JP2006119008A - Method for adjusting temperature characteristics of gyro sensor and gyro sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gyro sensor temperature characteristic adjusting method and a gyro sensor capable of suppressing an influence of fluctuation of a zero point voltage with respect to a temperature change and obtaining an accurate output of the gyro sensor.
A temperature characteristic adjustment method for a gyro sensor that corrects a temperature characteristic of a zero point voltage by adding a temperature characteristic of a zero point voltage and a temperature characteristic of a temperature sensor when no rotational angular velocity is applied. Thus, the primary correction target straight line 35 of the slope a is obtained from the measured value of the zero point voltage for each predetermined temperature of the gyro sensor 10, the approximate straight line 50 is obtained from the measured value of the output voltage for each predetermined temperature of the temperature sensor 80, and the approximate straight line The gain is adjusted so that the slope of 50 becomes (−a), the straight line 51 of the slope (−a) of the output voltage of the temperature sensor 80 is determined, and the zero-point voltage primary correction target straight line 35 of the gyro sensor 10 and A temperature characteristic correction output of the gyro sensor 10 is obtained by adding the straight line 51 after the gain adjustment of the temperature sensor.
[Selection] Figure 5

Description

  The present invention relates to a method for adjusting temperature characteristics of a gyro sensor, and a gyro sensor whose temperature characteristics are adjusted by the temperature characteristic adjusting method.

  Conventionally, the temperature characteristics of the zero point voltage (null voltage) when no rotational angular velocity is applied to the angular velocity sensor is linearly approximated by a linear equation using the least square method, and the voltage corresponding to the slope of this approximated line is added to the sensor output. The sensor output at the time of non-rotation at the reference temperature is configured to deviate by a voltage corresponding to the slope of the approximate straight line with respect to a predetermined reference voltage that has been determined in advance. There is known an angular velocity sensor that superimposes the gradient information on the temperature of the zero point voltage for correcting the voltage on the output of the angular velocity sensor so that it can be extracted.

  Further, as a method for adjusting the temperature characteristics of the angular velocity sensor, the angular velocity sensor includes a step of measuring an output voltage at the time of non-rotation at a reference voltage of the angular velocity sensor and comparing the output voltage with a predetermined known reference voltage. Analyzing the temperature characteristic of the zero point voltage approximated linearly, measuring the temperature, and calculating the zero point voltage correction value from the analyzed temperature characteristic of the zero point voltage of the angular velocity sensor and the measured temperature A method for adjusting the temperature characteristics of the angular velocity sensor is known, which includes a step of correcting the zero point voltage of the angular velocity sensor with a correction value of the zero point voltage (see, for example, Patent Document 1).

Japanese Patent No. 3292002 (pages 5, 6 and 4)

  In Patent Document 1, the temperature characteristics of the zero-point voltage of the angular velocity sensor are measured, and the slope of an approximate line obtained by approximating the temperature characteristics of the zero-point voltage with a linear equation using the least square method and a known reference voltage are obtained. In comparison, correction is made so as to shift by a voltage corresponding to the slope of the approximate straight line, but it is conceivable that the least square method includes a temperature characteristic outside the standard. In such a case, it is necessary to perform a standard guarantee inspection or the like in the pre-shipment inspection or the like, and there is a problem that the yield is estimated to be reduced at the final shipping stage and the cost is increased.

  The object of the present invention is to solve the above-mentioned problems, efficiently adjust the temperature characteristics of the gyro sensor, suppress the influence of the fluctuation of the zero point voltage with respect to the temperature change, and obtain an accurate output of the gyro sensor. It is an object of the present invention to provide a gyro sensor temperature characteristic adjusting method and a gyro sensor.

  The gyro sensor temperature characteristic adjusting method according to the present invention includes a gyro sensor that corrects the temperature characteristic of the zero point voltage by adding the temperature characteristic of the zero point voltage and the temperature characteristic of the temperature sensor when the rotational angular velocity is not applied. A temperature characteristic adjusting method, wherein a linear correction target straight line of a slope a is obtained from a measured value of a zero point voltage at each predetermined temperature of the gyro sensor, and an approximate straight line is obtained from a measured value of the output voltage at each predetermined temperature of the temperature sensor. The gain is adjusted so that the slope of the approximate straight line becomes (−a), the straight line of the slope (−a) of the output voltage of the temperature sensor is determined, and the zero point voltage of the gyro sensor is subject to primary correction The temperature characteristic correction output of the gyro sensor is obtained by adding the straight line and the straight line after gain adjustment of the temperature sensor.

