JP2009276072A - Abnormality determination method of acceleration sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an abnormality determination method of an acceleration sensor 1 capable of performing high-accuracy abnormality determination. <P>SOLUTION: A control part allows the acceleration sensor 1 to detect a first acceleration value G1, on a plane having a reference angle with respect to horizontal plane; allows the acceleration sensor 1 to detect a second acceleration value G2 on the same plane after detection of the first acceleration value G1; determines whether the absolute value of the difference between the first acceleration value G1 and the second acceleration value G2 is larger than a first abnormality determination threshold ΔG1; and determines that the acceleration sensor 1 has an abnormality, when the absolute value is larger than the first abnormality determination threshold ΔG1. According to such an abnormality determination method for the acceleration sensor 1, since the first acceleration value G1 and the second acceleration value G2 are detected on a plane having the same reference angle to the horizontal plane, there is no need for the first abnormality determination threshold ΔG1 to be estimated from output from another sensor, or the like, as in conventional abnormality determination threshold, and abnormality determination of the acceleration sensor 1 can be performed with high accuracy. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an abnormality determination method for an acceleration sensor, and is particularly suitable for application to abnormality determination with respect to secular change of an acceleration sensor mounted on a vehicle.

  An angular velocity sensor mounted on a vehicle may cause a deviation in an offset value due to aging. For this reason, in such an angular velocity sensor, offset correction or an abnormality determination of the angular velocity sensor is performed based on a difference between the detected offset value and a preset offset value.

  For example, in Patent Document 1, it is determined whether or not the vehicle is stationary, and when it is determined that the vehicle is stationary, the angular velocity sensor detects an offset value, and the detected offset value A sensor device is disclosed that performs offset correction when the difference from a preset offset value does not exceed the abnormality determination threshold, and determines that the angular velocity sensor is abnormal when it exceeds the abnormality determination threshold. ing.

Similarly, even in an acceleration sensor mounted on a vehicle, there may be a deviation in the offset value due to secular change. In the acceleration sensor, it is difficult to detect an accurate offset value because the acceleration sensor is affected by the vehicle posture even when the vehicle is not affected by the acceleration. For this reason, when determining the abnormality of the acceleration sensor, the offset value of the acceleration sensor is estimated from the output values of the angular velocity sensor, the steering angle sensor, the wheel speed sensor, etc. mounted on the vehicle, and this estimated value is actually There is known an abnormality determination method for determining that an acceleration sensor is abnormal when a difference from an offset value detected by the acceleration sensor exceeds a preset abnormality determination threshold. In such an abnormality determination method, the abnormality determination threshold is set to 0.4 G in consideration of the output error of the angular velocity sensor, the steering angle sensor, the wheel speed sensor, and the like and the influence of the vehicle posture.
JP 2005-331332 A

  However, the detection range of a general acceleration sensor is about 1.5 G, and a value of 0.4 G corresponds to an output fluctuation of 27 percent of the acceleration sensor. Since the output error of each sensor and the influence of the vehicle posture must be taken into consideration, a value smaller than 0.4G cannot be set as the abnormality determination threshold value. For this reason, there is a problem that the acceleration sensor can only perform abnormality determination with low accuracy.

  In addition, as described above, since the acceleration sensor is affected by the vehicle posture, it is difficult to detect an accurate offset value, and no offset correction is performed. For this reason, even when it is determined that there is no abnormality in the acceleration sensor in the abnormality determination, the offset value detected by the acceleration sensor may actually differ within the abnormality determination threshold, and the detection of acceleration is also low accuracy. There is a problem that it can only be done.

  An object of the present invention is to provide an acceleration sensor abnormality determination method capable of performing abnormality determination with high accuracy.

  In order to achieve the above object, according to the first aspect of the present invention, the acceleration sensor (1), the recording medium (3) in which the acceleration value is stored, and the control unit (in which the acceleration value is stored in the recording medium (3)). 100, 110, 200 to 240), and the control unit (100, 110, 200 to 240) detects the first acceleration value on the acceleration sensor (1) on a plane having a reference angle with respect to the horizontal plane. A step (100) of causing the recording medium (3) to store the first acceleration value detected by the acceleration sensor (1), and a reference angle with respect to the horizontal plane after the first acceleration value is detected. Whether the acceleration sensor (1) detects a second acceleration value on a surface having a difference (200) and whether the absolute value of the difference between the first acceleration value and the second acceleration value is greater than a first abnormality determination threshold value Step (22) ) And the absolute value is characterized by performing the step (240) determines that there is an abnormality in the acceleration sensor (1), the when greater than a first abnormality determination threshold value.

