KR20100025061A - Test apparatus of motion sensor and method thereof - Google Patents

Abstract

PURPOSE: A test apparatus of a motion sensor and a method thereof are provided to eliminate a test error by implementing a plurality of processes required for a motion sensor inspection as a series of processes in one apparatus. CONSTITUTION: A test program download unit(100) downloads a test program in a normal motion sensor. A testing unit(200) implements a parallel process through a SPI(Serial Peripheral Interface) communication of the motion sensors in which the test program is downloaded. A calibration, an axis twisting check, and compensation are processed for motion sensors. A firmware download unit(300) downloads a firmware in the plurality of motion sensors.

Description

Apparatus and method for testing a motion sensor

The present invention relates to an apparatus and method for inspecting a motion sensor, and more particularly, to an apparatus and a method for automatically performing a plurality of inspection processes related to a motion sensor.

Typically, the motion sensor is composed of a geomagnetic sensor and an acceleration sensor. For example, the 6-axis motion sensor consists of a 3-axis geomagnetic sensor and a 3-axis acceleration sensor.

In order to inspect such a motion sensor, a short check, a program downloading, a calibration of a geomagnetic sensor, a calibration of an acceleration sensor, and a good / bad inspection are performed.

Although a number of such processes can be performed in a series of steps to reduce the error of the inspection, it is currently performed at each inspection equipment and / or site. For example, in order to perform a calibration for a motion sensor, a calibration is performed for a geomagnetic sensor while changing the geomagnetic intensity of three axes in a three-axis geomagnetic simulator. The accelerometer is calibrated using a centrifuge or equipment that can rotate in multiple directions. In this calibration, two calibrations are performed on two pieces of equipment for a single motion sensor, which greatly complicates the efficiency, time and process of the equipment. In other words, after performing the calibration in the three-axis geomagnetic simulator, it is necessary to move between the equipment to be calibrated again in a centrifuge or the like. Therefore, the time required to move the motion sensor is required, and the hassle of having to set the motion sensor back in position in the moved equipment occurs.

As a result, there are many cases in which an environmental difference between processes occurs and an accurate measurement is not performed. This causes the occurrence of inspection error. In addition, the inspection takes a lot of time, and requires a large number of inspection personnel.

SUMMARY OF THE INVENTION The present invention has been proposed to solve the above-mentioned problems, and provides an apparatus and method for inspecting a motion sensor that enables the performance test of a component and a sensor of the motion sensor to be performed at one time. There is this.

In order to achieve the above object, an apparatus for inspecting a motion sensor according to a preferred embodiment of the present invention includes: a test program download unit for finding a motion sensor of good quality among a plurality of motion sensors to be inspected and downloading a test program; And an inspection unit for performing calibration and axis distortion correction for the downloaded motion sensor.

The test program download unit may include: a power output unit configured to provide test power from a power input unit to a plurality of motion sensors to be inspected; An overcurrent checker for recognizing a motion sensor in which excessive current flows among a plurality of motion sensors and cutting off a test power supplied to the motion sensor; And a program download unit for downloading a test program for a motion sensor in which excessive current does not flow among the plurality of motion sensors.

The inspection unit may include a geomagnetic generator that generates a geomagnetism; A jig in which a plurality of motion sensors to be inspected are seated and located inside the geomagnetic generator; A rotating part rotating the jig in the X-Y direction, the X-Z direction, and the Y-Z direction with a predetermined angular period with respect to each direction; And a controller configured to calibrate and axially distort the plurality of motion sensors using geomagnetic sensitivity and acceleration sensitivity of the plurality of motion sensors generated as the jig rotates at a predetermined angular period.

The rotating unit rotates the jig in a state in which the geomagnetism from the geomagnetic generation unit is applied to the plurality of motion sensors.

The rotating unit rotates the jig horizontally with respect to the X-Y direction with respect to the Z axis, vertically rotates the jig with respect to the X-Z direction with respect to the Y axis, and rotates the jig with respect to the Y-Z direction with respect to the X axis.

The controller performs calibration for the plurality of motion sensors based on the maximum and minimum values of the geomagnetic sensitivity and the acceleration sensitivity of the plurality of motion sensors generated as the jig rotates at a predetermined angular period.

The controller checks the axis shift of the motion sensor based on the middle value among the maximum, minimum, and middle values of the geomagnetic strengths of the plurality of motion sensors generated as the jig rotates at a predetermined angular period. In this case, the controller bisects the value obtained by using the median values of the diagonals among the intermediate values for each angular period, and determines the bisected value as the twisted angle of the corresponding axis.

The inspection unit may further include a firmware download unit that downloads firmware for the plurality of motion sensors that have been inspected.

On the other hand, a method for inspecting a motion sensor according to a preferred embodiment of the present invention, the test program download step of finding a motion sensor of good quality from the plurality of motion sensors to be inspected to download a test program; And an inspection step wherein the test program performs calibration and axis distortion correction for the downloaded motion sensor,

The test program download step and the inspection step are performed as a series of processes in one device.