Here, the zero point voltage indicates an output voltage when a rotational angular velocity is not applied to the gyro sensor. A temperature sensor having a predetermined temperature characteristic is selected and used in advance.
According to the present invention, the straight line of the slope a obtained from the measured value of the zero point voltage at each predetermined temperature of the gyro sensor and the straight line of the slope (−a) obtained by adjusting the gain of the approximate straight line of the temperature characteristic of the temperature sensor. , A temperature characteristic correction output of zero point voltage is obtained, so that the obtained zero point voltage correction output can obtain an output voltage whose temperature is corrected at each predetermined temperature.

  In the gyro sensor temperature characteristic adjusting method according to the present invention, a step of measuring a zero point voltage for each predetermined temperature of the gyro sensor, and a straight line indicating an upper limit value range and a straight line indicating a lower limit value range of the temperature characteristic are obtained. The step is compared with the slope of the straight line indicating the upper limit range of the temperature characteristic and the straight line indicating the lower limit range, a straight line having a large absolute value of the slope is selected, and the slope of the straight line is defined as a. A step of determining a linear correction target straight line a that passes through the center of a region including all point voltages, a step of measuring an output voltage at each predetermined temperature of the temperature sensor, and an approximation of temperature characteristics from the output voltage of the temperature sensor A step of obtaining a straight line, a step of adjusting a gain of an approximate straight line of the temperature sensor so as to have an inclination (−a), a straight line of the primary correction target and the temperature sensor The sum of the straight line that is in the adjustment, characterized in that it comprises the steps of: determining a primary correction line zero point voltage.

  According to such a temperature characteristic adjustment method, a straight line indicating the upper limit range and the lower limit range of the temperature characteristic of the gyro sensor is obtained, an area including all of the zero point voltages for each predetermined temperature is set, and the temperature Since the correction characteristics are obtained by adding the temperature characteristics of the sensors, all of the zero point voltages for each predetermined temperature can be corrected within the predetermined temperature characteristics range, and the gyroscope within the predetermined temperature characteristics management range can be obtained. The temperature characteristics of the sensor can be corrected.

  Further, in the present invention, before the step of obtaining the primary correction line of the zero point voltage, the step of determining that the measured value of the zero point voltage at each predetermined temperature of the gyro sensor is within a predetermined range; And a step of determining a defective product when the zero point voltage is outside a predetermined range.

  In this way, when the measured value of the zero point voltage of the gyro sensor at a predetermined temperature is outside the predetermined range, it is determined as a defective product, and the defective product is determined not to proceed to the next step. Since only the gyro sensor within the predetermined range can be eliminated and advanced to the next step, useless steps can be eliminated and the temperature characteristic of the gyro sensor can be adjusted efficiently. This also has the effect that the yield after the step of obtaining the primary correction line of the zero point voltage can be increased.

The above-described temperature characteristic adjustment method for the gyro sensor preferably includes a step of offset adjustment of the zero point voltage obtained from the primary correction line to a predetermined output voltage.
Here, the predetermined output voltage means, for example, a center voltage in a detection voltage range in which the minimum value of the zero point voltage after the primary correction is 0 V or more and the maximum value is the driving voltage or less.

  In this way, since the primary correction line is set to the predetermined voltage as described above, the zero point voltage is distributed within the center detection voltage range because the gyro sensor zero point voltage is distributed within the center detection voltage range. It can be detected as a voltage.

  Furthermore, in the above-described temperature characteristic adjustment method of the gyro sensor, the step of measuring the zero point voltage for each predetermined temperature of the gyro sensor and the step of measuring the output voltage for each predetermined temperature of the temperature sensor are performed in parallel. Preferably it is done.

  The measurement of the temperature characteristic is performed using, for example, a thermostat, etc., but the temperature characteristic at a predetermined temperature of the zero point voltage of the gyro sensor and the measurement at a predetermined temperature of the temperature sensor are measured in the same thermostat, At the same time and under the same conditions, accurate temperature characteristics can be obtained, and in order to measure the temperature characteristics, it takes time to set the temperature environment of the thermostat. The measurement time can be greatly shortened and the temperature characteristic adjustment of the gyro sensor can be made more efficient.

