JP2000187042A - Correction method for misalignment of multidimensional accelerometer and multidimensional acceleration measuring apparatus provided with the sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a correction method in which the error of a multidimensional accelerometer can be reduced by calculating respective correction output voltages which are computed by a specific expression on the basis of accelerations in directions of three right-angled axes and which correspond to two axes or three axes selected as respective detecting axes. SOLUTION: Accelerations in the directions of three axes, i.e., the X-axis, the Y-axis and the Z-axis which are at right angles to each other are detected. An expression is computed and processed. Respective correction output voltages which correspond respectively to two axes or three axes which are selected from the X-axis, the Y-axis and the Z-axis are detecting axes are found. In this case, sensor outputs are designated as VX to VZ, sensor sensitivities are designated as SFX to SFZ, and sensor output bias voltages are designated as VXB to VZB. In addition, misalignment angles which are formed by the sensitivity axis of a sensor corresponding to the sensor output VX with reference to the detecting axis Y and the detecting axis Z are sesignated as AAXY and AAXZ, misalignment angles which are formed by a sensor corresponding to the sensor output VY with reference to the detecting axis Z and the detecting axis Y are designated as AAYZ and AAYX, and misalignment angles which are formed by the sensitivity axis of a sensor with reference to the detecting axis X and the detecting axis Y are designated as AAZX and AAZY.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for correcting misalignment of a multi-dimensional acceleration sensor and a multi-dimensional acceleration measuring device provided with the sensor, and more particularly to a method for detecting acceleration of two or more axes simultaneously. The present invention relates to a method for correcting misalignment of a multidimensional acceleration sensor for correcting misalignment by arithmetic processing, and a multidimensional acceleration measuring device including the sensor.

[0002]

2. Description of the Related Art In recent years, a multidimensional acceleration sensor has been developed and used which detects acceleration in two or three axes selected from X, Y and Z axes orthogonal to each other by one sensor. As parameters representing the performance of the acceleration sensor, there are the following three parameters.

[0003] Sensitivity (Scale Factor):
Output per unit input. Zero G output (bias): An output when the input is zero. Misalignment:
It refers to the angular error between the ideal input axis and the actual input axis. That is, even if the mounting and fixing of the acceleration sensor to the object to be measured are ideally performed, the weight of the acceleration sensor does not mean that it is mounted and fixed in accordance with the ideal input axis. Always have a slight angular error with the target input shaft. This angle error is called misalignment.

A three-dimensional acceleration sensor capable of detecting accelerations in three X-, Y-, and Z-axes orthogonal to each other has been put to practical use. Here, the following description will be made assuming that the input axes of the X, Y, and Z axis outputs are positive directions of the X, Y, and Z axes. When considering the X-axis output, the input axis ideally coincides with the X-axis, but actually, as shown in FIG.
X 'is the input axis. This input axis OX ′ can be decomposed into a plane XOX and a plane XOY into OX1 ′ and OX2 ′. An angle AA _XZ formed between the X axis and OX1 ′ is misalignment of the X axis output in the Z axis direction. Then, the angle AA _XY of X-axis and OX2 'is misalignment in the Y-axis direction of the X axis output. Similarly, the Y-axis output and the Z-axis output also have misalignment. Where AA _ij
Represents misalignment of the i-axis output from the input axis in the j-axis direction, and AA represents an angle which is the amount of inclination, that is, misalignment.

The above-mentioned parameters indicating the performance of the acceleration sensor can be easily calculated using ± 1 g and 0 g of the gravitational acceleration. Here, the misalignment AA _XZ of the X-axis output in the Z-axis direction will be obtained. As shown in FIG. 3, it is assumed that the input axis of the X-axis output is inclined by AA in the Z-axis direction.

The X-axis output V.theta. When rotated about the Y-axis by .theta. = 90.degree. Vθ = SF × [α × sin (θ + AA) + B] α = gravitational acceleration (1 [g]; g = 9.8 m / s ² ) θ = set angle (0 °, 90 °, 180 °, 270 °) SF = Sensitivity B = Bias The output at each set angle is as follows: V ₀ ° = SF × [1 × sin (0 ° + AA) + B] V ₉₀ ° = SF × [1 × sin (90 ° + AA) ) + B] V ₁₈₀ ° = SF × [1 × sin (180 ° + AA) +
B] _V270 ° = SF × [1 × sin (270 ° + AA) +
B].