The test program download step may include a first step of providing test power from a power input unit to a plurality of motion sensors to be inspected; A second step of recognizing a motion sensor having excessive current flowing out of the plurality of motion sensors and cutting off the test power supplied to the motion sensor; And a third step of downloading a test program for a motion sensor in which excessive current does not flow among the plurality of motion sensors.

The inspecting step may include a first step of generating a geomagnetism; A second step of rotating the jig in which the plurality of motion sensors to be inspected are seated in the X-Y direction, the X-Z direction, and the Y-Z direction, each of which rotates at a predetermined angular period; And a third step of performing calibration and axis misalignment correction for the plurality of motion sensors using geomagnetic sensitivity and acceleration sensitivity of the plurality of motion sensors generated as the jig rotates at a predetermined angular period.

The second step of the inspection step is to rotate the jig while the generated geomagnetism is applied to the plurality of motion sensors.

The third step of the inspecting step is to calibrate the plurality of motion sensors based on the maximum and minimum values of the geomagnetic sensitivity and the acceleration sensitivity of the plurality of motion sensors generated as the jig rotates at a predetermined angular period.

The third step of the inspection step examines the axis shift for the motion sensor based on the median value among the maximum, minimum, and median values of the geomagnetic strengths of the multiple motion sensors generated as the jig rotates at a constant angular period. . In this case, the third step of the inspection step is to bisect the value obtained by using the median of the diagonals of the intermediate value for each angular period and to determine the bisected value as the twisted angle of the axis.

The method may further include a firmware download step of downloading firmware for the plurality of motion sensors in which the inspection in the inspection step is completed.

According to the present invention having such a configuration, a process such as short check of motion sensor, download of test program, calibration of geomagnetic sensor, calibration of acceleration sensor, positive judgment, firmware download and the like can be automatically performed in one device. .

That is, by performing a plurality of types of processes required for the inspection of the motion sensor as a series of processes in one device, there is an effect of eliminating inspection errors and significantly reducing inspection time.

In particular, in the case of a motion sensor composed of a three-axis geomagnetic sensor and a three-axis acceleration sensor, the geomagnetic sensor and the acceleration sensor are divided and calibrated and calibrated in the related art, but according to an embodiment of the present invention, the geomagnetic sensor and the acceleration sensor Calibration and axis misalignment can be performed simultaneously.

In addition, according to the embodiment of the present invention, when the axis displacement correction is completed after the calibration is completed, the azimuth error can be calculated by calculating the azimuth angle from the data of the geomagnetic sensor and the acceleration sensor received while rotating the motion sensor. Even the error of azimuth can be determined.

Hereinafter, an apparatus for inspecting a motion sensor according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings.

1 is a block diagram of an apparatus for inspecting a motion sensor according to an exemplary embodiment of the present invention.

An apparatus for inspecting a motion sensor according to an exemplary embodiment of the present invention includes a test program download unit 100, an inspection unit 200, and a firmware download unit 300.

The test program downloader 100 finds a normal motion sensor among the plurality of motion sensors to be inspected and downloads a test program (eg, test firmware).

The inspection unit 200 performs parallel processing through SPI (Serial Peripheral Interface) communication with the motion sensors from which the test program is downloaded, and checks the axis and calibration of the motion sensors to which the test program is downloaded. Correction of distortion is performed.

The firmware downloader 300 downloads firmware required for a plurality of motion sensors that have been calibrated by the inspector 200 and the axis skew correction. If the capacity of the storage device (not shown) provided in the motion sensor is sufficient, the firmware download unit 300 is not necessary. Hereinafter, a separate description of the firmware download unit 300 will be omitted.

2 is a diagram illustrating an internal configuration of the test program downloader 100 shown in FIG. 1. The test program downloader 100 will be described in more detail with reference to FIG. 2. Although FIG. 2 shows a configuration of a test program downloader for one motion sensor 16, an extended analysis is sufficiently possible with the configuration of a test program downloader for a plurality of motion sensors.

The test program downloader 100 includes a power inputter 110, a power outputter 120, an overcurrent checker 130, and a program downloader 140.

The power input unit 110 inputs a predetermined test power.

The power output unit 120 provides the test power from the power input unit 110 to the motion sensor 16 to be inspected.

The overcurrent checker 130 is electrically connected to a Vcc pin (not shown) of the motion sensor 16 to be inspected. The overcurrent checker 130 recognizes when excessive current flows to the motion sensor 16 due to damage to an internal component of the motion sensor 16 or incorrect wiring. When the overcurrent checker 130 detects that excessive current flows to the motion sensor 16 as the inspection target, the overcurrent checker 130 stops the power output from the power output unit 120 to cut off the power supplied to the motion sensor 16. The operation of the power output unit 120). That is, the motion sensor in which the supply of test power is stopped in this way is determined to be defective.

On the contrary, if it is recognized that normal current flows to the motion sensor 16 to be inspected, the overcurrent checker 130 instructs the program downloader 140 to download the test program to the motion sensor 16.