  According to such an abnormality determination method of the acceleration sensor (1), the first acceleration value and the second acceleration value are detected on a surface having the same reference angle with respect to the horizontal plane, and the first acceleration value and the second acceleration value are detected. Since the abnormality determination of the acceleration sensor (1) is performed using the absolute value of the difference from the acceleration value, the outputs of the other sensors, the first acceleration value, and the second acceleration value are detected like the conventional abnormality determination threshold value. It is not necessary to consider the influence of the tilt angle. For this reason, a value smaller than the conventional abnormality determination threshold can be set as the first abnormality determination threshold, and the abnormality determination of the acceleration sensor (1) can be performed with higher accuracy than the conventional acceleration sensor.

  For example, as in the invention described in claim 2, before the step (220) of determining whether or not the absolute value is larger than the first abnormality determination threshold, the control unit (100, 110, 200 to 240) The step (210) of determining whether or not the absolute value is larger than a second abnormality determination threshold value having a value smaller than the first abnormality determination threshold value is performed, and when the absolute value is larger than the second abnormality determination threshold value, the absolute value is A step (220) for determining whether or not it is larger than the first abnormality determination threshold is performed, and a step (230) for correcting the offset value of the acceleration sensor (1) when the absolute value is smaller than the first abnormality determination threshold is performed. Can be made.

  Further, as in the invention described in claim 3, the recording medium (3) is configured to be able to update the recording, and is stored in the recording medium (3) in the step (230) of correcting the offset value. Updating the first acceleration value based on the second acceleration value may be included.

  Further, as in the invention described in claim 4, the step (100) for detecting the first acceleration value and the step (200) for detecting the second acceleration value are performed when the acceleration sensor (1) is on a horizontal plane. It can also be made.

  Further, as in the invention described in claim 5, the control unit (100, 110, 200 to 240) causes the first acceleration value to be applied to the acceleration sensor (1) on a surface whose inclination angle with respect to the horizontal plane is the first predetermined angle. The first acceleration value is converted into a first conversion value that is a value detected on a surface having a reference angle with respect to the horizontal plane, and the first conversion value is converted to the recording medium (3). Storing (110), causing the acceleration sensor (1) to detect a second acceleration value on a surface having a second predetermined angle with respect to the horizontal plane after detecting the first acceleration value (200), A step (210) for converting the second acceleration value into a second converted value that is a value detected on a plane having a reference angle with respect to the horizontal plane, and an absolute value of a difference between the first converted value and the second converted value Is greater than the first abnormality determination threshold A step (220) determines, also possible to perform.

  According to such an abnormality determination method of the acceleration sensor (1), even when the first acceleration value and the second acceleration value are detected on surfaces having different inclination angles, the first acceleration value and the second acceleration value are calculated on the horizontal plane. Is converted into a first converted value and a second converted value that are values detected on a surface having a reference angle, and an abnormality is detected using an absolute value of a difference between the first converted value and the second converted value. Since the determination is performed, it is not necessary to consider the influence of the tilt angle at which the output of the other sensor and the first acceleration value and the second acceleration value are detected as in the conventional abnormality determination threshold. For this reason, a value smaller than the conventional abnormality determination threshold can be set as the first abnormality determination threshold, and the abnormality determination of the acceleration sensor (1) can be performed with higher accuracy than in the past.

  In addition, as in the invention described in claim 8, the control unit (100, 110, 200 to 240) detects the first acceleration value and the second acceleration value on a surface having a reference angle with respect to the horizontal plane. It is also possible to perform the step (210) of converting into a first converted value and a second converted value as values.

  Further, as in the inventions according to claims 6 and 9, the control unit (100, 110, 200 to 240) causes the first converted value and the second converted value in the step (210) of converting the acceleration value into the converted value. It is determined whether the absolute value of the difference from the converted value is greater than a second abnormality determination threshold having a value smaller than the first abnormality determination threshold. When the absolute value is greater than the second abnormality determination threshold, the absolute value is A step (230) of correcting the offset value of the acceleration sensor (1) can be performed when the absolute value is smaller than the first abnormality determination threshold value.