  The gyro sensor is a gyro sensor whose temperature characteristics are adjusted by the above-described temperature characteristic adjustment method of the gyro sensor, and obtains a primary correction target straight line of the inclination a from the measured value of the zero point voltage at each predetermined temperature of the gyro sensor, An approximate straight line is obtained from the measured value of the output voltage at a predetermined temperature of the temperature sensor, gain adjustment is performed so that the slope of the approximate line becomes (−a), and the slope of the output voltage (−a) of the temperature sensor is adjusted. A straight line is determined, and a linear correction target straight line of zero point voltage of the gyro sensor and a straight line after gain adjustment of the temperature sensor are added to output a temperature characteristic correction output of the gyro sensor.

  The gyro sensor whose temperature characteristic is adjusted in this way can output an accurate temperature characteristic correction output within a predetermined specification range of the gyro sensor, so that a highly reliable gyro sensor that reduces the influence of temperature in the usage environment can be obtained. Can be provided.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 and 2 are plan views for explaining the vibration operation of the gyro sensor according to the embodiment of the present invention, FIGS. 3 and 4 are explanatory views showing an example of the configuration of the embodiment, FIG. 5 is a process diagram, FIG. FIG. 13 is a graph showing specific steps.
(Embodiment)

First, the vibration operation of the gyro sensor 10 according to the present embodiment will be described.
1 and 2 are plan views for schematically explaining the operation of the gyro sensor 10 of the present embodiment. In FIGS. 1 and 2, each vibrating arm is simplified and represented by a line in order to easily explain the vibration mode.

  FIG. 1 is a plan view for explaining drive vibration. In FIG. 1, the drive vibration is a bending vibration indicated by an arrow A of the drive vibration arms 15A, 15B, 15C, and 15D, and a vibration state indicated by a solid line and a vibration state indicated by a two-dot chain line at a predetermined frequency. It is repeating. At this time, since the drive vibration arms 15A and 15B and the drive vibration arms 15C and 15D perform line-symmetric vibrations on the Y axis passing through the center point G, the base 12, the connection arms 13 and 14, and the detection vibration arms 16A. , 16B hardly vibrate.

  Here, the gyro sensor 10 is made of quartz and is a Z-cut of the X-axis called the electrical axis, the Y-axis called the mechanical axis, and the Z-axis called the optical axis and the Z-axis cut out in the plane direction. It is formed from a quartz substrate. The gyro sensor 10 is formed of a quartz substrate having a predetermined thickness, and its planar shape is developed on the XY plane in accordance with the crystal axis of the quartz and has a shape that is 180-degree symmetric with respect to the center point G. The center point G is the position of the center of gravity of the gyro sensor 10. The gyro sensor 10 formed in this way is called a double T-type gyro sensor.

  FIG. 2 is a plan view for explaining the detected vibration. In FIG. 2, the detected vibration repeats a vibration state indicated by a solid line and a vibration state indicated by a two-dot chain line at the frequency of the drive vibration described above. When the gyro sensor 10 is performing the drive vibration shown in FIG. 1 and the rotational angular velocity ω around the Z axis is applied to the gyro sensor 10, the detected vibration is indicated by the arrows on the drive vibration arms 15A, 15B and 15C, 15D. It is generated by the Coriolis force in the direction indicated by B.

  Thus, the drive vibrating arms 15A, 15B, 15C, and 15D perform the vibration indicated by the arrow B. The vibration indicated by the arrow B is a vibration in the circumferential direction with respect to the center point G. At the same time, the detection vibrating arms 16A and 16B vibrate in the direction opposite to the circumferential direction of the arrow B in response to the vibration of the arrow B as indicated by the arrow C.

  In the present invention, the output voltage of the gyro sensor when the rotational angular velocity ω is not applied to the gyro sensor 10 as shown in FIG. 2 (this is expressed as a zero point voltage), that is, the vibration shown in FIG. The gist of the present invention is to provide a method for adjusting the temperature characteristics of the zero point voltage of the gyro sensor 10 when the gyro sensor 10 is in the state.