The program downloader 140 downloads a test program (eg, test firmware) to the motion sensor 16 by a test program download command from the overcurrent checker 130.

3 is a diagram illustrating a schematic configuration of the inspection unit 200 illustrated in FIG. 1. 4 is a plan view of FIG. 3. 5 to 8 are photographs employed to explain the main part of the inspection unit 200 shown in FIG.

The inspection unit 200 includes a geomagnetic generator, a jig 14, a rotating unit, and a controller 50. The inspection unit 200 may be understood as a computer.

The geomagnetic generator includes a ring-shaped coil 12 supported by the support 18. The coil 12 is installed in the magnetic shield chamber 10. The geomagnetic generator generates a geomagnet having a constant intensity using the coil 12. The geomagnetism generated by the geomagnetism generator is applied in the horizontal direction (see FIG. 4) with respect to the motion sensor 16. The geomagnetic generator may be referred to as a three-axis geomagnetic simulator that generates a magnetic field in a predetermined direction in one coil and cancels an external magnetic field in the other two coils. Those skilled in the art can sufficiently implement the above-described configuration for the geomagnetic generating unit by using a known technique.

The jig 14 has a socket 15 (see FIGS. 6 and 7) to which the motion sensor 16 can be mounted and removed. The socket 15 is electrically connected to the controller 50. The jig 14 is positioned horizontally between the two coils 12. For example, when the motion sensor 16 performs the rotation operation by the rotating part after the motion sensor 16 is mounted in the socket 15, the motion sensor 16 is geomagnetic and acceleration for three axes (X, Y, Z axis) The socket 15 transmits the maximum value and the minimum value information about the sensitivity to the controller 50. Of course, the motion sensor 16 mounted on the socket 15 may be directly transmitted to the control unit 50, or may take a different manner.

The rotating part rotates the jig 14 horizontally and also vertically. For example, horizontal rotation in the rotation means a rotation like arrow A in FIG. 3, and vertical rotation in the rotation means rotation like arrow B in FIG. 3. The rotating part is equipped with a horizontal rotating motor 20 (see FIG. 8) for horizontal rotation and a vertical rotating motor 30 (see FIG. 8) for vertical rotation. In other words, the vertical rotation causes the jig 14 (more specifically, the motion sensor 16) to rotate in the XZ direction about the Y axis at a predetermined angular period, and the jig 14 (more specifically, the motion sensor 16). Means rotation in the YZ direction with respect to the X-axis at a predetermined angular period. Horizontal rotation means that the jig 14 (more specifically, the motion sensor 16) is rotated horizontally (ie, in the X-Y direction) at an angle with respect to the Z axis. In other words, the rotating part can be rotated in two axis directions (for example, in the X-Y direction, the X-Z direction, and the Y-Z direction).

Of course, the rotating portion includes a rotation drive mechanism (not shown) connecting the horizontal rotating motor 20 and the vertical rotating motor 30 with the jig 14. Most of the rotation drive mechanism is protected by the case 40. That is, the rotating unit rotates the motion sensor 16 to operate to obtain data necessary for calibration of the 3-axis geomagnetic sensor and the 3-axis acceleration sensor. Then, by driving the rotating unit, it is possible to obtain data necessary for the axis misalignment correction of the three-axis geomagnetic sensor and the three-axis acceleration sensor.

The rotation drive mechanism includes a horizontal turn 22 and a vertical turn 32. The horizontal rotating portion 22 is provided at the bottom of the jig 14 to rotate the jig 14 horizontally. One end of the vertical rotation part 32 is exposed to one end of the case 40 and fixedly coupled to one side of the jig 14. Those skilled in the art can sufficiently implement the configuration for the above-described rotation drive mechanism using known techniques. According to FIG. 3, when the vertical rotation motor 30 operates, the jig 14, the horizontal rotation motor 20, and the case 40 rotate together.

The controller 50 may offset the geomagnetic sensor and the acceleration sensor by using the maximum and minimum values of the geomagnetic sensitivity and the acceleration sensitivity with respect to three axes of the motion sensor 16 generated as the jig 14 rotates at a predetermined angular period. ) And the scale factor. In this way, the calibration for the motion sensor 16 is completed by obtaining the offset values and scale factors for the three-axis geomagnetic sensor and the acceleration sensor. Of course, after calibration, the controller 50 performs the axis misalignment check and correction for the three-axis geomagnetic sensor and the acceleration sensor, which will be described after the calibration.

Next, a method of calibrating a plurality of motion sensors 16 to be inspected by the inspection unit 200 will be described with reference to FIGS. 9 and 10. Since the inspection unit 200 may process in parallel with the plurality of motion sensors 16 and SPI communication, it may be understood that the plurality of motion sensors 16 are measured at about the same time.

First, the motion sensor 16 (which may be a plurality of motion sensors) to be inspected is seated in the socket 15 on the jig 14. As the geomagnetism generator generates the geomagnetism, the geomagnetism in the horizontal direction is applied to the motion sensor 16. When measuring the geomagnetic and acceleration together, if the motion sensor 16 is rotated horizontally (that is, rotated in the X-Y direction with respect to the Z axis), the acceleration is the same. Therefore, in order to measure the geomagnetism and the acceleration together, it rotates about the X axis or the Y axis.

