JP3124710B2 - Signal processing circuit for sensors using change in capacitance - Google Patents
Signal processing circuit for sensors using change in capacitanceInfo
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- JP3124710B2 JP3124710B2 JP07212617A JP21261795A JP3124710B2 JP 3124710 B2 JP3124710 B2 JP 3124710B2 JP 07212617 A JP07212617 A JP 07212617A JP 21261795 A JP21261795 A JP 21261795A JP 3124710 B2 JP3124710 B2 JP 3124710B2
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- capacitance
- electrode
- external force
- electrodes
- axis
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- Measuring Magnetic Variables (AREA)
Description
【０００１】[0001]
【発明の属する技術分野】この発明は、一対の電極距離
の変化に基づき多軸の力・加速度・磁気などの検出を行
う静電容量の変化を利用したセンサ用の信号処理回路の
改良に係り、例えば電極平面方向の力の検出感度を電極
間距離方向の検出電圧で制御することより、各電極間距
離の変動や差異などに関係なく電極平面方向の検出出力
を正確にしたことを特徴とする静電容量の変化を利用し
たセンサ用信号処理回路に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a signal processing circuit for a sensor using a change in capacitance for detecting a multiaxial force, acceleration, magnetism, etc. based on a change in a distance between a pair of electrodes. and wherein for example from controlling the detection sensitivity of the electrode plane direction force at a distance between electrodes direction of the detection voltage, it has exactly the detection output relationship without the electrode plane direction such as variation or difference of the respective inter-electrode distance The present invention relates to a signal processing circuit for a sensor using a change in electrostatic capacity.
【０００２】[0002]
【従来の技術】従来、容量式多軸力センサが、例えば特
願平４−１８１６７９号等により知られている。これ
は、電極間距離が力により動くことにより、電極間距離
の平均値に相当する容量で電極間方向の力を検出し、電
極の傾きで電極平面方向の力を検出するものである。詳
述すると、静電容量型加速度センサとして使用する場合
には、固定基板と可撓基板との各対向面に電極を着設し
て対向配置される静電容量素子を複数対設け、該基板面
に平行なＸＹ平面を設定しこれと直交するＺ軸のＸ，
Ｙ，Ｚ軸３次元方向の加速度の変化を、複数対の静電容
量素子間の静電容量変化に基づき各Ｘ，Ｙ，Ｚ軸方向成
分の検出を行う。2. Description of the Related Art Conventionally, a capacitive multi-axial force sensor has been known, for example, from Japanese Patent Application No. 4-181679. In this method, when the distance between the electrodes is moved by the force, the force in the direction between the electrodes is detected by the capacitance corresponding to the average value of the distance between the electrodes, and the force in the direction of the electrode plane is detected by the inclination of the electrodes. More specifically, when used as a capacitance-type acceleration sensor, a plurality of pairs of capacitance elements are provided on opposite sides of a fixed substrate and a flexible substrate, and electrodes are attached to each other. An XY plane parallel to the plane is set, and X,
A change in acceleration in the three-dimensional directions of the Y and Z axes is detected based on a change in capacitance between a plurality of pairs of capacitance elements.
【０００３】例えば、図３の縦断面に示すごとく、枠体
１０内に配置された固定基板１１と、これに所定の間隔
を設けて可撓基板１２を平行に配置し、固定基板１１の
下面を示す図２に示すごとく、この固定基板１１と可撓
基板１２との各対向面にそれぞれ電極２１〜２５を着設
して静電容量素子Ｃ21〜Ｃ25を形成する構成からなる。
可撓基板１２の下面には適当な質量を有する作動子１３
を設けてある。For example, as shown in a vertical section of FIG. 3, a fixed substrate 11 arranged in a frame 10 and a flexible substrate 12 are arranged in parallel with a predetermined interval between the fixed substrate 11 and the lower surface of the fixed substrate 11. as shown in FIG. 2 showing a consists configured to form an electrostatic capacitance element C 21 -C 25 and clamped by the respective electrodes 21 to 25 on each opposite face of this fixed substrate 11 and the flexible substrate 12.
An actuator 13 having an appropriate mass is provided on the lower surface of the flexible substrate 12.
Is provided.