From the above equation, the sensitivity SF, bias B, and misalignment AA can be obtained as follows. A
If A ≒ 0, it can be approximated as sinAA ≒ AA, cosAA ≒ 1, so that SF = (V ₉₀ ° −V ₂₇₀ °) / 2 B = (V ₉₀ ° + V ₂₇₀ °) / (2 × SF) = (V ₀ ° + V
₁₈₀ °) / (2 × SF) AA = (V ₀ ° −V ₁₈₀ °) / (2 × SF)

Next, the X-axis output when the acceleration sensor is rotated around the Y-axis is shown as a solid line in FIG. As described above, an acceleration sensor having misalignment has an output from the acceleration sensor and acceleration is applied even though the set angle is zero. In the conventional one-axis detection type acceleration sensor, when correcting this misalignment, when the acceleration sensor is attached and fixed to the measurement symmetric object, the misalignment is mechanically attached and fixed in the opposite direction. . Alternatively, the misalignment is used as an error within an allowable range as an amount that cannot remove the error.

[0009]

As described above, in the case of a one-axis detection type acceleration sensor, the misalignment is corrected by mechanically tilting the misalignment in the opposite direction when the acceleration sensor is fixedly mounted on the object to be measured. It can be corrected by mounting and fixing. However, in the case of a two-axis multi-dimensional acceleration sensor, even if it is attempted to mechanically correct the misalignment, the acceleration sensor 1
Since there is only one mounting surface for the base,
A mechanical mounting correction that satisfies all of the directions cannot be done in principle. Mechanically correcting the misalignment in one axis and one direction, on the contrary, leads to always increasing the misalignment in the other axis and other directions. The fact that the misalignment cannot be mechanically corrected is the same for the three-axis acceleration sensor.

According to the present invention, the error of the acceleration sensor is reduced by subtracting the output of the misalignment component from the output in the axial direction requiring the correction to cancel the misalignment of the input shaft of the axis requiring the correction. It is an object of the present invention to provide a method for correcting a misalignment of a multidimensional acceleration sensor which solves the above-mentioned problem, and a multidimensional acceleration measuring device provided with the sensor.

[0011]

According to the present invention, there is provided a multi-dimensional acceleration sensor for detecting accelerations in three axial directions of detection axes X, Y, and Z orthogonal to each other, wherein V _XC = V _X- (SF _X / SF _Y ). (V _Y -V _YB) sin
_{AA XY - (SF X / SF} Z) (V Z -V ZB) sinAA
_{XZ V YC = V Y - (} SF Y / SF Z) (V Z -V ZB) sin
_{AA YZ - (SF Y / SF} X) (V X -V XB) sinAA
_{YX V ZC = V Z - (} SF Z / SF X) (V X -V XB) sin
_{AA ZX - (SF Z / SF} Y) (V Y -V YB) sinAA
_A multidimensional acceleration that performs an arithmetic processing of a relationship of _ZY to obtain corrected output voltages V _XC , V _YC , and V _ZC corresponding to two or three axes selected from the detection axes X, Y, and Z, respectively. A sensor misalignment correction method is configured.

According to a second aspect of the present invention, there is provided a method for correcting misalignment of a multidimensional acceleration sensor, wherein the multidimensional acceleration sensor is a two-dimensional acceleration sensor. . In a third aspect of the present invention, in the method of correcting a misalignment of a multidimensional acceleration sensor, a misalignment angle correction calculation process is performed only on the other input axis with respect to a specific input axis. A misalignment angle correction method for a multidimensional acceleration sensor that obtains a virtual input axis orthogonal to a specific input axis to be configured.