  Further, as in the invention described in claim 7, the recording medium (3) is configured to be able to update the recording, and in the step (230) of correcting the offset value, the recording medium (3) is stored in the recording medium (3). The first converted value can be updated based on the second converted value. Further, as in the invention described in claim 10, the first acceleration value stored in the recording medium (3) can be updated based on the second converted value.

  Then, as in the invention described in claim 11, the step (100) of mounting the acceleration sensor (1) on the vehicle and detecting the first acceleration value is performed when the acceleration sensor (1) is attached to the vehicle. Can be made.

  Further, in the step (240) of determining that there is an abnormality in the acceleration sensor (1) as in the invention described in claim 12, the acceleration sensor (1) is provided outside the control unit (100, 110, 200 to 240). A signal indicating that there is an abnormality can be transmitted.

  The abnormality determination method for the acceleration sensor (1) is applied to a composite sensor including the acceleration sensor (1) and a physical quantity sensor that outputs a signal according to a change in physical quantity different from the acceleration. You can also

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

(First embodiment)
A first embodiment of the present invention will be described. FIG. 1 is a block diagram of a sensor system to which the acceleration sensor abnormality determination method of this embodiment is applied. In addition, the sensor system used for this embodiment is mounted in the vehicle.

  As shown in FIG. 1, the sensor system of this embodiment includes an acceleration sensor 1, a microcomputer 2 (hereinafter referred to as a microcomputer), and a memory 3 corresponding to a recording medium of the present invention.

  As the acceleration sensor 1, for example, a known sensor configured to include an acceleration detection element having a beam structure and a signal processing circuit that performs signal processing on an acceleration detected based on the displacement amount of the beam can be used. It is attached to the vehicle via a bracket or the like.

  The microcomputer 2 is composed of a known device having a control unit and the like, and is connected to the vehicle ECU 4. Further, the microcomputer 2 executes predetermined processing according to a control program stored in a memory (not shown) in the control unit.

  When receiving the acceleration value detection signal transmitted from the vehicle ECU 4, the control unit causes the acceleration sensor 1 to detect the acceleration value. In addition, an abnormality determination threshold is set in advance in the control unit, and the control unit determines whether or not the acceleration sensor 1 has an abnormality based on the acceleration value detected by the acceleration sensor 1.

  The vehicle ECU 4 transmits an acceleration value detection signal to the acceleration sensor 1 based on an external signal to the control unit.

  The memory 3 stores the acceleration value detected by the acceleration sensor 1, and for example, an EEPROM or the like that can update the recording is used.

  Next, an abnormality determination method for the acceleration sensor 1 of the present embodiment will be described. First, immediately after the acceleration sensor 1 is attached to the vehicle, the vehicle is arranged so that the acceleration sensor 1 is parallel to the horizontal plane, and the control unit detects the first acceleration value G1. Then, after elapse of a predetermined period after the first acceleration value G1 is detected, for example, at the time of vehicle inspection, the vehicle is arranged again so that the acceleration sensor 1 is parallel to the horizontal plane, and the second acceleration value G2 is set to the control unit. Let it be detected. Then, the control unit is caused to determine whether or not the acceleration sensor 1 has an abnormality due to secular variation or the like by comparing the absolute value of the difference between the first acceleration value G1 and the second acceleration value G2 with the abnormality determination threshold value. . Below, the specific procedure of the abnormality determination method of the acceleration sensor 1 is demonstrated. In the present embodiment, since the first acceleration value G1 and the second acceleration value G2 are detected in a state where the vehicle is arranged on a horizontal plane, the first acceleration value G1 and the second acceleration value G2 are detected by the acceleration sensor 1. This corresponds to the offset value.

  FIG. 2 is a flowchart showing a writing process when the control unit stores the first acceleration value G1 in the memory 3. The control unit performs the following process when an acceleration value detection signal is received from the vehicle ECU 4, and in the present embodiment, the first acceleration value G1 is detected immediately after the acceleration sensor 1 is attached to the vehicle.

  As shown in FIG. 2, in step 100, when an acceleration value detection signal is received from the vehicle ECU 4, the acceleration sensor 1 is caused to detect the first acceleration value G 1 and the process proceeds to step 110. In step 100, the first acceleration value G1 is detected in a state where the vehicle is placed on a horizontal surface so as not to be affected by the vehicle posture and the vehicle is stationary. In step 110, the first acceleration value G1 is written and stored in the memory 3, and the process is terminated.

