JPH09218266A - Distance measuring apparatus - Google Patents
Distance measuring apparatusInfo
- Publication number
- JPH09218266A JPH09218266A JP8022869A JP2286996A JPH09218266A JP H09218266 A JPH09218266 A JP H09218266A JP 8022869 A JP8022869 A JP 8022869A JP 2286996 A JP2286996 A JP 2286996A JP H09218266 A JPH09218266 A JP H09218266A
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- Length Measuring Devices By Optical Means (AREA)
- Optical Radar Systems And Details Thereof (AREA)
Abstract
Description
【0001】[0001]
【発明の属する技術分野】この発明は、測距装置に関
し、詳しくは、光路長による変調信号の位相差に基づい
て被測定物までの距離を測定する測距装置に関する。測
距装置から静止物までの精密な測定に適するばかりか、
双方又は何れかの移動に連れての連続測定にも好適とな
るような改良に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distance measuring device, and more particularly to a distance measuring device for measuring a distance to an object to be measured based on a phase difference of a modulation signal due to an optical path length. Not only suitable for precise measurement from ranging devices to stationary objects,
The present invention relates to an improvement suitable for continuous measurement with movement of both or either.
【0002】[0002]
【従来の技術】図4に示した従来の測距装置は、平坦な
ベース板1の上に本体2が搭載されたものである。この
本体2の内部には、半導体製のレーザ3や、このレーザ
3から出たレーザ光を発振信号Aで強度変調する変調部
4が収められていて、ベース板1上に乗載されて本体2
に対向する被測定物5に対して変調後のレーザ光Bが照
射されるようになっている。また、本体2の内部には、
被測定物5で反射したレーザ光Cを受けてこれに対応す
る検出信号Dを出力するフォトダイオード等の受光部6
や、発振信号Aと検出信号Dとの位相差に基づいて本体
2から被測定物5までの距離を算出する距離算出部7も
収められていて、その算出距離Gが表示部8に表示され
るようになっている。2. Description of the Related Art The conventional distance measuring device shown in FIG. 4 has a main body 2 mounted on a flat base plate 1. Inside the main body 2, a semiconductor laser 3 and a modulator 4 for intensity-modulating the laser light emitted from the laser 3 with an oscillation signal A are housed. Two
The modulated laser beam B is irradiated to the object to be measured 5 facing to. In addition, inside the main body 2,
A light receiving section 6 such as a photodiode that receives the laser beam C reflected by the DUT 5 and outputs a detection signal D corresponding to the laser beam C.
Alternatively, a distance calculation unit 7 that calculates the distance from the main body 2 to the DUT 5 based on the phase difference between the oscillation signal A and the detection signal D is also included, and the calculated distance G is displayed on the display unit 8. It has become so.
【0003】距離算出部7は、数百MHzの高周波数ω
M で発振して正弦波の発振信号Aを発生する発振回路7
1と、発振信号Aと検出信号Dとを入力とし乗積信号E
を出力する乗算回路72と、乗積信号Eを入力とし数H
zの低周波数ω1 以下の信号成分を通過させて位相信号
Fを出力するローパスフィルタ73と、発振信号Aをπ
/2の位相分だけ遅延させて移相発振信号A’を生成す
るπ/2移相回路74と、移相発振信号A’と検出信号
Dとを入力とし乗積信号E’を出力する乗算回路75
と、乗積信号E’を入力として位相信号F’を出力する
ローパスフィルタ76と、位相信号Fと位相信号F’と
の位相差に基づく後述の演算を行って算出距離Gを出す
演算回路77とからなるものである。乗算回路75は乗
算回路72と、ローパスフィルタ76はローパスフィル
タ73と、特性の揃ったものである。The distance calculation unit 7 has a high frequency ω of several hundred MHz.
Oscillation circuit 7 that oscillates at M to generate a sinusoidal oscillation signal A
1, the oscillation signal A and the detection signal D are input, and the product signal E
And a multiplication circuit 72 that outputs the product signal E
A low-pass filter 73 that outputs a phase signal F by passing a signal component of z having a low frequency ω 1 or less, and an oscillation signal A by π
Π / 2 phase shift circuit 74 for generating the phase shift oscillation signal A ′ by delaying by the phase of / 2, and multiplication for inputting the phase shift oscillation signal A ′ and the detection signal D and outputting the product signal E ′. Circuit 75
And a low-pass filter 76 that receives the product signal E ′ as an input and outputs a phase signal F ′, and an operation circuit 77 that performs an operation described later based on the phase difference between the phase signal F and the phase signal F ′ to obtain a calculated distance G. It consists of and. The multiplication circuit 75 has the same characteristics as the multiplication circuit 72, and the low-pass filter 76 has the same characteristics as the low-pass filter 73.
【0004】このような測距装置を用いた被測定物5ま
での距離測定は次のようにして行なわれる。発振信号A
で変調されたレーザ光B,Cが受光部6で電気信号に変
換されて検出信号Dとなったときには光路長に対応した
時間遅れによって、そのときの発振信号Aと検出信号D
との間には光路長に対応した位相差θが生じる。すなわ
ち、受光ゲインによる振幅をaとおいて、発振信号A=
cos(ωM ×t)に対して、検出信号D=a×cos
(ωM ×t−θ)が得られる。The distance to the object 5 to be measured using such a distance measuring device is measured as follows. Oscillation signal A
When the laser beams B and C modulated by the laser light are converted into an electric signal by the light receiving section 6 and become the detection signal D, the oscillation signal A and the detection signal D at that time are caused by the time delay corresponding to the optical path length.
And a phase difference θ corresponding to the optical path length is generated. That is, the oscillation signal A =
detection signal D = a × cos with respect to cos (ω M × t)
(Ω M × t−θ) is obtained.
【0005】次に、乗算回路72のオフセットをV72と
おき乗算回路75のオフセットをV75とおいて、乗積信
号E=a×cos(ωM ×t)×cos(ωM ×t−
θ)+V72、乗積信号E’=a×sin(ωM ×t)×
cos(ωM ×t−θ)+V75が得られる。ローパスフ
ィルタを経た後は直流分や低周波数成分が残って、位相
信号F=a×cos(θ)+V72、位相信号F’=a×
sin(θ)+V75が得られる。[0005] Next, at the V75 offset of offset V72 Distant multiplication circuit 75 of the multiplier circuit 72, multiplying the signal E = a × cos (ω M × t) × cos (ω M × t-
θ) + V72, product signal E ′ = a × sin (ω M × t) ×
cos (ω M × t−θ) + V 75 is obtained. After passing through the low-pass filter, DC components and low frequency components remain, and the phase signal F = a × cos (θ) + V72 and the phase signal F ′ = ax
sin (θ) + V75 is obtained.