【０００４】詳述するとここでは、該対向面間の外周部
に４個、中央部に１個の電極２１〜２５を設けて、固定
基板１１の電極２６と対をなして静電容量素子Ｃ21〜Ｃ
25を形成した構成、すなわち、電極面にて直交するＸ，
Ｙの２軸上に配置された各々２つの静電容量素子Ｃ21〜
Ｃ24と、前２軸の中央に静電容量素子Ｃ25を配置した構
成からなる。上記の構成において、Ｘ軸方向に加速度が
加わった場合、作動子１３を有する可撓基板１２が変形
することにより、固定基板１１と可撓基板１２との対向
面間の各電極１〜５間距離が変化することから、各静電
容量素子Ｃ21〜Ｃ24の静電容量が変化する。また、Ｚ軸
方向に加速度が加わった場合も同様に各静電容量素子Ｃ
21〜Ｃ25の静電容量が変化する。In detail, here, four electrodes 21 to 25 are provided at the outer peripheral portion between the opposing surfaces and one electrode 21 to 25 is provided at the center portion. 21 to C
25 , that is, X,
Each of two capacitance elements C 21 to C 21 arranged on two axes of Y
C 24 and a configuration in which a capacitance element C 25 is arranged at the center of the front two axes. In the above-described configuration, when acceleration is applied in the X-axis direction, the flexible substrate 12 having the actuator 13 is deformed, so that each of the electrodes 1 to 5 between the opposing surfaces of the fixed substrate 11 and the flexible substrate 12. since the distance changes, the capacitance of the capacitive element C 21 -C 24 is changed. Similarly, when acceleration is applied in the Z-axis direction, each of the capacitance elements C
Capacitance of 21 -C 25 changes.
【０００５】静電容量の変化より加速度の各成分の検出
は、例えば、Ｘ軸方向の加速度に対する出力として、静
電容量素子Ｃ21とＣ23の静電容量差（Ｃ21−Ｃ23）、Ｙ
軸方向の加速度に対する出力として、静電容量素子Ｃ22
とＣ24の静電容量差（Ｃ22−Ｃ24）、Ｚ軸方向の加速度
に対する出力として、静電容量素子Ｃ25の静電容量（Ｃ
25）あるいはＣ21＋Ｃ22＋Ｃ23＋Ｃ24として検出する。The detection of each component of the acceleration based on the change in the capacitance is performed, for example, as an output with respect to the acceleration in the X-axis direction, as a capacitance difference (C 21 −C 23 ) between the capacitance elements C 21 and C 23 , Y
As an output for the axial acceleration, the capacitance element C 22
The capacitance difference C 24 (C 22 -C 24) , as the output for the acceleration in the Z axis direction, the capacitance of the capacitance element C 25 (C
25) or is detected as C 21 + C 22 + C 23 + C 24.
【０００６】[0006]
【発明が解決しようとする課題】かかる構成からなる静
電容量型加速度センサなどのセンサにおいて、センサ基
板の平面方向の外力に対する出力感度は、電極間距離に
応じ変化するという問題がある。従来、この電極平面の
外力の検出感度の変動については、何ら補正を行ってい
なかったため、従来の補正回路では、電極間距離による
感度の変化が無視できないほど大きい問題があった。SUMMARY OF THE INVENTION In a sensor such as a capacitance type acceleration sensor having such a configuration, a sensor base is provided.
There is a problem that the output sensitivity to an external force in the plane direction of the plate changes according to the distance between the electrodes. Conventionally, no correction has been made for the variation in the detection sensitivity of the external force on the electrode plane. Therefore, the conventional correction circuit has a problem that the change in sensitivity due to the distance between the electrodes is so large that it cannot be ignored.
【０００７】この発明は、静電容量の変化を利用したセ
ンサ用信号処理回路における上記の問題を解消し、電極
間距離に関係なく電極平面の外力の検出感度をほぼ一定
にすることが可能な信号処理回路の提供を目的とし、さ
らに、簡単な回路でコストを大幅に上げることなく、電
極平面の外力の検出感度をほぼ一定にできる構成の提供
を目的としている。The present invention solves the above-mentioned problem in a sensor signal processing circuit utilizing a change in capacitance, and makes it possible to make the detection sensitivity of an external force on an electrode plane substantially constant regardless of the distance between the electrodes. It is another object of the present invention to provide a signal processing circuit, and to provide a configuration that can make the detection sensitivity of the external force on the electrode plane substantially constant with a simple circuit without significantly increasing the cost.
【０００８】[0008]
【課題を解決するための手段】発明者は、電極平面の外
力の検出感度をほぼ一定にできる構成を目的に信号回路
について種々検討した結果、電極平面方向の力の検出感
度を電極間距離方向の検出電圧で制御することより、電
極間距離の変動や差異に関係なく電極平面方向の検出感
度を一定にでき、検出出力を正確にできることを知見
し、この発明を完成した。The inventor of the present invention has conducted various studies on a signal circuit for the purpose of making the detection sensitivity of the external force on the electrode plane substantially constant. As a result, the detection sensitivity of the force in the electrode plane direction was reduced in the inter-electrode distance direction. Control with the detection voltage in the direction of the electrode plane regardless of the variation or difference in the distance between the electrodes .