Furthermore, claim 4 in misalignment angle correction method of a multi-dimensional acceleration sensor as set forth in claim 3, the detection output V _Y specific input shaft, corresponding to the orientation perpendicular to the input shaft The error of the multi-axis acceleration sensor which obtains the magnitude of the input angular velocity by calculating the square root of the sum of squares of the outputs of the input axes orthogonal to each other using the output V _XC obtained by calculating the acceleration component of the virtual input axis. An alignment correction method was constructed.

[0014] _{However, V XC = V X - (} SF X / SF Y) (V Y -V YB) sin
| -AA _YX -AA _XY | Here, claim 5 is provided with a multidimensional acceleration sensor that detects and outputs acceleration of three axes of detection axes X, Y, and Z orthogonal to each other, and outputs the sensor output V of each axis. A detection axis X arithmetic processing unit for inputting _X , V _Y , V _Z to obtain a correction output V _XC is provided, and a sensor output V _X , V _Y , V _Z of each axis is input, and a correction output V
Sensor output V _X of comprising a detection axis Y processing unit for obtaining the _YC each axis, V _Y, the multi-dimensional acceleration measurement device having a detection axis Z arithmetic processing unit for obtaining the correction output V _ZC enter the V _Z Configured.

However, the sensor outputs V _X , V _Y ,
V _Z , the sensor sensitivity of each axis SF _X , SF _Y , SF _Z , the sensor output bias voltage V _XB , V _YB , V _{ZB of} each axis, the sensitivity axis of the sensor corresponding to the sensor output V _X is the detection axis Y and the detection axis Misalignment angles AA _XY , AA _XZ , and misalignment angles AA _YZ and AA _YX , respectively, with respect to the detection axis Z and the detection axis X corresponding to the sensor output V _Y , respectively. , A misalignment angle A A _ZX where the sensitivity axis of the sensor corresponding to the sensor output V _Z forms the detection axis X and the detection axis Y, respectively.
Misalignment angle _{AA ZY, V XC = V X} - (SF X / SF Y) (V Y -V YB) sin
_{AA XY - (SF X / SF} Z) (V Z -V ZB) sinAA
_{XZ V YC = V Y - (} SF Y / SF Z) (V Z -V ZB) sin
_{AA YZ - (SF Y / SF} X) (V X -V XB) sinAA
_{YX V ZC = V Z - (} SF Z / SF X) (V X -V XB) sin
_{AA ZX - (SF Z / SF} Y) (V Y -V YB) sinAA
_ZY .

According to a sixth aspect of the present invention, in the multi-dimensional acceleration measuring device, the acceleration sensor is a two-dimensional acceleration sensor.
Claim 7: In the multidimensional acceleration measuring device described in claim 6, the detection axis X arithmetic processing unit 2 for inputting the sensor outputs V _X and V _Y of specific two axes and _obtaining the correction output V _XC is provided. provided, _{wherein, V XC = V X - (} SF X / SF Y) (V Y -V YB) sin
| −AA _YX −AA _XY | where the sum of squares of the detected output V _Y of the specific input axis and the output V _XC obtained by calculating the acceleration component of the virtual input axis corresponding to the direction orthogonal to the input axis A multidimensional acceleration measuring device including an input angular velocity calculating unit for calculating a square root was constructed.

[0017]

Embodiments of the present invention will be described with reference to the drawings. As in the description of FIG. 3, it is assumed that there are three axes, X, Y, and Z axes, which are orthogonal to each other, and that the Z axis coincides with the direction of gravitational acceleration, and sensitivity, bias, and error, which are three performance parameters of the acceleration sensor. It is assumed that the alignment is obtained in advance by measurement. Acceleration sensor is Y
The X-axis output when rotated about the axis is shown in FIG.
The solid line indicates the case with misalignment, and the broken line indicates the case without misalignment.

[0018] Here, the input shaft of the X-axis output is assumed that inclined by misalignment angle AA _XZ in the Z-axis direction, furthermore, the input shaft of the X axis output is tilted by the misalignment angle AA _XY in the Y-axis direction A method for correcting this misalignment will be described. In FIG. 5, the points on the solid line having misalignment at the set angle 0 ° and the set angle 180 ° are matched with the points on the broken line without misalignment, thereby performing misalignment correction for these two points. become. At other points, a certain ratio is set, and a point between the solid line and the broken line is made to correspond to the correction result.

