JP6357992B2 - Electronic equipment and calibration program - Google Patents

Description

  The present invention relates to an electronic device and a calibration program.

  In recent years, portable smart devices having a display unit capable of displaying map information and the like, such as smartphones, have become widespread. Many of such smart devices can be measured by, for example, GPS (Global Positioning System), and have a navigation function that uses current position information obtained by positioning and map information displayed on the display unit. Is provided.

  Since GPS positioning is a method for receiving and measuring radio waves transmitted from a plurality of artificial satellites, it is possible to perform positioning with high accuracy outdoors. On the other hand, since the reception sensitivity of radio waves transmitted from artificial satellites decreases indoors, it is difficult to estimate an accurate position by GPS positioning. Thus, for example, in an electronic device such as a smartphone, a movement locus may be estimated by autonomous navigation positioning using an acceleration sensor, a geomagnetic sensor, or the like.

  In autonomous navigation positioning, magnetic north is estimated by a geomagnetic sensor, and the traveling direction of an electronic device is estimated. However, in many electronic devices, because internal components affect the magnetic field, the geomagnetic sensor detects magnetism other than geomagnetism. As a result, it is difficult to estimate magnetic north correctly by simply measuring magnetism with a geomagnetic sensor. Therefore, calibration may be performed in which the influence of the magnetic field environment inside the electronic device on the geomagnetic sensor is estimated in advance and the offset subtracted from the sensor value of the geomagnetic sensor is calculated. The geomagnetic sensor is a normal magnetic sensor that detects not only geomagnetism but also magnetism generated from, for example, a magnet or metal. Hereinafter, the geomagnetic sensor and the magnetic sensor are collectively referred to as a geomagnetic sensor without any particular distinction.

  Because calibration uses the output of the geomagnetic sensor when the electronic device is in various postures, the user is required to perform a predetermined operation while holding the electronic device when performing calibration. There is. That is, a screen for requesting an operation of drawing, for example, a figure 8 while holding the electronic device may be displayed on the display unit. Then, an offset corresponding to the influence of the magnetic field environment inside the electronic device is calculated from the sensor value detected by the geomagnetic sensor while the electronic device moves to draw a figure 8.

JP 2005-172837 A JP 2009-2915 A

  By the way, when the magnetic field environment outside the electronic device changes, the magnetic field environment inside the electronic device also changes. For this reason, it is preferable to perform calibration again when the external magnetic field environment changes. That is, when it is detected that the external magnetic field environment has changed, the electronic device preferably requests the user to perform an operation for calibration.

  However, if calibration is executed every time the external magnetic field environment changes, there is a problem that the user is frequently required to perform an operation for calibration. In particular, if the magnetic field environment changes due to movement to an environment in which a magnetic force other than geomagnetism is acting strongly or an environment in which the geomagnetism is attenuated due to shielding by buildings, etc., a calibration operation is required and calibration is required. May be executed. However, even if calibration is executed, it is difficult for the geomagnetic sensor to accurately detect the geomagnetism under the above environment, and magnetic north is not estimated correctly. In other words, from the viewpoint of the purpose of estimating magnetic north, useless calibration of the geomagnetic sensor is performed, and the convenience of the electronic device is reduced.

  The disclosed technology has been made in view of the above point, and an object thereof is to provide an electronic device and a calibration program capable of efficiently executing calibration of a geomagnetic sensor.

In one aspect, an electronic device disclosed in the present application includes a magnetic sensor that measures magnetism including geomagnetism. The electronic device detects a change in the magnetic field environment based on the measurement value of the magnetic sensor, and when the change in the magnetic field environment is detected, the measurement value of the application using the measurement value of the magnetic sensor. It is determined whether only the azimuth use application that uses the azimuth for the azimuth estimation is activated, and when the application other than the azimuth utilization application is activated as a result of the determination, the user is requested to perform a predetermined operation. On the other hand, when only the azimuth application is running , the magnetic field inside the electronic device is not calculated using the measured value of the magnetic sensor obtained after requesting the predetermined operation without requesting the predetermined operation. A processor that executes a process of calculating an offset corresponding to an influence on the measurement value of the magnetic sensor;

  According to one aspect of the electronic device and the calibration program disclosed in the present application, there is an effect that the calibration of the geomagnetic sensor can be executed efficiently.

FIG. 1 is a block diagram showing a configuration of a communication terminal apparatus according to Embodiment 1. FIG. 2 is a block diagram illustrating functions of the processor according to the first embodiment. FIG. 3 is a flowchart showing the calibration process according to the first embodiment. FIG. 4 is a block diagram illustrating functions of the processor according to the second embodiment. FIG. 5 is a flowchart showing the automatic calibration process according to the second embodiment.