Degrees can turn a certain to finding the Rukoto can detect output accurately, and have completed the present invention.
【０００９】すなわち、この発明は、複数の電極を配置
した可動部の電極と固定部の電極とで構成した静電容量
素子の静電容量の変化に基き可動部に作用した外力を検
出するセンサ用信号処理回路において、電極平面のX軸
及びY軸方向の力を検出する静電容量素子の検出感度
を、電極間距離のZ軸方向の力を検出する静電容量素子
の容量変化で制御可能にして、各静電容量素子の電極間
距離に応じてX軸及びY軸方向の検出出力を補正する静電
容量の変化を利用したセンサ用の信号処理回路である。[0009] Namely, the present invention is based-out movable part to a change in the capacitance of the capacitance elements constituted by the electrode of the electrode and the fixed portion of the plurality of electrodes disposed <br/> the movable portion In the signal processing circuit for the sensor that detects the applied external force , the X-axis of the electrode plane
Sensitivity of Capacitance Element to Detect Force in Y and Y Axis
Is a capacitance element that detects the force in the Z-axis direction of the distance between the electrodes.
Between the electrodes of each capacitance element
It is a signal processing circuit for a sensor that uses a change in capacitance to correct the detection output in the X-axis and Y-axis directions according to the distance .
【００１０】[0010]
【発明の実施の形態】以下に、この発明を図面に基づい
て詳述する。図１は静電容量型センサの信号処理回路の
基本構成を示す回路図である。図４は電極間距離と静電
容量との関係を示すグラフ、図５は平均電極間距離の違
いによる電極平面方向外力の検出出力を示すグラフであ
る。図６はこの発明による信号処理回路の具体例を示す
回路図であり、図７は図６の信号処理回路の動作波形例
を示す説明図である。静電容量型センサは、前述した図
２、図３の構成からなる静電容量型加速度センサを対象
としている。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a circuit diagram showing a basic configuration of a signal processing circuit of a capacitance type sensor. FIG. 4 is a graph showing the relationship between the interelectrode distance and the capacitance, and FIG. 5 is a graph showing the detection output of the external force in the electrode plane direction due to the difference in the average interelectrode distance. FIG. 6 is a circuit diagram showing a specific example of the signal processing circuit according to the present invention, and FIG. 7 is an explanatory diagram showing an operation waveform example of the signal processing circuit of FIG. The capacitance type sensor is intended for the capacitance type acceleration sensor having the configuration shown in FIGS.
【００１１】図１において、電極間方向外力検出用の静
電容量素子１に、静電容量を電圧に変換するＣＶ変換回
路２を接続し、この回路の出力を電極間方向の検出出力
としている。電極平面方向外力検出用の静電容量素子
３，４は差動で動作し、それぞれ静電容量を電圧に変換
するＣＶ変換回路５，６に接続される。このＣＶ変換回
路の出力を演算増幅器７で減算し、この回路の出力を電
極平面方向の外力の検出出力としている。In FIG. 1, a CV conversion circuit 2 for converting a capacitance into a voltage is connected to a capacitance element 1 for detecting an external force between electrodes, and the output of this circuit is used as a detection output in a direction between electrodes. . The capacitance elements 3 and 4 for detecting external force in the electrode plane direction operate differentially and are respectively connected to CV conversion circuits 5 and 6 for converting capacitance to voltage. The output of this CV conversion circuit is subtracted by the operational amplifier 7, and the output of this circuit is used as the detection output of the external force in the electrode plane direction.
【００１２】一方、電極間距離方向の外力の検出出力
は、感度調整回路８，９に接続され、それぞれの感度調
整回路８，９が電極平面方向外力検出用の静電容量素子
３，４に接続される。この感度調整回路８，９は、電極
間方向外力に応じて電極平面方向検出用の静電容量の両
端に現れる電圧の振幅を制御するよう構成されている。On the other hand, the detection output of the external force in the direction of the distance between the electrodes is connected to sensitivity adjustment circuits 8 and 9, and the respective sensitivity adjustment circuits 8 and 9 are applied to the capacitance elements 3 and 4 for detecting the external force in the electrode plane direction. Connected. The sensitivity adjusting circuits 8 and 9 are configured to control the amplitude of the voltage appearing at both ends of the capacitance for detecting the electrode plane direction according to the external force in the inter-electrode direction.
