WO2019155687A1

WO2019155687A1 - Calibration device, measurement device, spherical body, calibration method and program

Info

Publication number: WO2019155687A1
Application number: PCT/JP2018/038168
Authority: WO
Inventors: 中川　真志; 東一奥野
Original assignee: アルプスアルパイン株式会社
Priority date: 2018-02-06
Filing date: 2018-10-12
Publication date: 2019-08-15
Also published as: JP2021056002A

Abstract

The present invention is provided with: an acceleration acquisition unit which acquires an acceleration output from an acceleration sensor; an angular velocity acquisition unit which acquires an angular velocity output from a gyro sensor; a first determination unit which determines, on the basis of the angular velocity acquired by the angular velocity acquisition unit, whether rotation of a measurement device is stable; a third determination unit which determines, on the basis of the acceleration acquired from the acceleration acquisition unit, whether the measurement device is in a free-fall state; and a correction value calculation unit which uses, as valid data, the acceleration acquired from the acceleration acquisition unit and calculates a correction value for the acceleration output from the acceleration sensor, when the first determination unit determines that the rotation of the measurement device is stable and the third determination unit determines that the measurement device is in the free-fall state.

Description

Calibration apparatus, measurement apparatus, sphere, calibration method, and program

The present invention relates to a calibration device, a measurement device, a sphere, a calibration method, and a program.

Conventionally, in various devices, acceleration generated in the device can be measured by an acceleration sensor mounted in the device. Among such devices, the acceleration output from the acceleration sensor is automatically performed when the device body is in a stationary state with a predetermined posture or when the user performs a predetermined operation on the device body. Some are designed to be calibrated.

For example, in Patent Document 1 below, when a free fall state of a mobile device is detected, a noise level of the signal is measured, and an accelerometer included in the mobile device is automatically calibrated based on a compensation signal based on the measured noise level. Techniques to do this are disclosed. Patent Document 1 below discloses a technique for compensating for rotation (angular velocity) of a sphere with respect to acceleration output from an accelerometer using a compensation coefficient based on a rotation vector measured by a three-axis gyroscope. It is disclosed.

Special table 2014-524037 gazette

However, in the technique disclosed in Patent Document 1, for example, when a configuration in which an accelerometer and a three-axis gyroscope are incorporated inside a sphere (for example, a ball for ball games), variation in the assembling position, Due to variations in the center of rotation, the relationship between the rotation (angular velocity) of the sphere and the centrifugal force actually generated on the sphere cannot be determined uniquely.

For this reason, in the technique of Patent Document 1 described above, the rotation (angular velocity) of the sphere is compensated for the acceleration output from the accelerometer using the compensation coefficient based on the rotation vector measured by the three-axis gyroscope. Even so, the centrifugal force actually generated in the sphere cannot be compensated, and therefore the acceleration output from the accelerometer cannot be corrected with high accuracy. Therefore, a calibration device capable of correcting the acceleration output from the acceleration sensor with high accuracy is required.

A calibration device according to an embodiment is a calibration device that calibrates a measurement device including an acceleration sensor and a gyro sensor, and includes an acceleration acquisition unit that acquires acceleration output from the acceleration sensor, and an angular velocity output from the gyro sensor. Based on the angular velocity acquisition unit to be acquired, the first determination unit that determines whether the rotation of the measuring device is stable based on the angular velocity acquired by the angular velocity acquisition unit, and the acceleration acquired by the acceleration acquisition unit A third determination unit that determines whether or not the measurement device is in a free fall state, and a case where the first determination unit determines that the rotation of the measurement device is stable, and the third determination unit determines the measurement device. Is determined to be in a free-fall state, the acceleration acquired by the acceleration acquisition unit is used as valid data to compensate for the acceleration output from the acceleration sensor. And a correction value calculation unit for calculating a value.

According to one embodiment, it is possible to realize a calibration device capable of correcting the acceleration output from the acceleration sensor with high accuracy.

It is a figure which shows schematic structure of the ball | bowl which concerns on one Embodiment. It is a figure which shows the hardware constitutions of the measurement module (measurement circuit) which concerns on one Embodiment. It is a figure which shows the function structure of the measurement module (measurement circuit) which concerns on one Embodiment. It is a figure which shows the determination pattern by the 2nd determination part in the measurement module (measurement circuit) which concerns on one Embodiment. It is a flowchart which shows the procedure of the process by the measurement module (measurement circuit) which concerns on one Embodiment. It is a figure which shows an example (1st example) of the measurement data by the measurement module which concerns on one Embodiment. It is a figure which shows an example (1st example) of the measurement data by the measurement module which concerns on one Embodiment. It is a figure which shows an example (2nd example) of the measurement data by the measurement module which concerns on one Embodiment. It is a figure which shows an example (2nd example) of the measurement data by the measurement module which concerns on one Embodiment.

Embodiment
Hereinafter, an embodiment will be described with reference to the drawings.

(Schematic configuration of the ball 10)
FIG. 1 is a diagram illustrating a schematic configuration of a ball 10 according to an embodiment. The ball 10 shown in FIG. 1 is an example of a “sphere” and has a spherical outer shape. As shown in FIG. 1, the ball 10 includes a measurement module 100, a pincushion layer 12, and a skin layer 14.

The measurement module 100 is an example of a “measurement device”. The measurement module 100 is provided substantially at the center inside the ball 10. The measurement module 100 includes a case 101 and a measurement circuit 102. The case 101 has a spherical outer shape and is a hollow member formed from a relatively hard material (for example, a hard resin). The measurement circuit 102 is a device that is fixedly disposed inside the case 101. The measurement circuit 102 includes an acceleration sensor 111, a gyro sensor 112, a geomagnetic sensor 113, and the like mounted on a circuit board 102A.

