JP4782914B2

JP4782914B2 - Multi-component force measuring method and apparatus

Info

Publication number: JP4782914B2
Application number: JP2000265323A
Authority: JP
Inventors: 鎮▲かく▼ 東島
Original assignee: 鎮▲かく▼ 東島
Priority date: 1999-09-01
Filing date: 2000-09-01
Publication date: 2011-09-28
Anticipated expiration: 2020-09-01
Also published as: JP2001141584A

Description

【０００１】
【産業上の利用分野】
この発明は多分力検出器と加速度計を組み合わせて分力を測定する多分力計測方法およびその装置に関する。
【０００２】
【従来の技術】
近年、種々の技術分野で多分力検出器を用いた計測が広く行われるようになってきている。多分力検出器はＸ，Ｙ，Ｚ三軸それぞれに作用する分力、つまり力Ｆ_X,Ｆ_Y,Ｆ_ZおよびモーメントＭ_X,Ｍ_Y,Ｍ_Zとして検出し、当該部位に作用する総合的な力の状態を的確に計測するために使用される。この場合、多分力検出器の取り付けられる固定台部分に望ましくない振動が加わったり、あるいは特定な振動が加わっていると、その振動の影響が測定誤差となって現れることになり、正しい計測はできない。
【０００３】
特開昭６２−１０２１２８号公報には上記の問題を克服する一つの方法が提案されている。ここで、図１を参照して一次元計測法でその原理を簡単に説明する。特定な対象物に装着された多分力検出器１が固定台に載っていて、この固定台に加速度計３が装着されている。多分力検出器１および加速度センサ３には測定対象範囲外の高周波信号成分の除去とインピーダンスを変換するため初段増幅器２と４がそれぞれ後続している。更に、加速度センサ３用の初段増幅器４には可変抵抗ＶＲ₁による利得調整と信号反転を行う調整器５が付属している。加算部６で前記多分力検出器１の出力から前記加速度センサ３の反転出力が加算される。つまり実質上両出力信号の差を形成する。差信号は更に可変増幅器７のところで可変抵抗ＶＲ₂により適当な出力に変換され、出力端８から外部に供給される。この場合、多分力検出器１には負荷が加わっていなら、固定台の受ける振動による慣性力のみが作用する。従って、多分力検出器１と加速度センサ３の出力信号を適切に調整すれば、両方の出力信号は相殺される。それ故、固定台に振動が加わっていても、振動による慣性力を除去した負荷だけによる生の分力を出力端８で得ることができる。
【０００４】
しかし、振動は直線運動とは限らない。実際の計測では回転を伴う場合が多い。このような状況の最も簡単な例を図２と図３に基づき説明する。図２には風洞１０内の航空機模型１１に作用する分力（矢印で示す風の流れ方向をＸ方向としＦ_Xと表す）を測定する配置を示す。模型１１はストラット１３を介して分力検出器１２に連結し、更にこのストラット１３は地面１５の上に載置された固定台１４の上に固定配置されている。この場合、振動は矢印αで暗示的に示す直線運動と矢印βで暗示的に示す回転運動が加わる。模型１１の重心に加速度センサを配置できれば、回転振動の影響を除くことができるが、一般にそのような加速度センサの配置は実用上不可能である。
【０００５】
無負荷状態、つまり模型１１に風を当てない状態で分力検出器１２もしくは模型１１に加わる複合加速度を求めるため、図２に示すように、ストラット１３の二個所Ｐ₁とＰ₂にそれぞれ一つの単一方向用の加速度センサを装着し、両者の検出信号から直線方向と回転方向の加速度を求めることができる。図２の配置で固定台１４に加わる振動の影響を除去するため、図３ａに示す信号処理を用いる。分力検出器１２，加算部２５，可変増幅器２６および出力端２７の配置は、図１の分力器側の回路と同じである。ストラット１３の個所Ｐ₁とＰ₂に配置された加速度計Ａ₁とＡ₂の検出出力信号は対応する初段増幅器２２と２３に導入される。直線運動αの加速度は加速度センサＡＣ₁とＡＣ₂の検出出力信号の和に比例し、回転運動βの加速度センサＡＣ₁とＡＣ₂の出力信号の差に比例する。分力検出器２１に働く両方の運動α，βによる複合加速度は和信号と差信号にそれぞれ適当な重みを付けた加算値として表せる。つまり、この加速度が振動方向の慣性力に相当する。調整回路２４はこれ等の係数を決めるもので、更に詳しくは図３ｂに示すように、加速度センサＡＣ₁とＡＣ₂の出力電流を演算増幅器Ａ₅の反転入力端にそれぞれ対応する可変抵抗ＶＲ_a,ＶＲ_bで適当に可変して流し込み、振動による慣性力を除去する。
【０００６】
一般に、加速度計は多分力検出器ほど性能が優れていない。特に、相互干渉度（例えばＸ方向の加速度センサがＹ方向の加速度の影響を受ける度合い）は２〜３％である。これに反して、多分力検出器の相互干渉度は± 0.1％の程度である。また、振動も上記のように模型を前後方向に動かす直線振動や回転振動だけとは限らない。このような相互干渉度に鑑み、単一方向用の最大で６つの加速度センサを用いるべきである。しかし、加速度センサの個数が増大すると、調整時の試行錯誤の回数が著しく増大し、実用上実行不可能である。特に測定対象物の数カ所で同時に同様な計測を行う必要がある場合には人力で調整することはもはや不可能である。
【０００７】
【発明が解決しようとする課題】
この発明の課題は、多分力検出器の固定台に望ましくない振動が加わっていたり、あるいは振動を強制的に加えている場合、振動による慣性力の寄与を除去した状態の多分力を簡単に、早く、しかも極めて高精度で計測できる多分力計測方法およびその装置を提供することにある。
【０００８】
【課題を解決するための手段】
上記の課題は、この発明により、請求項１または２に規定する慣性力に対する加速度成分の寄与度決定方法により解決されている。
【０００９】
更に、上記の課題は、この発明により、請求項５または６の多分力計測方法により解決されている。
【００１０】
更に、上記の課題は、この発明により、請求項９〜１４の何れか１項による多分力計測装置により解決されている。
【００１１】
この発明による他の有利な構成は、特許請求の範囲の従属請求項に記載されている。
【００１２】
【発明の実施の形態】
図４〜６を参照し６成分の加速度を検出して６分力を計測するこの発明の最も一般的な多分力計測装置の機能を説明する。
【００１３】
図４に示すように、加速度センサＡＣ₁〜ＡＣ₆と付属する初段増幅器ＰＡ₁〜ＰＡ₆が、例えば長方形のブロックの中に組み込まれている加速度検出部ＡＡの回路と、初段増幅器ＰＡ₁〜ＰＡ₆の出力信号をインターフェースＩＦ₁〜ＩＦ₆で受けアナログ・デジタル変換器ＡＤ₁〜ＡＤ₆でデジタル信号に変換するデジタル加速度処理部ＢＢの回路とを用意する。このようは配置では加速度検出部ＡＡの出力端ＣＴ₁〜ＣＴ₆からアナログ加速度信号が出力され、デジタル加速度処理部ＢＢの出力端からデジタル加速度信号がバスＣＳを介して次に述べる演算処理部に供給される。
【００１４】
次に、６分力Ｆ_X,Ｆ_Y,Ｆ_Z,Ｍ_X,Ｍ_Y,Ｍ_Zを測定する検出部Ｓ₁〜Ｓ₆を取り付けた固定台と、この固定台またはこの固定台に固定連結する部材中に配置された上記加速度検出部ＡＡを用い、実際の分力測定の前に測定分力に対する振動の影響を相殺する試験モード処理を説明する。
【００１５】
図５に示すように、各分力検出部Ｓ₁〜Ｓ₆にはそれぞれ対応する初段増幅器ＱＡ_S1〜ＱＡ_S6，加算部Ｃ₁〜Ｃ₆と可変増幅器ＶＡ₁〜ＶＡ₆が順次接続され、出力端Ｏ₁〜Ｏ₆に最終的な分力成分に相当する信号がそれぞれ出力する。加算部Ｃ₁〜Ｃ₆には、次に説明するように、加速度センサの検出信号を適当に処理した信号が導入され、分力検出部Ｓ₁〜Ｓ₆の出力信号から振動成分に相当する信号をそれぞれ除去する。
【００１６】
加速度検出部ＡＡの出力端ＣＴ₁〜ＣＴ₆から加速度信号が対応する調整器ＲＧ₁〜ＲＧ₆の入力端に導入される。ここで、入力された各加速度信号に適当な係数を掛けて加算し、各調整器ＲＧ₁〜ＲＧ₆の出力端ＯＬ₁〜ＯＬ₆に出力し、この出力信号をそれぞれ当該分力に対応する加算部Ｃ₁〜Ｃ₆に導入する。
【００１７】
ここで、問題となるのは試験モードで上記の係数をどのように決定するかにある。この発明によれば、これをマイクロプロセッサの助けにより二進デジタル信号処理で実行する。各分力検出部Ｓ₁〜Ｓ₆の分力信号は導線Ｌ₁〜Ｌ₆を介してデジタル演算処理部ＤＤに導入される。同時にデジタル加速度処理部ＢＢから加速度センサの出力信号に対応するデジタル信号もデジタル導線ＣＳを介してデジタル演算処理部ＤＤに導入される。
【００１８】
デジタル演算処理部ＤＤでは、図６に示すように、導線Ｌ₁〜Ｌ₆を介して供給された分力信号をそれぞれインターフェース、例えばサンプル・ホールド回路ＩＧ₁〜ＩＧ₆に導入した後、更に対応するアナログ・デジタル変換器ＡＤ₁〜ＡＤ₆でデジタル化する。この発明によれば、実際に分力測定を行う前の試験モードの時、つまり無負荷状態で分力を測定する時にデジタル加速度処理部ＢＢからバスＣＳを介して供給されたデジタル加速度信号の各々に適当なデジタル係数値を掛け算して全て加算し、加算値が先に求めたデジタル分力信号と一致するような、係数を各分力に対して見つける。この演算はデジタル演算処理部ＤＤ内のマイクロプロセッサμＰおよび付属する記憶器ＲＯＭとＲＡＭを用いて行う。
【００１９】
デジタル演算は内蔵されている発振器ＯＳと付属する分周器ＤＶにより発生させた特定のクロック信号に基づき行われる。周知のようにＲＡＭには演算途中の値が一時保管され、ＲＯＭには制御シーケンスやこの発明の主要部である上記係数の決定を実行するプログラムが書き込まれている。各分力に対してこのようにして求めたデジタル係数値をバッファＨ_1,バスＢＳ₁を介して対応する調整器ＲＧ₁の内部の係数回路Ｐ₁₁〜Ｐ₁₆に導入する。これ等の係数回路Ｐ₁₁〜Ｐ₁₆はデジタル・アナログ変換器（ＤＡＣ）で形成されていて、図６に示すように、ＤＡＣの基準信号入力端に加速度検出部ＡＡの出力端ＣＴ₁〜ＣＴ₆の加速度信号を導入し、バスＢＳ₁から供給されたデジタル係数値をＤＡＣのデジタル入力端に入力して、各加速度信号に特定な値を乗算した出力信号が出力端から出力される。これ等の乗算出力信号を演算増幅器Ａ₁₂から成る加算回路で加算して、調整器ＲＧ₁の出力端ＯＬ₁に出力する。
【００２０】
次に、上に述べた係数決定の演算の考え方を説明する。各加速度計の振幅の周波数特性、位相の周波数特性が理想的であり、かつ方向性に関する干渉特性が線形である場合を考える。この時はｎ個の振動状態について各々代表的な一点のみを考えればよい。図４に示した加速度検出部ＡＡの出力端ＣＴ₁〜ＣＴ₆から出力する加速度センサＡＣ₁〜ＡＣ₆の加速度信号をＥＡ₁〜ＥＡ₆とし、分力検出器Ｓ₁〜Ｓ₆に対する初段増幅器ＱＡ₁〜ＱＡ₆の分力信号をＥＦ₁〜ＥＦ₆とする。ここで、係数Ｋ_ij（ｉ＝１〜６，ｊ＝１〜６）を導入し、分力Ｆ_iに対する仮想加速度信号ＳＡ_iを
【００２１】
【外１】