【００１３】次に動作の詳細について説明する。一般に
静電容量式センサにおいては、外力と電極間距離ｄは比
例関係にあり、電極距離ｄと静電容量Ｃは図４に示すよ
うに反比例の関係にある。図４において、実線で示す電
極間距離ｄ1の点で一定の力が加わって変化した静電容
量分はＣ1となる。同様に、破線で示す電極間距離ｄ2の
点で同じ力が加わって変化した静電容量分はＣ2とな
る。このＣ1とＣ2を比較すると電極間距離の短いＣ1の
値が大きくなることが分かる。つまり電極間距離によっ
て同じ印加した力でも検出された静電容量値が異なり、
これが検出電圧の誤差となっている。Next, the operation will be described in detail. Generally, in a capacitance type sensor, the external force and the distance d between the electrodes are in a proportional relationship, and the electrode distance d and the capacitance C are in an inversely proportional relationship as shown in FIG. In FIG. 4, the capacitance component changed by applying a constant force at the point of the inter-electrode distance d 1 indicated by the solid line is C 1 . Similarly, at the point of the inter-electrode distance d 2 indicated by the broken line, the capacitance changed by applying the same force is C 2 . Shorter value of C 1 of the distance between electrodes Comparing this C 1 and C 2 is it can be seen significantly. In other words, the detected capacitance value differs with the same applied force depending on the distance between the electrodes,
This is the error of the detection voltage.
【００１４】仮に可動部電極が電極間方向の力により、
一点鎖線で示す平均電極間距離ｄ0に対し±１０％程度
動き、この点で電極間平面方向に平均電極間距離の５％
分に相当する力が加わった場合、電極間距離最大点と最
小点の電極平面方向の感度の差は下記のとおりとなる。
静電容量Ｃ＝（誘電率ε×電極面積Ｓ）÷電極間距離ｄ
より、誘電率と電極面積は固定であり電極間方向の力
を検出する静電容量分をＫCZとし、電極間平面方向の力
を検出する静電容量分をＫCXとすると、電極間距離の力
を検出する。It is assumed that the movable part electrode is moved by the force between the electrodes.
It moves about ± 10% with respect to the average inter-electrode distance d 0 indicated by a dashed line, and at this point, 5% of the average inter-electrode distance in the plane direction between the electrodes.
When a force equivalent to a minute is applied, the difference in sensitivity between the maximum point and the minimum point between the electrodes in the direction of the electrode plane is as follows.
Capacitance C = (dielectric constant ε × electrode area S) 面積 distance d between electrodes
The dielectric constant and the electrode area are fixed, and the capacitance for detecting the force in the direction between the electrodes is K CZ, and the capacitance for detecting the force in the plane between the electrodes is K CX. Detect the force of
【００１５】電極間距離の力を検出する平均電極間距離
の静電容量Ｃ0は、 Ｃ0＝ＫCZ÷ｄ0 、 電極間方向の外力で電極間距離最小点の静電容量Ｃ
1は、 Ｃ1＝ＫCZ÷（０．９×ｄ0） 、 電極間方向の外力で電極間距離最大点の静電容量Ｃ
2は、 Ｃ2＝ＫCZ÷（１．１×ｄ0） 。The capacitance C 0 of the average inter-electrode distance for detecting the force of the inter-electrode distance is C 0 = K CZ ÷ d 0 , and the external force in the inter-electrode direction is the capacitance C 0 of the minimum point of the inter-electrode distance.
1 is C 1 = K CZ ÷ (0.9 × d 0 ), and the external force in the direction between the electrodes is the capacitance C at the maximum point between the electrodes.
2 is C 2 = K CZ ÷ (1.1 × d 0 ).
【００１６】電極間平面方向の力を検出する、Ｃ0の状
態に電極平面方向の外力が加わった時の静電容量Ｃ
7は、 Ｃ7＝ＫCX÷（１．０×ｄ0−０．０５×ｄ0）＝ＫCX÷（０．９５×ｄ0） 、Ｃ0の状態に電極平面方向の外力が加わった時の静電
容量Ｃ8は、 Ｃ8＝ＫCX÷（１．０×ｄ0＋０．０５×ｄ0）＝ＫCX÷（１．０５×ｄ0） 、Ｃ1の状態に電極平面方向の外力が加わった時の静電
容量Ｃ3は、 Ｃ3＝ＫCX÷（０．９×ｄ0−０．０５×ｄ0）＝ＫCX÷（０．８５×ｄ0） 、Ｃ1の状態に電極平面方向の外力が加わった時の静電
容量Ｃ4は、 Ｃ4＝ＫCX÷（０．９×ｄ0＋０．０５×ｄ0）＝ＫCX÷（０．９５×ｄ0） 、Ｃ2の状態に電極平面方向の外力が加わった時の静電
容量Ｃ3は、 Ｃ5＝ＫCX÷（１．１×ｄ0−０．０５×ｄ0）＝ＫCX÷（１．０５×ｄ0） 、Ｃ2の状態に電極平面方向の外力が加わった時の静電
容量Ｃ4は、 Ｃ6＝ＫCX÷（１．１×ｄ0＋０．０５×ｄ0）＝ＫCX÷（１．０５×ｄ0） 。Detecting the force in the plane direction between the electrodes, the capacitance C when an external force in the plane direction of the electrode is applied to the state of C 0.