【0006】そして、オフセットV72,V75が無視でき
るときには、演算回路77によって、上記のF,F’の
式を連立させてaとθとを独立変数としてθを明示的に
求める演算が行われる。すなわち、位相信号Fと位相信
号F’との位相差θ=arctan-1(sin(θ)/
cos(θ))=arctan-1(F’/F)が演算さ
れる。さらに、既知の基本長をbとおきcを光速度とし
て算出距離G=θ×c/ωM +bが演算される。こうし
て、発振信号Aと検出信号Dとの位相差θに基づいて本
体2から被測定物5までの距離が算出される。算出距離
Gは表示部8等で確認される。Then, when the offsets V72 and V75 can be ignored, the arithmetic circuit 77 performs an arithmetic operation in which the above equations F and F'are made simultaneous to explicitly obtain θ with a and θ as independent variables. That is, the phase difference between the phase signal F and the phase signal F ′ θ = arctan −1 (sin (θ) /
cos (θ)) = arctan −1 (F ′ / F) is calculated. Further, the known basic length is set to b and c is the speed of light, and the calculated distance G = θ × c / ω M + b is calculated. In this way, the distance from the main body 2 to the DUT 5 is calculated based on the phase difference θ between the oscillation signal A and the detection signal D. The calculated distance G is confirmed on the display unit 8 or the like.
【0007】なお、高周波数ωM で動作する回路には制
約が多いことや測定精度確保の観点などから、乗算回路
72,75のオフセットV72,V75は無視し難いので、
これを除去する較正手段も用意される。すなわち、本体
2の内部には、反射鏡11と、周期的に又は温度変化等
に応じて較正処理の制御を行う較正制御回路12と、こ
れのモータ駆動制御に従って回転し較正時には変調部4
からのレーザ光を反射鏡11さらに受光部6へ導く回転
鏡13とを備えている。そして、演算回路77では、予
め較正時に既定距離対応の測定でオフセットV72,V75
を求めておいて、被測定物5の測定時にオフセットV7
2,V75の減算処理を行う。距離測定中も、温度変化等
を考慮して測定を中断し、ときどき較正を行うのであ
る。Note that the offsets V72 and V75 of the multiplication circuits 72 and 75 are difficult to ignore because there are many restrictions on the circuit that operates at the high frequency ω M and from the viewpoint of ensuring measurement accuracy.
A calibration means for removing this is also prepared. That is, inside the main body 2, a reflecting mirror 11, a calibration control circuit 12 that controls a calibration process periodically or according to a temperature change, and a motor driving control of the calibration control circuit 12, which rotates according to the motor drive control, and a modulation unit 4 during calibration.
And a rotating mirror 13 that guides the laser light from the reflecting mirror 11 to the light receiving unit 6. Then, in the arithmetic circuit 77, the offsets V72, V75 are measured in advance by the measurement corresponding to the predetermined distance at the time of calibration.
To obtain the offset V7 when measuring the DUT 5.
2. Subtract V75. Even during the distance measurement, the measurement is interrupted in consideration of the temperature change and the like, and the calibration is sometimes performed.
【0008】[0008]
【発明が解決しようとする課題】しかしながら、このよ
うな従来の測距装置では、乗算回路のオフセットを無視
して測定精度を我慢するか、反射鏡等の複雑な較正用光
学系等を付加して断続測定に限ることでコスト面や使用
形態面で我慢する必要があった。このため、例えば連続
形成されるロングレールの加工精度を常時監視する場合
や、移動体で地上の長尺物を連続して計測する場合、不
都合である。そこで、温度変化等に起因するオフセット
変動の影響を光学系に依らずに除去して測定精度の向上
を図るとともに製造コストの削減および連続測定も可能
なようにすることが課題となる。However, in such a conventional distance measuring device, the offset of the multiplication circuit is ignored to endure the measurement accuracy, or a complicated optical system for calibration such as a reflecting mirror is added. Therefore, it was necessary to put up with the cost and usage patterns by limiting the intermittent measurement. Therefore, for example, it is inconvenient when constantly monitoring the machining accuracy of long rails that are continuously formed, or when continuously measuring long objects on the ground with a moving body. Therefore, it is an object to improve the measurement accuracy by removing the influence of the offset variation caused by the temperature change and the like without depending on the optical system, reduce the manufacturing cost, and enable continuous measurement.
【0009】この発明は、このような課題を解決するた
めになされたものであり、高精度で連続測定可能な測距
装置を実現することを目的とする。The present invention has been made in order to solve such a problem, and an object thereof is to realize a distance measuring apparatus capable of continuous measurement with high accuracy.
【0010】[0010]
【課題を解決するための手段】このような課題を解決す
るために発明された第1乃至第2の解決手段について、
その構成および作用効果を以下に説明する。Means for Solving the Problems First and second solving means invented to solve such problems are as follows.
The configuration and operation and effect will be described below.
【0011】[第1の解決手段]第1の解決手段の測距
装置は(、出願当初の請求項1に記載の如く)、照射レ
ーザ光を変調した高周波数の発振信号と反射レーザ光の
検出信号とを乗積してから静的な又は低周波数の成分を
抽出して得た位相差に基づいて測定距離を算出する測距
装置において、前記乗積に際して、前記発振信号および
これと位相のみ異なる2つの移相発振信号のそれぞれに
ついて、前記検出信号との乗積を、同一乗算回路によっ
て中間周波数で時分割的に繰り返し行う手段と、前記位
相差を得る際に、これら3種の乗積値を用いて前記乗積
時のオフセット成分を独立変数とする演算を行う手段と
を備えたことを特徴とするものである。[First Solving Means] The distance measuring apparatus of the first solving means (as described in claim 1 at the beginning of the application) uses a high-frequency oscillating signal modulated from the irradiation laser light and a reflected laser light. In the ranging device for calculating the measurement distance based on the phase difference obtained by multiplying the detection signal and the static or low-frequency component, the oscillation signal and the phase with the oscillation signal are calculated during the multiplication. For each of the two phase-shift oscillation signals different from each other, means for repeatedly multiplying the detection signal by the same multiplication circuit at an intermediate frequency in a time-division manner, and for obtaining the phase difference, these three types of multiplication products are used. Means for performing an arithmetic operation using the product value as an independent variable, which is an offset component at the time of multiplication.
【0012】なお、この明細書では、上記の「移相発振
信号」とは、高周波数の発振信号の位相を所定量ずらし
て生成した高周波数の発振信号をいい、これらの発振信
号は位相差検出の際の基準信号となるものである。これ
に対し、「位相信号」とは、静的な又は低周波数で変化
する距離に対応した位相差情報を直接担う信号である静
的な又は低周波数の抽出成分の信号をいうものとする。In this specification, the "phase-shifted oscillation signal" means a high-frequency oscillation signal generated by shifting the phase of the high-frequency oscillation signal by a predetermined amount, and these oscillation signals have a phase difference. It serves as a reference signal for detection. On the other hand, the "phase signal" means a signal of a static or low-frequency extracted component that is a signal that directly bears phase difference information corresponding to a distance that changes statically or at low frequency.
【0013】このような第1の解決手段の測距装置にあ
っては、発振信号および2つの移相発振信号からなる3
つの基準信号から検出信号との乗積信号が得られる。3
つの基準信号は位相差が異なり且つ位相差のみが異なる
ものなので、2つの基準信号だけから検出信号との乗積
信号を得ていた従来に比べて、この場合は、位相差を得
る演算について、独立変数を増やすことなく有効な連立
式を1つ増やすことができる。In the distance measuring device of the first solving means, the oscillation signal and the two phase-shift oscillation signals are used as the three signals.