Next, a system configuration according to the temperature characteristic adjusting method of the gyro sensor of the present embodiment will be described.
3 and 4 are explanatory diagrams showing the configuration of the present system.
FIG. 3 shows the overall configuration of the present system. In FIG. 3, the system includes a gyro sensor 10, a drive unit 60, and a detection unit 70 as a basic configuration. Since the drive unit 60 has a well-known configuration, a description thereof will be omitted, but a drive signal is supplied to the drive arms 15A to 15D of the gyro sensor 10 described above. In addition, although not shown, a phase shift circuit that performs a 90-degree phase shift of the drive signal is provided in order to generate a signal synchronized with the detection unit 70 for removing the leakage vibration component from the drive unit 60.

  The detection unit 70 includes I / V conversion amplifiers 71 and 72 that convert a current generated from the detection electrode of the gyro sensor 10 into a voltage output in synchronization with the oscillation of the drive unit 60, and the I / V conversion amplifiers 71 and 72. The differential amplifier 73 that removes unnecessary components because of the reverse polarity of the output voltage, the synchronous detector 74 that removes unnecessary vibration line segments such as leakage vibration components other than the angular velocity component, and the gyro sensor 10 are individually used. In order to remove an unnecessary signal included in the output frequency output from the variable gain amplifier 75 that adjusts the variation sensitivity to a constant sensitivity and the detector 70 included in the angular velocity signal extracted by the synchronous detector 74. LPF (Low pass filter) 76.

In the present embodiment, since the rotational angular velocity ω is not applied, the output voltage obtained from the gyro sensor 10 is a zero point voltage. From the temperature characteristics of the zero point voltage and the temperature characteristics of a temperature sensor 80 (see FIG. 4), which will be described later, the linear lines respectively obtained are added, and the temperature of the gyro sensor 10 is adjusted by offset adjustment from the result. Allows characteristic adjustment.
A configuration relating to temperature characteristic adjustment of the gyro sensor 10 will be described with reference to FIG.

  FIG. 4 is an explanatory diagram showing a configuration of a system related to temperature characteristic adjustment of the gyro sensor 10 of the present embodiment. 4, the system relating to temperature characteristic adjustment detects a charge generated from the gyro sensor 10 and outputs it as a gyro sensor output, a temperature sensor 80, a temperature sensor amplifier 81, and a gyro sensor 10 described later. And a memory circuit 90 for determining a straight line to be corrected from the measured value of the zero point voltage for each temperature, gain adjustment of the temperature sensor amplifier, and determining an offset amount of the primary correction straight line.

In addition, an offset adjustment unit 91 that performs offset adjustment of the correction output according to a command from the memory circuit 90 and a sensitivity adjustment unit 92 that includes the above-described variable gain amplifier 75 for performing sensitivity gain adjustment are configured.
The detection unit 77 includes the I / V conversion amplifiers 71 and 72, the differential amplifier 73, and the synchronous detector 74 shown in FIG.
With such a system configuration, the temperature characteristic of the zero point voltage of the gyro sensor 10 of the present invention is adjusted, and the gyro sensor output voltage with the corrected temperature characteristic is output from the detection unit 77.

Subsequently, a temperature characteristic adjusting method of the gyro sensor according to the present embodiment will be described with reference to the drawings.
FIG. 5 is a process diagram illustrating a method for adjusting the temperature characteristic of the gyro sensor 10 according to the present embodiment, and FIGS. 6 to 13 are graphs illustrating a specific temperature characteristic adjustment state performed by the process. This will be described with reference to FIGS.

FIG. 5 shows a process related to the gyro sensor 10 on the left side and a process related to the temperature sensor 80 on the right side.
First, the zero point voltage of the gyro sensor 10 is measured for each predetermined temperature by the detection unit 77 in a thermostat (not shown) (ST1). FIG. 6 shows an example of the measurement result. The vertical axis y shows the measured value (unit V) of the zero point voltage, and the horizontal axis x shows the temperature to be measured (unit ° C). As measurement temperature, the range from -40 degreeC to 90 degreeC is measured for every 10 degreeC. Here, the temperature characteristic management range in the present embodiment is from −40 ° C. to 90 ° C. The zero point voltage at each of these temperatures varies as shown in FIG.