  Hereinafter, embodiments of an electronic device and a calibration program disclosed in the present application will be described in detail with reference to the drawings. In the following, as an electronic device, a communication terminal device such as a smartphone will be described as an example. In addition, this invention is not limited by this embodiment. In the present application, various application programs executed by the electronic device are simply referred to as applications.

(Embodiment 1)
FIG. 1 is a block diagram showing a configuration of communication terminal apparatus 100 according to Embodiment 1. A communication terminal device 100 shown in FIG. 1 includes a GPS unit 101, a radio unit 102, a memory 103, a processor 104, an audio input / output unit 105, a touch sensor unit 106, a display unit 107, a geomagnetic sensor 108, an acceleration sensor 109, and a gyro sensor 110. Have

  The GPS unit 101 is activated intermittently at a predetermined cycle, receives radio waves transmitted from artificial satellites via an antenna, and acquires positioning data including the latitude and longitude of the current position. The positioning data acquired by the GPS unit 101 is stored in a predetermined storage unit.

  The wireless unit 102 transmits and receives wireless signals via the antenna. In FIG. 1, the GPS unit 101 and the wireless unit 102 share the same antenna, but the communication terminal apparatus 100 may be provided with a plurality of antennas corresponding to the frequency bands used.

  The memory 103 includes, for example, a RAM (Random Access Memory) and temporarily stores data used by the processor 104.

  The processor 104 performs overall control of each unit of the communication terminal device 100. Specifically, the processor 104 performs autonomous navigation positioning that estimates the movement trajectory of the communication terminal device 100 using sensor data obtained by the geomagnetic sensor 108, the acceleration sensor 109, the gyro sensor 110, and the like. Further, the processor 104 performs calibration of the geomagnetic sensor 108 as necessary, and calculates an offset corresponding to the influence of the magnetic field inside the communication terminal device 100 on the sensor value of the geomagnetic sensor 108. Then, when providing the sensor value of the geomagnetic sensor 108 to the application, the processor 104 provides the corrected sensor value after the offset is removed. Detailed functions of the processor 104 will be described later.

  The audio input / output unit 105 includes, for example, a microphone and a speaker, and accepts input of audio information or outputs audio information.

  The touch sensor unit 106 is disposed so as to overlap the display unit 107, and detects, for example, a contact position by the user by detecting a change in capacitance. When the touch by the user is detected by the touch sensor unit 106, the user can operate the communication terminal device 100 by a touch operation.

  The display unit 107 includes a liquid crystal panel, for example, and displays images, characters, and the like. Specifically, the display unit 107 displays, for example, map information and trajectory information indicating the movement trajectory of the communication terminal device 100 in an overlapping manner.

  The geomagnetic sensor 108 is, for example, a triaxial magnetic sensor, and detects the magnetic strength of each of the three axes in the height, width, and thickness directions of the communication terminal device 100. Therefore, magnetic north can be estimated from the sensor value of the geomagnetic sensor 108.

  The acceleration sensor 109 is, for example, a three-axis acceleration sensor, and detects the magnitude of acceleration for each of the three axes in the height, width, and thickness directions of the communication terminal device 100. Therefore, it is possible to estimate the vertical direction in which gravity acts and the moving direction during movement from the sensor value of the acceleration sensor 109.

  The gyro sensor 110 is, for example, a triaxial angular velocity sensor, and detects the magnitude of the angular velocity for each of the three axes in the height, width, and thickness directions of the communication terminal device 100. Therefore, it is possible to estimate the rotation direction of the communication terminal device 100 and the change in the movement direction during movement from the sensor value of the gyro sensor 110.

  Next, functions of the processor 104 according to the first embodiment will be described with reference to FIG. FIG. 2 is a block diagram illustrating functions of the processor 104 according to the first embodiment. 2 includes a sensor value acquisition unit 201, a magnetic field change detection unit 202, a startup application determination unit 203, an operation request unit 204, an offset calculation unit 205, a general offset holding unit 206, a general offset removal unit 207, and an intensity calculation. A unit 208, an intensity determination unit 209, an azimuth offset holding unit 210, and an azimuth offset removal unit 211.

  The sensor value acquisition unit 201 acquires a geomagnetic sensor value indicating the intensity of magnetism measured by the geomagnetic sensor 108. Specifically, the sensor value acquisition unit 201 acquires a geomagnetic sensor value indicating the magnetic strength for each of the three axes in the height, width, and thickness directions of the communication terminal device 100. Normally, since the strength of geomagnetism does not change at the same position, when the geomagnetic sensor values obtained by changing the attitude of the communication terminal device 100 at a position where the magnetic field environment is constant are plotted on three-dimensional coordinates, the respective geomagnetic sensor values are plotted. The points corresponding to are arranged on one spherical surface. That is, the radius of this spherical surface corresponds to the strength of geomagnetism.