  FIG. 3 is a flowchart when the control unit performs the abnormality determination process. For example, this is performed at the time of vehicle inspection after a predetermined period has elapsed since the first acceleration value G1 was detected. This abnormality determination process is performed when the control unit determines that an acceleration value detection signal transmitted from the vehicle ECU 4 has been received.

  In step 200, when an acceleration value detection signal is received again from the vehicle ECU 4 after a predetermined period has elapsed since the first acceleration value G1 was detected, for example, half a year later, the acceleration sensor 1 is caused to detect the second acceleration value G2. Proceed to 210. In step 200, as in step 100, the second acceleration value G2 is detected in a state where the vehicle is placed on a horizontal surface so as not to be affected by the vehicle posture and the vehicle is stationary. Is done.

  Subsequently, in step 210, the first acceleration value G1 stored in the memory 3 is read, the absolute value of the difference between the first acceleration value G1 and the second acceleration value G2 detected in step 200, and the second abnormality Comparison with the determination threshold value ΔG2 is performed. Specifically, it is determined whether or not the absolute value of the difference between the first acceleration value G1 and the second acceleration value G2 is greater than the first abnormality determination threshold value ΔG1, and the absolute value of the difference is the second abnormality determination threshold value ΔG2. If it is determined that the value is larger than the second abnormality determination threshold value ΔG2, the process ends. Note that the second abnormality determination threshold value ΔG2 does not need to consider the output error of other sensors and the influence of the vehicle posture when the first acceleration value G1 and the second acceleration value G2 are detected as in the prior art. For example, it can be set to 0.01G.

  In step 220, the absolute value of the difference between the first acceleration value G1 and the second acceleration value G2 detected in step 200 is further compared with the first abnormality determination threshold value ΔG1. Specifically, as in step 210, it is determined whether or not the absolute value of the difference between the first acceleration value G1 and the second acceleration value G2 is greater than the first abnormality determination threshold value ΔG1, and the absolute value of the difference is When it is determined that it is smaller than the first abnormality determination threshold value ΔG1, the process proceeds to step 230, and when it is determined that it is larger than the first abnormality determination threshold value ΔG1, the process proceeds to step 240. The first abnormality determination threshold ΔG1 is also the vehicle attitude when the output error of the other sensors, the first acceleration value G1, and the second acceleration value G2 are detected as in the conventional case, similarly to the second abnormality determination threshold ΔG2. For example, it can be set to 0.1G.

  In step 230, the offset value is corrected based on the second acceleration value G2 detected in step 200, and the first acceleration value G1 stored in the memory 3 is updated based on the second acceleration value G2. . In this embodiment, the acceleration value stored in the memory 3 is updated by updating the acceleration value stored in the memory 3 from the first acceleration value G1 to the second acceleration value G2. For this reason, when the abnormality determination of the acceleration sensor 1 is performed next, it is performed based on the second acceleration value G2 newly stored in the memory 3 and the acceleration value detected after a predetermined period has elapsed.

  In step 240, a signal indicating that the acceleration sensor 1 is abnormal is transmitted to an alarm device (not shown), and the alarm device is operated to notify the operator that the acceleration sensor 1 is abnormal.

  According to such an abnormality determination method of the acceleration sensor 1, the first acceleration value G1 and the second acceleration value G2 are detected so as not to be affected by the vehicle posture, and the first acceleration value G1 and the second acceleration value are detected. Since the abnormality determination of the acceleration sensor 1 is performed based on the absolute value of the difference from G2, the output error of the other sensors, the first acceleration value G1, and the second acceleration value G2 are detected like the conventional abnormality determination threshold value. The first abnormality determination threshold value ΔG1 may be set to a value lower than the abnormality determination threshold value of the conventional acceleration sensor. Therefore, it is possible to determine the abnormality of the acceleration sensor 1 with higher accuracy than the conventional acceleration sensor abnormality determination method. Specifically, in the present embodiment, the first abnormality determination threshold value ΔG1 can be set to 0.1 G, and four times higher accuracy than the conventional acceleration sensor abnormality determination method can be obtained.

  Further, since the second acceleration value G2 is detected with high accuracy so as not to be affected by the vehicle posture, the offset value of the acceleration sensor 1 can also be corrected.