と定める。ＥＡ_i,ＥＦ_i,ＳＡ_i(i＝１〜６）をそれぞれベクトルＥＡ，ＥＦ，ＳＡ
【００２２】
【外２】

で表すことにする。更に、係数Ｋ_ij（i ＝１〜６， j＝１〜６）を６×６成分の行列 [Ｋ] にして
【００２３】
【外３】

と表すことができる。このベクトル・行列表示を用いると、式(1) は
ＳＡ＝ [Ｋ] ＥＡ (4)
となる。
【００２４】
試験モードで互いに異なる６つの振動状態の加速度出力信号ＥＡ ^(m)および分力出力信号ＥＦ ^(m)（ｍ＝１〜６）を測定する。これに応じて、式 (4)により対応する仮想加速度ＳＡ ^(m)（ｍ＝１〜６）が求まる。ここで、ベクトルＥＡ ⁽¹⁾，ＥＡ ⁽²⁾, ... , ＥＡ ⁽⁶⁾をこの順に並べると、６×６成分の行列
【００２５】
【外４】

を加速度行列として定義できる。同様な手順で、分力行列 [ＥＦ] および仮想加速度行列 [ＳＡ] も定義できる。この行列を用いれば、式(4) は
[ＳＡ] ＝ [Ｋ] ・ [ＥＡ] (6)
と表せる。
【００２６】
試験モードで多分力検出器から求めた各分力信号の大きさと加速度センサの対応する合成分力の大きさが一致していれば、加算器Ｃ₁〜Ｃ₆で互いに相殺され、振動による信号成分を分力信号から除去できる。言い換えれば、係数 [Ｋ] が適切に選択されていれば、互いに異なる６つの振動状態のとき仮想加速度信号は多分力検出器で求めた分力信号に一致しなければならない。即ち、
[ＳＡ] ≡ [ＥＦ] (7)
でなくてはならい。従って、式(6) と式(7) から、係数[Ｋ] は
[Ｋ] ＝ [ＳＡ] ・ [ＥＡ] ^-1 (8)
として求まる。ここで [ ]^-1は逆行列を意味する。
【００２７】
通常の場合は、各々の加速度計に振幅・位相の周波数特性の相違があり、また多分力検出器の対応する周波数特性も異なる。加速度計の干渉特性にも非線形性が含まれている。また、電気雑音、アナログ・デジタル変換器の変換器誤差などある。更に、同一加振状態を設定して加振しても、加振波形は正しい正弦波とはならず、その周波数、振幅も機械的な限界があり、厳密には一定にすることは困難である。このように実際には誤差の要因が複雑に絡まっているので、考え方は同じでも作業は単純にはならない場合が多い。このような場合には同一振動状態でも振幅や周波数の条件を変え、その各々条件内でもデータのサンプリング数をできる限り多くおり、係数 [Ｋ] の精度を高める必要がある。サンプリング数としては数百〜数千点が必要となる場合がある。
【００２８】
係数 [Ｋ] を求めるには種々の方法が考えられるが、その一例として最小二乗法がある。この方法ではデータのサンプリング総数＝Ｗ（ｖ＝１〜Ｗ），ｉ成分の分力に対する誤差の二乗和Ｄ_i
【００２９】
【外５】