A product signal of the detected signal and the reference signal is obtained from the two reference signals. 3
Since the two reference signals have different phase differences and different phase differences only, in this case, in comparison with the conventional case where the product signal with the detection signal is obtained from only two reference signals, in this case, You can increase the number of valid simultaneous equations without increasing the number of independent variables.
【0014】そして、これら3種の乗積値を用いて乗積
時のオフセット成分を独立変数とする演算が行われる。
この場合、乗算回路が共通なので乗積時のオフセット成
分は唯1つである。そして、有効な連立式が1つ増加し
ているので、独立変数が1つ増えても演算処理で直接算
出可能である。そこで、乗積時のオフセット成分を演算
だけで的確に除去することができる。しかも、この演算
は中間周波数で繰り返されるので、静的な又は低周波数
で変化する距離は、実質的に連続測定される。Then, using these three types of product values, an operation is performed using the offset component at the time of product as an independent variable.
In this case, since the multiplication circuit is common, there is only one offset component when multiplying. Since the number of valid simultaneous equations is increased by one, even if the number of independent variables is increased by one, it can be directly calculated by the arithmetic processing. Therefore, the offset component at the time of multiplication can be accurately removed only by calculation. Moreover, since this operation is repeated at intermediate frequencies, static or low frequency varying distances are measured substantially continuously.
【0015】これにより、温度変化等に起因するオフセ
ット変動の影響を光学系に依らずに、簡易な演算処理で
除去することができる。したがって、この発明によれ
ば、高精度で連続測定可能な測距装置を実現することが
できる。This makes it possible to remove the influence of the offset fluctuation caused by the temperature change and the like by a simple calculation process without depending on the optical system. Therefore, according to the present invention, it is possible to realize a range finder capable of continuous measurement with high accuracy.
【0016】[第2の解決手段]第2の解決手段の測距
装置は(、出願当初の請求項2に記載の如く)、照射レ
ーザ光を変調した高周波数の発振信号と反射レーザ光の
検出信号とを乗積してから静的な又は低周波数の成分を
抽出して得た位相差に基づいて測定距離を算出する測距
装置において、前記乗積に先だって、前記検出信号の乗
積相手の信号についてその位相を中間周波数で反転させ
てから、前記静的な成分又は前記低周波数以下の成分を
除去する手段と、前記乗積の後に、前記静的な又は前記
低周波数の成分に代えて前記中間周波数の成分を抽出し
てから、前記位相差を得る手段とを備えたことを特徴と
するものである。[Second Solving Means] The distance measuring apparatus of the second solving means (as described in claim 2 at the beginning of the application) is a high-frequency oscillation signal obtained by modulating the irradiation laser beam and a reflected laser beam. In the distance measuring device for calculating the measurement distance based on the phase difference obtained by multiplying the detection signal and the static or low-frequency component, the product of the detection signal is added prior to the multiplication. Means for inverting the phase of the signal of the other party at an intermediate frequency and then removing the static component or the component below the low frequency; and, after the multiplication, to the static or the low frequency component. Instead, it is provided with a means for obtaining the phase difference after extracting the intermediate frequency component.
【0017】このような第2の解決手段の測距装置にあ
っては、検出信号との乗積に先だって、検出信号の乗積
相手となる基準信号としての発振信号や移相発振信号
は、その位相が中間周波数で反転させられる。そして、
これらの基準信号から、低周波数以下の成分が除去され
る。そこで、基準信号は不所望な直流成分を含まない且
つ中間周波数で位相が反転するものとなり、かかる基準
信号が乗積に供される。In the distance measuring device of the second solving means, the oscillation signal and the phase-shift oscillation signal as the reference signal, which is the multiplication partner of the detection signal, are prior to the multiplication with the detection signal. Its phase is inverted at the intermediate frequency. And
From these reference signals, low frequency components and below are removed. Therefore, the reference signal does not include an undesired DC component and has a phase inverted at the intermediate frequency, and the reference signal is used for multiplication.
【0018】このようにして中間周波変調された基準信
号と検出信号とが乗積されると、単純な発振信号と検出
信号との乗積では準静的成分であった位相差の成分が、
中間周波数の成分にも含まれるようになる。これに対
し、乗算時に初めて加えられる乗算時のオフセットは準
静的なままである。そして、静的な成分に代えて中間周
波数の成分を抽出してから位相差が求められる。そこ
で、この位相差には、もはや乗算時のオフセットが含ま
れていない。When the intermediate frequency modulated reference signal and the detection signal are thus multiplied, the phase difference component, which was a quasi-static component in the simple oscillation signal and detection signal multiplication, becomes
It is also included in the intermediate frequency component. On the other hand, the offset during multiplication, which is added for the first time during multiplication, remains quasi-static. Then, the phase difference is obtained after extracting the intermediate frequency component instead of the static component. Therefore, this phase difference no longer includes the offset at the time of multiplication.
【0019】これにより、乗算時のオフセットを無視し
た簡易な演算処理で位相差に基づく距離算出を行うだけ
で、何時でも、光学系に依らずに、温度変化等に起因す
るオフセット変動の影響を除去して、正確な距離を測定
することができる。したがって、この発明によれば、高
精度で連続測定可能な測距装置を実現することができ
る。As a result, the distance calculation based on the phase difference is performed by a simple calculation process that ignores the offset at the time of multiplication, and the influence of the offset fluctuation caused by the temperature change or the like is always obtained regardless of the optical system. It can be removed and an accurate distance can be measured. Therefore, according to the present invention, it is possible to realize a range finder capable of continuous measurement with high accuracy.
【0020】[0020]
【発明の実施の形態】このような第1乃至第2の解決手
段で達成された本発明の測距装置について、これを実施
するための形態を説明する。BEST MODE FOR CARRYING OUT THE INVENTION A mode for carrying out the distance measuring apparatus of the present invention achieved by the first and second solving means will be described.