First, as for the correction of the misalignment amount AA _XZ , when this is converted into an input acceleration, g _XZ = 1 × sinAA _XZ is converted into an output voltage. This voltage corresponds to the correction amount. ΔV _XZ = SF _X × g _XZ Referring to FIG. 5, in order to set the misalignment amount AA _XZ to 0, the X-axis output voltage V _X at the angle setting of 0 ° is Δ
If V _XZ is subtracted and ΔV _XZ is added to the X-axis output voltage V _X at the angle setting of 180 °, appropriate correction has been made for these two points. However, for any other angle setting, if ΔV _XZ is corrected as a constant value, sensitivity will be reduced. By the way, when the X-axis output is zero g input, that is, when the Z-axis output is +1 g input, if ΔV _XZ is subtracted by 100%, this is an appropriate correction, and when the X-axis output is ± 1 g input. That is, when the Z-axis output is zero g, it is not necessary to correct ΔV _XZ . From the above, when the Z-axis output is a value between these two outputs, the correction amount ΔV _XZ may be a value proportional to the acceleration input to the Z-axis output. Therefore,
To determine this ratio, the acceleration applied to the Z axis is replaced by the ratio.

Here, the Z-axis input acceleration: α _z is α _z = (V _Z −V _ZB ) / SF _Z where V _Z : Z-axis output voltage V _ZB : Z-axis zero G bias output voltage X Corrected output voltage corrected at an arbitrary position of the axis output: V _XC is V _XC = V _X −ΔV _XZ × α _Z = V _X −SF _X × sin (AA _XZ ) × (V _Z −V _ZB ) / SF _Z = V _X - a _{(SF X / SF Z) (} V Z -V ZB) sinAA XZ.

The output characteristics of the acceleration sensor are shown in a graph.
As shown in FIG. The solid line is the characteristic curve before correction.
The dashed line is the characteristic curve after correction according to the present invention.
You. This corrected characteristic curve corresponds to the misalignment shown in FIG.
Reduces misalignment by approaching dashed lines with no alignment
You can see that it is done. Next, the misalignment amount A
A_XYOf the misalignment AA _XZComplement
As in the positive case, when this is converted to input acceleration, g_XY= 1 × sin (AA_XY) Convert this to output voltage. This voltage corresponds to the correction amount.
You.

ΔV _X = SF _X × g _X Referring to FIG. 5, in order to set the misalignment amount _AAXY to 0, it is necessary to calculate ΔX from the X-axis output voltage V _X at an angle setting of 0 °.
If V _XY is subtracted, and ΔV _XY is added to the X-axis output voltage V _X at the angle setting of 180 °, the two points have been properly corrected. However, for any other angle setting, if ΔV _XY is corrected as a constant value, sensitivity will be reduced. Incidentally, when the X-axis output is zero g input, i.e. to when Y axis output is a + 1 g input This is subtracted the [Delta] V _XY 100% is a proper correction, X-axis output at ± 1 g Input , i.e. it is not necessary to correct the [Delta] V _XY when Y axis output is zero g input. From the above, when the Y-axis output is a value between these two outputs, the correction amount [Delta] V _XY will be may be a value proportional to the acceleration which is input to the Y-axis output. Therefore,
To determine this ratio, the acceleration applied to the Y axis is replaced with the ratio.

Here, Y-axis input acceleration: α _Y is α _Y = (V _Y -V _YB ) / SF _Y where V _Y : Y-axis output voltage V _YB : Y-axis zero G bias output voltage X Corrected output voltage corrected at an arbitrary position of the axis output: V _XC is V _XC = V _X -ΔV _XY × α _Y = V _X -SF _X × sinAA _XY × (V _Y -V _YB ) / SF _Y = V _X - a _{(SF X / SF Y) (} V Y -V YB) sinAA XY.