  The magnetic field change detection unit 202 monitors the geomagnetic sensor value acquired by the sensor value acquisition unit 201 and detects a change in the magnetic field environment from the change in the geomagnetic sensor value. Specifically, the magnetic field change detection unit 202 detects a change in the magnetic field environment by determining whether or not the radius of the spherical surface obtained by plotting the geomagnetic sensor values on the three-dimensional coordinates has changed greatly. That is, for example, if the dispersion of the radius of the spherical surface is greater than or equal to a predetermined threshold, the magnetic field change detection unit 202 determines that the magnetic field environment has changed.

  When the change in the magnetic field environment is detected by the magnetic field change detection unit 202, the activation application determination unit 203 confirms what application is currently activated. And the starting application determination part 203 determines whether only the application using the azimuth | direction estimated from the geomagnetic sensor value is starting. That is, an application that uses a geomagnetic sensor value includes an application that uses a geomagnetic sensor value to obtain magnetic strength instead of a direction (hereinafter referred to as a “magnetic application application”), such as a magnetometer application. In addition, there is an application (hereinafter referred to as an “azimuth use application”) that uses a geomagnetic sensor value in order to estimate the direction, such as an application of an electronic compass. Therefore, the activated application determination unit 203 determines whether or not the currently activated application is only the direction use application. Note that the activation application determination unit 203 holds information including, for example, a list of applications that can be executed by the communication terminal device 100 and whether or not the geomagnetic sensor values and directions of each application are used. And the starting application determination part 203 can determine whether the application currently started is only a direction utilization application with reference to the hold | maintained information.

  The operation request unit 204 calculates the offset of the calibration when the change of the magnetic field environment is detected by the magnetic field change detection unit 202 and the activation application determination unit 203 determines that the magnetic application is also activated. The unit 205 is inquired. That is, the operation requesting unit 204 determines whether or not a sufficient number of samples of the geomagnetic sensor values for calculating the offset have been collected to the offset calculating unit 205 after the magnetic field environment has changed. Inquire. Then, when a sufficient number of samples have not been collected, the operation request unit 204 requests the user to perform an operation for calibration. That is, for example, the operation request unit 204 causes the audio input / output unit 105 or the display unit 107 to output a message requesting to perform the operation of drawing the figure 8 while holding the communication terminal device 100. The operation request unit 204 also periodically inquires of the offset calculation unit 205 whether or not calibration is possible after making an operation request for calibration once, until the calibration is possible. Request operation.

  On the other hand, even if a change in the magnetic field environment is detected by the magnetic field change detection unit 202, the operation request unit 204 stops the operation request for calibration when only the direction use application is activated. Therefore, even if the magnetic field environment changes, if only the direction utilization application is activated, a message requesting an operation for calibration is not output from the audio input / output unit 105 or the display unit 107. .

  The offset calculation unit 205 collects the geomagnetic sensor values acquired by the sensor value acquisition unit 201 and calculates an offset corresponding to the influence of the magnetic field inside the communication terminal device 100 from the collected samples of the geomagnetic sensor values. Specifically, the offset calculation unit 205 calculates the center coordinates of the spherical surface obtained by plotting the sample geomagnetic sensor values on the three-dimensional coordinates when the calibration request is made from the operation request unit 204. Then, when the number of collected samples is sufficient and the center coordinates of the spherical surface can be calculated, the offset calculation unit 205 notifies the operation request unit 204 that calibration is possible. Then, the offset calculation unit 205 outputs the calculated three-axis component of the center coordinate to the general offset holding unit 206 as an offset. On the other hand, the offset calculation unit 205 notifies the operation request unit 204 that the calibration is impossible when the number of collected samples is insufficient and the center coordinates of the spherical surface cannot be calculated.

  The general offset holding unit 206 holds the offset output from the offset calculation unit 205 as a general offset applied to the magnetic application. At this time, the general offset holding unit 206 updates the general offset held in advance to the general offset newly output from the offset calculation unit 205. Therefore, the general offset holding unit 206 holds the latest offset calculated by the offset calculation unit 205 as a general offset. In the initial state, the general offset holding unit 206 may hold an initial offset value calculated based on a geomagnetic sensor value acquired in a predetermined magnetic field environment. Further, the general offset holding unit 206 may store and hold the general offset in the memory 103, for example.