In the measurement module 100, the axial directions of these three axes (X axis, Y axis, Z axis) are set in advance so that the X axis direction, the Y axis direction, and the Z axis direction are all predetermined directions. Is defined. For example, the directions parallel to the surface of the circuit board 102A are defined as the X-axis direction and the Y-axis direction, and the direction perpendicular to the surface of the circuit board 102A is defined as the Z-axis direction. The acceleration sensor 111 and the gyro sensor 112 are the acceleration and angular velocity generated in the measurement module 100 (ie, the acceleration generated in the ball 10) for each of the three axes (X axis, Y axis, and Z axis) whose axial directions are defined in advance. , Angular velocity) can be detected. The geomagnetic sensor 113 can detect geomagnetism for each of the three axes (X axis, Y axis, Z axis) whose axial directions are defined in advance.

The bobbin layer 12 is provided outside the measurement module 100 so as to cover the outer surface of the measurement module 100. The bobbin layer 12 is formed by winding a plurality of yarns (for example, cotton yarn, wool yarn, rubber yarn) on the outer surface of the measurement module 100. The skin layer 14 is a member constituting the outer surface of the ball 10, and is provided on the outer side of the bobbin layer 12 so as to cover the outer surface of the bobbin layer 12. The skin layer 14 is formed of a material such as leather (for example, cowhide, artificial leather, etc.).

The ball 10 configured in this way is used as a ball for ball games (for example, for baseball, soccer, golf, etc.), and when the ball 10 flies, the acceleration and angular velocity of the ball 10 , And geomagnetism can be continuously measured by the measurement module 100. Further, the ball 10 can communicate with an external information processing device (for example, a smartphone, a tablet terminal, a personal computer, a server, etc.), and each measurement data (acceleration, angular velocity, and geomagnetism) is transmitted to the external information processing device. Can be output to.

The external information processing apparatus displays each measurement data (acceleration, angular velocity, and geomagnetism) acquired from the ball 10 by, for example, a display or used for analysis of how the ball 10 is rotated. be able to.

(Hardware configuration of measurement module 100)
FIG. 2 is a diagram illustrating a hardware configuration of the measurement module 100 (measurement circuit 102) according to the embodiment. As shown in FIG. 2, the measurement circuit 102 of the measurement module 100 includes an acceleration sensor 111, a gyro sensor 112, a geomagnetic sensor 113, a microcomputer 114, a memory 115, a communication interface (I / F) 116, and a battery 117. Yes. In the measurement circuit 102, these hardware are mounted on a circuit board 102A (see FIG. 1) and are electrically connected to each other by wiring formed on the circuit board 102A.

The acceleration sensor 111 detects the acceleration generated in the measurement module 100 (that is, the ball 10) for each of the three predefined axes (X axis, Y axis, Z axis). The acceleration detected by the acceleration sensor 111 is supplied to the microcomputer 114. As the acceleration sensor 111, for example, a strain gauge type acceleration sensor, a piezoresistive type acceleration sensor, a piezoelectric type acceleration sensor, or the like can be used.

The gyro sensor 112 detects an angular velocity generated in the measurement module 100 (that is, the ball 10) for each of three predefined axes (X axis, Y axis, and Z axis). The angular velocity detected by the gyro sensor 112 is supplied to the microcomputer 114. As the gyro sensor 112, for example, a vibration type gyro sensor, a capacitance type gyro sensor, or the like can be used.

The geomagnetic sensor 113 detects the geomagnetism of each of three predefined axes (X axis, Y axis, Z axis). The geomagnetism detected by the geomagnetic sensor 113 is supplied to the microcomputer 114. As the geomagnetic sensor 113, for example, a magnetoresistive sensor, a hall sensor, or the like can be used.

The microcomputer 114 is an example of a “calibration device” and a “computer”. The microcomputer 114 includes a processor, and the processor implements various functions included in the measurement module 100 by executing a program stored in the memory 115 or the like. For example, the microcomputer 114 has a function of outputting each measurement data (acceleration, angular velocity, and geomagnetism) supplied from each sensor to an external information processing apparatus via the communication I / F 116. For example, the microcomputer 114 has a function of calibrating the acceleration detected by the acceleration sensor 111 based on each measurement data (acceleration and angular velocity) supplied from each sensor.

The memory 115 stores, for example, a program executed by the microcomputer 114 and various data used when the microcomputer 114 executes the program. As the memory 115, for example, a RAM (Random Access Memory) or the like can be used.

The communication I / F 116 controls communication with an external information processing apparatus. For example, in this embodiment, BLE (Bluetooth Low Energy), which is a wireless communication method with relatively low power consumption, is used as a communication method by the communication I / F 116. However, the present invention is not limited to this, and other various wireless communication methods (for example, Wi-Fi, NFC (Near Field Communication), etc.) or various wired communication methods (for example, USB (Universal) are used as communication methods by the communication I / F 116. Serial Bus) etc. may be used.

The battery 117 supplies DC power to each part of the measurement module 100. For example, in the present embodiment, a primary battery (for example, a silver oxide battery, a lithium battery, or the like) is used as the battery 117. However, the present invention is not limited to this, and various secondary batteries (for example, a lithium ion secondary battery, a lithium ion polymer secondary battery, a nickel hydrogen secondary battery, etc.) may be used as the battery 117.

(Functional configuration of measurement module 100)
FIG. 3 is a diagram illustrating a functional configuration of the measurement module 100 (measurement circuit 102) according to the embodiment. As shown in FIG. 3, the measurement circuit 102 of the measurement module 100 includes a main control unit 300, an acceleration acquisition unit 301, an angular velocity acquisition unit 302, a geomagnetism acquisition unit 303, a first determination unit 304, a second determination unit 305, and a third. A determination unit 306, a correction value calculation unit 307, a value holding unit 308, a correction value writing unit 309, a correction value storage unit 310, a correction unit 311, an output unit 312, and a power supply control unit 313 are provided.