【0021】[第1の実施の形態]本発明の第1の実施
形態にあっては、上述した第1の解決手段を実施するた
めに、被測定物への照射レーザ光を高周波数の発振信号
で変調する手段と、被測定物からの反射レーザ光の検出
信号と前記発振信号およびこれを移相して生成した移相
発振信号とを乗積する手段と、この乗積信号から静的な
又は低周波数の成分を抽出する手段とを備え、この抽出
成分から前記発振信号と前記検出信号との位相差を求め
て前記被測定物までの測定距離を算出する測距装置にお
いて、前記移相発振信号として位相の異なる第1移相発
振信号および第2移相発振信号を生成する手段と、前記
乗積に際し、前記高周波数と前記低周波数との中間周波
数で時分割的に、前記検出信号と前記発振信号とを乗積
すること、前記検出信号と前記第1移相発振信号とを乗
積すること、及び前記検出信号と前記第2移相発振信号
とを乗積することとを同一乗算回路によって繰り返し行
う手段と、前記位相差を求めるに際し、これらの3種の
乗積値を用いて前記位相差と前記検出信号の振幅と前記
乗積時のオフセット成分とを独立変数とする演算を行う
手段とを備えたことを特徴とする。[First Embodiment] In the first embodiment of the present invention, in order to carry out the above-mentioned first solving means, a laser beam irradiated to an object to be measured is oscillated at a high frequency. A means for modulating the signal, a means for multiplying the detection signal of the reflected laser light from the object to be measured, the oscillation signal and a phase-shift oscillation signal generated by shifting the phase of the oscillation signal, and a static signal from the multiplication signal. And a means for extracting a low-frequency component, and a distance measuring device for calculating a measurement distance to the object to be measured by obtaining a phase difference between the oscillation signal and the detection signal from the extracted component, Means for generating a first phase-shifted oscillation signal and a second phase-shifted oscillation signal having different phases as a phase oscillation signal, and the detection in time division at an intermediate frequency between the high frequency and the low frequency during the multiplication. Multiplying the signal with the oscillating signal, Means for repeatedly multiplying a signal by the first phase-shift oscillation signal and multiplying the detection signal by the second phase-shift oscillation signal by the same multiplication circuit, and obtaining the phase difference. In this case, there is provided means for performing calculation using these three kinds of product values as independent variables of the phase difference, the amplitude of the detection signal, and the offset component at the time of product.
【0022】[第2の実施の形態]本発明の第2の実施
形態にあっては、上述した第2の解決手段を実施するた
めに、被測定物への照射レーザ光を高周波数の発振信号
で変調する手段と、被測定物からの反射レーザ光の検出
信号と前記発振信号およびこれを移相して生成した移相
発振信号とを乗積する乗積手段と、この乗積信号から静
的な又は低周波数の成分を抽出する抽出手段とを備え、
この抽出成分から前記発振信号と前記検出信号との位相
差を求めて前記被測定物までの測定距離を算出する測距
装置において、前記乗積手段の前に設けられ、前記高周
波数と前記低周波数との中間周波数で前記発振信号およ
び前記移相発振信号の位相を反転させるとともに、前記
静的な成分又は前記低周波数以下の成分を除去する手段
と、前記抽出手段に代えて前記乗積手段の後に設けら
れ、前記乗積信号から前記中間周波数の成分を抽出する
とともに、この抽出成分の信号からその振幅を抽出する
手段とを備えたことを特徴とする。[Second Embodiment] In the second embodiment of the present invention, in order to carry out the above-mentioned second solving means, a laser beam irradiated to an object to be measured is oscillated at a high frequency. Means for modulating with a signal, a multiplication means for multiplying the detection signal of the reflected laser light from the object to be measured, the oscillation signal and a phase-shift oscillation signal generated by phase-shifting the oscillation signal, and from this multiplication signal And a means for extracting a static or low-frequency component,
In the distance measuring device for calculating the measurement distance to the object to be measured by obtaining the phase difference between the oscillation signal and the detection signal from the extracted component, the distance measuring device is provided before the multiplication means, and the high frequency and the low frequency. A means for inverting the phases of the oscillation signal and the phase-shift oscillation signal at an intermediate frequency with the frequency, and removing the static component or the component below the low frequency; and the multiplication means instead of the extraction means. And means for extracting the component of the intermediate frequency from the product signal and extracting the amplitude of the signal of the extracted component.
【0023】[0023]
[第1実施例]本発明の測距装置の第1実施例につい
て、その具体的な構成を、図1のブロック図を引用して
説明する。この測距装置は、基準信号を増やして乗積時
のオフセット成分を演算だけで連続して除去するように
距離算出部を改良したものである。すなわち従来例にお
ける図4の距離算出部7を図1の距離算出部70で置き
換えて、従来例の図4における反射鏡11等の光学系依
存の較正手段を不要としたものである。そこで、同一の
構成要素には同一の符合を付して示し、その再度の説明
は割愛する。以下、距離算出部70を中心に説明する。[First Embodiment] A specific configuration of the first embodiment of the distance measuring apparatus of the present invention will be described with reference to the block diagram of FIG. This distance measuring device is an improved distance calculating unit that increases the number of reference signals and continuously removes the offset component at the time of multiplication by calculation. That is, the distance calculating unit 7 of FIG. 4 in the conventional example is replaced with the distance calculating unit 70 of FIG. 1, and the calibration means dependent on the optical system such as the reflecting mirror 11 in FIG. 4 of the conventional example is unnecessary. Therefore, the same components are designated by the same reference numerals, and the description thereof will be omitted. Hereinafter, the distance calculation unit 70 will be mainly described.
【0024】距離算出部70は、発振信号Aをπの位相
分だけ遅延させて移相発振信号A”を生成するπ移相回
路74aがπ/2移相回路74と並列に追加され、これ
に後続して発振信号A,移相発振信号A’,移相発振信
号A”の3信号を入力とし制御信号に応じて何れか1つ
を出力する切換回路75aも設けられ、検出信号Dの乗
積相手として乗算回路72に入力される信号には発振信
号Aに代えて切換回路75aの出力信号を用いるもので
ある。乗算回路75は不要なものとなっている。In the distance calculating section 70, a π phase shift circuit 74a for delaying the oscillation signal A by a phase of π to generate a phase shift oscillation signal A ″ is added in parallel with the π / 2 phase shift circuit 74. Subsequent to the above, a switching circuit 75a for inputting three signals of an oscillation signal A, a phase-shift oscillation signal A ', and a phase-shift oscillation signal A "and outputting any one of them according to a control signal is also provided. Instead of the oscillation signal A, the output signal of the switching circuit 75a is used as the signal input to the multiplication circuit 72 as the multiplication partner. The multiplication circuit 75 is unnecessary.
【0025】切換回路75aの制御信号は、切換制御回
路75bによって生成されるが、切換回路75aに発振
信号A,移相発振信号A’,移相発振信号A”を順次繰
り返して選択させるために、数百MHzの高周波数ωM
と数Hzの低周波数ω1 との間の数KHzの中間周波数
ωK で値がサイクリックに変化する。これにより、距離
算出部70は、乗積に際して発振信号Aおよびこれと位
相のみ異なる2つの移相発振信号A’,A”のそれぞれ
について検出信号Dとの乗積を同一乗算回路72によっ
て中間周波数ωK で時分割的に繰り返し行うものとなっ
ている。The control signal for the switching circuit 75a is generated by the switching control circuit 75b, but in order to cause the switching circuit 75a to select the oscillation signal A, the phase-shifted oscillation signal A ', and the phase-shifted oscillation signal A "sequentially and repeatedly. , High frequency of several hundred MHz ω M
And the low frequency ω 1 of several Hz, the value changes cyclically at an intermediate frequency ω K of several KHz. As a result, the distance calculation unit 70 causes the same multiplication circuit 72 to multiply the product of the oscillation signal A and the two phase-shifted oscillation signals A ′ and A ″ having different phases from the detection signal D by the same multiplication circuit 72. It is repeated in time division at ω K.