(Other embodiments)
In the first embodiment, the first acceleration value G1 and the second acceleration value G2 are detected in a state where the vehicle is arranged on the horizontal plane so that the acceleration sensor 1 is parallel to the horizontal plane. The acceleration value G1 and the second acceleration value G2 may be detected on surfaces having the same inclination angle with respect to the horizontal plane, or may be detected on surfaces having different inclination angles with respect to the horizontal plane. May be.

  In this case, for example, in step 210 described above, the control unit uses the inclination angle of the surface on which the vehicle is measured, which is measured by an inclination angle sensor mounted on the vehicle, and the first acceleration value G1 and the first acceleration value. The step 210 is performed using the absolute value of the difference between the first conversion value and the second conversion value by converting the two acceleration values G2 into the first conversion value and the second conversion value so as to be the values detected on the horizontal plane. In addition, the determination in step 220 can be performed, and the offset value in step 230 can be corrected using the second converted value. Further, when the offset value is corrected in step 230, the first acceleration value G1 stored in the memory 3 can be updated based on the second converted value.

  Further, for example, in step 110 described above, the control unit is set to a value obtained by detecting the first acceleration value G1 on the horizontal plane using an inclination angle measured by an inclination angle sensor or the like mounted on the vehicle. The first converted value can be converted into the first converted value, and the first converted value can be stored in the memory 3. In step 210, the second acceleration value G2 is detected again on the horizontal plane by using the tilt angle measured by the tilt angle sensor or the like mounted on the vehicle, so that the second value is detected. Converting into a converted value, making the determination in step 210 and step 220 using the first converted value and the second converted value, and correcting the offset value in step 230 using the second converted value. You can also. Further, when the offset value is corrected in step 230, the first converted value stored in the memory 3 can be updated based on the second converted value.

  Furthermore, the inclination angle of the surface on which the vehicle is arranged is obtained in advance by an angle meter or the like, and the first acceleration value G1 and the second acceleration value G2 are detected on the horizontal plane by using the inclination angle. The first converted value and the second converted value are converted so as to be a value, and the determination of step 210 and step 220 is performed using the first converted value and the second converted value, and the second converted value is used. Then, the offset value in step 230 may be corrected.

  In addition, when the offset value in step 230 is corrected, the difference between the first acceleration value G1 and the second acceleration value G2 or the first conversion value is stored in the memory. And the second conversion value can be updated based on the difference.

  Further, in the first embodiment, the example in which the memory 3 configuring the sensor system is mounted on the vehicle has been described, but the memory 3 may not be mounted on the vehicle. The memory 3 may be incorporated in the acceleration sensor 1 or may be incorporated in the microcomputer 2. The memory 3 is not limited to an EEPROM, and can be used using, for example, a non-updatable RAM. In this case, when the offset value of the acceleration sensor 1 in step 230 is corrected, the second acceleration value G2 cannot be stored in the memory 3 in the memory 3, but the memory 3 is prevented from being updated due to a malfunction of the control unit. can do.

  In the first embodiment, a sensor system may be configured using a plurality of acceleration sensors 1. For example, the control unit determines that the acceleration sensor 1 is abnormal when the acceleration sensor 1 is disposed in the vehicle via the same bracket so that acceleration in different axial directions can be detected. At step 240, it can be determined whether the acceleration sensor 1 is abnormal or the bracket is abnormal. Specifically, the absolute value of the difference between each of the first acceleration value G1 and the second acceleration value G2 is larger than the first abnormality determination threshold value ΔG1 when the control unit performs the determination in step 220, When the values of the second acceleration values G2 obtained by the respective acceleration sensors 1 are greatly different, it is estimated that the respective acceleration sensors 1 change with time. Can be determined to be in an abnormal state due to secular change. For this reason, in step 240, for example, when the acceleration sensor 1 is determined to be abnormal and when it is determined that there is an abnormality in the bracket, the alarm is operated differently to warn the operator. Also good.

  Furthermore, in the first embodiment, in step 210, the flow proceeds to step 220 when the absolute value of the difference between the first acceleration value G1 and the second acceleration value G2 exceeds the second abnormality determination threshold value ΔG2. However, the second abnormality determination threshold value ΔG2 may be set to 0, and the process may proceed to step 220 when the first acceleration value G1 and the second acceleration value G2 are different.