  The general offset removal unit 207 removes the general offset held by the general offset holding unit 206 from the geomagnetic sensor value acquired by the sensor value acquisition unit 201, and provides the obtained correction sensor value to the magnetic application. Further, the general offset removal unit 207 outputs the correction sensor value to the intensity calculation unit 208.

  The intensity calculating unit 208 calculates the magnetic intensity using the correction sensor value output from the general offset removing unit 207. That is, the intensity calculation unit 208 calculates, for example, the square root of the sum of squares of the correction sensor values for each of the three axes as the intensity.

  The strength determination unit 209 determines whether or not the strength calculated by the strength calculation unit 208 is included in a range corresponding to the geomagnetic strength. Then, when the calculated strength is included in the range corresponding to the geomagnetic strength, the strength determination unit 209 outputs an offset equal to the general offset held in the general offset holding unit 206 to the azimuth offset holding unit 210. To do. That is, it is considered that the magnetic field environment when the magnetic intensity corrected by the general offset is within the range of the normal geomagnetic intensity is an environment where only the geomagnetism is detected by the geomagnetic sensor 108. Therefore, since the general offset calculated in such a magnetic field environment is also an appropriate offset when estimating the direction from the geomagnetic sensor value, the strength determination unit 209 applies an offset equal to the general offset to the direction use application. Output as an orientation offset.

  The azimuth offset holding unit 210 holds the azimuth offset output from the strength determination unit 209. At this time, the azimuth offset holding unit 210 updates the azimuth offset held in advance with the azimuth offset newly output from the strength determination unit 209. In the initial state, the azimuth offset holding unit 210 may hold an initial offset value calculated based on a geomagnetic sensor value acquired in a predetermined magnetic field environment. Further, the azimuth offset holding unit 210 may store and hold the azimuth offset in the memory 103, for example.

  The azimuth offset removal unit 211 removes the azimuth offset held by the azimuth offset holding unit 210 from the geomagnetic sensor value acquired by the sensor value acquisition unit 201, and provides the obtained corrected sensor value to the azimuth application.

  Next, calibration processing in communication terminal apparatus 100 configured as described above will be described with reference to the flowchart shown in FIG.

  When the communication terminal apparatus 100 is in operation, the geomagnetic sensor value measured by the geomagnetic sensor 108 is periodically acquired by the sensor value acquisition unit 201 (step S101). The acquired geomagnetic sensor value has a three-axis component in the height, width, and thickness direction of the communication terminal device 100. Then, the magnetic field change detection unit 202 monitors the geomagnetic sensor value and determines whether or not the external magnetic field environment has changed (step S102). Specifically, the magnetic field change detection unit 202 plots the geomagnetic sensor values acquired as needed in three-dimensional coordinates, and determines whether or not the radius of the spherical surface defined from the plotted points has changed.

  Here, since the magnetic intensity does not change unless the external magnetic field environment changes, each axis component of the geomagnetic sensor value changes according to the change in the attitude of the communication terminal apparatus 100, but the geomagnetic sensor value on three-dimensional coordinates. The points corresponding to are arranged on one spherical surface. Therefore, when the dispersion of the radius of the spherical surface is large, it is considered that the external magnetic field environment has changed. Therefore, the magnetic field change detection unit 202 determines whether or not the magnetic field environment has changed by determining whether or not the dispersion of the radius of the spherical surface obtained by plotting the geomagnetic sensor values is greater than or equal to a predetermined threshold. Is done.

  As a result of this determination, if it is determined that the radius of the spherical surface does not change and the magnetic field environment does not change (No in step S102), the geomagnetic sensor value acquired by the sensor value acquisition unit 201 continues to be the magnetic field change detection unit 202. Be monitored by. On the other hand, when it is determined that there is a change in the magnetic field environment (Yes in step S102), the activated application determining unit 203 determines whether or not the activated application is only the direction use application (step S103). If the only application that is running is the direction use application (Yes in step S103), it is determined that calibration is not necessary, and the geomagnetic sensor value acquired by the sensor value acquisition unit 201 is the magnetic field change detection unit 202. Be monitored by.

  Thus, even if the magnetic field environment changes, when only the direction use application is activated, the calibration is not necessary for the following reason. That is, first, when the geomagnetic sensor 108 changes from a magnetic field environment that detects only geomagnetism to a magnetic field environment that detects magnetism other than geomagnetism, it is difficult to estimate magnetic north due to magnetism other than geomagnetism. For this reason, even if calibration is executed, it is difficult for the direction utilization application to estimate an accurate direction from the geomagnetic sensor value. Therefore, in order to prevent unnecessary execution of calibration, calibration is not executed when only the direction utilization application is activated.