【0026】距離算出部70は、ローパスフィルタ7
3,76と並列に、同特性のローパスフィルタ76aが
追加して設けられ、乗算回路72とローパスフィルタ7
3との間には、乗算回路72の出力を入力とし切換制御
回路75bからの制御信号に応じてローパスフィルタ7
3,ローパスフィルタ76,ローパスフィルタ76aの
何れか1つへ選択的に入力信号を出力する切換回路75
cも、介挿されている。そして、それぞれディーティ
(1/3)で、発振信号Aと検出信号Dとの乗積信号E
をローパスフィルタ73で処理し、発振信号A’と検出
信号Dとの乗積信号E’をローパスフィルタ76で処理
し、発振信号A”と検出信号D”との乗積信号E”をロ
ーパスフィルタ76bで処理するものとなっている。こ
れにより、位相信号F,F’は信号レベルだけが従来の
1/3のものになり、位相信号F”は位相信号Fに対し
て位相差成分だけが反転したものとなる。The distance calculation unit 70 includes a low pass filter 7
A low-pass filter 76a having the same characteristics is additionally provided in parallel with the third and the third circuits 76, 76, and the multiplication circuit 72 and the low-pass filter 7
3, the output of the multiplication circuit 72 is input to the low-pass filter 7 in accordance with the control signal from the switching control circuit 75b.
3, a switching circuit 75 for selectively outputting an input signal to any one of the low-pass filter 76 and the low-pass filter 76a
c is also inserted. Then, at each duty (1/3), the product signal E of the oscillation signal A and the detection signal D is obtained.
Is processed by the low-pass filter 73, the product signal E ′ of the oscillation signal A ′ and the detection signal D is processed by the low-pass filter 76, and the product signal E ″ of the oscillation signal A ″ and the detection signal D ″ is processed by the low-pass filter 73. Therefore, the phase signals F and F'have only the signal level of 1/3 of the conventional level, and the phase signal F "has only the phase difference component with respect to the phase signal F. It will be inverted.
【0027】演算回路77aは、位相信号Fと位相信号
F’とに加えて位相信号F”をも用いて位相差に基づく
後述の演算を行う。すなわち、位相差を得る際にこれら
3種の乗積値を用いて乗積時のオフセット成分を独立変
数とする演算を行って算出距離Gを出すものとなってい
る。The arithmetic circuit 77a uses the phase signal F ″ in addition to the phase signal F and the phase signal F ′ to perform the later-described arithmetic operation based on the phase difference. The calculated distance G is calculated by using the product value to perform an operation using the offset component at the time of product as an independent variable.
【0028】この実施例の測距装置について、その動作
を説明する。The operation of the distance measuring device of this embodiment will be described.
【0029】従来と同様に受光ゲインによる振幅をaと
おき乗算回路72のオフセットをV72とおいて、発振信
号A=cos(ωM ×t)に対して、移相発振信号A’
=sin(ωM ×t)、移相発振信号A”=−cos
(ωM ×t)、さらに検出信号D=a×cos(ωM ×
t−θ)が得られる。As in the conventional case, the amplitude due to the light receiving gain is set to a and the offset of the multiplication circuit 72 is set to V72, and for the oscillation signal A = cos (ω M × t), the phase shift oscillation signal A '
= Sin (ω M × t) , phase-shift oscillation signal A "= - cos
(Ω M × t), further detection signal D = a × cos (ω M ×
t-θ) is obtained.
【0030】次に、乗算回路72,切換回路75cによ
って、周波数ωK で且つディーティ(1/3)で、乗積
信号E=a×cos(ωM ×t)×cos(ωM ×t−
θ)+V72、乗積信号E’=a×sin(ωM ×t)×
cos(ωM ×t−θ)+V72、乗積信号E”=−a×
cos(ωM ×t)×cos(ωM ×t−θ)+V72が
得られる。ローパスフィルタを経た後は直流分が残っ
て、位相信号F=(a×cos(θ)+V72)/3、位
相信号F’=(a×sin(θ)+V72)/3、位相信
号F”=(−a×cos(θ)+V72)/3が得られ
る。Next, the multiplication circuit 72, the switching circuit 75c, and at duty (1/3) at a frequency omega K, multiplied signal E = a × cos (ω M × t) × cos (ω M × t-
θ) + V72, product signal E ′ = a × sin (ω M × t) ×
cos (ω M × t−θ) + V72, product signal E ″ = − a ×
cos (ω M × t) × cos (ω M × t-θ) + V72 is obtained. After passing through the low-pass filter, the DC component remains, and the phase signal F = (a × cos (θ) + V72) / 3, the phase signal F ′ = (a × sin (θ) + V72) / 3, the phase signal F ″ = (−a × cos (θ) + V72) / 3 is obtained.
【0031】そして、演算回路77aによって、上記の
F,F’,F”の式を連立させてaとθとV72とを独立
変数としてθを明示的に求める演算が行われる。すなわ
ち、先ず位相信号Fと位相信号F”とからV72/3=
(F+F”)/2を演算してオフセット成分V72を消去
する準備をしておき、その後、位相信号Fと位相信号
F’との位相差θ=arctan-1(sin(θ)/c
os(θ))=arctan-1((F’−V72/3)/
(F−V72/3))=((2×F’−F−F”)/(F
−F”))が演算される。Then, the arithmetic circuit 77a performs an arithmetic operation to express the above equations F, F ', F "simultaneously to explicitly obtain .theta. With a, .theta. And V72 as independent variables. From the signal F and the phase signal F ″, V72 / 3 =
(F + F ″) / 2 is calculated to prepare for erasing the offset component V72, and then the phase difference θ between the phase signal F and the phase signal F ′ θ = arctan −1 (sin (θ) / c
os (θ) = arctan -1 ((F'-V72 / 3) /
(F−V72 / 3)) = ((2 × F′−F−F ″) / (F
-F ")) is calculated.
【0032】こうして、乗算回路72のオフセット成分
が明示的に除去されて、その影響を受けない正確な位相
差が求められる。そして、オフセット成分除去のための
特別な較正処理は行うことなく、既知の基本長をbとお
きcを光速度とした算出距離G=θ×c/ωM +bの演
算、及びその表示がなされる。In this way, the offset component of the multiplication circuit 72 is explicitly removed, and an accurate phase difference that is not affected by the offset component is obtained. Then, without performing a special calibration process for removing the offset component, the calculation of the calculated distance G = θ × c / ω M + b where the known basic length is b and c is the light velocity, and the display thereof is performed. It
【0033】なお、演算回路77aが周波数ωK で位相
信号F等をサンプリングして演算するデジタル回路であ
りマイクロプロセッサ等を主体として構成されるような
場合には、回路簡素化の観点から、切換回路75bやロ
ーパスフィルタ73,76,76aの機能も演算回路に
取り込んでプログラム処理によって行うようにしてもよ
い。あるいは、切換回路75aの機能だけを演算回路に
取り込んで、ローパスフィルタを1個に纏めて算出距離
Gの信号ラインに対し直列に介挿するようにしてもよ
い。この場合は、周波数ωK は周波数ω1 と分離可能で
これに近い数十Hz程度が好ましい。In the case where the arithmetic circuit 77a is a digital circuit for sampling the phase signal F and the like at the frequency ω K and performing arithmetic operation and is mainly composed of a microprocessor or the like, switching is performed from the viewpoint of circuit simplification. The functions of the circuit 75b and the low-pass filters 73, 76, 76a may be incorporated in the arithmetic circuit and may be performed by program processing. Alternatively, only the function of the switching circuit 75a may be incorporated in the arithmetic circuit, and a single low-pass filter may be collected and inserted in series with the signal line of the calculated distance G. In this case, the frequency ω K is separable from the frequency ω 1 and is preferably several tens Hz which is close to this.