The main control unit 300 controls the entire processing by the measurement circuit 102. For example, the main control unit 300 controls the start of processing by the measurement circuit 102, the end of processing, the repetition of processing, the execution of processing by each functional unit, and the like.

The acceleration acquisition unit 301 acquires the acceleration output from the acceleration sensor 111. Specifically, the acceleration acquisition unit 301 acquires the acceleration of each of the three axes (X axis, Y axis, and Z axis) output from the acceleration sensor 111.

The angular velocity acquisition unit 302 acquires the angular velocity output from the gyro sensor 112. Specifically, the angular velocity acquisition unit 302 acquires the angular velocities of the three axes (X axis, Y axis, and Z axis) output from the gyro sensor 112. In this document, “angular velocity of the X axis” means an angular velocity having the X axis as a rotation axis. Similarly, “Y-axis angular velocity” means an angular velocity with the Y-axis as a rotation axis, and “Z-axis angular velocity” means an angular velocity with the Z-axis as a rotation axis.

The geomagnetism acquisition unit 303 acquires the geomagnetism output from the geomagnetic sensor 113. Specifically, the geomagnetism acquisition unit 303 acquires the geomagnetism of each of the three axes (X axis, Y axis, Z axis) output from the geomagnetic sensor 113.

The first determination unit 304 determines whether or not the rotation of the measurement module 100 is stable (hereinafter referred to as “rotation stable state”) based on the angular velocity acquired by the angular velocity acquisition unit 302. . Specifically, the first determination unit 304 determines that the difference between the latest angular velocity and the angular velocity immediately before the latest angular velocity is the first threshold value for all three axes (X axis, Y axis, Z axis). When the state of being equal to or less than th1 continues for N consecutive times, it is determined that the rotation is stable (that is, the angular velocity is stable, the angular velocity displacement amount is small). Note that the first determination unit 304 may determine the rotational stable state using a moving average value of a predetermined number of angular velocities. Thereby, the 1st determination part 304 can suppress the misjudgment by the noise contained in angular velocity, and can perform the determination of a rotation stable state with higher precision.

Based on the angular velocity acquired by the angular velocity acquiring unit 302, the second determining unit 305 determines whether centrifugal force is generated for each of the three axes (X axis, Y axis, Z axis) in the measurement module 100. To do.

Here, with reference to FIG. 4, the determination method of whether the centrifugal force by the 2nd determination part 305 has arisen is demonstrated concretely. FIG. 4 is a diagram illustrating a determination pattern by the second determination unit 305 in the measurement module 100 (measurement circuit 102) according to an embodiment.

As illustrated in FIG. 4, the second determination unit 305 determines that no centrifugal force is generated in the Z axis when both the X-axis angular velocity and the Y-axis angular velocity are equal to or less than a predetermined second threshold th2. To do. This is because, in one or both of the X axis and the Y axis, when the measurement module 100 rotates with the axis as a rotation axis, centrifugal force is generated in the Z axis direction.

Further, the second determination unit 305 determines that centrifugal force is not generated on the Y axis when both the X-axis angular velocity and the Z-axis angular velocity are equal to or less than a predetermined second threshold th2. This is because, in one or both of the X axis and the Z axis, when the measurement module 100 rotates with the axis as a rotation axis, centrifugal force is generated in the Y axis direction.

The second determination unit 305 determines that centrifugal force is not generated on the X axis when both the angular velocity of the Y axis and the angular velocity of the Z axis are equal to or less than a predetermined second threshold th2. This is because, in one or both of the Y axis and the Z axis, when the measurement module 100 rotates with the axis as a rotation axis, centrifugal force is generated in the X axis direction.

The third determination unit 306 determines whether or not the measurement module 100 (that is, the ball 10) is in a free fall state based on the acceleration acquired by the acceleration acquisition unit 301. In particular, the third determination unit 306 determines whether or not the measurement module 100 (that is, the ball 10) is in a free fall state based on a moving average value of a predetermined number of accelerations. Specifically, the third determination unit 306, for all three axes (X axis, Y axis, Z axis), when the moving average value of a predetermined number of accelerations is equal to or less than a predetermined third threshold th3, It is determined that the ball 10 is in a free fall state. As described above, the third determination unit 306 determines the free fall state by using the moving average value of the acceleration, thereby suppressing erroneous determination due to noise included in the acceleration, and determining the free fall state. It can be performed with higher accuracy.

The correction value calculation unit 307 calculates the correction value of the acceleration output from the acceleration sensor 111 based on the acceleration acquired by the acceleration acquisition unit 301. Specifically, the correction value calculation unit 307 determines that all three axes (X axis, Y axis, Z axis) in the measurement module 100 are in a rotationally stable state by the first determination unit 304, and the first 3 When the determination unit 306 determines that the ball 10 is in a free fall state, the second determination unit 305 determines that the centrifugal force is not generated (at least one of the X axis, the Y axis, and the Z axis). 1), using the acceleration of the axis acquired by the acceleration acquisition unit 301 as effective data, the correction value of the acceleration of the axis output from the acceleration sensor 111 is calculated. Here, when the ball 10 is in the free fall state (that is, the 0G state), it is ideal that the angular velocity of each of the three axes is “0”. Therefore, for example, the correction value calculation unit 307 includes three axes ( For each of the X axis, the Y axis, and the Z axis, the acceleration acquired by the acceleration acquisition unit 301 (that is, the difference value from “0”) can be calculated as it is as a correction value for acceleration.