In this state, the rotating unit rotates the motion sensor 16 in the X-Z direction with respect to the Y axis as shown in FIG. 9. This is rotated using the vertical rotation motor 30. First, the geomagnetic and acceleration are sensed by setting the motion sensor 16 to the same state as in FIG. 9A. If the arrow in the geomagnetic direction and the arrow on the X axis are in the same direction, the minimum value is detected. If the arrow in the gravity acceleration direction and the arrow on the X axis are in the same direction, the minimum value is detected. If the arrow on the gravity acceleration direction and the arrow on the X axis are opposite directions, the maximum value is detected. The same applies to the Y axis and the Z axis.

That is, in the state as shown in FIG. 9A, the geomagnetic sensor in the motion sensor 16 detects the maximum value of the geomagnetism in the X-axis direction, and the acceleration sensor in the motion sensor 16 measures the minimum value of the acceleration in the Z-axis direction. Will be detected. The signal detected by the motion sensor 16 is sent to the controller 50.

Thereafter, the rotating unit rotates the jig 14 by 90 degrees in the clockwise direction in the state of FIG. 9A using the vertical rotating motor 30. That is, the rotating unit rotates the jig 14 such that the motion sensor 16 is rotated 90 degrees in the X-Z direction with respect to the Y axis. As a result, the state becomes as shown in FIG. In this case, the acceleration sensor in the motion sensor 16 detects the maximum value of the acceleration in the X-axis direction, and the geomagnetic sensor in the motion sensor 16 detects the maximum value of the geomagnetic in the Z-axis direction. The signal sensed by the motion sensor 16 is sent to the controller 50.

Then, the rotating unit rotates the jig 14 by 90 degrees in the clockwise direction in the state of FIG. 9B using the vertical rotating motor 30. As a result, the state becomes as shown in FIG. 9C. In this case, the geomagnetic sensor in the motion sensor 16 detects the minimum value of the geomagnetism in the X-axis direction, and the acceleration sensor in the motion sensor 16 detects the maximum value of the acceleration in the Z-axis direction. The signal sensed by the motion sensor 16 is sent to the controller 50.

Thereafter, the rotating unit rotates the jig 14 by 90 degrees clockwise in the state of FIG. 9C using the vertical rotating motor 30. As a result, the state becomes as shown in FIG. In this case, the acceleration sensor in the motion sensor 16 detects the minimum value of the acceleration in the X-axis direction, and the geomagnetic sensor in the motion sensor 16 detects the minimum value of the geomagnetic in the Z-axis direction. The signal sensed by the motion sensor 16 is sent to the controller 50.

As described above, after the motion sensor 16 is rotated in the XZ direction with respect to the Y axis at a 90-degree period, a signal for calibration is obtained, and the state of FIG. 9 (a) is changed to Z using the horizontal rotating motor 20 of the rotating part. Rotate 90 degrees counterclockwise from the axis to make it as shown in (e) of FIG. In other words, the maximum and minimum values of the X-axis and the Z-axis of the geomagnetic sensor and the acceleration sensor are known by the rotation as shown in FIG. 9. However, the maximum and minimum values of the Y-axis of the geomagnetic sensor and the acceleration sensor are not known by the rotation as shown in FIG. 9. Accordingly, the maximum and minimum values of the Y-axis of the geomagnetic sensor and the acceleration sensor are measured by rotating the lens 90 degrees in the counterclockwise direction and then rotating it in the vertical direction.

 As shown in FIG. 10, the motion sensor 16 is rotated in the Y-Z direction based on the X axis. This is rotated using the vertical rotation motor 30. First, the motion sensor 16 detects the geomagnetism and the acceleration in a state as shown in (e) of FIG. In this case, the geomagnetic sensor in the motion sensor 16 detects the maximum value of the geomagnetism in the Y-axis direction, and the acceleration sensor in the motion sensor 16 detects the minimum value of the acceleration in the Z-axis direction. The signal sensed by the motion sensor 16 is sent to the controller 50.

The rotary part rotates the jig 14 90 degrees clockwise in the state of FIG. 10E using the vertical rotation motor 30. That is, the rotating unit rotates the jig 14 such that the motion sensor 16 is rotated 90 degrees in the Y-Z direction with respect to the X axis. As a result, the state becomes as shown in FIG. In this case, the acceleration sensor in the motion sensor 16 detects the maximum value of the acceleration in the Y-axis direction, and the geomagnetic sensor in the motion sensor 16 detects the maximum value of the geomagnetic in the Z-axis direction. The signal sensed by the motion sensor 16 is sent to the controller 50.

Then, the rotating unit rotates the jig 14 by 90 degrees clockwise in the state of FIG. 10 (f) using the vertical rotating motor 30. As a result, the state becomes as shown in FIG. In this case, the geomagnetic sensor in the motion sensor 16 detects the minimum value of the geomagnetism in the Y-axis direction, and the acceleration sensor in the motion sensor 16 detects the maximum value of the acceleration in the Z-axis direction. The signal sensed by the motion sensor 16 is sent to the controller 50.