【0034】[第2実施例]本発明の測距装置の第2実
施例について、その具体的な構成を、図2のブロック図
を引用して説明する。ここでも、特徴のある距離算出部
を説明する。[Second Embodiment] A specific configuration of a second embodiment of the distance measuring apparatus of the present invention will be described with reference to the block diagram of FIG. Here again, the characteristic distance calculator will be described.
【0035】図2のこの距離算出部は、発振信号Aと検
出信号Dとの位相差θを得るための乗積に先だって検出
信号Dの乗積相手の信号A,A’についてその位相を中
間周波数ωK で反転させてから低周波数ω1 以下の成分
を除去するために、乗算回路72,75の前に、発振回
路710と乗算回路731,762とハイパスフィルタ
732,ハイパスフィルタ762とが介挿されたもので
ある。This distance calculation unit in FIG. 2 intermediates the phases of the signals A and A'to be multiplied by the detection signal D prior to the multiplication to obtain the phase difference θ between the oscillation signal A and the detection signal D. In order to remove components below the low frequency ω 1 after being inverted at the frequency ω K , the oscillation circuit 710, the multiplication circuits 731 and 762, the high-pass filter 732, and the high-pass filter 762 are interposed before the multiplication circuits 72 and 75. It has been inserted.
【0036】発振回路710は、数百MHzの高周波数
ωM と数Hzの低周波数ω1 との間の数KHzの中間周
波数ωK で発振し、±1の値をディーティ50%でとる
発振信号Hを発生するものである。乗算回路731は、
発振信号Aと発振信号Hとを入力として乗積信号E1を
出力するものである。これにより、乗積信号E1は、高
周波数ωM の発振信号であって、その位相が中間周波数
ωK で反転するものとなっている。The oscillation circuit 710 oscillates at an intermediate frequency ω K of several KHz between a high frequency ω M of several hundred MHz and a low frequency ω 1 of several Hz, and an oscillation of ± 1 at a duty of 50%. The signal H is generated. The multiplication circuit 731 is
The oscillation signal A and the oscillation signal H are input and the product signal E1 is output. As a result, the product signal E1 is an oscillation signal of high frequency ω M , and its phase is inverted at the intermediate frequency ω K.
【0037】ハイパスフィルタ732は、乗積信号E1
を入力として周波数ωK 以上の成分だけを通過させるこ
とで乗積信号E2を生成するものである。これにより、
乗積信号E2は、直流成分や周波数ω1 の低周波数成分
が除去されたものとなる。そして、乗算回路72で、検
出信号Dと乗積されるようになっている。なお、乗積信
号E1,E2は、乗積用に変調された基準信号とでも呼
ぶべきものであるが、簡単のためこのように呼ぶ。次の
乗積信号E1’,E2’も同じである。The high pass filter 732 receives the product signal E1.
Is input and only the component of frequency ω K or higher is passed to generate the product signal E2. This allows
The product signal E2 has the DC component and the low frequency component of the frequency ω 1 removed. Then, the multiplication circuit 72 multiplies the detection signal D. The product signals E1 and E2 should be called the reference signals modulated for the product, but for simplicity, they are called in this way. The same applies to the next product signals E1 'and E2'.
【0038】乗算回路761は、乗算回路731と同様
にして、発振信号A’,Hから、高周波数ωM の発振信
号であってその位相が中間周波数ωK で反転する乗積信
号E1’を生成する。また、ハイパスフィルタ762
は、ハイパスフィルタ732と同様にして、乗積信号E
1’から、直流成分や周波数ω1 の低周波数成分が除去
された乗積信号E2’を生成する。そして、乗算回路7
5で、乗積信号E2’が検出信号Dと乗積されるように
なっている。Similar to the multiplication circuit 731, the multiplication circuit 761 produces, from the oscillation signals A ′ and H, a product signal E1 ′ which is an oscillation signal of high frequency ω M and whose phase is inverted at the intermediate frequency ω K. To generate. In addition, the high pass filter 762
In the same manner as the high pass filter 732,
A product signal E2 ′ from which the DC component and the low frequency component of the frequency ω 1 are removed is generated from 1 ′. Then, the multiplication circuit 7
At 5, the product signal E2 'is multiplied with the detection signal D.
【0039】また、図2の距離算出部は、発振信号Aと
検出信号Dとの位相差θを求めるための乗積の後に中間
周波数ωK の成分を抽出しそれから位相差θを得るため
に、乗算回路72,75の後に、バンドパスフィルタ7
33,763と振幅検出回路734,764とがそれぞ
れ直列に介挿されたものである。Further, the distance calculating section of FIG. 2 extracts the component of the intermediate frequency ω K after the multiplication for obtaining the phase difference θ between the oscillation signal A and the detection signal D, and obtains the phase difference θ from it. , The multiplication circuits 72 and 75, and then the bandpass filter 7
33 and 763 and the amplitude detection circuits 734 and 764 are respectively inserted in series.
【0040】バンドパスフィルタ733は、乗算回路7
2の出力する乗積信号E3を入力とし中間周波数ωK を
含む所定帯域の信号成分を通過させて乗積信号E4を生
成するものである。振幅検出回路734は、検波回路や
ローパスフィルタ等からなり、乗積信号E4からその振
幅の信号である位相信号Fを生成するものである。これ
により、位相信号Fは、ローパスフィルタによって低周
波数ω1 以下の準静的な信号となっている。The bandpass filter 733 is a multiplication circuit 7
The product signal E3 output by 2 is input, and the product signal E4 is generated by passing a signal component in a predetermined band including the intermediate frequency ω K. The amplitude detection circuit 734 is composed of a detection circuit, a low-pass filter, etc., and generates a phase signal F which is a signal of the amplitude from the product signal E4. As a result, the phase signal F is a quasi-static signal having a low frequency ω 1 or less due to the low pass filter.
【0041】同様に、バンドパスフィルタ763は、乗
算回路75の出力する乗積信号E3’を入力とし中間周
波数ωK を含む所定帯域の信号成分を通過させて乗積信
号E4’を生成するものであり、振幅検出回路764
は、乗積信号E4’からその振幅の信号である位相信号
F’を生成するものである。位相信号F’も、低周波数
ω1 以下の準静的な信号となっている。Similarly, the bandpass filter 763 receives the product signal E3 'output from the multiplication circuit 75 as an input and passes the signal component in a predetermined band including the intermediate frequency ω K to generate a product signal E4'. And the amplitude detection circuit 764
Is to generate a phase signal F ′ which is a signal of the amplitude from the product signal E4 ′. The phase signal F ′ is also a quasi-static signal having a low frequency ω 1 or less.