Next, the straight line 30 on the highest voltage side of the zero point voltage is obtained from the above measurement result (ST2).
FIG. 7 shows how to obtain the straight line 30. In FIG. 7, first, the highest voltage of the measured zero point voltage is selected. In the present embodiment, the point 21 indicates the maximum voltage. Here, a straight line 31 passing through the point 21 and parallel to the x-axis is obtained, and the straight line 31 is counterclockwise (in the direction of arrow E in the figure) or clockwise (in the figure, in the direction of arrow F). The points where the straight line 31 first intersects are compared, the linear coefficient connecting the point and the point 21 is compared, and the straight line having the larger absolute value of the primary coefficient is selected. In FIG. 7, point 22 is selected. Next, the point 21 and the point 22 are connected by a straight line 30. Let the equation of this straight line 30 be y = ax + b. This straight line 30 is a straight line indicating the upper limit range of the zero point voltage.

Next, a straight line 40 on the lowest voltage side of the zero point voltage is obtained (ST3).
FIG. 8 shows how to obtain the straight line 40. In FIG. 8, first, a point indicating the lowest voltage of the zero point voltage is selected. In the present embodiment, the point 23 indicates the minimum voltage. Here, a straight line 41 passing through the point 23 and parallel to the x-axis is obtained, and the straight line 41 is centered around the point 23 in the clockwise direction (G direction in the figure) or counterclockwise (in the figure, H direction). Rotate and compare the first intersecting points, compare the linear coefficient of the straight line connecting the point and the point 23, and select the straight line with the larger absolute value of the primary coefficient. In FIG. 8, the point 24 is selected, and a straight line 40 connecting the point 23 and the point 24 is obtained. Let the equation of the straight line 40 be y = cx + d. This straight line 40 is a straight line indicating the lower limit value range of the zero point voltage.

  It should be noted that the straight line 30 and the straight line 40 described above are selected and determined so that the zero-point voltage at each measured temperature is included in the region between the two lines.

Subsequently, the primary correction target straight line 35 is determined (ST4).
FIG. 9 shows how to obtain the primary correction target straight line 35. In FIG. 9, first, the slopes of the straight line 30 and the straight line 40 obtained previously are compared, and a straight line having a large slope is selected. In this embodiment, the inclinations a and c of the respective straight lines are compared. Temporarily, a straight line 30 having a large inclination is selected as a> c, and this straight line is moved parallel to the y-axis to a point including all measured zero-point temperatures. In the present embodiment, the straight line 32 is obtained by moving to the point 23. This linear equation is assumed to be y = ax + e. Then, a straight line 35 passing through the center of the straight line 30 and the straight line 32 is obtained. Accordingly, the straight line 35 is a straight line passing through the center of the upper limit value range and the lower limit value range of the zero point voltage. The equation of this straight line 35 is represented by y = ax + (b + e) / 2. The straight line 35 is a primary correction target straight line that is a basis for performing temperature correction of the gyro sensor 10 in subsequent steps.

Here, the primary correction range of the zero point voltage is obtained (ST5). The primary correction range means a region to be corrected among the zero point temperatures measured at each temperature. In FIG. 9, the distance 33 between the straight line 30 and the straight line 32 parallel to the y-axis is represented by (b−e), and the inclination of the straight lines 30 and 32 is a. Therefore, the vertical distance between the straight line 30 and the straight line 32. 34 is represented by (b−e) / (a ² +1) ^1/2 . This region includes the zero point voltage at each temperature. The range represented by (b−e) / (a ² +1) ^1/2 is the primary correction range (hereinafter, the vertical distance 34 is represented as the primary correction range 34).

Next, the primary correction range 34 and the specification range L are compared (ST6). In FIG. 9, the primary correction range 34 obtained in ST5 is compared with a preset specification range L (standard value not shown), and outside the predetermined specification range represented by the primary correction range 34> specification range L. These gyro sensors are excluded as non-standard products, and the gyro sensor existing in the range represented by the primary correction range 34 <specification range L shifts to the next step.
Further, the temperature sensor 80 is measured in parallel with the above-described steps ST1 to ST6.

First, the output voltage of the temperature sensor 80 is measured for each predetermined temperature in the thermostatic chamber (ST11). FIG. 10 shows an example of the measurement result. The vertical axis (y) shows the measured value (unit V) of the output voltage of the temperature sensor 80, and the horizontal axis (x) shows the temperature to be measured (unit ° C). The temperature is measured from −40 ° C. to 90 ° C. every 10 ° C. Here, the range from −40 ° C. to 90 ° C. corresponds to the temperature characteristic management range of the gyro sensor 10 in this embodiment.
Note that the measurement of the output voltage of the temperature sensor 80 is preferably performed in parallel in the same thermostatic chamber as the measurement of the temperature characteristic of the gyro sensor 10 in order to set the same measurement conditions.