Thereafter, the rotating unit rotates the jig 14 by 90 degrees in the clockwise direction in the state of FIG. 10G by using the vertical rotating motor 30. As a result, the state becomes as shown in FIG. In this case, the acceleration sensor in the motion sensor 16 detects the minimum value of the acceleration in the Y-axis direction, and the geomagnetic sensor in the motion sensor 16 detects the minimum value of the geomagnetic in the Z-axis direction. The signal sensed by the motion sensor 16 is sent to the controller 50.

The controller 50 may know the maximum and minimum values of the geomagnetism and the acceleration of the three axes based on the input signal, and use the values to obtain the offset values and scale factors of the geomagnetic sensor and the acceleration sensor. Obtaining the offset value and the scale factor is well understood by those skilled in the art.

The following description is one example for explaining the calibration operation performed by the controller 50. For example, if the output of pure geomagnetic sensor is called Bx, By, Bz, and the output of pure acceleration sensor is Ax, Ay, Az, the final output of the motion sensor with the offset removed and the sensitivity constant Can be expressed as in Equation 1 below.

(Equation 1)

은 지자기센서(3축 센서)에서 측정된 값이고,

은 가속도센서(3축 센서)에서 측정된 값이다.

은 순수한 지자기센서의 출력에 포함된 오프셋값이고,

은 순수한 가속 도센서의 출력에 포함된 오프셋값이다.

은 순수한 지자기센서의 출력에 포함된 감도이고,

은 순수한 가속도센서의 출력에 포함된 감도이다.here,

Is the value measured from the geomagnetic sensor (3-axis sensor),

Is the value measured by the acceleration sensor (3-axis sensor).

Is the offset value included in the output of the pure geomagnetic sensor,

Is the offset value included in the output of the pure accelerometer.

Is the sensitivity included in the output of the pure geomagnetic sensor,

Is the sensitivity included in the output of a pure accelerometer.

In order to find the offset and to maintain a constant sensitivity, the following equation 2 can be obtained by knowing the maximum and minimum values of all axes of the geomagnetic sensor and the acceleration sensor.

(Equation 2)

은 센서 각 축의 최대값이고,

은 센서 각 축의 최소값이다. 지자기센서의 감도 단위는 gauss/count 로서, 디지털 출력 1 카운트(count)에 해당하는 자기의 세기가 얼마인지를 나타낸다. 가속도센서의 감도 단위는 gravity/count로서, 디지털 출력 1 카운트(count)에 해당하는 가속도의 크기가 얼마인지를 나타낸다. 예를 들어, 본 출원인은 1카운트의 디지털 출력이 0.002gauss의 일정한 출력으로 나타나도록 세팅한 감도(즉, 0.002gauss/count)의 지자기센서를 사용한다. 그에 따라, 상기 식 2에서 지자기센서의 설정된 감도의 크기는 200counts가 된다(지구자기장이 0.4gauss이기 때문에 0.4gauss를 기준으로 측정함). 본 출원인은 1카운트의 디지털 출력이 0.00125gravity의 일정한 출력으로 나타나도록 세팅한 감도(즉, 0.00125gravity/count)의 가속도센서를 사용한다. 그에 따라, 상기 식 2에서 가속도센서의 설정된 감도의 크기는 800counts가 된다(중력가속도가 1gravity 이기 때문에 1gravity를 기준으로 측정함).here,

Is the maximum value of each axis of the sensor,

Is the minimum value of each axis of the sensor. The unit of sensitivity of the geomagnetic sensor is gauss / count, which indicates how much magnetic intensity corresponds to one count of the digital output. The sensitivity unit of the acceleration sensor is gravity / count, which indicates the magnitude of the acceleration corresponding to one count of the digital output. For example, we use a geomagnetic sensor with sensitivity (ie 0.002gauss / count) set so that one count of digital outputs appears to be a constant output of 0.002gauss. Accordingly, the magnitude of the set sensitivity of the geomagnetic sensor in Equation 2 is 200counts (measured based on 0.4gauss because the earth magnetic field is 0.4gauss). Applicant uses an accelerometer with a sensitivity (i.e. 0.00125gravity / count) set so that one count of digital outputs appears to be a constant output of 0.00125gravity. Accordingly, the magnitude of the set sensitivity of the acceleration sensor in Equation 2 is 800 counts (measured based on 1gravity because the gravity acceleration is 1gravity).

In this way, the inspection unit 200 can remove the offset of each axis due to receiving the maximum value and the minimum value of the geomagnetic sensor and the acceleration sensor can be constantly adjusted to the set sensitivity. In this way, the inspection unit 200 performs the calibration of the geomagnetic sensor and the acceleration sensor at a very high speed.

This time, the axis skew check and correction for the motion sensors that are the inspection targets performed by the inspection unit 200 will be described.