7 is C 7 = K CX ÷ (1.0 × d 0 −0.05 × d 0 ) = K CX ÷ (0.95 × d 0 ), and an external force in the electrode plane direction is applied to the state of C 0 . the capacitance C 8 of time, C 8 = K CX ÷ ( 1.0 × d 0 + 0.05 × d 0) = K CX ÷ (1.05 × d 0), the electrode plane direction of the state of C 1 the capacitance C 3 when an external force is applied of, C 3 = K CX ÷ ( 0.9 × d 0 -0.05 × d 0) = K CX ÷ (0.85 × d 0), C 1 The capacitance C 4 when an external force in the direction of the electrode plane is applied to the state described above is as follows: C 4 = K CX ÷ (0.9 × d 0 + 0.05 × d 0 ) = K CX ５ (0.95 × d 0), the capacitance C 3 when the external force of the electrode plane direction is applied to the state of C 2 is, C 5 = K CX ÷ ( 1.1 × d 0 -0.05 × d 0) = K CX ÷ (1.05 × d 0), the capacitance C 4 when the external force of the electrode plane direction is applied to the state of C 2 is, C 6 = K CX (1.1 × d 0 + 0.05 × d 0) = K CX ÷ (1.05 × d 0).
【００１７】検出される力は静電容量に比例することよ
り、電極平面方向の静電容量を電圧に変化する係数をＫ
VXとすると、ｄ1とｄ2の電極平面方向の検出電圧ＶX1、
およびＶX2は下記式となる。Since the detected force is proportional to the capacitance, the coefficient for changing the capacitance in the electrode plane direction into a voltage is represented by K
Assuming that VX , the detection voltage V X1 in the electrode plane direction of d 1 and d 2 ,
And V X2 are as follows.
【００１８】[0018]
【数１】 (Equation 1)
【００１９】[0019]
【数２】 (Equation 2)
【００２０】[0020]
【数３】 (Equation 3)
【００２１】上記検出電圧を比較すると同じ外力にもか
かわらず大きな違いがあることが分かる。基本的には、
電極間平面方向に５％の外力を加え、２つの静電容量を
作動方式で検出する方式なので上記式の右側の最初の係
数は０．０５×２＝０．１００が真値である。従って、
ｄ1の点では＋２４％、ｄ2の点では−１７％の検出誤差
となっていることが分かる。この状態を図５に平均電極
間距離の違いによる電極間方向検出出力として示す。Comparing the detection voltages, it can be seen that there is a large difference despite the same external force. Basically,
Since an external force of 5% is applied in the plane direction between the electrodes to detect two capacitances by the operation method, the first coefficient on the right side of the above equation is 0.05 × 2 = 0.100, which is a true value. Therefore,
In respect of + 24% of d 1, in terms of d 2 it is understood that the -17% of detection error. This state is shown in FIG. 5 as an inter-electrode direction detection output based on the difference in the average inter-electrode distance.
【００２２】この発明によれば、上記ＶX1とＶX2を平均
電極間距離で下記のように補正することができる。電極
間距離方向の静電容量を電圧に変換する係数をＫCZとす
ると、ｄ0の点の平均電極間距離の検出電圧ＶZ0は、 ＶZ0＝ＫVZ×Ｃ0＝ＫVZ×ＫCZ÷ｄ0 、 ｄ1の点の平均電極間距離の検出電圧ＶZ1は、 ＶZ1＝ＫVZ×Ｃ1＝ＫVZ×ＫCZ÷（０．９×ｄ0） 、 ｄ2の点の平均電極間距離の検出電圧ＶZ2は、 ＶZ2＝ＫVZ×Ｃ2＝ＫVZ×ＫCZ÷（１．１×ｄ0） 、 となる。According to the present invention, V X1 and V X2 can be corrected by the average distance between the electrodes as follows. Assuming that the coefficient for converting the capacitance in the inter-electrode distance direction into a voltage is K CZ , the detection voltage V Z0 of the average inter-electrode distance at the point d 0 is V Z0 = K VZ × C 0 = K VZ × K CZ The detection voltage V Z1 of the average distance between the electrodes at d 0 and d 1 is V Z1 = K VZ × C 1 = K VZ × K CZ ０．９ (0.9 × d 0 ), the average of the points at d 2 The detection voltage V Z2 of the distance between the electrodes is as follows: V Z2 = K VZ × C 2 = K VZ × K CZ ÷ (1.1 × d 0 ).