を求め、Ｄ_iが最小になる係数Ｋ_ijを求める。即ち、
【００３０】
【外６】

を満たすＫ_ijを求める。
【００３１】
試験モードで係数 [Ｋ] が式(8) として、または式 (10) の解から求まれば、これを用いて実際の多分力計測で固定台に加わる振動による慣性力を除去した分力Ｆ^*を求めることができる。この分力Ｆ^*に相当する電気分力信号値ＥＦ ^*は多分力検出器が実際に測定する電気分力信号値ＥＦと加速度センサの測定する電気加速度信号値ＥＡから、
ＥＦ ^*＝ＥＦ− [Ｋ] ＥＡ (11)
として求めることができる。
【００３２】
上記の例は多分力検出器の分力成分を６とし、これに応じて使用する加速度センサの総数が６であるとして説明した。しかし、実際には６分力を計測する必要がなく、それに応じて加速度センサの総数が６以外の場合も生じる。また、測定すべき分力の成分が６であっても、加速度センサを配置する占有スペースや被測定対象物の形状等のために、６個以上の加速度センサを使用しなければ、必要な全ての加速度成分を計測できない場合もある（これについては次の段落で説明する）。このような場合でも、試験モードで測定する独立した振動状態の個数をｍ（≠６）とし、また式(1) で加速度センサについての加算指数ｊを１からｍまでとすると、 [Ｋ] を求めることができる。この時の [Ｋ] は
【００３３】
【外７】

となる。この時、前述べの式(1) は
【００３４】
【外８】

となる以外は、式(2) 〜(8) は同じ形で表せる。
【００３５】
６成分の加速度を測定できる加速度センサの望ましい配置は、特開平９−７２８０２号公報のように、立方体のブロックに６個の加速度センサを図７(a) に示すように配置し、その感度方向は図示のようにする。つまりＸ，Ｙ，Ｚ軸上にそれぞれ間隔を保って二つの加速度センサＡ_Y,Ａ_Y',Ｂ_Z,Ｂ_Z',Ｃ_X,Ｃ_X' を配置し、感度方向は下付指数で指定する方向にある。つまり、上記の場合それぞれＹ，Ｚ，Ｘの方向である。このようにすると３つの直交方向の直線加速度に対応する信号α_x,α_Y,α_Zは、
【００３６】
【外９】

であり、３つの直交方向の回転加速度に対応する信号α_Rx,α_RY,α_RZは、
【００３７】
【外１０】

である。ここで、Ｓは対応するセンサの検出信号を意味する。
【００３８】
実際の計測では多分力検出器の固定台が、例えば縦方向（Ｚ軸方向）に著しく短くなる場合が往々生じる得る。そのような場合には、図７(a) のような加速度センサＣ_X,Ｃ_X′をＺ軸上に配置できず、例えば図７(b) の配置を採用することになる。上記の式 (14), (15) で採用した規則を各記号に適用すると、３つの直交方向の直線加速度に対応する信号α_x,α_Y,α_Zは、
【００３９】
【外１１】