The control unit 50 in the inspection unit 200 determines an intermediate value among the maximum, minimum, and median values of the geomagnetic intensity of the motion sensor 16 generated as the jig 14 rotates at a predetermined angle (eg, 90 degrees). Select. The controller 50 checks the axis shift of the motion sensor 16 with the selected median of each angular period. That is, the controller 50 bisects the values obtained using the median values of the diagonals among the selected median angular periods, and determines the bisected values as the skewed angles of the corresponding axes. For example, in the case of the motion sensor 16 rotated in the X-Y direction (that is, rotated on the XY plane), the value obtained by dividing the value obtained by using the intermediate values of the diagonals is equal to the following Equation 3

(Equation 3)

False angle of the X axis (θ) ≒ (θ1 + θ2) / 2

Incorrect angle of the Y axis (φ) ≒ (φ1 + φ2) / 2

θ1 = Arctan (X2 / sensitivity) * 180 / π

θ2 = Arctan (X4 / -sensitivity) * 180 / π

φ1 = Arctan (Y1 / sensitivity) * 180 / π

φ2 = Arctan (Y3 / -sensitivity) * 180 / π

Obtained by Here, θ1 and θ2 are diagonal, and φ1 and φ2 are diagonal. X2 is the median of the geomagnetic intensity detected by the X-axis sensor at 90 degrees, X4 is the median of the geomagnetic intensity detected by the X-axis sensor at 270 degrees, and Y1 is the geomagnetic intensity detected by the Y-axis sensor at 0 degrees The median value of Y3 is the median value of the geomagnetic intensity detected by the Y-axis sensor at 180 degrees. X-axis sensor is a sensor for detecting the geomagnetism of the X-axis, Y-axis sensor is a sensor for detecting the geomagnetism of the Y-axis. The geomagnetic sensor is a 3-axis (X, Y, Z) sensor, so it has an internal X-axis sensor, Y-axis sensor, and Z-axis sensor. The unit of sensitivity of the geomagnetic sensor is gauss / count, which indicates how much magnetic intensity corresponds to one count of the digital output. For example, we use a geomagnetic sensor with sensitivity (ie 0.002gauss / count) set so that one count of digital outputs appears to be a constant output of 0.002gauss. Therefore, for example, the sensitivity is set to 200 counts in Equation 3 above (measured based on 0.4gauss because the earth magnetic field is 0.4gauss).

Equation 3 expresses the rotation on the XY plane, for example, and can be modified by transforming it into an XZ plane and a YZ plane. In other words, when the sensor is rotated on the XZ plane, the median of the geomagnetic intensity can be obtained for each angle (0 degrees, 90 degrees, 180 degrees, 270 degrees) in the X and Z axes. In the case of rotation, the median of the geomagnetic intensity can be obtained for each angle (0 degrees, 90 degrees, 180 degrees, 270 degrees) in the Y-axis and Z-axis sensors. The equation for obtaining the wrong angle of the X axis, the wrong angle of the Z axis, the wrong angle of the Y axis in the YZ plane, and the wrong angle of the Z axis can be obtained.

FIG. 11 is an example of a diagram for explaining a shaft misalignment check in the inspector illustrated in FIG. 1, and FIG. 12 is a diagram illustrating a state of a sensor during jig rotation in the XY direction when the shaft misalignment check is performed in the inspector illustrated in FIG. 1. The figure shown.

As shown in FIG. 11, when the geomagnetic strength at each point is equal to 0.4 gauss, when the motion sensor 16 is rotated in the XY direction with respect to the Z axis (that is, rotated clockwise at 90 ° intervals) At each angle, the maximum, median and minimum values of geomagnetic intensity can be obtained. The minimum value is detected when the arrow in the geomagnetic direction and the arrow on the X axis are in the same direction, and the maximum value is detected when the arrow in the geomagnetic direction and the arrow on the X axis are opposite. do. The same applies to the Y axis and the Z axis.

However, when the installation position of the motion sensor 16 is wrong, the profile of the geomagnetic strength for each point tends to be directed to one side. For example, when the geomagnetic intensity at each point described in the lower part of FIG. 12 is 0.34 gauss on the left and 0.38 gauss on the right, as shown in FIG. (Eg right).

Even when the geomagnetic strength at each point is different, as shown in FIG. 12, when the motion sensor 16 is rotated in the XY direction with respect to the Z axis (that is, rotated clockwise in 90 degree increments), the geomagnetic strength at each angle is obtained. The maximum, median and minimum values of can be obtained. Of course, there is a high possibility that there is an offset in the X and Y axes at this time.

FIG. 13 is a graph illustrating an example of axis misalignment on the XY plane, and FIG. 14 is a diagram illustrating a result when the X axis is shifted by 10 degrees with respect to the Y axis. In order to know the degree of axis misalignment of three-axis sensor such as geomagnetic sensor or acceleration sensor, it is necessary to check how much the axis of X, Y, Z axis is distorted in each XY, XZ, YZ plane. To determine this, the sensor should be rotated in each of the XY, XZ, and YZ planes.