【００２３】この検出電圧に一定比例定数ＫZHを乗じた
値で、前記電極間平面方向の検出電圧のゲインをｄ0の
点の補正係数を１とし、平均電極間距離が狭いときは小
さく、広いときは大きくなるよう制御する。ＶX1の補正
後の検出電圧をＶX3とすると、下記式になる。A value obtained by multiplying the detected voltage by a constant proportional constant K ZH , the gain of the detected voltage in the inter-electrode plane direction is set to a correction coefficient at the point of d 0 , and is small when the average inter-electrode distance is short. When it is wide, it is controlled to be large. Assuming that the detected voltage after the correction of V X1 is V X3 , the following equation is obtained.
【００２４】[0024]
【数４】 ただし、ＶZ1−ＶZ0＝（ＫCZ×ＫCZ÷ｄ0）×（１÷０．９−１） ＝（ＫVZ×ＫCZ÷ｄ0）×０．１１１(Equation 4) Here, V Z1 −V Z0 = (K CZ × K CZ ÷ d 0 ) × (1 ÷ 0.9-1) = (K VZ × K CZ ÷ d 0 ) × 0.111
【００２５】ここで、ＶX1は（Ｖ Z1 −Ｖ Z0 ）に対し基本
的には作動方式のため２倍の変化量であり、これに対応
し、ＫZH×（ＫVZ×ＫCZ÷ｄ0）を２とするようＫZHを
調整すれば、ＶX3は下記式となる。Here, V X1 is basically twice as large as (V Z1 −V Z0 ) because of the operation method, and corresponding to this, K ZH × (K VZ × K CZ ÷ d If K ZH is adjusted so that 0 ) is 2, V X3 is given by the following equation.
【００２６】[0026]
【数５】 (Equation 5)
【００２７】ＶX2の補正後の検出電圧をＶX4とすると、
下記式となる。Assuming that the detected voltage after the correction of V X2 is V X4 ,
It becomes the following formula.
【００２８】[0028]
【数６】 但し、ＶZ2−ＶZ0＝（ＫVZ×ＫCZ÷ｄ0）×（１−１÷１．１） ＝（ＫVZ×ＫCZ÷ｄ0）×−０．０９１(Equation 6) However, V Z2 −V Z0 = (K VZ × K CZ ÷ d 0 ) × (1-1 ÷ 1.1) = (K VZ × K CZ ÷ d 0 ) × −0.091
【００２９】ここで、前述と同様にＫZH×（ＫVZ×ＫCZ
÷ｄ0）を２とするようにＫZHを調整すれば、ＶX4を得
る。Here, as described above, K ZH × (K VZ × K CZ
By adjusting K ZH so that ÷ d 0 ) is 2, V X4 is obtained.
【００３０】[0030]
【数７】 (Equation 7)
【００３１】以上のようにこの発明によれば、平均電極
間距離が異なっていても電極平面方向の力の検出感度を
１％程度の誤差に補正することができる。As described above, according to the present invention, even if the average inter-electrode distance is different, the force detection sensitivity in the electrode plane direction can be corrected to an error of about 1%.
【００３２】[0032]
【実施例】この発明の一実施例として図６の信号処理回
路について説明する。電極間方向外力検出用の静電容量
素子１，３，４には外部から一定振幅のクロックパルス
が印加される。この電極間方向外力検出用の静電容量と
ほぼ等しい固定容量２ｂが同様な回路で並列に接続さ
れ、前記検出用静電容量に印加したパルスと逆相のパル
スが一定振幅で印加される。FIG. 6 shows a signal processing circuit according to an embodiment of the present invention. A clock pulse having a constant amplitude is externally applied to the capacitance elements 1, 3, and 4 for detecting the external force between the electrodes. A fixed capacitance 2b substantially equal to the capacitance for detecting an external force in the inter-electrode direction is connected in parallel by a similar circuit, and a pulse having a constant amplitude and a pulse opposite in phase to the pulse applied to the capacitance for detection is applied.