The value holding unit 308 holds the acceleration determined as valid data. For example, when it is determined that only the X-axis acceleration is valid data, the value holding unit 308 holds the X-axis acceleration. After that, if the Y-axis acceleration is determined to be valid data, and if the Z-axis acceleration is determined to be valid data, the value holding unit 308 further holds the Y-axis and Z-axis accelerations. As a result, the value holding unit 308 holds the acceleration of each of the three axes (X axis, Y axis, and Z axis). Therefore, the correction value calculation unit 307 uses the three axes (X axis, Y axis, and Z axis) held by the value holding unit 308 to use the three axes (X axis) output from the acceleration sensor 111. , Y axis, and Z axis) can be calculated.

Further, the value holding unit 308 can hold a plurality of accelerations determined to be valid data for each of the three axes (X axis, Y axis, and Z axis). Accordingly, the correction value calculation unit 307 calculates an average value of a plurality of accelerations held in the value holding unit 308 for each of the three axes (X axis, Y axis, and Z axis), and uses the average value. Thus, the correction value of the acceleration output from the acceleration sensor 111 can be calculated. As described above, the correction value calculation unit 307 calculates the average value of the plurality of accelerations as the correction value, thereby smoothing noise included in the plurality of accelerations and calculating a correction value with higher accuracy. it can.

The correction value writing unit 309 writes the correction values of the three axes (X axis, Y axis, Z axis) calculated by the correction value calculation unit in the correction value storage unit 310. The correction value storage unit 310 stores the correction values of the three axes (X axis, Y axis, and Z axis) written by the correction value writing unit 309. Here, when a correction value is already stored in the correction value storage unit 310, the correction value writing unit 309 overwrites the correction value storage unit 310 with a new correction value. As a result, the latest correction value is always stored in the correction value storage unit 310.

The correction unit 311 uses the three axis (X axis, Y axis, Z axis) correction values stored in the correction value storage unit 310 to obtain the three axes (X axis, Y) acquired by the acceleration acquisition unit 301. Axes and Z-axis) are corrected. For example, the correction unit 311 calculates the three axes (X axis, Y axis) stored in the correction value storage unit 310 from the accelerations of the three axes (X axis, Y axis, Z axis) acquired by the acceleration acquisition unit 301. , Z axis) is subtracted.

The output unit 312 outputs acceleration, angular velocity, and geomagnetism. Specifically, the output unit 312 outputs the acceleration of each of the three axes (X axis, Y axis, and Z axis) corrected by the correction unit 311. The output unit 312 outputs the angular velocities of the three axes (X axis, Y axis, and Z axis) acquired by the angular velocity acquisition unit 302. The output unit 312 outputs the geomagnetism of each of the three axes (X axis, Y axis, and Z axis) acquired by the geomagnetism acquisition unit 303. For example, the output unit 312 outputs acceleration, angular velocity, and geomagnetism to an external information processing apparatus (for example, a smartphone, a tablet terminal, a personal computer, a server, etc.) via the communication I / F 116.

The power control unit 313 controls the power on and off of the measurement module 100. For example, when the power supply control unit 313 determines that the ball 10 is in a free fall state based on the acceleration acquired by the acceleration acquisition unit 301 when the measurement module 100 is powered off (or in sleep mode). Then, the measurement module 100 is turned on. As a method for determining this free fall state, for example, a determination method similar to the determination method by the third determination unit 306 can be used. Further, for example, when the power supply control unit 313 determines that the ball 10 is in a stationary state for a certain period based on the acceleration acquired by the acceleration acquisition unit 301, the power supply of the measurement module 100 is turned off (or in sleep mode). ). Thereby, the measurement module 100 according to the present embodiment turns on and off the power of the measurement module 100 without providing a power switch by a user operation (that is, without exposing a physical switch to the outer surface of the ball 10). Can be switched.

Each function of the measurement module 100 described above is realized by various hardware (see FIG. 2) and software included in the measurement module 100. For example, main control unit 300, acceleration acquisition unit 301, angular velocity acquisition unit 302, geomagnetism acquisition unit 303, first determination unit 304, second determination unit 305, third determination unit 306, correction value calculation unit 307, correction value writing The unit 309, the correction unit 311, the output unit 312, and the power supply control unit 313 are realized by the microcomputer 114 executing the program stored in the memory 115. For example, the value holding unit 308 and the correction value storage unit 310 are realized by the memory 115.

The program executed by the microcomputer 114 may be provided in a state of being introduced into the measurement module 100 in advance, or may be provided from the outside and introduced into the measurement module 100. In the latter case, this program may be provided by an external storage medium (for example, a USB memory, a memory card, a CD-ROM, etc.), or provided by downloading from a server on a network (for example, the Internet, etc.). You may do it.

(Processing procedure by the measurement module 100)
FIG. 5 is a flowchart illustrating a processing procedure performed by the measurement module 100 (measurement circuit 102) according to an embodiment. The processing shown in FIG. 5 is executed in the measurement module 100 when, for example, the user gives a processing start instruction to the ball 10 and then freely drops the ball 10 from a state of being held by hand. It is processing.

First, the main control unit 300 determines whether or not a predetermined process start event has occurred (step S501). The predetermined process start event may be any event. For example, the reception of a process start instruction from an external information processing apparatus may be used as the predetermined process start event. If it is determined in step S501 that the predetermined process start event has not occurred (step S501: No), the main control unit 300 executes the process of step S501 again.

On the other hand, when it is determined in step S501 that a predetermined process start event has occurred (step S501: Yes), the acceleration acquisition unit 301 outputs the three axes (X axis, Y axis, Z) output from the acceleration sensor 111. The acceleration of each axis is acquired (step S502). Further, the angular velocity acquisition unit 302 acquires the angular velocities of the three axes (X axis, Y axis, Z axis) output from the gyro sensor 112 (step S503).