The X-axis output after the correction is as shown in FIG. 6, indicating that misalignment is reduced. The solid line is the characteristic curve before correction, and the one-dot chain line is the characteristic curve after correction. As described above, the corrected output voltage V _XC of the X-axis output is the corrected output voltage after subtracting both ΔV _XZ × α _Z and ΔV _XY × α _Y from V _X.

[0025] _{V XC = V X -ΔV XZ ×} α Z -ΔV XY × α Y = V X - (SF X / SF Z) (V Z -V ZB) sinAA XZ - (SF X / SF Y) (V _Y- V _YB ) sinAA _XY or more, the misalignment AA _XZ and the misalignment AA _XY have been described. However, other misalignments can be corrected in the same manner.

Here, a multidimensional acceleration measuring apparatus according to the present invention will be described with reference to FIG. 1. Reference numeral 1 denotes a three-dimensional acceleration detecting and outputting three axes of detection axes X, Y and Z orthogonal to each other. It is an acceleration sensor. Sensor output V _X of each axis from the three-dimensional acceleration sensor 1, V _Y, V _Z is obtained. The multi-dimensional acceleration measuring device further includes a detection axis X operation processing unit 2, a detection axis Y operation processing unit 3, and a detection axis Z operation processing unit 4.

The detection axis X arithmetic processing unit 2 outputs the sensor output of each axis.
V_X, V_Y, V_ZAnd output the correction output V_XCFind and detect
The axis Y operation processing unit 3 calculates the sensor output V of each axis._X, V_Y, V_Z
And output the correction output V_YC, And the detection axis Z arithmetic processing unit 4
Is the sensor output V of each axis_X, V _Y, V_ZEnter
Force V_ZCAsk for. More than using a three-dimensional acceleration sensor
The multi-dimensional acceleration measuring device is used for detecting
Focus on any two of the three axes X, Y, and Z
To operate as a two-dimensional acceleration measuring device
You. In addition, this multi-dimensional acceleration measuring device is
-Dimensional acceleration measurement device using two-dimensional acceleration sensor
Can be placed.

In other words, the misalignment correction described above means that the actual output of the X input axis of the acceleration sensor in the misaligned state is virtually converted into the output of the X detection axis. Means that. This misalignment correction requires that the actual X input axis and the actual Y input axis satisfy the orthogonality condition, but it is not always necessary to match the X detection axis and the Y detection axis. In this case, a suitable seismometer can be configured. This will be specifically described below.

A multiaxial acceleration sensor is used as a seismic sensor for outputting a signal for controlling the operation of an elevator when an earthquake occurs. In the case of a multi-axis acceleration sensor that senses horizontal sway, it is not fixed in which direction the earthquake sways, so a multi-axis acceleration sensor having uniform sensitivity in all directions is required. Referring to FIG. 7, the principle of detecting all directions of the shaking will be described. FIG. 7A is a perspective view illustrating a seismic device that is a multidimensional acceleration measuring device, and FIG. 7B is a diagram illustrating the output of a multiaxial acceleration sensor and the direction of shaking.
(C) is a diagram for explaining misalignment correction of the input shaft.

Referring to FIG. 7A, the multi-axis acceleration sensor 5 is fixed to a mount 6. The Z axis of the multi-axis acceleration sensor 5 is an input axis of a P wave which is a longitudinal wave of the earthquake,
Detects wave sway components. Both the X-axis and the Y-axis of the multi-axis acceleration sensor 5 are input axes of S-waves, which are transverse waves of an earthquake. Referring to FIG. 7 (b), the magnitude of the sway wave V = √ (V _X ² + V _Y ² ) and the direction of the s wave are synthesized by vector combining the X input axis component V _X and the Y input axis component V _Y. Can be requested.

In general, many multi-axis acceleration sensors having high sensitivity have a structure having a detection sensitivity axis in one or two specific directions. Therefore, as described with reference to FIG. Are combined to obtain omnidirectional detection sensitivity. As an actual synthesis method,
The following method is adopted. Calculation of vector composition is performed by a computer.