【００３３】電極間方向の外力がゼロの場合は、この固
定容量２ｂの両端波形と電極間方向外力検出用静電容量
１の両端波形は同じであり演算増幅器Ｕ1の出力はゼロ
となる。ここに電極間方向に外力が加われば電極間方向
外力検出用静電容量１が変化し、同静電容量の両端の電
圧波形も変化するため、演算増幅器Ｕ1に出力が現れ
る。この出力電圧を同期検波平滑回路２ａにて同期検波
し平滑することで電極間方向外力を検出している。The external force of the inter-electrode direction in the case of zero, the output of the ends waveform and the inter-electrode direction external force across the waveform of the detection capacitance 1 fixed capacitor 2b are the same operational amplifier U 1 is zero. Here the inter-electrode direction external force detection electrostatic capacitance 1 is changed if Kuwaware external force in the inter-electrode direction, to change the voltage waveform across the same capacitive, output appears to the operational amplifier U 1. This output voltage is synchronously detected and smoothed by the synchronous detection and smoothing circuit 2a to detect an external force between the electrodes.
【００３４】電極平面方向外力の検出についても基本的
には同じ考え方であり、電極平面方向外力検出用静電容
量素子３，４が差動式で前述の固定容量２ｂ分にも検出
用静電容量素子３，４が接続される。そして各々の静電
容量が逆に増減するために電極間方向の外力の検出に比
べ倍の検出出力を得ることができる。ここで電極間方向
の検出電圧は分圧回路にも接続され、一定の比で分圧さ
れて差動式電極平面方向外力検出用静電容量を駆動して
いるパルスの振幅を可変できるようにしている。このパ
ルスの振幅は電極間方向外力検出用静電容量が増加すれ
ば振幅減となるようにし、前述の電極平面方向外力の検
出出力の補正を行う。[0034] is basically the same idea to also detect the electrode plane direction external force detection electrostatic at electrode planar direction force detection electrostatic capacitance element 3, 4 is a differential equation in the aforementioned fixed capacitor 2b min The capacitance elements 3 and 4 are connected. Since the respective capacitances increase and decrease in the opposite manner, it is possible to obtain twice the detection output as compared with the detection of the external force in the direction between the electrodes. Here, the detection voltage in the direction between the electrodes is also connected to a voltage dividing circuit, and the voltage is divided at a fixed ratio so that the amplitude of the pulse driving the capacitance for detecting the external force in the direction of the differential electrode plane can be varied. ing. The amplitude of this pulse is made to decrease as the inter-electrode direction external force detection capacitance increases, and the above-described detection output of the electrode plane direction external force is corrected.
【００３５】以上の実施例では、電極間平面方向の検出
感度を変えるために駆動パルスの振幅を変える方式で説
明したが、電極平面方向外力の検出出力に乗算器を設け
てもよく、また、ＦＥＴなどを使用して抵抗値変化によ
るゲイン変化として扱う手段を採用することができる。In the above embodiment, the method of changing the amplitude of the driving pulse to change the detection sensitivity in the inter-electrode plane direction has been described. However, a multiplier may be provided for the detection output of the external force in the electrode plane direction. It is possible to employ a means for treating the gain as a gain change due to a resistance value change using an FET or the like.
【００３６】[0036]
【発明の効果】この発明による静電容量型センサ用信号
処理回路は、電極平面方向の力の検出感度を電極間距離
方向の検出電圧で制御する非常に簡単でかつ安価な回路
により、１つの可動部と固定部で複数の電極を持つ多軸
力センサの平均電極間距離が異なっていても、電極平面
方向外力の検出感度をほぼ一定にでき、高性能センサを
提供できるようになる。The signal processing circuit for a capacitance type sensor according to the present invention is a simple and inexpensive circuit for controlling the detection sensitivity of the force in the direction of the electrode plane by the detection voltage in the direction of the distance between the electrodes. Even if the average distance between the electrodes of the multi-axis force sensor having a plurality of electrodes is different between the movable part and the fixed part, the detection sensitivity of the external force in the electrode plane direction can be made substantially constant, and a high-performance sensor can be provided.
【図１】静電容量型センサの信号処理回路の基本構成を
示す回路図である。FIG. 1 is a circuit diagram showing a basic configuration of a signal processing circuit of a capacitance type sensor.
【図２】静電容量型センサの平面説明図である。FIG. 2 is an explanatory plan view of a capacitance type sensor.
【図３】静電容量型センサの断面説明図である。FIG. 3 is an explanatory sectional view of a capacitance type sensor.
【図４】電極間距離と静電容量との関係を示すグラフで
ある。FIG. 4 is a graph showing a relationship between a distance between electrodes and a capacitance.
【図５】平均電極間距離の違いによる電極平面方向外力
の検出出力を示すグラフである。FIG. 5 is a graph showing a detection output of an external force in an electrode plane direction depending on a difference in an average inter-electrode distance.
【図６】この発明による信号処理回路の具体例を示す回
路図である。FIG. 6 is a circuit diagram showing a specific example of a signal processing circuit according to the present invention.