Actually, since acceleration is repeatedly output from the acceleration sensor 111, in step S502, the acceleration acquisition unit 301 repeatedly acquires acceleration. Similarly, since the angular velocity is actually output repeatedly from the gyro sensor 112, the angular velocity acquisition unit 302 repeatedly acquires the angular velocity in step S503.

Then, the first determination unit 304 rotates all three axes (X axis, Y axis, Z axis) in the measurement module 100 based on the angular velocities (moving average values of the three axes) acquired in step S503. It is determined whether or not it is in a stable state (step S504). In step S504, when it is determined that all three axes are not in the rotation stable state (step S504: No), the main control unit 300 returns the process to step S502.

On the other hand, when it is determined in step S504 that all the three axes are in a rotationally stable state (step S504: Yes), the third determination unit 306 determines the acceleration (moving average of each of the three axes) acquired in step S502. Based on (value), it is determined whether or not the ball 10 is in a free fall state (step S505). If it is determined in step S505 that the ball 10 is not in the free fall state (step S505: No), the main control unit 300 returns the process to step S502.

On the other hand, when it is determined in step S505 that the ball 10 is in a free fall state (step S505: Yes), the second determination unit 305 determines the three axes in the measurement module 100 based on the angular velocity acquired in step S503. It is determined whether or not centrifugal force is generated for each of the (X axis, Y axis, and Z axis) (step S506).

Then, among the accelerations of the three axes (X axis, Y axis, and Z axis) acquired in step S502, the value holding unit 308 determines the acceleration of the axis determined to have no centrifugal force generated in step S506. It is held as valid data (step S507).

Thereafter, the main control unit 300 determines whether or not a certain amount of acceleration is held in the value holding unit 308 for each of the three axes (X axis, Y axis, and Z axis) (step S508). If it is determined in step S508 that a certain amount of acceleration is not held in the value holding unit 308 (step S508: No), the main control unit 300 returns the process to step S502.

On the other hand, when it is determined in step S508 that a certain amount of acceleration has been held in the value holding unit 308 (step S508: Yes), the correction value calculation unit 307 has three axes (X axis, Y axis, Z axis). For each, an average value of a plurality of accelerations held in the value holding unit 308 is calculated as an acceleration correction value output from the acceleration sensor 111 (step S509). Then, the correction value writing unit 309 writes the correction values of the three axes (X axis, Y axis, and Z axis) calculated in step S509 in the correction value storage unit 310 (step S510). Thereafter, the main control unit 300 ends the series of processes shown in FIG.

In the example shown in FIG. 5, the measurement module 100 repeatedly executes a series of processes until a certain amount of acceleration is held in the value holding unit 308, but is not limited thereto. For example, the measurement module 100 may execute a series of processes shown in FIG. 5 once periodically (for example, every day, every week, every time the measurement module 100 is activated, etc.). . In this case, the measurement module 100 may calculate an acceleration correction value at a timing when a certain amount of acceleration is held in the value holding unit 308.

(An example of measurement data by the measurement module 100)
FIG. 6 is a diagram illustrating an example (first example) of measurement data obtained by the measurement module 100 according to an embodiment. FIG. 7 is a diagram illustrating an example (second example) of measurement data obtained by the measurement module 100 according to an embodiment.

FIG. 6 shows measurement data measured by the measurement module 100 provided inside the ball 10 when the user freely drops the ball 10. In particular, FIG. 6 shows measurement data when the ball 10 falls freely without rotation. FIG. 6A represents acceleration measurement data, where the horizontal axis represents time, and the vertical axis represents acceleration. FIG. 6B represents angular velocity measurement data, where the horizontal axis represents time and the vertical axis represents angular velocity.

6A and 6B, the period S1 is a period in which the ball 10 is held in the user's hand. The period S2 is a period in which the ball 10 is rolled from the user's hand. The period S3 is a period in which the ball 10 is in a free fall state.

In FIGS. 6A and 6B, the solid line represents the X-axis acceleration. The broken line represents the Y-axis acceleration. Also, the alternate long and short dash line represents the Z-axis acceleration.

As shown in period S3 of FIG. 6A, when the ball 10 is in a free fall state (that is, 0G state), the accelerations of the three axes (X axis, Y axis, Z axis) are converged around 0 It will be stable. Here, in the example shown in FIG. 6, as shown in the period S3 in FIG. 6B, when the ball 10 is in a free fall state, each of the angular velocities of the three axes (X axis, Y axis, Z axis) is near zero. It is shown that the ball 10 is in a stable state after being converged, that is, the ball 10 is in a substantially non-rotating state.

In this case, in the measurement module 100 of the present embodiment, the first determination unit 304 determines that the ball 10 is in a rotationally stable state, and the second determination unit 305 determines each of the three axes (X axis, Y axis, Z axis). It is determined that the centrifugal force is not generated in the ball, and the third determination unit 306 determines that the ball 10 is in a free fall state. Therefore, in this case, the measurement module 100 determines that each acceleration of the three axes (X axis, Y axis, Z axis) in the period S3 is valid data by using the correction value calculation unit 307, and uses these accelerations. A correction value of acceleration of each of the three axes (X axis, Y axis, Z axis) is calculated. At this time, since each of the accelerations of the three axes (X axis, Y axis, Z axis) has an ideal value of 0, the correction value calculation unit 307 uses the difference value from the ideal value as a correction value. Can be calculated.