  Further, when the magnetic field environment changes within a range where the geomagnetic sensor 108 detects only geomagnetism, the offset does not change greatly. That is, the change in the magnetic field environment is relatively small within the range in which the geomagnetic sensor 108 detects only the geomagnetism, and even if a change in the magnetic field environment is detected, the geomagnetic sensor value is corrected by using the same azimuth offset. It is possible.

  Furthermore, when the geomagnetic sensor 108 changes from a magnetic field environment that detects magnetism other than geomagnetism to a magnetic field environment that detects only geomagnetism, it is possible to estimate the direction from the geomagnetic sensor value. However, in this embodiment, the general offset and the azimuth offset are held separately, and the azimuth offset is not updated when the geomagnetic sensor 108 changes to a magnetic field environment that detects magnetism other than geomagnetism. For this reason, even when the geomagnetic sensor 108 changes to a magnetic field environment that detects only geomagnetism, it is not necessary to update the held azimuth offset.

  For these reasons, if the activation application determination unit 203 determines that only the direction use application is activated, it is determined that calibration is unnecessary and is not executed. For this reason, the operation | movement for calibration is not requested | required with respect to a user, and the frequency of the operation | movement request | requirement for calibration can be reduced. In other words, the calibration of the geomagnetic sensor 108 can be executed efficiently.

  On the other hand, when not only the direction utilization application but also the magnetic utilization application is activated (No in step S103), the operation requesting unit 204 makes an inquiry about whether or not calibration is possible to the offset calculating unit 205. In response to this inquiry, the offset calculation unit 205 determines whether a sufficient number of geomagnetic sensor value samples have been collected and calibration is possible (step S104). In other words, the offset calculation unit 205 collects the geomagnetic sensor values acquired by the sensor value acquisition unit 201. However, when receiving an inquiry from the operation request unit 204, the offset calculation unit 205 performs an offset from the sample collected after the magnetic field environment has changed. Try to calculate. As a result, if the sample is insufficient and the offset cannot be calculated (No in step S104), the operation request unit 204 is notified to that effect, and a message requesting an operation for calibration is sent to the audio input / output unit 105 or The data is output from the display unit 107 (step S109). The offset calculated by the offset calculation unit 205 corresponds to the center coordinate of the spherical surface obtained by plotting the sample of the geomagnetic sensor value on the three-dimensional coordinate, and the deviation of the center coordinate from the origin is the communication terminal device 100. This is due to the internal magnetic field environment.

  When a calibration operation request is made, the user changes the attitude of the communication terminal apparatus 100 to draw, for example, a figure 8 in accordance with the operation request. During this time, the geomagnetic sensor value is acquired by the sensor value acquisition unit 201 (step S110), and the offset calculation unit 205 determines whether or not the offset can be calculated again (step S104). As described above, while there are not enough samples of the geomagnetic sensor values to execute the calibration, the calibration operation is requested and the geomagnetic sensor values are collected.

  When sufficient samples are collected and calibration is possible (step S104 Yes), the general offset held by the general offset holding unit 206 is updated with the offset calculated from the sample (step S105). Thereafter, when the geomagnetic sensor value acquired by the sensor value acquisition unit 201 is provided to the magnetic application, a correction sensor value obtained by removing a new general offset from the geomagnetic sensor value by the general offset removal unit 207 is obtained. Will be provided.

  When the general offset held in the general offset holding unit 206 is updated, the corrected sensor value obtained by removing the new general offset by the general offset removing unit 207 is output to the intensity calculating unit 208. Then, the intensity calculation unit 208 calculates the magnetic intensity from the correction sensor value (step S106). That is, the intensity calculation unit 208 calculates, for example, the square root of the square sum of the three-axis components of the correction sensor value. Then, the strength determining unit 209 determines whether or not the calculated strength is included in a geomagnetic strength range of, for example, about 35 to 50 μT (microtesla) (step S107).

  As a result of this determination, if the strength is not included in the range of the geomagnetic strength (No in step S107), the processing ends without updating the bearing offset held in the bearing offset holding unit 210. Therefore, in a situation where magnetism other than geomagnetism exists or the geomagnetism is attenuated, the calculated offset is not held as a bearing offset. For this reason, the appropriate azimuth offset remains held in the azimuth offset holding unit 210. For example, even when the communication terminal apparatus 100 moves to a place where only geomagnetism is detected, the appropriate azimuth offset is immediately removed. It becomes possible to do.

