の実施例を示し、低域通過ろ波器２４゜２５
の各出力ｖｌｉ＋ Ｖ２ｉの極性に応じて同期検波回路
３２．３４の参照信号の位相を同期検波回路２２．２３
の参照信号ＶＦＩｍ＋Ｖｒ！ｍに対し＋９０°。FIG. 3 shows another embodiment, in which the low-pass filter 24°25
The phase of the reference signal of the synchronous detection circuit 32.34 is determined according to the polarity of each output vli+V2i of the synchronous detection circuit 22.23.
The reference signal VFIm+Vr! +90° to m.
−９０°に切替えている。即ち同期検波回路３２゜３４
の出力の極性は同期検波回路２２．２３の出力の極性と
一部しており、コンパレータ５７，５８で同期検波回路
２２．２３の各出力”１ｍ＋ ＶＺ＆の極性を判断し
、その出力でスイッチ素子５１．５４を制御し、同期検
波回路３２．３４の参照信号を１８０°位相差のある信
号Ｖ□、とＶｒｌｂ ＋ ＶｒｔｈとＩ−の切替えを行
う。つまり同期検波回路の出力が負となる時は参照信号
を逆位相のものとして同期検波回路の出力を正とする。-90°. That is, the synchronous detection circuit 32°34
The polarity of the output of the synchronous detection circuit 22.23 is part of the polarity of the output of the synchronous detection circuit 22.23, and the polarity of each output ``1m+VZ&'' of the synchronous detection circuit 22.23 is determined by the comparators 57 and 58, and the switch element is 51.54, the reference signal of the synchronous detection circuit 32.34 is switched between the signal V□ with a 180° phase difference, Vrlb + Vrth, and I-.In other words, when the output of the synchronous detection circuit becomes negative assumes that the reference signal is of opposite phase and that the output of the synchronous detection circuit is positive.
この結果低域通過ろ波器３６．３Ｂの出力ｖ１ｂ’ ＋
ｖｚｂ′は、Ｖ＋ｂ’ −Ｉ Ｋ＋ｓｉｎΔφｌ・５
ｉｎ（θ−θｔ ）−ＱＤＶｇｂ’ −１ＫＩＣｏＳΔ
φ１・５ｉｎ２（θ−θｆ）・・・（１２）
となり、入力角速度に対応したｓｉｎΔφ、 ｃｏｓΔ
φ成分の極性を無関係に位相差（θ−θｆ）情報を出力
することができる。この位相差θ−θ、が零になるよう
に自動位相調整器４５を制御する。つまり出力■１に’
＋ ＶＺｋ′を、第１図、第２図で示した信号Ｖ＠Ｉ
＋ ｖａｚの代りに使用する。なお増幅器４２の電気
ろ波器は一般に比例微分積分形のものが用いられる。As a result, the output of the low-pass filter 36.3B is v1b' +
vzb' is V+b' -I K+sinΔφl・5
in(θ−θt)−QDVgb′−1KICoSΔ
φ1・5in2(θ−θf)...(12), and sinΔφ, cosΔ corresponding to the input angular velocity
Phase difference (θ-θf) information can be output regardless of the polarity of the φ component. The automatic phase adjuster 45 is controlled so that this phase difference θ-θ becomes zero. In other words, the output ■1'
+ VZk' as the signal V@I shown in Figures 1 and 2
+ Use in place of vaz. Incidentally, the electric filter of the amplifier 42 is generally of a proportional differential-integral type.
「発明の効果」
位相差Δφが±ｍπ（ｍ＝０．ｌ、２・・・）に対し約
±π／４の範囲では、ｓｉｎΔφ成分、±（２ｍ＋１）
・−（ｍ−０，１，２・・・）に対し約±π／４の範囲
では、ｃｏｓΔφ成分をジャイロ出力とし取り出すこと
によって人力角速度の計測範囲の拡大をはかった光干渉
角速度針（光フアイバジャイロ）において環境条件等の
変化によって位相変調器１５の入出力位相特性が変動し
ても同期検波回路における被同期検波信号と参照信号と
を入力範囲全域に渡って同相に保つことができ、光干渉
角速度針（光フアイバジャイロ）のスケールファクタを
安定に保つことができる。"Effect of the invention" In the range where the phase difference Δφ is about ±π/4 with respect to ±mπ (m=0.l, 2...), the sinΔφ component, ±(2m+1)
・In the range of about ±π/4 for -(m-0, 1, 2...), the optical interference angular velocity needle (optical Even if the input/output phase characteristics of the phase modulator 15 change due to changes in environmental conditions in the fiber gyro, the synchronously detected signal and the reference signal in the synchronous detection circuit can be kept in phase over the entire input range, The scale factor of the optical interference angular velocity needle (optical fiber gyro) can be kept stable.