On the other hand, FIG. 7 shows measurement data measured by the measurement module 100 provided inside the ball 10 when the user freely drops the ball 10. In particular, FIG. 7 shows measurement data when the ball 10 freely falls with rotation. FIG. 7A represents acceleration measurement data, where the horizontal axis represents time and the vertical axis represents acceleration. FIG. 7B represents angular velocity measurement data, where the horizontal axis represents time and the vertical axis represents angular velocity.

7A and 7B, a period S4 is a period in which the ball 10 is in a state of being thrown up from the user's hand. The period S5 is a period in which the ball 10 is in a free fall state.

7A and 7B, the solid line represents the X-axis acceleration. The broken line represents the Y-axis acceleration. Also, the alternate long and short dash line represents the Z-axis acceleration.

As shown in a period S5 in FIG. 7A, when the ball 10 is in a free fall state (ie, 0G state), the acceleration of each of the three axes (X axis, Y axis, and Z axis) converges near zero. It will be stable. Here, in the example shown in FIG. 7, as shown in the period S5 in FIG. 7B, when the ball 10 is in a free fall state, each of the angular velocities of the three axes (X axis, Y axis, Z axis) is near zero. It is shown that the ball 10 is not in a converged state, that is, the ball 10 is in a rotating state.

In this case, in the measurement module 100 of the present embodiment, the third determination unit 306 determines that the ball 10 is in a free fall state. However, in the example shown in FIG. 7B, since the value of the angular velocity of the X axis in the period S5 is not stable, the first determination unit 304 determines that the ball 10 is not in a stable rotation state. Further, in the example shown in FIG. 7B, since the values of the angular velocities of the three axes (X axis, Y axis, Z axis) in the period S5 are all equal to or greater than the predetermined second threshold th2, the second determination is made. The unit 305 determines that centrifugal force is generated in each of the three axes (X axis, Y axis, and Z axis). Therefore, in this case, the measurement module 100 determines that each acceleration of the three axes (X axis, Y axis, Z axis) in the period S5 is invalid data by using the correction value calculation unit 307, and uses these accelerations. The correction value of acceleration of each of the three axes (X axis, Y axis, Z axis) is not calculated.

As described above, the measurement module 100 of the present embodiment is measured by the acceleration sensor 111 when it is determined that the measurement module 100 is in the rotation stable state based on the angular velocity measured by the gyro sensor 112. A configuration is adopted in which the acceleration correction value output from the acceleration sensor 111 is calculated using the acceleration as effective data. As a result, even if the measurement module 100 of the present embodiment is mounted on the spherical ball 10 that easily rotates, the measurement module 100 outputs from the acceleration sensor 111 using only the acceleration measured when the ball 10 is in the rotation stable state. The acceleration correction value can be calculated. Therefore, the measurement module 100 according to the present embodiment can eliminate the influence due to the large amount of displacement of the rotation of the measurement module 100, and thus can correct the acceleration output from the acceleration sensor 111 with high accuracy. .

In addition, the measurement module 100 according to the present embodiment centrifuges each of the three axes (X axis, Y axis, Z axis) in the measurement module 100 (that is, the ball 10) based on the angular velocity measured by the gyro sensor 112. It is determined whether or not a force is generated, and is output from the acceleration sensor 111 using the acceleration of the axis measured by the acceleration sensor 111 as valid data for an axis determined to have no centrifugal force. A configuration for calculating a correction value of acceleration of the axis is employed. As a result, even if the measurement module 100 of this embodiment is mounted on the spherical ball 10 that is likely to rotate, only the acceleration measured when the centrifugal force due to the rotation of the ball 10 is not generated is used. A correction value of acceleration output from the sensor 111 can be calculated. Therefore, the measurement module 100 of the present embodiment can eliminate the influence of the centrifugal force due to the rotation of the measurement module 100, and thus can correct the acceleration output from the acceleration sensor 111 with high accuracy.

In particular, the measurement module 100 according to the present embodiment is configured so that even if a centrifugal force is generated in a part of three axes (X axis, Y axis, and Z axis), Since the acceleration of the axis is determined as valid data (that is, the acceleration of all axes is not invalidated in general), a sufficient amount of valid data necessary for calculating the correction value is obtained relatively early. Can be collected.

In addition, the measurement module 100 according to the present embodiment is measured by the acceleration sensor 111 when it is determined that the measurement module 100 (that is, the ball 10) is in a free fall state based on the acceleration measured by the acceleration sensor 111. A configuration for calculating a correction value of acceleration output from the acceleration sensor 111 by using the acceleration as effective data is adopted. Thereby, even if the measurement module 100 of this embodiment is mounted on the spherical ball 10 in which it is difficult to calibrate the acceleration in a predetermined posture, the measurement module 100 can be moved in three axes (X-axis) only by freely dropping the ball 10. , Y axis, Z axis) can create a reference state in which each acceleration is an ideal value (that is, 0), and therefore, the acceleration correction value for each of the three axes (X axis, Y axis, Z axis) Can be calculated easily and with high accuracy.

In addition, the measurement module 100 of the present embodiment allows the measurement module 100 (that is, the ball 10) to freely fall a plurality of times, so that each time at least one of the X axis, the Y axis, and the Z axis, The acceleration measured by the acceleration sensor 111 can be obtained as effective data. The measurement module 100 according to the present embodiment includes an acceleration that is obtained by determining that the measurement module 100 is in a free-falling state a plurality of times, and at least one effective data of the X axis, and the Y axis. Each of the X-axis, Y-axis, and Z-axis output from the acceleration sensor 111 using at least one acceleration of the valid data and acceleration of at least one valid data of the Z-axis. An acceleration correction value can be calculated. In short, the measurement module 100 of the present embodiment allows the measurement module 100 to freely fall a plurality of times and obtain at least one effective data for each of the X axis, the Y axis, and the Z axis. It is possible to calculate correction values for acceleration of each of the Y axis and the Z axis. The free fall of the measurement module 100 may be performed every time the measurement module 100 is activated, for example. In this case, the activation interval of the measurement module 100 may be any day, week, month, or the like.