  Also, if the result of determination in step S107 is that the intensity is within the range of geomagnetic intensity (Yes in step S107), the direction offset held in the direction offset holding unit 210 by the strength determination unit 209 is equal to the general offset. (Step S108). That is, when calibration is executed in a situation where only geomagnetism is detected, the general offset and the azimuth offset are updated to new offsets obtained by calibration. Thereafter, when the geomagnetic sensor value acquired by the sensor value acquisition unit 201 is provided to the bearing application, the correction sensor value obtained by removing the new bearing offset from the geomagnetic sensor value by the bearing offset removing unit 211 is obtained. Will be provided. For this reason, the correction sensor value from which the azimuth | direction offset according to the newest magnetic field environment was removed can be provided to an azimuth | direction utilization application.

  As described above, according to the present embodiment, when a change in the magnetic field environment is detected from the geomagnetic sensor value, it is determined whether the active application is only the direction use application, and only the direction use application is determined. If so, the operation for calibration is not required. When calibration is performed, the calculated offset is held as a general offset, while the azimuth offset used when providing the geomagnetic sensor value to the azimuth utilization application is held separately. Then, only when the magnetic intensity is within the range of the geomagnetic intensity, the azimuth offset is updated to a value equal to the general offset. For this reason, an operation request for unnecessary calibration is not made to the user, and in a situation where the azimuth can be accurately estimated, a correction sensor value from which an appropriate azimuth offset is always removed is sent to the azimuth utilization application. Provided. In other words, the calibration of the geomagnetic sensor can be executed efficiently.

  In the first embodiment, the calibration is executed using the geomagnetic sensor value when the operation for calibration is requested. However, automatic calibration is executed separately from the calibration. May be. That is, the general offset and the azimuth offset may be updated using a sample of the geomagnetic sensor value collected when the posture of the communication terminal apparatus 100 is changed due to normal use. Such automatic calibration can be performed in parallel with calibration accompanied by an operation request for calibration.

(Embodiment 2)
A feature of the second embodiment is that it is determined whether or not automatic calibration is performed in accordance with a change in posture of the communication terminal device during normal use. If automatic calibration is possible, an operation request for calibration is required. It is a point to suppress.

  The configuration of communication terminal apparatus 100 according to Embodiment 2 is the same as that of communication terminal apparatus 100 shown in FIG. In the second embodiment, the function of the processor 104 in FIG. 1 is different from that in the first embodiment.

  FIG. 4 is a block diagram illustrating functions of the processor 104 according to the second embodiment. 4, the same parts as those in FIG. 2 are denoted by the same reference numerals, and the description thereof is omitted. The processor 104 illustrated in FIG. 4 has a configuration in which an operation request unit 303 is provided instead of the operation request unit 204 of the processor 104 illustrated in FIG. 2, and an attitude change detection unit 301 and an automatic calibration determination unit 302 are added.

  The posture change detection unit 301 acquires acceleration sensor values and angular velocity sensor values detected by the acceleration sensor 109 and the gyro sensor 110, respectively. Then, the posture change detection unit 301 detects that the posture of the communication terminal device 100 has changed based on the acceleration sensor value and the angular velocity sensor value.

  If the automatic calibrator 302 detects a change in posture of the communication terminal device 100, whether the conditions for executing automatic calibration are satisfied based on the number of posture changes within the predetermined time and the angle of the changed posture are satisfied. Judge whether or not. That is, the automatic calibrating unit 302 executes automatic calibration when it is determined that a relatively large number of posture changes are detected within a predetermined time and the posture of the communication terminal apparatus 100 has changed to various angles. Judge that the condition is met.

  If the automatic calibration determination unit 302 determines that the condition is satisfied, the automatic calibration determination unit 302 inquires of the offset calculation unit 205 whether or not calibration is possible. That is, the automatic calibration determination unit 302 inquires of the offset calculation unit 205 whether or not a sufficient number of samples of the geomagnetic sensor values within the predetermined time and sufficient to calculate the offset have been collected. Then, if a sufficient number of samples have not been collected, the automatic calibration determination unit 302 continues to wait for posture change detection by the posture change detection unit 301.

  On the other hand, when a sufficient number of samples have been collected, the automatic calibration determination unit 302 suppresses the operation request for calibration by the operation request unit 303. In other words, when sufficient samples have been collected and automatic calibration is executed, the automatic calibration determination unit 302 suppresses calibration that requires a calibration operation request, and prevents duplicate calibration from being executed.