  In the first embodiment, the control unit causes the acceleration sensor 1 to detect the first acceleration value G1 and the second acceleration value G2 based on the acceleration value detection signal transmitted from the vehicle ECU 4. However, the acceleration value The detection signal may be directly transmitted from the outside to the control unit to cause the acceleration sensor 1 to detect the first acceleration value G1 and the second acceleration value G2.

  Further, in the first embodiment, the abnormality determination process of the acceleration sensor 1 is performed by the control unit provided in the microcomputer 2. For example, the control unit provided in the vehicle ECU 4 may be used. it can.

  Further, the abnormality determination method for the acceleration sensor 1 of the present invention can be applied to a composite sensor of the acceleration sensor 1 and a physical quantity sensor that changes with respect to a physical quantity different from the acceleration. For example, the acceleration sensor 1 and the angular velocity sensor It can apply to the inertia sensor comprised with having.

It is a figure which shows the block diagram of the sensor system used for the abnormality determination method in 1st Embodiment of this invention. It is a flowchart which shows the write-in process when a control part memorize | stores a 1st acceleration value in memory. It is a flowchart when a control part performs the abnormality determination process of an acceleration sensor.

Explanation of symbols

1 Acceleration sensor 2 Microcomputer 3 Memory 4 Vehicle ECU

Claims (13)