V = √ (V _X ² + V _Y ² ) Assuming the output of the two axes and the axis intermediate between the two axes, the sum of the outputs of the two axes projected on the axis is determined, and the sum of these is calculated. Is obtained and the result similar to the vector synthesis is approximately output. Of these synthesis methods, in particular,
This method can be implemented with a relatively simple circuit configuration, and is therefore convenient as a synthesizing method for a multi-axis acceleration sensor.

In the calculation or synthesis of the omnidirectional detection sensitivity as described above, the two axes of the X input axis and the Y input axis must be orthogonal. However, since the actual multi-axis acceleration sensor is manufactured with variations in the degree of orthogonality between the two input axes, a reference axis is set on the mounting base, and the output of both input axes is corrected based on this. The angle of the input shaft direction is corrected by adding and subtracting each other by a circuit. This is shown in FIG.
As specifically described with reference to (c), an X reference axis and a Y reference axis that are orthogonal to each other are set on the mounting base 2. Here, the X reference axis is compared with the actual X input axis of the multi-axis acceleration sensor, and a misalignment angle _AAxy of the X input axis between the X reference axis and the X reference axis is detected. Similarly, the Y reference axis is compared with the actual Y input axis of the multi-axis acceleration sensor, and the misalignment angle AA _yx of the Y input axis between the Y reference axis and the Y reference axis is detected. This misalignment angle AA _xy is _shifted from the X input axis to the X reference axis side by +
The problem is solved by correcting only _AAxy . Regarding the misalignment angle AA _yx , the Y input axis is set to −A on the Y reference axis side.
The problem is solved by correcting by _Ayx . When this correction is performed, a total of two correction circuits are required because the misalignment angle correction in the input axis direction is performed for both the X input axis and the Y input axis.

However, as described above, in the seismometer, the actual X input axis and the actual Y input axis need to satisfy the orthogonal condition, but they do not always need to coincide with the X detection axis and the Y detection axis. . In this case, handling one of the input shaft of the multi-axis acceleration sensor as a reference axis, by adding wrinkled misalignment angle AA _yx of one input shaft to the reference axis misalignment angle AA _xy of the other input shaft,
By performing the angle correction of the added misalignment angle (AA _yx + AA _yx ) only on the other virtual input axis orthogonal to the reference axis, the magnitude and direction of the required input acceleration can be known. . Hereinafter, a specific description will be given with reference to FIGS. 8 and 9. FIG. 8 is a diagram for explaining an embodiment of the input shaft misalignment correction, and FIG. 9 is a diagram showing an apparatus for performing the misalignment correction of FIG.

In FIG. 8, the X axis and the Y axis indicate the true directions and are orthogonal. A misalignment angle AA _YX exists between the Y axis and the actual Y input axis of the acceleration sensor, and a misalignment angle AA _XY exists between the X axis and the actual X input axis of the acceleration sensor. However, the misalignment angle is measured with the direction of the arrow in FIG. 2 being positive.

With the X axis set to 0 °, the actual direction of the Y input axis is (90 ° −AA _YX ) and the actual direction of the X input axis is (AA _XY ). −X input shaft direction) = (90 ° −AA)
_YX) - is (AA _XY). If the difference in this direction is 90 °, both input axes are orthogonal. Here, the orthogonality between the direction of the actual Y input axis and the direction of the actual X input axis is represented by | (90 ° −AA _YX ) − (AA _XY ) −90 ° | = | −A
A _YX -AA _XY | The fact that this value is 0 means that the direction of the actual Y input axis is orthogonal to the direction of the actual X input axis. The axis with orthogonality 0 is the orthogonal XY coordinate axis AA _YX
This is the X axis rotated and moved only by. This X axis is a virtual X input axis.

As a result, the orthogonality = | −AA _YX −AA _XY | is the misalignment angle of the virtual X input shaft. As the correction equation, V _XC in the equation for obtaining the correction output voltage is used.
Use _{V XC = V X - (SF} X / SF Y) (V Y -V YB) sin
_{AA XY - (SF X / SF} Z) (V Z -V ZB) sinAA
_XZ this case, from where the third term in the Z-axis is _{0, V XC = V X -} (SF X / SF Y) (V Y -V YB) sin
AA _XY . In this formula, the preceding orthogonality instead of misalignment angle AA _XY of X input shaft: | -AA _YX -AA _XY | calculated by substituting.