【0042】なお、位相信号Fと位相信号F’とを受け
て算出距離Gを演算する演算回路770は、乗算回路7
2,75のオフセットV72,V75が存在しないときにお
ける既述の演算を行って、位相信号Fと位相信号F’と
の位相差に基づく算出距離Gを出すようになっている。
これにより、演算回路770は、従来より簡易なものと
なっている。The arithmetic circuit 770, which receives the phase signal F and the phase signal F ′ and calculates the calculated distance G, is a multiplication circuit 7.
When the offsets V72 and V75 of 2,75 do not exist, the above-described calculation is performed to obtain the calculated distance G based on the phase difference between the phase signal F and the phase signal F '.
Thereby, the arithmetic circuit 770 is simpler than the conventional one.
【0043】この実施例の測距装置について、図3の信
号波形例を参照しながら、その動作を説明する。The operation of the distance measuring apparatus of this embodiment will be described with reference to the signal waveform example of FIG.
【0044】従来と同様に受光ゲインによる振幅をaと
おき乗算回路72,75のオフセットをそれぞれV72,
V75とおき乗算回路731,761のオフセットをそれ
ぞれV31,V61とおいて、発振信号Aと検出信号Dとの
位相差θが求められる様子を中心に説明する(図3
(a),(b)参照)。先ず、発振信号A=cos(ω
M×t)に対して(図3(c)参照)、移相発振信号
A’=sin(ωM ×t)、さらに検出信号D=a×c
os(ωM ×t−θ)が得られる。As in the conventional case, the amplitude due to the light receiving gain is set to a and the offsets of the multiplication circuits 72 and 75 are set to V72 and
A description will be given centering on a case where the phase difference θ between the oscillation signal A and the detection signal D is obtained by setting the offsets of V75 and the alternate multiplication circuits 731 and 761 to V31 and V61, respectively (FIG.
(See (a) and (b)). First, the oscillation signal A = cos (ω
M × t) (see FIG. 3C), the phase shift oscillation signal A ′ = sin (ω M × t) and the detection signal D = a × c
os (ω M × t−θ) is obtained.
【0045】次に、発振回路710によって周波数ωK
で正負反転の発振信号H=±1が供給され(図3(d)
参照)、乗算回路731によって周波数ωK で正負交互
の乗積信号E1=±cos(ωM ×t)+V31が生成さ
れる(図3(e)参照)。そして、ハイパスフィルタ7
32によって、V31が除去されて、周波数ωK で正負交
互の乗積信号E2=±cos(ωM ×t)が得られ、こ
れと検出信号Dとから乗算回路72によって周波数ωK
で正負交互の乗積信号E3=±a×cos(ωM ×t)
×cos(ωM ×t−θ)+V72=±a×(cos(2
×ωM ×t)+cos(θ))+V72が得られる(図3
(f)参照)。Next, the frequency ω K is generated by the oscillation circuit 710.
The positive and negative inversion oscillation signal H = ± 1 is supplied at (Fig. 3 (d)
See), alternating positive and negative of the product signal E1 = ± cos (ω M × t) + V31 is generated (FIG. 3 (e) at the frequency omega K by multiplier circuit 731 references). And the high pass filter 7
32 removes V31 and obtains a product signal E2 = ± cos (ω M × t) of alternating positive and negative at the frequency ω K. From this and the detection signal D, the multiplication circuit 72 causes the frequency ω K
Alternating positive and negative product signal E3 = ± a × cos (ω M × t)
× cos (ω M × t−θ) + V72 = ± a × (cos (2
× ω M × t) + cos (θ)) + V72 is obtained (FIG. 3)
(F)).
【0046】そして、バンドパスフィルタ733を経る
と、直流分や低周波数成分が落ち、さらに周波数ωM 以
上の成分も落ちて、乗積信号E4には周波数ωK の成分
だけが残る。そこで、乗積信号E4=a×cos(ωK
×t)×cos(θ)が得られる。この乗積信号E4に
は、もはや乗算回路72のオフセットV72は含まれてい
ない。この乗積信号E4から振幅検出回路734により
位相信号F=a×cos(θ)が得られる。After passing through the bandpass filter 733, the direct current component and the low frequency components drop, and further the components of the frequency ω M and above drop, and only the component of the frequency ω K remains in the product signal E4. Therefore, the product signal E4 = a × cos (ω K
Xt) * cos (θ) is obtained. The product signal E4 no longer includes the offset V72 of the multiplication circuit 72. The phase signal F = a × cos (θ) is obtained from the product signal E4 by the amplitude detection circuit 734.
【0047】繰り返しとなる説明は割愛するが、同様に
して、移相発振信号A’と検出信号Dとから乗算回路7
5等により位相信号F’=a×sin(θ)が得られ
る。これにも乗算回路75のオフセットV75は含まれて
いない。こうして、乗算回路72,75のオフセット成
分を含まない位相信号F,F’が常時生成される。Although the repeated explanation is omitted, the multiplication circuit 7 is similarly calculated from the phase shift oscillation signal A'and the detection signal D.
5, the phase signal F ′ = a × sin (θ) is obtained. This also does not include the offset V75 of the multiplication circuit 75. In this way, the phase signals F and F ′ that do not include the offset components of the multiplication circuits 72 and 75 are always generated.
【0048】そして、オフセット成分除去のための特別
な較正処理を行うもまでもなく、位相差θ=arcta
n-1(F’/F)の演算によって正確な位相差θが求め
られ、その後、既知の基本長をbとおきcを光速度とし
た算出距離G=θ×c/ωM+bの演算、及びその表示
がなされる。Then, there is no need to perform a special calibration process for removing the offset component, and the phase difference θ = arcta
An accurate phase difference θ is obtained by the calculation of n −1 (F ′ / F), and thereafter, a known basic length is set to b and a calculated distance G is defined as c is the speed of light G = θ × c / ω M + b , And its display are made.
【0049】これにより、光学系に依らずに、しかも高
周波数では良い分離特性を得難い切換回路も用いずに、
一般的な高周波帯域用の乗算回路やフィルタ回路を用い
た演算処理で簡便に、しかも連続して、正確な位相差を
得ることができた。As a result, without using the optical system, and without using the switching circuit in which it is difficult to obtain good separation characteristics at high frequencies,
An accurate phase difference could be obtained easily and continuously by arithmetic processing using a general high-frequency band multiplication circuit or filter circuit.
【0050】[0050]
【発明の効果】以上の説明から明らかなように、本発明
の第1の解決手段の測距装置にあっては、基準信号を増
やして乗積時のオフセット成分を演算だけで連続して除
去するようにしたことにより、光学系に依らずに、高精
度で連続測定可能な測距装置を実現することができたと
いう有利な効果が有る。As is apparent from the above description, in the distance measuring device according to the first solution of the present invention, the reference signal is increased and the offset component at the time of multiplication is continuously removed only by calculation. By doing so, there is an advantageous effect that it is possible to realize a distance measuring device that can perform continuous measurement with high accuracy regardless of the optical system.