  Next, an approximate line 50 of the output voltage of the temperature sensor is obtained by connecting points representing the output voltage at each temperature (ST12). As the temperature sensor 80, a sensor having a predetermined inclination and linearity is selected and specified in advance.

Subsequently, gain adjustment is performed so that the approximate straight line 50 of the output voltage of the temperature sensor becomes a slope that cancels the slope a of the primary correction target straight line 35 of the zero point voltage of the gyro sensor 10 (ST13).
FIG. 11 shows this step (ST13). In FIG. 11, a straight line 51 having a slope (-a) opposite to the slope of the primary correction target straight line 35 is obtained by adjusting the approximate straight line 50 indicating the temperature characteristics of the temperature sensor 80 obtained in ST12 (ST14). The straight line 51 and the primary correction target straight line 35 are gain-adjusted so as to intersect at a position of 25 ° C., which is generally normal temperature. The gain adjustment amount is written in the memory circuit 90 as a primary correction coefficient. The equation of the straight line 51 obtained in step ST14 (see FIG. 11) is represented by y = −ax + f.

Then, the primary correction target straight line 35 and the gain-adjusted straight line 51 are added (synthesized) to determine a primary correction straight line (ST20). FIG. 12 shows the state. In FIG. 12, a straight line 36 parallel to the x-axis is obtained by adding the primary correction target straight line 35 and the gain-adjusted straight line 51. The equation for line 36 is given by y = x + {(b + e) / 2 + f} / 2. That is, the straight line 36 indicates that the zero point voltage for each measurement temperature of the gyro sensor is {(b + e) / 2 + f} / 2 volts (V). This zero point voltage is the center value of the generation region of the zero point temperature.
Further, obtaining the straight line 36 in this way is called primary temperature correction, and the straight line 36 is called a primary correction straight line.

Subsequently, the primary correction straight line 36 is offset adjusted to a predetermined voltage (ST21).
FIG. 13 shows the state of offset adjustment. In FIG. 13, the primary correction straight line 36 is offset to a predetermined voltage value. In the offset adjustment, the difference between the zero point voltage indicated by the primary correction straight line 36 and a predetermined voltage is converted into the number of adjustment bits and written to the memory circuit 90. This offset voltage is the center voltage of the detection voltage range in which the minimum value of the zero point voltage after primary correction is 0 V or more and the maximum value is at least the drive voltage or less, and is a value that is appropriately set according to the width of the detection voltage range It is. The offset amount is J in FIG. 13, and the predetermined voltage is 2.5 V in this embodiment. Therefore, the offset amount J is represented by J = 2.5 − {(b + e) / 2 + f} / 2. The equation of the offset straight line 37 is represented by y = 2.5, and this straight line 37 is a straight line after temperature characteristic correction. Then, the zero point voltage for each temperature falls within the region indicated by the primary correction range 34.

The primary correction range 34 is indicated by (b−e) / (a ² +1) ^1/2 as described in ST5 (see FIG. 9). Therefore, the zero point voltage for each temperature is in the range of 2.5 ± {(be) / (a ² +1) ^1/2 } / 2, and the temperature characteristic adjustment (temperature correction) of the gyro sensor is completed. . The gyro sensor output that has been subjected to temperature characteristic adjustment (temperature correction) in this way is output from the detection unit 77 as a temperature characteristic correction output.

  It should be noted that the above-described zero point voltage of the gyro sensor 10 and the output voltage of the temperature sensor 80, the determination of each straight line, the determination of the gain adjustment amount, and the determination of the offset amount are performed by the memory circuit 90 and software.

  Therefore, according to the above-described embodiment, the gain of the primary correction target straight line 35 of the slope a obtained from the measured value of the zero point voltage at each predetermined temperature of the gyro sensor 10 and the approximate straight line of the temperature characteristic of the temperature sensor 80 is adjusted. Since the primary correction straight line 36 of the zero point voltage correction output is obtained by adding the straight line 51 of the slope (−a), the obtained zero point voltage correction output is temperature-corrected at each predetermined temperature. Output voltage can be obtained.