  Similar to the operation request unit 204 of the first embodiment, the operation request unit 303 inquires of the offset calculation unit 205 whether or not calibration is possible. The operation requesting unit 303 requests the user to perform an operation for calibration when a sufficient number of samples have not been collected. However, when the request for the calibration operation is suppressed by the automatic calibration determination unit 302, the operation request unit 303 does not request an operation for calibration even if a sufficient number of samples have not been collected. That is, even if the magnetic field environment has changed and the magnetic application is running, the operation requesting unit 303 stops the calibration operation request according to the instruction from the automatic calibrating unit 302.

  In addition, similar to the operation request unit 204 of the first embodiment, the operation request unit 303 may detect that the magnetic field change detection unit 202 detects a change in the magnetic field environment, Does not require an action for calibration.

  Next, automatic calibration processing in the communication terminal apparatus 100 configured as described above will be described with reference to the flowchart shown in FIG.

  During operation of the communication terminal device 100, the acceleration sensor value and the angular velocity sensor value measured by the acceleration sensor 109 and the gyro sensor 110 are periodically acquired by the posture change detection unit 301 (step S201). Then, the posture change detection unit 301 monitors the acceleration sensor value and the angular velocity sensor value, and determines whether or not the posture of the communication terminal apparatus 100 has changed (step S202).

  As a result of this determination, when it is determined that there is no attitude change of the communication terminal device 100 (No in step S202), the attitude change detection unit 301 continues to monitor the acceleration sensor value and the angular velocity sensor value. On the other hand, when it is determined that there is a posture change (step S202 Yes), the automatic calibrator 302 determines whether or not a condition for executing automatic calibration is satisfied (step S203). Specifically, the automatic calibration determination unit 302 determines whether, for example, the number of posture changes within a predetermined time or the angle of the changed posture is sufficient to execute calibration.

  If it is determined that the condition for executing automatic calibration is not satisfied (No in step S203), the acceleration sensor value and the angular velocity sensor value are continuously monitored by the posture change detection unit 301. If it is determined that the conditions for executing automatic calibration are satisfied (Yes in step S203), the automatic calib determining unit 302 inquires of the offset calculating unit 205 whether or not calibration is possible. In response to this inquiry, the offset calculation unit 205 determines whether a sufficient number of geomagnetic sensor value samples have been collected and calibration is possible (step S204). That is, the offset calculation unit 205 collects the geomagnetic sensor values acquired by the sensor value acquisition unit 201, but when receiving an inquiry from the automatic calibrating determination unit 302, the offset calculation unit 205 calculates the offset from the samples collected within a predetermined time. Try to calculate. As a result, if the sample is insufficient and the offset cannot be calculated (No in step S204), this is notified to the automatic calibrator 302. In this case, since the calibration cannot be executed, the acceleration sensor value and the angular velocity sensor value are continuously monitored by the posture change detection unit 301. As described above, the attitude change of the communication terminal apparatus 100 is continuously monitored until the attitude change of the communication terminal apparatus 100 satisfies the condition for executing the automatic calibration and the calibration can be executed.

  When a sufficient sample is collected and calibration is possible when the conditions for executing the automatic calibration are satisfied (Yes in step S204), the automatic calibration determination unit 302 detects the execution of the automatic calibration. In other words, the automatic calib judgment unit 302 senses that the offset calculation unit 205 has calculated the offset. Then, the automatic calibration determination unit 302 outputs an instruction to suppress the operation request for calibration to the operation request unit 303 (step S205).

  In the present embodiment, as in the first embodiment, when a change in the magnetic field environment is detected and it is determined that the magnetic application is also activated, the operation request unit 303 performs calibration for the calibration. An operation request is made. However, at the same time, the automatic calibration determination unit 302 manages the execution of automatic calibration that does not require an operation for calibration. Therefore, when automatic calibration is executed, it is not necessary to request the user to perform an operation for calibration. Therefore, when automatic calibration is executed, an operation request by the operation request unit 303 is suppressed to prevent an unnecessary operation request from being made to the user. As a result, an unnecessary operation request for calibration is not made to the user, and the frequency of operation requests can be reduced.

  After the operation request is suppressed in this manner, the general offset held by the general offset holding unit 206 is updated with the offset calculated by the offset calculating unit 205 when performing the automatic calibration (step S206). Thereafter, when the geomagnetic sensor value acquired by the sensor value acquisition unit 201 is provided to the magnetic application, a correction sensor value obtained by removing a new general offset from the geomagnetic sensor value by the general offset removal unit 207 is obtained. Will be provided.