【図７】図６の信号処理回路の動作波形例を示す説明図
である。FIG. 7 is an explanatory diagram showing an example of an operation waveform of the signal processing circuit of FIG. 6;
１，３，４ 静電容量素子 ２，５，６ ＣＶ変換回路 ２ａ，７ａ 同期検波平滑回路 ２ｂ 固定容量 ７，Ｕ1，Ｕ2 演算増幅器 ８，９ 感度調整回路 １０ 枠体 １１ 固定基板 １２ 可撓基板 １３ 作動子 ２６ 電極 Ｃ21〜Ｃ25 静電容量素子1,3,4 capacitance device 2, 5, 6 CV conversion circuit 2a, 7a synchronous detection and smoothing circuit 2b fixed volume 7, U 1, U 2 operational amplifiers 8 and 9 sensitivity adjustment circuit 10 the frame 11 fixed substrate 12 Friendly Flexible substrate 13 Actuator 26 Electrode C 21 to C 25 Capacitance element
Claims (2)
定部の電極とで構成した静電容量素子の静電容量の変化
に基き可動部に作用した外力を検出するセンサ用信号処
理回路において、電極平面のX軸及びY軸方向の外力を検
出する静電容量素子の検出感度を、電極間距離のZ軸方
向の外力を検出する静電容量素子の容量変化で制御可能
にして、各静電容量素子の電極間距離に応じてX軸及びY
軸方向の検出出力を補正する静電容量の変化を利用した
センサ用信号処理回路。1. A sensor for detecting an external force acting on the base-out movable part of the change of the capacitance of the capacitive element is constituted by a plurality of electrodes and the placed movable portion of the electrode fixing portions of the electrode In the signal processing circuit, the external force in the X-axis and Y-axis directions of the electrode plane is detected.
The detection sensitivity of the output capacitance element to the Z-axis
Can be controlled by changing the capacitance of the capacitive element that detects external force
And the X axis and Y according to the distance between the electrodes of each capacitance element.
A signal processing circuit for a sensor that uses a change in capacitance to correct a detection output in an axial direction .
路が接続された静電容量素子の静電容量を電圧に変換す
るCV変換回路を有し、Z軸方向の外力検出用の静電容量
素子と同等容量の固定容量にパルスと逆相のパルスが一
定振幅で印加される同期検波平滑回路を有し、Z軸方向
の静電容量素子の検出電圧を分圧回路を介してX軸及びY
軸方向の静電容量素子の感度調整回路に入力し、X軸及
びY軸方向の静電容量素子を駆動しているパルスの振幅
を制御する請求項1に記載の静電容量の変化を利用した
センサ用信号処理回路。 2. A sensitivity adjusting circuit capable of applying a clock pulse.
Converts the capacitance of the capacitive element to which the
Capacitance for detecting external force in the Z-axis direction
A pulse with a phase opposite to that of the pulse
It has a synchronous detection and smoothing circuit applied at a constant amplitude, in the Z-axis direction.
X-axis and Y-axis via the voltage dividing circuit
Input to the sensitivity adjustment circuit of the capacitive element in the axial direction,
And the amplitude of the pulse driving the capacitance element in the Y-axis direction
Utilizing the change in capacitance according to claim 1 for controlling
Signal processing circuit for sensors.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP07212617A JP3124710B2 (en) | 1995-07-28 | 1995-07-28 | Signal processing circuit for sensors using change in capacitance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP07212617A JP3124710B2 (en) | 1995-07-28 | 1995-07-28 | Signal processing circuit for sensors using change in capacitance |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0943068A JPH0943068A (en) | 1997-02-14 |
| JP3124710B2 true JP3124710B2 (en) | 2001-01-15 |
Family
ID=16625649
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP07212617A Expired - Fee Related JP3124710B2 (en) | 1995-07-28 | 1995-07-28 | Signal processing circuit for sensors using change in capacitance |
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| Country | Link |
|---|---|
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6759362B2 (en) | 1999-06-30 | 2004-07-06 | Union Carbide Chemicals & Plastics Technology Corporation | Mixed metal alkoxide complexes and polymerization catalysts made therefrom |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5631529B2 (en) | 2007-03-09 | 2014-11-26 | パナソニック株式会社 | Acceleration sensor |
-
1995
- 1995-07-28 JP JP07212617A patent/JP3124710B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6759362B2 (en) | 1999-06-30 | 2004-07-06 | Union Carbide Chemicals & Plastics Technology Corporation | Mixed metal alkoxide complexes and polymerization catalysts made therefrom |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0943068A (en) | 1997-02-14 |
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