The embodiments of the present invention have been described in detail above, but the present invention is not limited to these embodiments, and various modifications or changes can be made within the scope of the gist of the present invention described in the claims. It can be changed.

For example, in the above embodiment, the calibration device (microcomputer 114) of the present invention is provided integrally with the acceleration sensor 111, the gyro sensor 112, and the measurement module 100. However, the calibration device of the present invention is not limited to this. The acceleration sensor 111 and the gyro sensor 112 may be provided separately.

Moreover, in the said embodiment, although the measuring device (measurement module 100) of this invention is provided in the spherical body (ball | bowl 10) which has the pincushion layer 12, it is not restricted to this, The measuring device of this invention is a pincushion layer. It may be provided in a sphere that does not have a sphere or any device other than a sphere.

In the above embodiment, the measurement module 100 is provided with both the first determination unit 304 and the second determination unit 305. However, the measurement module 100 is not limited thereto, and the measurement module 100 includes the first determination unit 304 and the first determination unit 304. Either one of the two determination units 305 may be provided.

Further, in the above embodiment, some or all of the plurality of functions (see FIG. 3) that the measurement module 100 (measurement circuit 102) has may be provided outside the measurement module 100. For example, in the above embodiment, the output unit 312 outputs the acceleration corrected by the correction unit 311 to an external information processing apparatus. However, the present invention is not limited to this, and for example, the output unit 312 acquires the acceleration. The acceleration acquired by the unit 301 and the correction value stored in the correction value storage unit 310 may be output to an external information processing apparatus so that the acceleration is corrected by the external information processing apparatus. .

In the above embodiment, the output unit 312 may output each measurement data (acceleration, angular velocity, and geomagnetism) in real time, accumulate each measurement data in the memory 115, and at a predetermined timing. You may make it output collectively.

In the above embodiment, the correction value calculation unit 307 calculates the correction values for the three axes in a state where the accelerations (effective data) for the three axes (X axis, Y axis, and Z axis) are aligned. However, the present invention is not limited to this, and the correction value may be calculated when valid data is obtained for each axis.

In the above embodiment, the third determination unit 306 determines that the acceleration (moving average value) of each of the three axes (X axis, Y axis, Z axis) is equal to or less than a predetermined third threshold th3. The ball 10 is determined to be in a free-fall state, but the present invention is not limited to this. For example, the combined vector value of the acceleration of each of the three axes (X axis, Y axis, Z axis) or its movement When the average value is equal to or less than the predetermined fourth threshold th4, it may be determined that the ball 10 is in a free fall state.

This international application claims priority based on Japanese Patent Application No. 2018-019573 filed on Feb. 6, 2018, the entire contents of which are incorporated herein by reference.

10 balls (sphere)
12 Pincushion layer 14 Skin layer 100 Measuring module (measuring device)
DESCRIPTION OF SYMBOLS 101 Case 102 Measuring circuit 102A Circuit board 111 Acceleration sensor 112 Gyro sensor 113 Geomagnetic sensor 114 Microcomputer (calibration apparatus, computer)
115 Memory 116 Communication I / F
117 battery 300 main control unit 301 acceleration acquisition unit 302 angular velocity acquisition unit 303 geomagnetism acquisition unit 304 first determination unit 305 second determination unit 306 third determination unit 307 correction value calculation unit 308 value holding unit 309 correction value writing unit 310 correction Value storage unit 311 Correction unit 312 Output unit 313 Power supply control unit