となり、３つの直交方向の回転加速度に対応する信号α_Rx,α_RY,α_RZは、
【００４０】
【外１２】

となる。結局、式 (16) と (27) から分かるように、このような配置では３つの直交方向の直線および回転加速度に対して加速度センサの個数を６にすることは実際には不可能で８となる。
【００４１】
この発明によれば、図６のデジタル演算処理部ＤＤの記憶器ＲＡＭおよび／またはＲＯＭに式 (8)の係数Ｋおよび／または式 (10) の解の係数Ｋの演算、および式 (11) による実効分力の演算に相当するプログラムを保管する。もちろん、試験モードでの処理で何れの演算を実行するかは、図示していない表示手段や外部入力手段を用いて指定でき、その時に必要なパラメータの値をサンプリングする手順や、試験モードで予め求めた調整係数値や、調整器ＲＧ_iのデジタル・アナログ変換器Ｐi1, Ｐi2, ...,Ｐi6（ｉ＝１〜６）に調整係数値を送る手順も記憶器ＲＯＭに書き込んでおく必要がある。
【００４２】
図４〜６に示した実施例では、分力および加速度をアナログ信号で処理し、係数調整のみをデジタル処理する方式である。この方式以外に、多分力検出器と加速度センサで検知し、初段増幅器で増幅した信号をその後全てデジタルで処理する方式も考えられる。この方式でも調整係数の決定は図６に示したデジタル演算回路ＤＤと同じ演算処理に従い、出力端ＣＴ₁〜ＣＴ₆のアナログ出力信号を使用しないでデジタル加速度処理部ＢＢのデジタル信号のみを使用し、全てデジタル演算回路ＤＤの中で処理される。出力信号はデジタルでも、またアナログでも出力できる。後者の場合では、デジタル出力信号を最終段の回路中のＤＡＣでアナログ信号に変換する。
【００４３】
以上の説明では６分力について６加速度成分検出システムを用いて６成分の振動の影響を除去する最も一般的な説明を行った。しかし、実際の計測では以下の３つの場合も想定される。
【００４４】
（１）ある特定な運動成分の振動が全く含まれないかあるいは無視できるほど
小さい。
【００４５】
（２）ある特定な運動成分の振動を含めたまま分力を計測する。
【００４６】
（３）ある特定な運動成分もしくは全ての運動成分の振動を除去した状態と除
去しない状態での分力を必要に応じてその都度切り換えて計測する。
【００４７】
上記（１）と（２）の場合には、対応する加速度成分を計測する加速度センサを排除し、振動成分を含めた状態で計測を行う。このため、不要な加速度センサの個数と付属する回路素子の部品点数を低減できる。同時に、引き算処理と関連する計算プログラムを簡素化でき、演算速度を高めることができる。これに対して、上記（３）の場合には、今まで説明した振動除去回路構成にあって、特定なもしくは全ての振動成分の振動の影響を引算する回路を使用するか使用しないかを選定する切換スイッチを対応する分力信号経路に設ける。
【００４８】
図４〜６に例示的に示した回路は、説明の都合上、最も典型的なアナログ回路、例えば電流加算を実施する演算増幅器を使用したが、その他の適当な回路も採用でき、更にデジタル回路で加速度信号のデジタル加速度処理部ＢＢと総合的なデジタル演算処理部ＤＤを別々の構成要素として説明したが、これ等は実際には一体にすべきものである。また、記憶器ＲＡＭ，ＲＯＭをそれぞれ１個用いた回路で説明したが、実際に種々のものを使用する必要がある。特に最近のデジタル回路技術の進歩により、デジタル処理部を科学計算専用の市販の回路ボードで構成することもでき、必要であれば、このデジタル処理部を表示ユニットや入出力ユニットを保有しているパソコンで構成することもできる。この場合、記憶器ＲＯＭはパソコンに内蔵されている外部記憶装置、例えばフロッピーディスクおよび／またはハードディスク装置で代用できる。このように種々の変形、改良等が考えられる。しかし、特許請求の範囲に規定する構成を備えた方法や装置は全てこの発明の範疇に属することは言うまでもない。
【００４９】
【実施例】
図８に示す自動車に振動を加えるシステムに対してこの発明による装置を実際に適用した。自動車５０の各車輪５１_1,５１₂に独立して振動を加えるため加振装置５６_1,５６₂を用い、加振装置の上にＺ方向とＹ方向の分力を検知する二分力検出器５４_1,５４₂をそれぞれ載置し、この検出器の上の支持板５２_1,５２₂にそれぞれ車輪５１_1,５１₂を載せた。更に、加振装置にＺ方向とＹ方向の加速度を検出する２成分加速度検出器（図示せず）を装備し、加速度検出器の検出信号を図３に示すような調整器２４を配置し、調整係数を調整して二分力検出器５４_1,５４₂の出力から振動による寄与を除去する試験を行った。
【００５０】
各車輪５１に対して二分力検出器５４を用いてＺ方向に周波数 14 Ｈz の純正弦波状の振動を加えた時のＦ_ZとＦ_Y分力をそれぞれ測定した。図９にその様子を示す。Ｆ_Y分力は所謂干渉効果により生じたもので、Ｆ_Z分力より約 100分の１だけ小さい。更に、加速度検出器の検出信号に適当な係数を掛けて対応する分力とし、先に二分力検出器で求めた値からこの対応する分力を引き算した。最適に調整された状態での合成分力を図１０に示す。この時のＦ_Z分力は補償なしの場合に比べて約 100分の１に低減している。Ｆ_Y分力（14 mＶ＝ 1.4Ｎ）は増幅器の動作限界範囲（５ mＶ＝ 0.5Ｎ）まで低減させることができた。二つの調整係数の設定には、図３の中の可変抵抗器ＶＲ_a,ＶＲ_b（ポテンシオメータ）を使用した。僅か二方向であっても互いに干渉があるため、手動調整では十数分間の時間を必要とした。しかし、この発明の回路を採用したら殆ど瞬時に最良調整状態を実現できた。
【００５１】
【発明の効果】
以上、説明したように、この発明の多分力計測装置により、多分力検出器の固定台に望ましくない振動が加わっていたり、あるいは振動を強制的に加えている場合、分力を簡単に、早く、しかも極めて高精度で計測できる。
【図面の簡単な説明】
【図１】一般的な従来のシステムの回路図、
【図２】二成分の分力計測システムの模式配置図、
【図３】図２で採用するシステム構成を示す回路図、
【図４】加速度検出器部とデジタル処理部の構成を示す回路図、
【図５】この発明によるシステムの全体構成を示す回路図、
【図６】図５の回路で１分力の成分に対する係数調整と付属する演算処理部の回路図、
【図７】加速度センサを設置する場合の二つの代表的な配置、
【図８】自動車の車輪に対する加振試験の模式側面図、
【図９】振動の寄与を除去していない場合の二分力の測定データ、
【図１０】振動の寄与を相殺した場合の二分力の測定データである。
【符号の説明】
Ｓ₁〜Ｓ₆ 分力検出器
ＡＣ₁〜ＡＣ₆ 加速度センサ
ＰＡ₁〜ＰＡ₆ 初段増幅器
ＱＡ₁〜ＱＡ₆ 初段増幅器
ＶＡ₁〜ＶＡ₆ 可変増幅器
ＡＤ₁〜ＡＤ₆ アナログ・デジタル変換器
ＩＦ₁〜ＩＦ₆ インターフェース（サンプル・ホールド回路）
ＡＡ加速度検出部
ＢＢデジタル加速度処理部
ＤＤデジタル演算処理部
ＲＧ₁〜ＲＧ₆ 調整器
Ｃ₁〜Ｃ₆ 加算部
Ｐ₁₁〜Ｐ₆₆ 係数回路[0001]
[Industrial application fields]
The present invention relates to a multi-component force measuring method and apparatus for measuring a component force by combining a multi-component detector and an accelerometer.
[0002]
[Prior art]
In recent years, measurement using a multi-component force detector has been widely performed in various technical fields. The multi-component force detector detects the component force acting on each of the X, Y, and Z axes, that is, the forces F _X, F _Y, F _Z and the moments M _X, M _Y, M _{Z and} comprehensively acts on the relevant part. Used to accurately measure the state of force. In this case, if an undesirable vibration is applied to the fixed base part to which the force detector is attached or a specific vibration is applied, the influence of the vibration will appear as a measurement error and correct measurement cannot be performed. .
[0003]
Japanese Patent Laid-Open No. 62-102128 proposes one method for overcoming the above-mentioned problems. Here, the principle will be briefly described with reference to FIG. The force detector 1 mounted on a specific object is placed on a fixed base, and the accelerometer 3 is mounted on the fixed base. The multi-component force detector 1 and the acceleration sensor 3 are respectively followed by first-stage amplifiers 2 and 4 for removing high-frequency signal components outside the measurement target range and converting impedance. Further, the first-stage amplifier 4 for the acceleration sensor 3 is provided with a regulator 5 that performs gain adjustment and signal inversion by the variable resistor VR ₁ . The addition unit 6 adds the inverted output of the acceleration sensor 3 from the output of the multi-force detector 1. That is, a difference between both output signals is formed substantially. The difference signal is further converted into an appropriate output by the variable resistor VR ₂ at the variable amplifier 7 and supplied to the outside from the output terminal 8. In this case, if a load is applied to the force detector 1, only the inertial force due to the vibration received by the fixed base acts. Accordingly, if the output signals of the force detector 1 and the acceleration sensor 3 are appropriately adjusted, both output signals are canceled out. Therefore, even if vibration is applied to the fixed base, a raw component force only from the load from which the inertial force due to vibration is removed can be obtained at the output end 8.
[0004]
However, vibration is not always linear motion. Actual measurement often involves rotation. The simplest example of such a situation will be described with reference to FIGS. FIG. 2 shows an arrangement for measuring the component force acting on the aircraft model 11 in the wind tunnel 10 (the wind flow direction indicated by the arrow is the X direction and is expressed as F _X ). The model 11 is connected to a component force detector 12 via a strut 13, and the strut 13 is fixedly arranged on a fixed base 14 placed on the ground 15. In this case, the vibration is applied with a linear motion implicitly indicated by an arrow α and a rotational motion implicitly indicated by an arrow β. If an acceleration sensor can be arranged at the center of gravity of the model 11, the influence of rotational vibration can be eliminated. However, in general, such an acceleration sensor is not practically arranged.
[0005]
Unloaded condition, i.e. for obtaining a composite acceleration applied to the component force detector 12 or model 11 in a state in which not expose the wind model 11, as shown in FIG. 2, respectively two locations P ₁ and P ₂ of the strut 13 one Two acceleration sensors for a single direction are mounted, and accelerations in the linear direction and the rotational direction can be obtained from the detection signals of both. In order to remove the influence of vibration applied to the fixed base 14 in the arrangement of FIG. 2, the signal processing shown in FIG. 3a is used. The arrangement of the component force detector 12, the adding unit 25, the variable amplifier 26, and the output terminal 27 is the same as that of the circuit on the component component side in FIG. The detection output signals of the accelerometers A ₁ and A ₂ arranged at the points P ₁ and P ₂ of the strut 13 are introduced into the corresponding