  Further, the straight lines 30 and 32 of the upper limit value range and the lower limit value range of the temperature characteristic of the gyro sensor 10 are obtained, an area including all of the zero point voltages for each predetermined temperature is set, and the temperature characteristic of the temperature sensor 80 is shown. Since a straight line 51 obtained by subtracting the approximate straight line 50 is added to obtain a zero point voltage correction output, all zero point voltages for each predetermined temperature are corrected within a predetermined temperature characteristic range. The temperature characteristic of the gyro sensor 10 within a predetermined temperature characteristic management range can be corrected.

  Further, when the measured value of the zero point voltage of the gyro sensor 10 at each predetermined temperature is outside the predetermined specification range L, it is determined as a defective product, and the defective product is eliminated by not proceeding to the next step. Since only the gyro sensor 10 within the predetermined specification range L can be advanced to the next step, it is possible to efficiently adjust the temperature characteristic of the gyro sensor 10 by eliminating a useless step. This also has the effect that the yield after the step of obtaining the primary correction line 36 of the zero point voltage can be increased.

  In addition, since the zero point voltage obtained from the primary correction straight line 36 is offset adjusted to the predetermined output voltage 2.5V, the zero point voltage of the gyro sensor 10 is distributed around the predetermined output voltage 2.5V. Therefore, the fluctuation range of the center value of the zero point voltage for each individual gyro sensor becomes small, and the detected value of the output voltage becomes a size that can be easily processed, so that the detection power can be increased.

  Furthermore, by measuring the temperature characteristics of the gyro sensor 10 at each predetermined temperature of the zero point voltage and measuring the temperature sensor 80 at each predetermined temperature in the same thermostatic chamber under the same conditions at the same time, accurate temperature characteristics can be obtained. In addition, the measurement time can be greatly shortened as compared with the method performed separately, and the temperature characteristic adjustment of the gyro sensor 10 can be made more efficient.

It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, in the above-described embodiment, the double T-type gyro sensor is exemplified, but the temperature characteristic adjusting method of the gyro sensor according to the present invention can also be applied to a triangular prism angular velocity sensor, an H-type gyro sensor, and the like.

  In the above-described embodiment, the measurement of the temperature characteristic of the gyro sensor 10 and the measurement of the temperature characteristic of the temperature sensor 80 are exemplified in parallel in the same constant temperature bath. However, the temperature characteristic of the gyro sensor 10 is illustrated. And measurement of the temperature characteristics of the temperature sensor 80 can be performed while shifting the time, or using a separate thermostatic chamber.

  Furthermore, in the above-described embodiment, in ST6 (see FIG. 5), the primary correction range 34 obtained in ST5 is compared with a preset specification range L (standard value not shown), and the primary correction range 34 is compared. > Gyro sensors outside the specified specification range represented by the specification range L are excluded as non-standard products, but when the zero point voltage is measured in ST1, the measured zero point voltage is within the specification range L. When it is determined whether or not there is a use range L, it is possible to select a process to be excluded as a nonstandard product.

  In this way, the non-standard product does not have to flow to the steps after ST2, so the yield in the steps after ST2 can be improved.

  Therefore, according to the above-described embodiment, the gyro sensor can efficiently adjust the temperature characteristic of the gyro sensor, suppress the influence of the fluctuation of the zero point voltage with respect to the temperature change, and obtain an accurate output of the gyro sensor. A temperature characteristic adjusting method for a sensor and a gyro sensor can be provided.