Here, the acceleration measuring apparatus will be described with reference to FIG. 9. This corresponds to a simplification of the embodiment of FIG. 1, where 1 is the acceleration of two axes of the X input axis and the Y input axis. Is a two-dimensional acceleration sensor that detects and outputs Acceleration sensor output V _Y of the acceleration sensor output V _X and Y input shaft of the X input shaft from the two-dimensional acceleration sensor 1 is obtained. This acceleration measuring device further includes only one detection axis X arithmetic processing unit 2. The detection axis X arithmetic processing unit 2 inputs these acceleration sensor outputs V _X and V _Y and outputs a corrected output voltage V
Calculate and output _XC .

V _XC = V _X- (SF _X / SF _Y ) (V _Y-
V _YB ) sin | −AA _YX −AA _XY | This V _XC is converted to a virtual X input axis obtained by rotating the orthogonal XY coordinate axis by A A _YX and output as a misalignment angle |
−AA _YX −AA _XY | is the corrected output voltage.

[0040]

As described above, according to the present invention, it is possible to cancel the misalignment of the input shaft in a certain direction by subtracting the output of the misalignment component from the output in a certain axial direction. Thus, the acceleration in the axial direction to be detected can be accurately measured.

In a two-axis acceleration sensor for detecting omnidirectional vibration or acceleration, attention is paid to the fact that the X and Y input axes only need to be relatively orthogonal to each other. Instead of performing misalignment angle correction of the mounting angle of the input axis and the Y input axis for two axes,
By performing misalignment angle correction of only the other input axis with reference to one input axis, one of the reference input axes is made orthogonal to the virtual other input axis, and the correction circuit is reduced from two for convenience. It can be simplified to one, which leads to simplification of the configuration of the acceleration measuring device and cost reduction.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an embodiment.

FIG. 2 is an explanatory diagram of an input shaft and misalignment.

FIG. 3 is an explanatory diagram of misalignment.

FIG. 4 is an explanatory diagram of an evaluation method of the acceleration sensor.

FIG. 5 is an output characteristic diagram of the acceleration sensor.

FIG. 6 is an output characteristic diagram of an acceleration sensor in which misalignment has been corrected.

FIG. 7 is a view for explaining the principle of detection of all directions of shaking.

FIG. 8 is a view for explaining an embodiment of misalignment correction of an input shaft.

FIG. 9 is a diagram showing an apparatus for performing the misalignment correction of FIG. 8;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Multi-dimensional acceleration sensor 2 Detection axis X calculation processing part 3 Detection axis Y calculation processing part 4 Detection axis Z calculation processing part 5 Multi-axis acceleration sensor 6 Mounting base

Claims (7)