Claims

A calibration device for calibrating a measurement device including an acceleration sensor and a gyro sensor,
An acceleration acquisition unit for acquiring the acceleration output from the acceleration sensor;
An angular velocity acquisition unit that acquires the angular velocity output from the gyro sensor;
A first determination unit that determines whether rotation of the measurement device is stable based on the angular velocity acquired by the angular velocity acquisition unit;
A third determination unit that determines whether or not the measurement device is in a free-fall state based on the acceleration acquired by the acceleration acquisition unit;
When the first determination unit determines that the rotation of the measurement device is stable, and when the third determination unit determines that the measurement device is in a free fall state, the acceleration acquisition unit A calibration apparatus comprising: a correction value calculation unit that calculates a correction value of an acceleration output from the acceleration sensor using the acquired acceleration as valid data.
The first determination unit includes:
The calibration device according to claim 1, wherein it is determined whether or not the rotation of the measurement device is stable based on a moving average value of a predetermined number of the angular velocities.
The first determination unit includes:
For all of the X-axis, Y-axis, and Z-axis in the measuring device, the difference between the latest angular velocity and the angular velocity immediately before the latest angular velocity is not more than a predetermined first threshold value. The calibration device according to claim 2, wherein if the rotation continues for a predetermined number of times or more, the rotation of the measurement device is determined to be stable.
A calibration device for calibrating a measurement device including an acceleration sensor and a gyro sensor,
An acceleration acquisition unit for acquiring the acceleration output from the acceleration sensor;
An angular velocity acquisition unit that acquires the angular velocity output from the gyro sensor;
A second determination unit that determines whether centrifugal force is generated for each of the X axis, the Y axis, and the Z axis in the measurement device based on the angular velocity acquired by the angular velocity acquisition unit;
A third determination unit that determines whether or not the measurement device is in a free-fall state based on the acceleration acquired by the acceleration acquisition unit;
When the third determination unit determines that the measurement device is in a free fall state, it is determined that no centrifugal force is generated by the second determination unit among the X axis, the Y axis, and the Z axis. A correction value calculation unit that calculates a correction value of the acceleration of the axis output from the acceleration sensor, using the acceleration of the axis acquired by the acceleration acquisition unit as valid data for the acquired axis. A calibration device characterized by that.
The correction value calculation unit
Obtained by determining that the measuring device is in the free fall state a plurality of times,
The acceleration taken as the valid data of at least one of the X-axis,
The acceleration taken as the valid data of at least one of the Y-axis,
The correction value of the acceleration of each of the X-axis, the Y-axis, and the Z-axis output from the acceleration sensor is calculated using at least one of the effective data of the Z-axis and the acceleration. The calibration device according to claim 4, wherein:
The second determination unit includes
When both the angular velocity of the X axis and the angular velocity of the Y axis are equal to or less than a predetermined second threshold, it is determined that the centrifugal force is not generated with respect to the Z axis,
When both the angular velocity of the X axis and the angular velocity of the Z axis are equal to or less than the predetermined second threshold, it is determined that the centrifugal force is not generated with respect to the Y axis,
It is determined that the centrifugal force is not generated with respect to the X axis when both the angular velocity of the Y axis and the angular velocity of the Z axis are equal to or less than the predetermined second threshold value. The calibration apparatus according to 4 or 5.
The third determination unit includes:
The calibration device according to any one of claims 1 to 6, wherein it is determined whether or not the measurement device is in a free fall state based on a moving average value of a predetermined number of the accelerations.
The third determination unit includes:
When the moving average value of the predetermined number of accelerations is less than or equal to a predetermined third threshold for all of the X axis, Y axis, and Z axis in the measuring device, it is determined that the measuring device is in a free fall state The calibration device according to claim 7, wherein:
Each time the third determination unit determines that the measurement device is in a free fall state, the third determination unit further includes a value holding unit that holds the acceleration that is effective data in the free fall state,
The correction value calculation unit
The calibration apparatus according to claim 1, wherein the correction value is calculated using a plurality of the accelerations held by the value holding unit.
The correction value calculation unit
The calibration device according to claim 9, wherein the correction value is calculated using an average value of the plurality of accelerations held by the value holding unit.
The acceleration sensor;
The gyro sensor;
A measuring device comprising: the calibration device according to claim 1.
A sphere having the measuring device according to claim 11 inside.
The sphere according to claim 12, further comprising a wound layer formed outside the measuring device.
A method for calibrating a measuring device including an acceleration sensor and a gyro sensor,
An acceleration acquisition step of acquiring the acceleration output from the acceleration sensor;
An angular velocity acquisition step of acquiring an angular velocity output from the gyro sensor;
A first determination step of determining whether rotation of the measuring device is stable based on the angular velocity acquired in the angular velocity acquisition step;
A third determination step of determining whether or not the measurement device is in a free fall state based on the acceleration acquired in the acceleration acquisition step;
When it is determined that the rotation of the measurement device is stable in the first determination step, and when it is determined that the measurement device is in a free fall state in the third determination step, in the acceleration acquisition step A correction value calculating step of calculating a correction value of the acceleration output from the acceleration sensor using the acquired acceleration as valid data.
A method for calibrating a measuring device including an acceleration sensor and a gyro sensor,
An acceleration acquisition step of acquiring the acceleration output from the acceleration sensor;
An angular velocity acquisition step of acquiring an angular velocity output from the gyro sensor;
A second determination step of determining whether centrifugal force is generated for each of the X axis, the Y axis, and the Z axis in the measurement device based on the angular velocity acquired in the angular velocity acquisition step;
A third determination step of determining whether or not the measurement device is in a free fall state based on the acceleration acquired in the acceleration acquisition step;
When it is determined in the third determination step that the measuring device is in a free fall state, it is determined that no centrifugal force is generated in the second determination step among the X axis, the Y axis, and the Z axis. A correction value calculation step of calculating a correction value of the acceleration of the axis output from the acceleration sensor using the acceleration of the axis acquired in the acceleration acquisition step as effective data for the acquired axis. A calibration method characterized by the above.
A program for calibrating a measuring device including an acceleration sensor and a gyro sensor,
Computer
An acceleration acquisition unit for acquiring the acceleration output from the acceleration sensor;
An angular velocity acquisition unit for acquiring the angular velocity output from the gyro sensor;
A first determination unit that determines whether rotation of the measurement device is stable based on the angular velocity acquired by the angular velocity acquisition unit;
A third determination unit that determines whether or not the measurement device is in a free-fall state based on the acceleration acquired by the acceleration acquisition unit; and
When the first determination unit determines that the rotation of the measurement device is stable, and when the third determination unit determines that the measurement device is in a free fall state, the acceleration acquisition unit A program for functioning as a correction value calculation unit that calculates a correction value of acceleration output from the acceleration sensor using the acquired acceleration as valid data.
A program for calibrating a measuring device including an acceleration sensor and a gyro sensor,
Computer
An acceleration acquisition unit for acquiring the acceleration output from the acceleration sensor;
An angular velocity acquisition unit for acquiring the angular velocity output from the gyro sensor;
A second determination unit that determines whether centrifugal force is generated for each of the X axis, the Y axis, and the Z axis in the measurement device, based on the angular velocity acquired by the angular velocity acquisition unit;
A third determination unit that determines whether or not the measurement device is in a free-fall state based on the acceleration acquired by the acceleration acquisition unit; and
When the third determination unit determines that the measurement device is in a free fall state, it is determined that no centrifugal force is generated by the second determination unit among the X axis, the Y axis, and the Z axis. With respect to the obtained axis, the acceleration of the axis acquired by the acceleration acquisition unit is used as effective data, and the correction value calculation unit calculates a correction value of the acceleration of the axis output from the acceleration sensor. Program for.