The top view which shows the drive vibration of the gyro sensor which concerns on embodiment of this invention. The top view which shows the detection vibration of the gyro sensor which concerns on embodiment of this invention. Explanatory drawing which shows the system of temperature characteristic adjustment of the gyro sensor which concerns on embodiment of this invention. Explanatory drawing which shows the system of temperature characteristic adjustment of the gyro sensor which concerns on embodiment of this invention. Process drawing which shows the temperature characteristic adjustment method of the gyro sensor which concerns on embodiment of this invention. The graph which shows the measurement result of 0 point voltage for every predetermined temperature of the gyro sensor which concerns on embodiment of this invention. The graph which shows the straight line 30 by the side of the highest voltage of 0 point voltage of the gyro sensor which concerns on embodiment of this invention. The graph which shows the straight line 40 by the side of the lowest voltage of the zero point voltage of the gyro sensor which concerns on embodiment of this invention. The graph which shows the primary correction | amendment target straight line 35 of the gyro sensor which concerns on embodiment of this invention. The graph which shows the measurement result of the output voltage for every predetermined temperature of the temperature sensor which concerns on embodiment of this invention. The graph which shows gain adjustment of the temperature sensor which concerns on embodiment of this invention. The graph which shows the primary correction | amendment straight line 36 of the gyro sensor which concerns on embodiment of this invention. The graph which shows the offset adjustment of the gyro sensor which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Gyro sensor, 35 ... Primary correction object straight line, 36 ... Primary correction straight line, 50 ... Approximate straight line, 51 ... Straight line after gain adjustment, 80 ... Temperature sensor.

Claims (6)

A temperature characteristic adjustment method for a gyro sensor that corrects the temperature characteristic of the zero point voltage by adding the temperature characteristic of the zero point voltage and the temperature characteristic of the temperature sensor when no rotational angular velocity is applied,
A primary correction target straight line of the slope a is obtained from the measured value of the zero point voltage at each predetermined temperature of the gyro sensor,
An approximate straight line is obtained from the measured value of the output voltage at each predetermined temperature of the temperature sensor, gain adjustment is performed so that the slope of the approximate line becomes (−a), and the slope of the output voltage (−a) of the temperature sensor. Determine the straight line
A temperature characteristic adjustment method for a gyro sensor, wherein a linear correction target straight line for the zero point voltage of the gyro sensor and a straight line after gain adjustment of the temperature sensor are added to obtain a temperature characteristic correction output of the gyro sensor. In the temperature characteristic adjustment method of the gyro sensor that corrects the temperature characteristic of the zero point voltage,
Measuring a zero point voltage for each predetermined temperature of the gyro sensor;
Obtaining a straight line indicating an upper limit range and a lower limit range of the temperature characteristic; and
The straight line indicating the upper limit value range and the straight line indicating the lower limit range of the temperature characteristic are compared, a straight line having a large absolute value is selected, and the straight line has a slope of a. Determining a primary correction target straight line with an inclination a passing through the center of a region including all of
Measuring an output voltage at each predetermined temperature of the temperature sensor;
Obtaining an approximate line of temperature characteristics from the output voltage of the temperature sensor;
Adjusting the gain so that the approximate straight line of the temperature sensor has an inclination (−a);
Adding the primary correction target straight line and the temperature-adjusted straight line of the temperature sensor to determine a zero-point voltage primary correction straight line;
A temperature characteristic adjusting method for a gyro sensor, comprising: In the temperature characteristic adjustment method of the gyro sensor according to claim 1 or 2,
Before obtaining the primary correction line of the zero point voltage,
Determining that the measured value of the zero point voltage at each predetermined temperature of the gyro sensor is within a predetermined range;
A step of determining a defective product when the zero point voltage is outside a predetermined range;
A temperature characteristic adjusting method for a gyro sensor, comprising: The temperature characteristic adjustment method of the gyro sensor according to claim 1 or 2, further comprising a step of offset adjusting a zero point voltage obtained from the primary correction line to a predetermined output voltage. Method. In the temperature characteristic adjustment method of the gyro sensor according to any one of claims 1 to 4,
Measuring a zero point voltage for each predetermined temperature of the gyro sensor;
Measuring an output voltage at each predetermined temperature of the temperature sensor;
A method for adjusting the temperature characteristics of a gyro sensor, characterized in that A gyro sensor whose temperature characteristics are adjusted by the temperature characteristic adjusting method according to any one of claims 1 to 5,
A primary correction target straight line of the slope a is obtained from the measured value of the zero point voltage at each predetermined temperature of the gyro sensor,
An approximate straight line is obtained from the measured value of the output voltage at each predetermined temperature of the temperature sensor, gain adjustment is performed so that the slope of the approximate line becomes (−a), and the slope of the output voltage (−a) of the temperature sensor. Determine the straight line
A gyro sensor that outputs a temperature characteristic correction output of the gyro sensor by adding a straight line subject to primary correction of a zero point voltage of the gyro sensor and a straight line after gain adjustment of the temperature sensor.

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