[Claims] 1. A detection axis X perpendicular to each other, Y, in a multidimensional acceleration sensor for detecting a three-axis direction acceleration of the _{Z, V XC = V X -} (SF X / SF Y) (V Y -V YB) sin
_{AA XY - (SF X / SF} Z) (V Z -V ZB) sinAA
_{XZ V YC = V Y - (} SF Y / SF Z) (V Z -V ZB) sin
_{AA YZ - (SF Y / SF} X) (V X -V XB) sinAA
_{YX V ZC = V Z - (} SF Z / SF X) (V X -V XB) sin
_{AA ZX - (SF Z / SF} Y) (V Y -V YB) sinAA
_{It is characterized in that} the arithmetic processing of the relationship of _ZY is performed to obtain the corrected output voltages V _XC , V _YC , V _ZC corresponding to the selected two axes or three axes among the detected axes X, Y, Z, respectively. Correction method for a multidimensional acceleration sensor. However, the sensor output V _X of the axes, V _Y, V _Z, sensor sensitivity SF _X of the axes, SF _Y, SF _Z sensor output bias voltage V _XB of each axis, V _YB, V _ZB, the sensor output V _X Misalignment angle A between the sensitivity axis of the sensor corresponding to the detection axis Y and the detection axis Z.
A _XY , misalignment angle AA _XZ , misalignment angle A formed by the sensor sensitivity axis corresponding to sensor output V _Y with detection axis Z and detection axis X, respectively
A _YZ , misalignment angle AA _YX , misalignment angle A formed by the sensor sensitivity axis corresponding to sensor output V _Z with detection axis X and detection axis Y, respectively
_AZX , misalignment angle _AAZY . 2. The method for correcting misalignment of a multidimensional acceleration sensor according to claim 1, wherein the multidimensional acceleration sensor is a two-dimensional acceleration sensor. 3. The method for correcting misalignment of a multidimensional acceleration sensor according to claim 2, wherein a misalignment angle correction calculation process is performed only on the other input axis with respect to a specific input axis. A method for correcting a misalignment angle of a multidimensional acceleration sensor, wherein a virtual input axis orthogonal to a specific input axis is obtained. 4. The method for correcting a misalignment angle of a multidimensional acceleration sensor according to claim 3, wherein a detection output V _Y of a specific input axis and a virtual input axis corresponding to a direction orthogonal to the input axis. Of the multi-axis acceleration sensor, wherein the magnitude of the input angular velocity is obtained by calculating the square root of the sum of squares of the outputs of the input axes orthogonal to each other using the output V _XC obtained by calculating the acceleration component of Misalignment correction method. _{However, V XC = V X - (} SF X / SF Y) (V Y -V YB) sin
| -AA _YX -AA _XY | 5. A multi-dimensional acceleration sensor for detecting and outputting accelerations on three axes X, Y, and Z orthogonal to each other, and receiving sensor outputs V _X , V _Y , and V _Z of each axis. A detection axis X operation processing unit for obtaining a correction output V _XC by using the detection axis Y operation processing unit for inputting the sensor outputs V _X , V _Y , and V _Z of each axis to obtain a correction output V _YC . A multi-dimensional acceleration measuring device, comprising: a detection axis Z arithmetic processing unit for inputting sensor outputs V _X , V _Y , and V _Z of each axis to obtain a correction output V _ZC . However, the sensor output V _X of the axes, V _Y, V _Z, sensor sensitivity SF _X of the axes, SF _Y, SF _Z sensor output bias voltage V _XB of each axis, V _YB, V _ZB, the sensor output V _X Misalignment angle A between the sensitivity axis of the sensor corresponding to the detection axis Y and the detection axis Z.
A _XY , misalignment angle AA _XZ , misalignment angle A formed by the sensor sensitivity axis corresponding to sensor output V _Y with detection axis Z and detection axis X, respectively
A _YZ , misalignment angle AA _YX , misalignment angle A formed by the sensor sensitivity axis corresponding to sensor output V _Z with detection axis X and detection axis Y, respectively
A _ZX, misalignment angle _{AA ZY, V XC = V X} - (SF X / SF Y) (V Y -V YB) sin
_{AA XY - (SF X / SF} Z) (V Z -V ZB) sinAA
_{XZ V YC = V Y - (} SF Y / SF Z) (V Z -V ZB) sin
_{AA YZ - (SF Y / SF} X) (V X -V XB) sinAA
_{YX V ZC = V Z - (} SF Z / SF X) (V X -V XB) sin
_{AA ZX - (SF Z / SF} Y) (V Y -V YB) sinAA
_ZY . 6. The multi-dimensional acceleration measuring device according to claim 5, wherein the acceleration sensor is a two-dimensional acceleration sensor. 7. The multi-dimensional acceleration measuring device according to claim 6, further comprising a detection axis X arithmetic processing unit for inputting sensor outputs V _X and V _Y of specific two axes and _obtaining a correction output V _XC. , Where: V _XC = V _X- (SF _X / SF _Y ) (V _Y -V _YB ) sin
| −AA _YX −AA _XY | where the sum of squares of the detected output V _Y of the specific input axis and the output V _XC obtained by calculating the acceleration component of the virtual input axis corresponding to the direction orthogonal to the input axis A multidimensional acceleration measuring device comprising an input angular velocity calculating unit for calculating a square root.