first stage amplifiers

22 and 23. Acceleration of linear motion α is proportional to the sum of the detection output signal of the acceleration sensor AC ₁ and AC _2, proportional to the difference of the acceleration sensor AC ₁ and AC ₂ output signals of the rotational movement beta. The combined acceleration due to both movements α and β acting on the component force detector 21 can be expressed as an added value obtained by appropriately weighting the sum signal and the difference signal. That is, this acceleration corresponds to the inertial force in the vibration direction. The adjustment circuit 24 determines these coefficients. More specifically, as shown in FIG. 3b, the variable current VR _a corresponding to the inverting input terminal of the operational amplifier A _{5 is} applied to the output currents of the acceleration sensors AC ₁ and AC _2. _, VR _b is appropriately varied and poured to remove the inertial force caused by vibration.
[0006]
In general, accelerometers do not perform as well as perhaps force detectors. In particular, the degree of mutual interference (for example, the degree to which the acceleration sensor in the X direction is affected by the acceleration in the Y direction) is 2 to 3%. On the other hand, the mutual interference of the force detector is about ± 0.1%. Further, the vibration is not limited to linear vibration or rotational vibration that moves the model in the front-rear direction as described above. In view of such mutual interference, a maximum of six acceleration sensors for a single direction should be used. However, when the number of acceleration sensors increases, the number of trial and error during adjustment increases remarkably and is impractical. In particular, when it is necessary to perform the same measurement simultaneously at several places on the measurement object, it is no longer possible to adjust manually.
[0007]
[Problems to be solved by the invention]
The problem of the present invention is that when an undesirable vibration is applied to the fixed base of the force detector, or when the vibration is forcibly applied, the force of the state in which the contribution of the inertial force due to the vibration is removed, It is an object of the present invention to provide a multi-component force measuring method and apparatus capable of measuring quickly and with extremely high accuracy.
[0008]
[Means for Solving the Problems]
According to the present invention, the above problem is solved by the method for determining the contribution degree of the acceleration component to the inertial force defined in

claim

1 or 2.
[0009]
Furthermore, the above-described problems are solved by the multi-component force measuring method according to

claim

5 or 6 according to the present invention.
[0010]
Furthermore, said subject is solved by the multiple force measuring device by any one of Claims 9-14 by this invention.
[0011]
Other advantageous configurations according to the invention are described in the dependent claims.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIGS. 4 to 6, the function of the most general multi-component force measuring apparatus according to the present invention for measuring six component forces by detecting six component accelerations will be described.
[0013]
As shown in FIG. 4, acceleration sensors AC _{1 to} AC ₆ and attached first-stage amplifiers PA _{1 to} PA ₆ include, for example, a circuit of an acceleration detection unit AA incorporated in a rectangular block, and first-stage amplifiers PA ₁ to PA ₆ . A circuit of a digital acceleration processing unit BB that receives an output signal of PA ₆ by interfaces IF _{1 to} IF ₆ and converts it into a digital signal by analog / digital converters AD _{1 to} AD ₆ is prepared. In this arrangement, analog acceleration signals are output from the output terminals CT _{1 to} CT ₆ of the acceleration detection unit AA, and the digital acceleration signal is output from the output terminal of the digital acceleration processing unit BB to the arithmetic processing unit described below via the bus CS. Supplied.
[0014]
Next, a fixed base on which detectors S _{1 to} S ₆ for measuring six component forces F _X, F _Y, F _Z, M _X, M _{Y, and} M _Z are attached, and this fixed base or this fixed base is fixedly connected A test mode process for canceling the influence of vibration on the measured component force before the actual component force measurement using the acceleration detector AA arranged in the member to be described will be described.
[0015]
As shown in FIG. 5, the first-stage amplifier QA _S1 ~QA _S6 respectively on each component force detector S ₁ to S ₆ corresponding, addition section C ₁ -C ₆ and the variable amplifier VA ₁ to VA ₆ are sequentially connected, Signals corresponding to final component components are output to the output terminals O _{1 to} O ₆ , respectively. As will be described below, a signal obtained by appropriately processing the detection signal of the acceleration sensor is introduced into the adding units C _{1 to} C ₆ , and corresponds to the vibration component from the output signals of the component force detecting units S _{1 to} S _6. Remove each signal.
[0016]
Acceleration signals are introduced from the output terminals CT _{1 to} CT _{6 of the} acceleration detector AA to the input terminals of the corresponding adjusters RG _{1 to} RG ₆ . Here, the sum is multiplied by an appropriate coefficient to each acceleration signals input, and outputs to an output terminal OL ₁ ~OL ₆ of the regulator RG ₁ ~RG _6, the corresponding output signal to each said component of force Introduced into the addition units C _{1 to} C ₆ .
[0017]
Here, the problem is how to determine the above coefficients in the test mode. According to the invention, this is performed with binary digital signal processing with the aid of a microprocessor. The component force signals of the component force detection units S _{1 to} S ₆ are introduced into the digital arithmetic processing unit DD via the conducting wires L _{1 to} L ₆ . At the same time, a digital signal corresponding to the output signal of the acceleration sensor from the digital acceleration processing unit BB is also introduced into the digital arithmetic processing unit DD via the digital lead CS.
[0018]
In the digital arithmetic processing unit DD, as shown in FIG. 6, the component signals supplied via the conducting wires L _{1 to} L ₆ are respectively introduced into the interfaces, for example, the sample and hold circuits IG _{1 to} IG ₆ , and further supported. Digitizing is performed by the analog / digital converters AD _{1 to} AD ₆ . According to the present invention, each of the digital acceleration signals supplied from the digital acceleration processing unit BB via the bus CS in the test mode before actually measuring the component force, that is, when measuring the component force in the no-load state. Multiply appropriate digital coefficient values and add them all, and find a coefficient for each component force such that the added value matches the digital component force signal previously determined. This calculation is performed using the microprocessor μP in the digital calculation processing unit DD and the attached memory ROM and RAM.
[0019]
Digital calculation is performed based on a specific clock signal generated by a built-in oscillator OS and a frequency divider DV attached thereto. As is well known, a value in the middle of calculation is temporarily stored in the RAM, and a control sequence and a program for determining the coefficient, which is a main part of the present invention, are written in the ROM. The digital coefficient value thus obtained for each component force is introduced into the coefficient circuits P _{11 to} P ₁₆ inside the corresponding regulator RG ₁ via the buffer H _{1 and the} bus BS ₁ . These coefficient circuits P _{11 to} P ₁₆ are formed by digital-to-analog converters (DACs). As shown in FIG. 6, the reference signal input terminal of the DAC is connected to the output terminals CT _{1 to} CT of the acceleration detector AA. introducing a ₆ acceleration signal, by inputting a digital coefficient value supplied from the bus BS ₁ to the digital input of DAC, the output signal multiplied by a specific value to the acceleration signal is outputted from the output terminal. The multiplication output signal of this or the like are added in the addition circuit consisting of the operational amplifier A _12, to an output terminal OL ₁ of the regulator RG _1.
[0020]
Next, the way of thinking of the coefficient determination described above will be described. Consider a case where the frequency characteristics of the amplitude and the phase of each accelerometer are ideal and the interference characteristics related to directionality are linear. At this time, only one representative point needs to be considered for each of the n vibration states. An acceleration signal of the acceleration sensor AC ₁ to Ac ₆ for outputting from the output terminal CT ₁ to CT ₆ acceleration detection section AA shown in FIG. 4 and EA ₁ ~EA _6, the first-stage amplifier for component force detector S ₁ to S ₆ The component signals of QA _{1 to} QA ₆ are defined as EF ₁ to EF ₆ . Here, the coefficient K _ij (i = 1 to 6, j = 1 to 6) is introduced, and the virtual acceleration signal SA _i with respect to the component force F _{i is} expressed as follows.
[Outside 1]

It is determined. EA _i, EF _i, SA _i (i = 1 to 6) are respectively converted into vectors EA , EF , SA
[0022]
[Outside 2]

It will be expressed as Further, the coefficient K _ij (i = 1 to 6, j = 1 to 6) is changed to a 6 × 6 component matrix [K].
[Outside 3]

It can be expressed as. Using this vector / matrix representation, equation (1) becomes
SA = [K] EA (4)
It becomes.
[0024]
The acceleration output signal EA ^(m) and the component force output signal EF ^(m) (m = 1 to 6) in six different vibration states are measured in the test mode. In response to this, the corresponding virtual acceleration SA ^(m) (m = 1 to 6) is obtained by the equation (4). Here, when vectors EA ⁽¹⁾ , EA ⁽²⁾ ,..., EA ⁽⁶⁾ are arranged in this order, a 6 × 6 component matrix
[Outside 4]