An acceleration sensor (1) that outputs a signal in response to a change in acceleration;
A recording medium (3) in which acceleration values detected by the acceleration sensor (1) are stored;
A controller (100, 110, 200 to 240) for storing the acceleration value detected by the acceleration sensor (1) in the recording medium (3),
Abnormality determination of the acceleration sensor (1) for determining the abnormality of the acceleration sensor (1) based on the acceleration value detected by the acceleration sensor (1) in the control unit (100, 110, 200 to 240). A method,
(100) causing the acceleration sensor (1) to detect a first acceleration value on a surface having a reference angle with respect to a horizontal plane;
Storing the first acceleration value detected by the acceleration sensor (1) in the recording medium (3) (110);
(200) causing the acceleration sensor (1) to detect a second acceleration value on a surface having the reference angle with respect to a horizontal plane after detecting the first acceleration value;
Determining whether an absolute value of a difference between the first acceleration value and the second acceleration value is greater than a first abnormality determination threshold value (220);
And a step (240) of determining that the acceleration sensor (1) is abnormal when the absolute value is greater than the first abnormality determination threshold.   The control unit (100, 110, 200 to 240) determines whether the absolute value is greater than the first abnormality determination threshold value before determining (220) the first acceleration value and the second acceleration. Determining whether the absolute value of the difference from the value is greater than a second abnormality determination threshold value having a value smaller than the first abnormality determination threshold value, and the absolute value is determined to be the second abnormality determination value; A step (220) of determining whether the absolute value is greater than the first abnormality determination threshold value when larger than a threshold value is performed, and the acceleration sensor (1) when the absolute value is smaller than the first abnormality determination threshold value. 2. The acceleration sensor abnormality determination method according to claim 1, wherein a step (230) of correcting the offset value is performed.   The recording medium (3) is configured to be able to update the recording. In the step of correcting the offset value (230), the first acceleration value stored in the recording medium (3) is used. 3. The acceleration sensor abnormality determination method according to claim 2, further comprising updating based on the second acceleration value.   The step (100) for detecting the first acceleration value and the step (200) for detecting the second acceleration value are performed when the acceleration sensor (1) is on a horizontal plane. 4. The acceleration sensor abnormality determination method according to any one of 3 above. An acceleration sensor (1) that outputs a signal in response to a change in acceleration;
A recording medium (3) in which a conversion value converted based on the acceleration value detected by the acceleration sensor (1) is stored;
A controller (100, 110, 200 to 240) for storing the acceleration value detected by the acceleration sensor (1) in the recording medium (3),
Abnormality determination of the acceleration sensor (1) for determining the abnormality of the acceleration sensor (1) based on the acceleration value detected by the acceleration sensor (1) in the control unit (100, 110, 200 to 240). A method,
A step (100) of causing the acceleration sensor (1) to detect a first acceleration value on a surface whose inclination angle with respect to a horizontal plane is a first predetermined angle;
The first acceleration value is converted into a first conversion value that is a value detected on a surface having a reference angle with respect to a horizontal plane, and the first conversion value is stored in the recording medium (3) (110). When,
(200) causing the acceleration sensor (1) to detect a second acceleration value on a surface having an inclination angle with respect to a horizontal plane being a second predetermined angle after detecting the first acceleration value;
Converting the second acceleration value into a second conversion value that is a value detected on a surface having the reference angle with respect to a horizontal plane (210);
Determining whether an absolute value of a difference between the first converted value and the second converted value is greater than the first abnormality determination threshold value (220);
And a step (240) of determining that the acceleration sensor (1) is abnormal when the absolute value is greater than the first abnormality determination threshold.   In the step (210) of converting the second acceleration value to the second converted value, the absolute value of the difference between the first converted value and the second converted value is smaller than the first abnormality determination threshold value. Determining whether or not the absolute value is larger than the first abnormality determination threshold when the absolute value is larger than the second abnormality determination threshold. 6. The acceleration sensor abnormality determination according to claim 5, wherein a step (230) of correcting an offset value of the acceleration sensor (1) is performed when the absolute value is smaller than the first abnormality determination threshold value. Method.   The recording medium (3) is configured to be able to update recording, and in the step of correcting the offset value (230), the first converted value stored in the recording medium (3) is used. The method according to claim 6, further comprising updating based on the converted second converted value. An acceleration sensor (1) that outputs a signal in response to a change in acceleration;
A recording medium (3) in which acceleration values detected by the acceleration sensor (1) are stored;
A controller (100, 110, 200 to 240) for storing the acceleration value detected by the acceleration sensor (1) in the recording medium (3),
Abnormality determination of the acceleration sensor (1) for determining the abnormality of the acceleration sensor (1) based on the acceleration value detected by the acceleration sensor (1) in the control unit (100, 110, 200 to 240). A method,
A step (100) of causing the acceleration sensor (1) to detect a first acceleration value on a surface whose inclination angle with respect to a horizontal plane is a first predetermined angle;
Storing the first acceleration value detected by the acceleration sensor (1) in the recording medium (3) (110);
(200) causing the acceleration sensor (1) to detect a second acceleration value on a surface having an inclination angle with respect to a horizontal plane being a second predetermined angle after detecting the first acceleration value;
A predetermined calculation is performed on the first acceleration value and the second acceleration value, and the first acceleration value and the second acceleration value are set to values detected on a plane having the same inclination angle. Converting the second acceleration value into a first converted value and a second converted value (210);
Determining whether the absolute value of the difference between the first converted value and the second converted value is greater than the first abnormality determination threshold (220);
And a step (240) of determining that the acceleration sensor (1) is abnormal when the absolute value is greater than the first abnormality determination threshold.   In the step (210) of converting the first acceleration value and the second acceleration value into the first conversion value and the second conversion value, the absolute value of the difference between the first conversion value and the second conversion value Determining whether the absolute value is greater than the second abnormality determination threshold value, and the absolute value is greater than the second abnormality determination threshold value. It is determined whether or not it is larger than one abnormality determination threshold value, and when the absolute value is smaller than the first abnormality determination threshold value, a step (230) of correcting an offset value of the acceleration sensor (1) is performed. The acceleration sensor abnormality determination method according to claim 8.   The recording medium (3) is configured to be able to update the recording. In the step of correcting the offset value (230), the first acceleration value stored in the recording medium (3) is used. The acceleration sensor abnormality determination method according to claim 9, further comprising updating based on the converted second converted value.   The acceleration sensor (1) is mounted on a vehicle, and the step (100) of detecting the first acceleration value is performed when the acceleration sensor (1) is attached to the vehicle. Item 11. The abnormality determination method for an acceleration sensor according to any one of Items 1 to 10.   In the step (240) of determining that the acceleration sensor (1) is abnormal, a signal indicating that the acceleration sensor (1) is abnormal is transmitted to the outside of the control unit (100, 110, 200 to 240). The acceleration sensor abnormality determination method according to any one of claims 1 to 11, further comprising:   The abnormality determination method for an acceleration sensor (1) according to any one of claims 1 to 12, comprising the acceleration sensor (1) and a physical quantity sensor that outputs a signal in accordance with a change in physical quantity different from the acceleration. An abnormality determination method for a composite sensor, which is applied to a composite sensor configured as described above.

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