FIG. 13 is a definition and explanation of axis misalignment based on the XY plane. It is assumed that the sensitivity of the X-axis and the Y-axis is the same as ± 200, and the motion sensor 16 has a zero offset with the X-axis turned 10 degrees with respect to the Y-axis. "0" offset means that the geomagnetic strength at each point has the same Gaussian value. Since the offset is "0", the intersection point between the dotted lines is located at the origin as shown in FIG. The motion sensor 16 is rotated at intervals of 90 degrees as shown in FIG. 12 to check geomagnetic intensity at 0 degrees, 90 degrees, 180 degrees, and 270 degrees. The values sensed by this (maximum value, minimum value, median value) are displayed as shown in FIG. 14.

The distorted angle θ of the X axis and the distorted angle φ of the Y axis of FIG. 13 are obtained as in Equation 4 below.

(Equation 4)

θ = θ1 = θ2 = Arctan (X2 / Sensitivity) * 180 / π

               = Arctan (X4 / -sensitivity) * 180 / π

φ = φ1 = φ2 = Arctan (Y1 / sensitivity) * 180 / π

               = Arctan (Y3 / -sensitivity) * 180 / π

On the graph of FIG. 13, θ1 and θ2 are diagonal, and φ1 and φ2 are diagonal. In FIG. 14, X2 is the median of the geomagnetic intensity detected by the X-axis sensor at a position of 90 degrees (Geomagnetic X median ("34" in FIG. 12B)), and X4 is the X-axis sensor at the position of 270 degrees. The median value of the geomagnetism intensity detected (the geomagnetic X median value (-34) in FIG. 12 (d)), and Y1 is the median value of the geomagnetism intensity detected at the position of 0 degrees by the Y-axis sensor ((a ), Y3 is the median value of geomagnetic intensity detected by the Y-axis sensor at a position of 180 degrees (the geomagnetic Y median value ("0") in FIG. 12C). X-axis sensor is a sensor for detecting the geomagnetism of the X-axis, Y-axis sensor is a sensor for detecting the geomagnetism of the Y-axis. The geomagnetic sensor is a 3-axis (X, Y, Z) sensor, so it has an internal X-axis sensor, Y-axis sensor, and Z-axis sensor. The unit of sensitivity of the geomagnetic sensor is gauss / count, which indicates how much magnetic intensity corresponds to one count of the digital output. For example, we use a geomagnetic sensor with sensitivity (ie 0.002gauss / count) set so that one count of digital outputs appears to be a constant output of 0.002gauss. Therefore, for example, the sensitivity is set to 200 counts in Equation 4 above (measured based on 0.4gauss because the earth magnetic field is 0.4gauss).

The controller 50 bisects the sum of the diagonals and determines the bisected values as the distorted angles of the corresponding axes.

That is, using Equation 3 as described above as follows

Calculate the skew angle of the X and Y axes.

The calculation shows that the X axis is 9.7 degrees misaligned with respect to the Y axis. Of course, it was assumed that the X-axis was shifted by 10 degrees with respect to the Y-axis, but it was calculated that the X-axis was shifted by 9.7 degrees with respect to the Y-axis based on the Y-axis. This means that the axis deflection calculation method in the present invention is very useful.

As described above, when the calibration of the plurality of motion sensors 16 and the shaft misalignment correction are completed in the inspection unit 200, the azimuth error may be obtained by calculating the azimuth angle based on the data of the geomagnetic sensor and the acceleration sensor received while driving the rotating unit. Accordingly, there is an effect that can determine the error to the azimuth angle without additionally rotating the motion sensor.

On the other hand, the present invention is not limited only to the above-described embodiment, but can be modified and modified within the scope not departing from the gist of the present invention, the technical idea to which such modifications and variations are also applied to the claims Must see

1 is a block diagram of an apparatus for inspecting a motion sensor according to an exemplary embodiment of the present invention.

FIG. 2 is an internal configuration diagram of the test program download unit shown in FIG. 1.

3 is a view showing a schematic configuration of the inspection unit shown in FIG.

4 is a plan view of FIG. 3.

5 to 8 are photographs employed to explain the main part of the inspection unit shown in FIG.

9 to 10 are views for explaining a method for calibrating a motion sensor in the inspection unit shown in FIG.

FIG. 11 is an example of a diagram for describing a shaft misalignment check in the inspection unit illustrated in FIG. 1.

FIG. 12 is a view illustrating a state of a sensor when the jig rotates in the X-Y direction at the time of the shaft misalignment check in the inspection unit illustrated in FIG. 1.

Fig. 13 is a graph showing an example of shaft misalignment on the XY plane.

14 is a diagram showing the result when the X axis is shifted by 10 degrees with respect to the Y axis.