Can be defined as an acceleration matrix. A force matrix [EF] and a virtual acceleration matrix [SA] can be defined in the same procedure. Using this matrix, equation (4) becomes
[SA] = [K] · [EA] (6)
It can be expressed.
[0026]
If the magnitude of each component force signal obtained from the multi-component force detector in the test mode matches the magnitude of the corresponding synthesized component force of the acceleration sensor, the adders C _{1 to} C ₆ cancel each other, and the signal due to vibration The component can be removed from the component force signal. In other words, if the coefficient [K] is appropriately selected, the virtual acceleration signal must match the component force signal obtained by the multi-component force detector in six different vibration states. That is,
[SA] ≡ [EF] (7)
Must be. Therefore, from equation (6) and equation (7), the coefficient [K] is
[K] = [SA]-[EA] ^-1 (8)
It is obtained as Where [] ^-1 means an inverse matrix.
[0027]
In the normal case, each accelerometer has a difference in frequency characteristics of amplitude and phase, and the corresponding frequency characteristics of the multi-force detector are also different. The interference characteristics of accelerometers also include nonlinearity. There are also electrical noise, converter error of analog / digital converter, and so on. Furthermore, even if the same vibration state is set and vibration is performed, the vibration waveform is not a correct sine wave, and its frequency and amplitude are mechanically limited. is there. In this way, since the factors of errors are actually complicated, the work is often not simplified even though the idea is the same. In such a case, it is necessary to change the amplitude and frequency conditions even in the same vibration state, to increase the number of data samplings within each condition as much as possible, and to improve the accuracy of the coefficient [K]. As the number of samplings, hundreds to thousands of points may be required.
[0028]
Various methods can be considered for obtaining the coefficient [K]. One example is the least square method. In this method, the total number of data samplings = W (v = 1 to W), the sum of squares of errors D _{i with} respect to the component of i component
[0029]
[Outside 5]

And a coefficient K _ij that minimizes D _i is obtained. That is,
[0030]
[Outside 6]

Find K _ij that satisfies.
[0031]
In the test mode, if the coefficient [K] is obtained as the equation (8) or from the solution of the equation (10), the component force F is used to remove the inertial force due to the vibration applied to the fixed base in the actual multicomponent force measurement. ^* Can be requested. From the electrical acceleration signal value EA to measure the electrical component force signal value EF and the acceleration sensor electrical component force signal value EF ^* is perhaps the force detector is actually measured that corresponds to this component force F ^*,
EF ^* = EF- [K] EA (11)
Can be obtained as
[0032]
In the above example, it is assumed that the component force component of the multi-component force detector is 6, and the total number of acceleration sensors used according to this is 6. However, actually, it is not necessary to measure the six component forces, and accordingly, the total number of acceleration sensors may be other than six. Moreover, even if the component of the component force to be measured is 6, all the necessary components are required unless six or more acceleration sensors are used because of the occupied space in which the acceleration sensor is arranged or the shape of the measurement object. May not be measured (this will be explained in the next paragraph). Even in such a case, if the number of independent vibration states measured in the test mode is m (≠ 6) and the addition index j for the acceleration sensor is 1 to m in equation (1), [K] is Can be sought. [K] at this time is [0033]
[Outside 7]

It becomes. At this time, the expression (1) described above is
[Outside 8]

Except that, the equations (2) to (8) can be expressed in the same form.
[0035]
A desirable arrangement of an acceleration sensor capable of measuring six-component acceleration is as shown in FIG. 7 (a), in which six acceleration sensors are arranged in a cubic block as disclosed in JP-A-9-72802. Is as shown. In other words, two acceleration sensors A _Y, A _Y ', B _Z, B _Z ', C _X, C _X 'are arranged on the X, Y, Z axes at intervals, and the sensitivity direction is specified by a subscript index. It is in the direction to do. That is, in the above case, the directions are Y, Z, and X, respectively. In this way, the signals α _x, α _Y, α _Z corresponding to the three linear accelerations in the orthogonal direction are
[0036]
[Outside 9]

The signals α _Rx, α _RY, α _RZ corresponding to the three rotational accelerations in the orthogonal direction are
[0037]
[Outside 10]

It is. Here, S means a detection signal of the corresponding sensor.
[0038]
In actual measurement, it may often happen that the fixing base of the force detector is significantly shortened, for example, in the longitudinal direction (Z-axis direction). In such a case, the acceleration sensors C _{X and} C _X ′ as shown in FIG. 7A cannot be arranged on the Z axis, and for example, the arrangement shown in FIG. 7B is adopted. Applying the rules adopted in equations (14) and (15) above to each symbol, the signals α _x, α _Y, α _Z corresponding to the three linear accelerations in the orthogonal direction are
[0039]
[Outside 11]

The signals α _Rx, α _RY, α _RZ corresponding to the rotational accelerations in the three orthogonal directions are
[0040]
[Outside 12]