第１図はこの発明の実施例の要部を示すブロック図、第
２図はその一部の変形例を示すブロック図、第３図はこ
の発明の他の実施例の要部を示すブロック図、第４図は
従来の光干渉角速度計を示すブロック図、第５図は計測
範囲を拡大した光干渉角速度計の要部を示すブロック図
、第６図は第５図の動作の説明に供するための各部の出
力を示す図である。FIG. 1 is a block diagram showing the main part of an embodiment of the invention, FIG. 2 is a block diagram showing a partial modification thereof, and FIG. 3 is a block diagram showing the main part of another embodiment of the invention. , Fig. 4 is a block diagram showing a conventional optical interference angular velocity meter, Fig. 5 is a block diagram showing the main parts of an optical interference angular velocity meter with an expanded measurement range, and Fig. 6 serves to explain the operation of Fig. 5. FIG.
Claims (4)
させる手段と、 その干渉手段と上記光学路の一端との間にこれらに継続
的に配されて右回り光と左回り光とに位相変化を与える
位相変調手段と、 上記干渉光の光強度を電気信号として検出する光電変換
手段と、 その光電変換手段からの出力の内上記変調手段の変調周
波数の任意の奇数波成分を同期検波する第１同期検波手
段と、 上記光電変換手段からの出力の内、上記変調周波数の任
意の偶数波成分を同期検波する第２同期検波手段と、 上記光電変換手段の出力を、上記第１同期検波手段の参
照信号に対し９０°の位相差をもった参照信号で検波す
る第３同期検波手段と、 上記光電変換手段の出力を、上記第２同期検波手段の参
照信号に対し９０°の位相差をもった参照信号で検波す
る第４同期検波手段と、 上記第１同期検波手段の出力と上記第３同期検波手段の
出力とによって上記第１同期検波手段に印加される参照
信号と入力として印加される信号の内被同期検波成分と
の位相差情報を出力する第１位相検知手段と、 上記第２同期検波手段の出力と上記第４同期検波手段の
出力とによって上記第２同期検波手段に印加される参照
信号と入力として印加される信号の内被同期検波成分と
の位相差情報を出力する第２位相検知手段と、 上記第１位相検知手段と上記第２位相検知手段とからの
各信号により上記第１同期検波手段と上記第２同期検波
手段とにおける参照信号と被同期検波信号との位相が常
に同相となるように制御する制御手段とを有する光干渉
角速度計。(1) An optical path that goes around at least once, means for passing clockwise light and counterclockwise light through the optical path, means for interfering with the clockwise light and counterclockwise light that have propagated through the optical path, and the interference. a phase modulation means that is disposed continuously between the means and one end of the optical path to change the phase of the clockwise light and the counterclockwise light; and a photoelectric device that detects the optical intensity of the interference light as an electrical signal. a first synchronous detection means for synchronously detecting an arbitrary odd-numbered wave component of the modulation frequency of the modulation means of the output from the photoelectric conversion means; a second synchronous detection means for synchronously detecting an arbitrary even number wave component; and a third synchronous detection means for detecting the output of the photoelectric conversion means with a reference signal having a phase difference of 90° with respect to the reference signal of the first synchronous detection means. synchronous detection means; fourth synchronous detection means for detecting the output of the photoelectric conversion means with a reference signal having a phase difference of 90° with respect to the reference signal of the second synchronous detection means; and the first synchronous detection means. and a first phase detection device that outputs phase difference information between the reference signal applied to the first synchronous detection means and the synchronously detected component of the signal applied as an input by the output of the third synchronous detection means and the output of the third synchronous detection means. means, and the position of the reference signal applied to the second synchronous detection means by the output of the second synchronous detection means and the output of the fourth synchronous detection means and the coherently detected component of the signal applied as an input. A second phase detection means outputs phase difference information, and each signal from the first phase detection means and the second phase detection means is used to generate a reference signal and a received signal in the first synchronous detection means and the second synchronous detection means. An optical interference gyrometer comprising a control means for controlling the phase of the synchronous detection signal so that the phase thereof is always in the same phase as the synchronous detection signal.