<Description of Symbols for Major Parts of Drawings>

100: test program download unit 110: power input unit

120: power output unit 130: overcurrent check unit

140: program download unit 200: inspection unit

300: firmware download unit

Claims (19)

 A test program downloader for finding a motion sensor of good quality from among a plurality of motion sensors to be inspected and downloading a test program; And Apparatus for inspecting the motion sensor, characterized in that the test program for performing a calibration and axis distortion correction for the downloaded motion sensor. The method according to claim 1, The test program download unit, A power output unit for providing test power from a power input unit to the plurality of motion sensors that are the inspection targets; An overcurrent checker for recognizing a motion sensor in which excessive current flows among the plurality of motion sensors and cutting off a test power supplied to the motion sensor; And Apparatus for inspecting the motion sensor, characterized in that it comprises a program download unit for downloading a test program for the motion sensor does not flow excessive current among the plurality of motion sensors. The method according to claim 1, The inspection unit, A geomagnetic generator for generating a geomagnetism; A plurality of jigs on which the plurality of motion sensors to be inspected are seated and located inside the geomagnetic generator; A rotating part rotating the jig in the X-Y direction, the X-Z direction, and the Y-Z direction, and rotating at regular angles with respect to each direction; And And a control unit configured to calibrate and calibrate the plurality of motion sensors by using geomagnetic sensitivity and acceleration sensitivity of the plurality of motion sensors generated as the jig rotates at a predetermined angular period. Device to check. The method according to claim 3, The rotating unit is a device for inspecting a motion sensor, characterized in that for performing the rotation of the jig in a state that the geomagnetic from the geomagnetic generator is applied to the plurality of motion sensors. The method according to claim 3, The rotating unit is a device for inspecting a motion sensor, characterized in that for rotating the jig horizontally with respect to the Z-axis relative to the X-Y direction. The method according to claim 3, The rotating unit is a device for inspecting a motion sensor, characterized in that for vertically rotating the jig with respect to the Y axis with respect to the X-Z direction. The method according to claim 3, The rotating unit is a device for inspecting the motion sensor, characterized in that for vertically rotating the jig with respect to the Y-Z direction with respect to the Y-Z direction. The method according to claim 3, The controller is configured to calibrate the plurality of motion sensors based on maximum and minimum values of geomagnetic sensitivity and acceleration sensitivity of the plurality of motion sensors generated as the jig rotates at a predetermined angular period. Device for inspecting sensors. The method according to claim 3, The controller may be configured to check the shaft misalignment with respect to the motion sensor based on an intermediate value among the maximum, minimum, and median values of the geomagnetic strengths of the plurality of motion sensors generated as the jig rotates at a predetermined angular period. Device for inspecting motion sensors. The method according to claim 9, The control unit is a device for inspecting a motion sensor, characterized in that for dividing the value obtained by using the median of the diagonal of the intermediate value for each predetermined angular period and determine the bisected value as the twisted angle of the corresponding axis. The method according to claim 1, Apparatus for inspecting the motion sensor, characterized in that further comprising a firmware download unit for downloading the firmware for the plurality of motion sensors that the inspection is completed.  A test program download step of finding a motion sensor of good quality from among a plurality of motion sensors to be inspected and downloading a test program; And The test program includes an inspection step of performing calibration and axis distortion correction for the downloaded motion sensor, The test program downloading step and the inspection step is a method for inspecting a motion sensor, characterized in that performed in a series of processes on one device. The method according to claim 12, The test program download step, A first step of providing test power from a power input unit to a plurality of motion sensors that are the inspection object; A second step of recognizing a motion sensor in which excessive current flows among the plurality of motion sensors and cutting off the test power supplied to the motion sensor; And And a third step of downloading a test program for a motion sensor among which the excessive current does not flow among the plurality of motion sensors. The method according to claim 12, The inspection step, A first step of generating a geomagnetism; A second step of rotating the jig in which the plurality of motion sensors, which are the inspection target, is seated in the X-Y direction, the X-Z direction, and the Y-Z direction, each of which rotates at a predetermined angular period; And And a third step of performing calibration and axis distortion correction for the plurality of motion sensors using geomagnetic sensitivity and acceleration sensitivity of the plurality of motion sensors generated as the jig rotates at a predetermined angular period. How to inspect the sensor. The method according to claim 14, The second step is a method for inspecting a motion sensor, characterized in that for rotating the jig in the state in which the generated geomagnetic is applied to the plurality of motion sensors. The method according to claim 14, In the third step, the plurality of motion sensors may be calibrated based on maximum and minimum values of geomagnetic sensitivity and acceleration sensitivity of the plurality of motion sensors generated as the jig rotates at a predetermined angular period. How to check the motion sensor. The method according to claim 14, The third step is to check the axis shift for the motion sensor based on the middle value among the maximum, minimum, and median of the magnetic strength of the plurality of motion sensors generated as the jig rotates at a predetermined angular period. Method of inspecting the motion sensor, characterized in that. The method according to claim 17, The third step is a method for inspecting a motion sensor, characterized in that for dividing the value obtained by using the median of the diagonals of the predetermined intermediate period period and the bisected value as the distorted angle of the corresponding axis. The method according to claim 12, And a firmware download step of downloading firmware for the plurality of motion sensors in which the inspection in the inspection step is completed.

Images