It becomes. Eventually, as can be seen from equations (16) and (27), with such an arrangement, it is actually impossible to reduce the number of acceleration sensors to six for three orthogonal straight lines and rotational acceleration. Become.
[0041]
According to the present invention, the calculation of the coefficient K of equation (8) and / or the coefficient K of the solution of equation (10) in the storage RAM and / or ROM of the digital arithmetic processing unit DD of FIG. Stores the program equivalent to the calculation of effective component force by. Of course, which calculation is executed in the process in the test mode can be designated by using a display means or an external input means (not shown), and the necessary parameter values at that time are sampled in advance or in the test mode. adjustment coefficient values or determined, regulator RG _i of a digital-to-analog converter Pi1, Pi2, ..., is necessary to write the instructions also storage device ROM to send an adjustment coefficient values Pi6 (i = 1~6) is there.
[0042]
In the embodiments shown in FIGS. 4 to 6, the component force and acceleration are processed by analog signals, and only coefficient adjustment is digitally processed. In addition to this method, a method in which the signal detected by the multi-force detector and the acceleration sensor and amplified by the first stage amplifier is digitally processed thereafter is also conceivable. Even in this method, the adjustment coefficient is determined in accordance with the same arithmetic processing as the digital arithmetic circuit DD shown in FIG. 6, and only the digital signal of the digital acceleration processing unit BB is used without using the analog output signals of the output terminals CT _{1 to} CT _6. Are all processed in the digital arithmetic circuit DD. The output signal can be output digitally or analogly. In the latter case, the digital output signal is converted into an analog signal by the DAC in the final stage circuit.
[0043]
In the above description, the most general description of removing the influence of the vibration of the six components using the six acceleration component detection system for the six component forces has been given. However, the following three cases are assumed in actual measurement.
[0044]
(1) The vibration of a specific motion component is not included at all or is negligibly small.
[0045]
(2) The component force is measured while including the vibration of a specific motion component.
[0046]
(3) The component force in the state where the vibration of a specific motion component or all the motion components is removed and the state where it is not removed are switched and measured as necessary.
[0047]
In the case of (1) and (2) above, the acceleration sensor that measures the corresponding acceleration component is excluded, and the measurement is performed with the vibration component included. For this reason, it is possible to reduce the number of unnecessary acceleration sensors and the number of parts of attached circuit elements. At the same time, the calculation program related to the subtraction process can be simplified, and the calculation speed can be increased. On the other hand, in the case of (3) above, whether the circuit for subtracting the influence of vibration of a specific or all vibration component is used or not in the vibration removal circuit configuration described so far. A selector switch to be selected is provided in the corresponding component force signal path.
[0048]
The circuits illustrated in FIGS. 4 to 6 use the most typical analog circuits, for example, operational amplifiers that perform current addition, for convenience of explanation, but other suitable circuits may be employed, and digital circuits. In the above description, the digital acceleration processing unit BB for acceleration signals and the overall digital arithmetic processing unit DD have been described as separate components, but these should be integrated in practice. Further, although the circuit using one memory RAM and one ROM has been described, it is necessary to actually use various types of memories. In particular, due to recent advances in digital circuit technology, the digital processing unit can be configured with a commercially available circuit board dedicated to scientific calculation. If necessary, this digital processing unit has a display unit and input / output unit. It can also be configured with a personal computer. In this case, the storage ROM can be replaced with an external storage device built in the personal computer, such as a floppy disk and / or a hard disk device. As described above, various modifications and improvements can be considered. However, it goes without saying that all methods and apparatuses having the configuration defined in the claims belong to the category of the present invention.
[0049]
【Example】
The apparatus according to the present invention was actually applied to the system for applying vibration to the automobile shown in FIG. Each wheel 51 _1, 51 ₂ independently vibrated to apply vibration of a motor vehicle 50 56 _1, 56 ₂ using a two-component force detector for detecting the Z-direction and Y-direction component force on the vibrating device 54 _{1 and} 54 ₂ were placed, and wheels 51 _{1 and} 52 ₂ were placed on support plates 52 _{1 and} 52 ₂ above the detectors, respectively. Furthermore, the vibration device is equipped with a two-component acceleration detector (not shown) for detecting the acceleration in the Z direction and the Y direction, and the adjuster 24 as shown in FIG. A test was conducted to remove the contribution of vibration from the outputs of the _{two-component} force detectors 54 _{1 and} 54 ₂ by adjusting the adjustment coefficient.
[0050]
Using the two component force detector 54 for each wheel 51, F _Z and F _Y component forces were measured when a pure sine wave vibration having a frequency of 14 Hz was applied in the Z direction. This is shown in FIG. The F _Y component is caused by the so-called interference effect, and is approximately 1/100 smaller than the F _Z component. Further, the detection signal of the acceleration detector is multiplied by an appropriate coefficient to obtain a corresponding component force, and the corresponding component force is subtracted from the value previously obtained by the two-component force detector. FIG. 10 shows the resultant component force in an optimally adjusted state. F _Z component force at this time is reduced to about 1/100 as compared with the case without compensation. The F _Y component (14 mV = 1.4 N) could be reduced to the operational limit range of the amplifier (5 mV = 0.5 N). The variable resistors VR _{a and} VR _b (potentiometers) in FIG. 3 were used for setting the two adjustment factors. Even in only two directions, there is an interference with each other, so manual adjustment required a time of several tens of minutes. However, when the circuit of the present invention is employed, the best adjustment state can be realized almost instantaneously.
[0051]
【The invention's effect】
As described above, the multi-component force measuring device according to the present invention makes it possible to easily and quickly apply the component force when undesirable vibration is applied to the fixed base of the multi-component force detector or when vibration is forcibly applied. Moreover, it can measure with extremely high accuracy.
[Brief description of the drawings]
FIG. 1 is a circuit diagram of a general conventional system;
FIG. 2 is a schematic layout diagram of a two-component component force measurement system,
FIG. 3 is a circuit diagram showing a system configuration adopted in FIG. 2;
FIG. 4 is a circuit diagram showing a configuration of an acceleration detector unit and a digital processing unit;
FIG. 5 is a circuit diagram showing the overall configuration of a system according to the present invention;
6 is a circuit diagram of a coefficient adjustment for the component of one component force and an attached arithmetic processing unit in the circuit of FIG.
FIG. 7 shows two typical arrangements when installing an acceleration sensor.
FIG. 8 is a schematic side view of a vibration test for a vehicle wheel;
FIG. 9 shows the measurement data of the two component forces when the contribution of vibration is not removed,
FIG. 10 is measurement data of a two-component force when the contribution of vibration is canceled.
[Explanation of symbols]
S ₁ to S ₆ component force detector AC ₁ to Ac ₆ acceleration sensor PA ₁ ~PA _6-stage amplifier QA ₁ ~QA _6-stage amplifier VA ₁ to VA ₆ variable amplifier AD ₁ to AD ₆ analog to digital converter IF ₁ ~ IF ₆ interface (sample and hold circuit)
AA acceleration detector BB digital acceleration processor DD digital processing unit RG ₁ ~RG ₆ regulator C ₁ -C ₆ adder unit P ₁₁ to P ₆₆ coefficient circuit

Claims

A multi-component force detector that is fixed between the object to be measured and the reference portion via the connecting member and measures M kinds of component forces with M being 2 or more and 6 or less, and m fixed to the connecting member and m is a positive integer And determining the contribution of the acceleration component to the inertial force due to the vibration applied to the connecting member when no external force acts on the measurement object.
The number m of acceleration sensors is equal to the number M of component components,
A signal value EFi (k) for i component force is obtained in vibration states k independent from each other, where k = 2 to n; n ≧ M and i = 1 to M,
At the same time, signal values EAj (k) of all acceleration sensors are obtained, where j = 1 to m,
Using an unknown coefficient Kij for the acceleration sensor signal value EAj for each i component force,
Kij is determined for all vibration states k and i component forces so that an addition value obtained by adding the multiplication value KijEAj (k) for all j matches the obtained component force signal value EFi (k), and inertia. Acceleration component contribution to force
A method characterized by that.

A multi-component force detector that is fixed between the object to be measured and the reference portion via the connecting member and measures M kinds of component forces with M being 2 or more and 6 or less, and m fixed to the connecting member and m is a positive integer And determining the contribution of the acceleration component to the inertial force due to the vibration applied to the connecting member when no external force acts on the measurement object.
A signal value EFi (k) for i component force is obtained in vibration states k independent from each other, where k = 2 to n; n ≧ M and i = 1 to M,
At the same time, signal values EAj (k) of all acceleration sensors are obtained, where j = 1 to m,
Using an unknown coefficient Kij for the acceleration sensor signal value EAj for each i component force,
The least square method is used so that the sum obtained by adding the multiplication value KijEAj (k) for all j and the square value of the difference between the calculated component force signal values EFi (k) for all k is minimized. Kij is determined for all i component forces, and the contribution of the acceleration component to the inertial force is determined.
A method characterized by that.

3. The method according to claim 1, wherein the number m of the acceleration sensors is a number capable of detecting vibration components equal to the number M of component components to be measured.

3. The method according to claim 1, wherein the number m of the acceleration sensors is a number capable of detecting vibration components smaller than the number M of component components to be measured.

A multi-component force detector that is fixed between the object to be measured and the reference portion via the connecting member and measures M kinds of component forces with M being 2 or more and 6 or less, and m fixed to the connecting member and m is a positive integer In the multi-component force measurement method for measuring the component force acting on the measurement object under the condition that the inertia force due to the vibration applied to the connection member is excluded, using m acceleration sensors
In the case of actual external force measurement, the component force signal value EFi of the multi-component force detector and the signal value EAj of the acceleration sensor are obtained, and the multiplication value KijEAj is added to all j using the coefficient Kij obtained by the method of claim 1. A value EFi * obtained by subtracting the component force signal value EFi by an integrated value is an external force signal value of i component force, where i = 1 to M.
This is a method for measuring force.

A multi-component force detector that is fixed between the object to be measured and the reference portion via the connecting member and measures M kinds of component forces with M being 2 or more and 6 or less, and m fixed to the connecting member and m is a positive integer In the multi-component force measurement method for measuring the component force acting on the measurement object under the condition that the inertia force due to the vibration applied to the connection member is excluded, using m acceleration sensors
In the case of actual external force measurement, the component force electric signal value EFi of the multi-component force detector and the signal value EAj of the acceleration sensor are obtained, respectively, and the multiplication value KijEAj is added to all j using the coefficient Kij obtained by the method of claim 2. A value EFi * obtained by subtracting the component force signal value EFi by the integrated value is defined as an external force signal value of i component force, where i = 1 to M.
This is a method for measuring force.