の出力と、上記第３同期検波手段の出力とを乗算する手
段であり、上記第２位相検知手段は上記第２同期検波手
段の出力と、上記第４同期検波手段の出力とを乗算する
手段である請求項１記載の光干渉角速度計。(2) The first phase detection means is means for multiplying the output of the first synchronous detection means by the output of the third synchronous detection means, and the second phase detection means is means for multiplying the output of the first synchronous detection means by the output of the third synchronous detection means. 2. The optical interference gyrometer according to claim 1, further comprising means for multiplying the output of said fourth synchronous detection means by the output of said fourth synchronous detection means.
の出力の極性によって上記第３同期検波手段の出力の極
性を反転する手段であり、上記第２位相検知手段は上記
第２同期検波手段の出力の極性によって上記第４同期検
波手段の出力の極性を反転する手段である請求項１記載
の光干渉角速度計。(3) The first phase detection means is means for inverting the polarity of the output of the third synchronous detection means according to the polarity of the output of the first synchronous detection means, and the second phase detection means is a means for inverting the polarity of the output of the third synchronous detection means. 2. The optical interference gyrometer according to claim 1, further comprising means for inverting the polarity of the output of said fourth synchronous detection means depending on the polarity of the output of said detection means.
って生じる上記右回り光と左回り光との位相差が±ｍπ
（ｍ＝０、１、２、・・・）に対し約±π／４の範囲で
あることを検出する第１範囲検出手段と、上記右回り光
と左回り光との位相差が±（２ｍ＋１）・π／２（ｍ＝
０、１、２、・・・）に対し約±π／４の範囲であるこ
とを検出する第２範囲検出手段と、上記第１範囲検出手
段によって上記第２位相検知手段からの信号を上記制御
手段へ伝達し、上記第２範囲検出手段からの信号によっ
て上記第１位相検知手段からの信号を上記制御手段に伝
達する手段とを具備する請求項１乃至３の何れかに記載
の光干渉角速度計。(4) The phase difference between the clockwise light and the counterclockwise light caused by the input angular velocity applied in the circumferential direction of the optical path is ±mπ
(m=0, 1, 2, . . . ), a first range detection means detects that the range is about ±π/4, and a phase difference between the clockwise light and the counterclockwise light is ±( 2m+1)・π/2(m=
0, 1, 2, ...), and the first range detection means detects the signal from the second phase detection means. 4. The optical interference according to claim 1, further comprising means for transmitting a signal from said first phase detecting means to said control means in response to a signal from said second range detecting means. angular velocity meter.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63137781A JPH06103186B2 (en) | 1988-06-03 | 1988-06-03 | Optical interference gyro |
| US07/236,435 US4883358A (en) | 1987-09-02 | 1988-08-25 | Fiber optic gyro stabilized by harmonic components of detected signal |
| DE3844745A DE3844745C2 (en) | 1987-09-02 | 1988-09-01 | |
| FR888811437A FR2618545B1 (en) | 1987-09-02 | 1988-09-01 | FIBER OPTIC GYROSCOPE |
| DE3829731A DE3829731A1 (en) | 1987-09-02 | 1988-09-01 | FIBER OPTICAL GYPSY |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63137781A JPH06103186B2 (en) | 1988-06-03 | 1988-06-03 | Optical interference gyro |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01305363A true JPH01305363A (en) | 1989-12-08 |
| JPH06103186B2 JPH06103186B2 (en) | 1994-12-14 |
Family
ID=15206694
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63137781A Expired - Lifetime JPH06103186B2 (en) | 1987-09-02 | 1988-06-03 | Optical interference gyro |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06103186B2 (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS629214A (en) * | 1985-07-08 | 1987-01-17 | Japan Aviation Electronics Ind Ltd | Optical interference angular velocity meter |
-
1988
- 1988-06-03 JP JP63137781A patent/JPH06103186B2/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS629214A (en) * | 1985-07-08 | 1987-01-17 | Japan Aviation Electronics Ind Ltd | Optical interference angular velocity meter |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH06103186B2 (en) | 1994-12-14 |
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