【0051】また、本発明の第2の解決手段の測距装置
にあっては、位相差の成分を中間周波数の成分に残して
準静的な乗算時のオフセットを分離除去するようにした
ことにより、光学系に依らずに演算処理で簡便に、高精
度で連続測定可能な測距装置を実現することができたと
いう有利な効果を奏する。In the distance measuring apparatus according to the second solution of the present invention, the phase difference component is left as the intermediate frequency component and the offset during quasi-static multiplication is separated and removed. As a result, there is an advantageous effect that it is possible to realize a distance measuring device capable of performing continuous measurement with high accuracy simply and easily by calculation processing without depending on the optical system.
【図1】 本発明の測距装置の第1実施例についてのブ
ロック図である。FIG. 1 is a block diagram of a first embodiment of a distance measuring device according to the present invention.
【図2】 本発明の測距装置の第2実施例についてのブ
ロック図である。FIG. 2 is a block diagram of a second embodiment of the distance measuring device according to the present invention.
【図3】 その信号波形の例である。FIG. 3 is an example of the signal waveform.
【図4】 従来の測距装置の模式図兼ブロック図であ
る。FIG. 4 is a schematic diagram and a block diagram of a conventional distance measuring device.
1 ベース板 2 本体 3 レーザ 4 変調部 5 被測定物 6 受光部 7 距離算出部 8 表示部 11 反射鏡 12 較正制御回路 13 回転鏡 70 距離算出部 71 発振回路 72 乗算回路 73 ローパスフィルタ(LPF) 74 π/2移相回路 75 乗算回路 73 ローパスフィルタ(LPF) 77 演算回路 74a π移相回路 75a 切換回路 75b 切換制御回路 77a 演算回路 710 発振回路 731 乗算回路 732 ハイパスフィルタ(HPF) 733 バンドパスフィルタ(BPF) 764 振幅検出回路 761 乗算回路 762 ハイパスフィルタ(HPF) 763 バンドパスフィルタ(BPF) 764 振幅検出回路 770 演算回路 1 Base plate 2 Main body 3 Laser 4 Modulator 5 Object to be measured 6 Light receiving part 7 Distance calculating part 8 Display part 11 Reflecting mirror 12 Calibration control circuit 13 Rotating mirror 70 Distance calculating part 71 Oscillation circuit 72 Multiplying circuit 73 Low-pass filter (LPF) 74 π / 2 phase shift circuit 75 multiplication circuit 73 low pass filter (LPF) 77 arithmetic circuit 74a π phase shift circuit 75a switching circuit 75b switching control circuit 77a arithmetic circuit 710 oscillation circuit 731 multiplication circuit 732 high pass filter (HPF) 733 band pass filter (BPF) 764 Amplitude detection circuit 761 Multiplier circuit 762 High-pass filter (HPF) 763 Band-pass filter (BPF) 764 Amplitude detection circuit 770 Operation circuit
Claims (2)
号と反射レーザ光の検出信号とを乗積してから静的な又
は低周波数の成分を抽出して得た位相差に基づいて測定
距離を算出する測距装置において、前記乗積に際して前
記発振信号およびこれと位相のみ異なる2つの移相発振
信号のそれぞれについて前記検出信号との乗積を同一乗
算回路によって中間周波数で時分割的に繰り返し行う手
段と、前記位相差を得る際にこれら3種の乗積値を用い
て前記乗積時のオフセット成分を独立変数とする演算を
行う手段とを備えたことを特徴とする測距装置。1. A measurement based on a phase difference obtained by multiplying a high-frequency oscillation signal obtained by modulating irradiation laser light and a detection signal of reflected laser light and then extracting a static or low-frequency component. In the distance measuring device for calculating the distance, the product of the oscillation signal and the detection signal of each of the two phase-shifted oscillation signals whose phases are different from that of the oscillation signal are time-divided at the intermediate frequency by the same multiplication circuit. A distance measuring device comprising means for repeatedly performing the calculation and means for calculating the phase difference by using these three types of product values and using the offset component at the time of the product as an independent variable. .
号と反射レーザ光の検出信号とを乗積してから静的な又
は低周波数の成分を抽出して得た位相差に基づいて測定
距離を算出する測距装置において、前記乗積に先だって
前記検出信号の乗積相手の信号についてその位相を中間
周波数で反転させてから前記静的な成分又は前記低周波
数以下の成分を除去する手段と、前記乗積の後に前記静
的な又は前記低周波数の成分に代えて前記中間周波数の
成分を抽出してから前記位相差を得る手段とを備えたこ
とを特徴とする測距装置。2. A measurement based on a phase difference obtained by multiplying a high-frequency oscillation signal obtained by modulating an irradiation laser beam and a detection signal of a reflected laser beam and then extracting a static or low-frequency component. In a range finder for calculating a distance, a means for inverting the phase of a signal of a product of the detection signal to be multiplied by the intermediate frequency before the product, and then removing the static component or the component of the low frequency or lower. And a means for obtaining the phase difference after extracting the intermediate frequency component instead of the static or low frequency component after the product, and the distance measuring device.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP8022869A JPH09218266A (en) | 1996-02-08 | 1996-02-08 | Distance measuring apparatus |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP8022869A JPH09218266A (en) | 1996-02-08 | 1996-02-08 | Distance measuring apparatus |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH09218266A true JPH09218266A (en) | 1997-08-19 |
Family
ID=12094710
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP8022869A Pending JPH09218266A (en) | 1996-02-08 | 1996-02-08 | Distance measuring apparatus |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH09218266A (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2012021968A (en) * | 2010-07-15 | 2012-02-02 | Samsung Electro-Mechanics Co Ltd | Distance measurement module, display device including the same, method for measuring distance of display device |
KR101539556B1 (en) * | 2014-01-17 | 2015-07-28 | 여태운 | Apparatus for measuring distance using dual frequency laser |
US9492313B2 (en) | 2006-04-20 | 2016-11-15 | University Of Pittsburgh - Of The Commonwealth System Of Higher Education | Method and apparatus of noninvasive, regional brain thermal stimuli for the treatment of neurological disorders |
WO2020100808A1 (en) * | 2018-11-16 | 2020-05-22 | ソニーセミコンダクタソリューションズ株式会社 | Optical ranging device and optical ranging method |
-
1996
- 1996-02-08 JP JP8022869A patent/JPH09218266A/en active Pending
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9492313B2 (en) | 2006-04-20 | 2016-11-15 | University Of Pittsburgh - Of The Commonwealth System Of Higher Education | Method and apparatus of noninvasive, regional brain thermal stimuli for the treatment of neurological disorders |
JP2012021968A (en) * | 2010-07-15 | 2012-02-02 | Samsung Electro-Mechanics Co Ltd | Distance measurement module, display device including the same, method for measuring distance of display device |
KR101539556B1 (en) * | 2014-01-17 | 2015-07-28 | 여태운 | Apparatus for measuring distance using dual frequency laser |
WO2020100808A1 (en) * | 2018-11-16 | 2020-05-22 | ソニーセミコンダクタソリューションズ株式会社 | Optical ranging device and optical ranging method |
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