The multi-component force measuring method according to claim 5 or 6, wherein the number m of the acceleration sensors is a number capable of detecting vibration components equal to the number M of component components to be measured.

The multi-component force measuring method according to claim 5 or 6, wherein the number m of the acceleration sensors is a number capable of detecting vibration components smaller than the number M of component components to be measured.

A multi-component force detector that is fixed between the object to be measured and the reference portion via the connecting member and measures M kinds of component forces with M being 2 or more and 6 or less, and m fixed to the connecting member and m is a positive integer A multi-component force measuring device that measures the component force applied to the measurement object under the condition that the inertial force due to the vibration applied to the connection member is excluded,
Analog / digital conversion means for converting the analog output signals of the multi-force detector and the acceleration sensor into corresponding digital signals, respectively.
An input means for entering the required numerical values and formulas,
Storage means for storing an arithmetic program for determining the coefficient Kij according to the method of claim 1;
Arithmetic processing means for calculating a coefficient Kij as a digital value from the digital acceleration signal value and the digital component force signal value according to the arithmetic program;
In order to multiply each analog acceleration signal value EAj by the digital coefficient Kij calculated by the arithmetic processing means, the multiplication circuit of the digital / analog converter, the addition circuit for adding the multiplication value KijEAj to all the acceleration components j, and i component force An analog processing circuit comprising: a subtracting circuit that subtracts the multiplication value KijEAj obtained by adding all the acceleration components from the analog signal value EFi to an analog external force signal value EFi * of i component force; A multi-component force measuring device characterized by comprising.

A multi-component force detector that is fixed between the object to be measured and the reference portion via the connecting member and measures M kinds of component forces with M being 2 or more and 6 or less, and m fixed to the connecting member and m is a positive integer A multi-component force measuring device that measures the component force applied to the measurement object under the condition that the inertial force due to the vibration applied to the connection member is excluded,
Analog / digital conversion means for converting the analog output signals of the multi-force detector and the acceleration sensor into corresponding digital signals, respectively.
An input means for entering the required numerical values and formulas,
Storage means for storing a calculation program for determining the coefficient Kij according to the method of claim 2;
Arithmetic processing means for calculating a coefficient Kij as a digital value from the digital acceleration signal value and the digital component signal value according to the arithmetic program;
In order to multiply each analog acceleration signal value EAj by the digital coefficient Kij calculated by the arithmetic processing means, the multiplication circuit of the digital / analog converter, the addition circuit for adding the multiplication value KijEAj to all the acceleration components j, and i component force An analog processing unit comprising: a subtracting circuit that subtracts the multiplication value KijEAj obtained by adding all acceleration components from the analog signal value EFi of the signal to obtain an analog external force signal value EFi * of a component force; A multi-component force measuring device characterized by comprising.

A multi-component force detector that is fixed between the object to be measured and the reference portion via the connecting member and measures M kinds of component forces with M being 2 or more and 6 or less, and m fixed to the connecting member and m is a positive integer A multi-component force measuring device that measures the component force applied to the measurement object under the condition that the inertial force due to the vibration applied to the connection member is excluded,
Analog / digital conversion means for converting the analog output signals of the multi-force detector and the acceleration sensor into corresponding digital signals, respectively.
An input means for entering the required numerical values and formulas,
The first calculation program for determining the coefficient Kij according to the method of claim 1 and the external force signal value EFi * of i component force to be measured from the digital acceleration signal value EAj and the digital component signal value EFi according to the multiple force measurement method of claim 5 Storage means for storing a second arithmetic program for obtaining
Arithmetic processing means for calculating the coefficient Kij as a digital value from the digital acceleration signal value and the digital component force signal value according to the first calculation program, and for obtaining the external force signal value EFi * of i component force as the digital value according to the second calculation program;
A multi-component force measuring device comprising: an electric processing device comprising:

A multi-component force detector that is fixed between the object to be measured and the reference portion via the connecting member and measures M kinds of component forces with M being 2 or more and 6 or less, and m fixed to the connecting member and m is a positive integer A multi-component force measuring device that measures the component force applied to the measurement object under the condition that the inertial force due to the vibration applied to the connection member is excluded,
Analog / digital conversion means for converting the analog output signals of the multi-force detector and the acceleration sensor into corresponding digital signals, respectively.
An input means for entering the required numerical values and formulas,
The first calculation program for determining the coefficient Kij according to the method of claim 2 and the external force signal value EFi * of i component force to be measured from the digital acceleration signal value EAj and the digital component signal value EFi according to the multiple force measurement method of claim 6. Storage means for storing a second arithmetic program for obtaining
Arithmetic processing means for calculating the coefficient Kij as a digital value from the digital acceleration signal value and the digital component force signal value according to the first calculation program, and for obtaining the external force signal value EFi * of i component force as the digital value according to the second calculation program;
A multi-component force measuring device comprising: an electric processing device comprising:

A multi-component force that includes a multi-component force detector that measures M types of component forces that are fixed between the measurement object and the reference portion via the connecting member and M is 2 or more and 6 or less, and that outputs an output signal as a digital signal EFi. An object to be measured under a condition that includes a detection device and an acceleration measurement device that includes m acceleration sensors in which m is a positive integer and outputs an output signal as a digital signal EAj , and that eliminates inertial force due to vibration applied to the connecting member In a multi-component force measuring device that measures the component force applied to an object,
An input means for entering the required numerical values and formulas,
The first calculation program for determining the coefficient Kij according to the method of claim 1 and the external force signal value EFi * of i component force to be measured from the digital acceleration signal value EAj and the digital component signal value EFi according to the multiple force measurement method of claim 5 Storage means for storing a second arithmetic program for obtaining
Arithmetic processing means for calculating the coefficient Kij as a digital value from the digital acceleration signal value and the digital component force signal value according to the first calculation program, and for obtaining the external force signal value EFi * of i component force as the digital value according to the second calculation program;
A multi-component force measuring device comprising: an electric processing device comprising:

A multi-component force that includes a multi-component force detector that measures M types of component forces that are fixed between the measurement object and the reference portion via the connecting member and M is 2 or more and 6 or less, and that outputs an output signal as a digital signal EFi. An object to be measured under a condition that includes a detection device and an acceleration measurement device that includes m acceleration sensors in which m is a positive integer and outputs an output signal as a digital signal EAj , and that eliminates inertial force due to vibration applied to the connecting member In a multi-component force measuring device that measures the component force applied to an object,
An input means for entering the required numerical values and formulas,
An external force signal value EFi * of i component force to be measured from the digital acceleration signal value EAj and the digital component force signal value EFi according to the first calculation program for determining the coefficient Kij by the method of claim 2 and the multiple component force measurement method of claim 6. Storage means for storing a second arithmetic program for obtaining
Arithmetic processing means for calculating the coefficient Kij as a digital value from the digital acceleration signal value and the digital component force signal value according to the first calculation program, and for obtaining the external force signal value EFi * of i component force as the digital value according to the second calculation program;
A multi-component force measuring device comprising: an electric processing device comprising:

The multi-component force measuring device according to claim 9, wherein the number m of the acceleration sensors is a number capable of detecting vibration components equal to the number M of component components to be measured.

15. The multi-component force measuring device according to claim 9, wherein the number m of the acceleration sensors is a number capable of detecting vibration components smaller than the number M of component components to be measured.