  When the general offset held in the general offset holding unit 206 is updated, the corrected sensor value obtained by removing the new general offset by the general offset removing unit 207 is output to the intensity calculating unit 208. Then, the intensity calculation unit 208 calculates the magnetic intensity from the correction sensor value (step S207). That is, the intensity calculation unit 208 calculates, for example, the square root of the square sum of the three-axis components of the correction sensor value. Then, the strength determination unit 209 determines whether or not the calculated strength is included in a geomagnetic strength range of, for example, about 35 to 50 μT (microtesla) (step S208).

  As a result of this determination, if the intensity is not included in the range of the geomagnetic intensity (No in step S208), the processing ends without updating the azimuth offset held in the azimuth offset holding unit 210. Therefore, in a situation where magnetism other than geomagnetism exists or the geomagnetism is attenuated, the calculated offset is not held as a bearing offset. For this reason, the appropriate azimuth offset remains held in the azimuth offset holding unit 210. For example, even when the communication terminal apparatus 100 moves to a place where only geomagnetism is detected, the appropriate azimuth offset is immediately removed. It becomes possible to do.

  If the result of determination in step S208 is that the intensity is within the range of geomagnetism intensity (Yes in step S208), the direction offset held in the direction offset holding unit 210 by the strength determination unit 209 is equal to the general offset. (Step S209). That is, when calibration is executed in a situation where only geomagnetism is detected, the general offset and the azimuth offset are updated to new offsets obtained by calibration. Thereafter, when the geomagnetic sensor value acquired by the sensor value acquisition unit 201 is provided to the bearing application, the correction sensor value obtained by removing the new bearing offset from the geomagnetic sensor value by the bearing offset removing unit 211 is obtained. Will be provided. For this reason, the correction sensor value from which the azimuth | direction offset according to the newest magnetic field environment was removed can be provided to an azimuth | direction utilization application.

  As described above, according to the present embodiment, when a change in the magnetic field environment is detected from the geomagnetic sensor value, it is determined whether the active application is only the direction use application, and only the direction use application is determined. If so, the operation for calibration is not required. In addition, when a change in posture of the communication terminal apparatus is detected and the change in posture satisfies the conditions for executing automatic calibration, and automatic calibration is executed, an operation request for calibration is suppressed. Therefore, an unnecessary operation request for calibration is not made to the user, and the frequency of operation requests for calibration can be reduced.

  The operation of communication terminal apparatus 100 described in each of the above embodiments can be described as a program executable by a computer. In this case, this program can be stored in a computer-readable recording medium and introduced into the computer. Examples of the computer-readable recording medium include a portable recording medium such as a CD-ROM, a DVD disk, and a USB memory, and a semiconductor memory such as a flash memory.

DESCRIPTION OF SYMBOLS 101 GPS part 102 Radio | wireless part 103 Memory 104 Processor 105 Audio input / output part 106 Touch sensor part 107 Display part 108 Geomagnetic sensor 109 Acceleration sensor 110 Gyro sensor 201 Sensor value acquisition part 202 Magnetic field change detection part 203 Activation application determination part 204,303 Operation | movement Request unit 205 Offset calculation unit 206 General offset holding unit 207 General offset removal unit 208 Strength calculation unit 209 Strength determination unit 210 Orientation offset holding unit 211 Orientation offset removal unit 301 Attitude change detection unit 302 Automatic calibration determination unit

Claims (5)

An electronic device including a magnetic sensor for measuring magnetism including geomagnetism,
Detecting a change in the magnetic field environment based on the measurement value of the magnetic sensor,
When a change in the magnetic field environment is detected, it is determined whether only an azimuth-use application that uses the measurement value for azimuth estimation among applications that use the measurement value of the magnetic sensor is running.
As a result of the determination, when an application other than the direction use application is activated, a predetermined operation is requested to the user, while when only the direction utilization application is activated, the predetermined operation is not requested. ,
A processor that executes a process of calculating an offset corresponding to an influence of a magnetic field inside the electronic device on a measured value of the magnetic sensor using a measured value of the magnetic sensor obtained after requesting the predetermined operation; An electronic device characterized by that. The processor is
Hold the calculated offset as a general offset for applications other than the bearing application,
Removing the retained general offset from the measured value of the magnetic sensor;
Calculate the magnetic strength based on the measured value after removing the general offset,
Determine whether the calculated intensity is within the range corresponding to the geomagnetic intensity,
As a result of the determination, when the calculated intensity is included in a range corresponding to the intensity of geomagnetism, a process of holding an offset equal to the general offset as an azimuth offset for the azimuth using application is further executed. The electronic device according to claim 1. The processor is
Detecting a change in posture of the electronic device;
Determining whether the measurement value of the magnetic sensor obtained within the period in which the posture change is detected satisfies a condition for calculating the offset;
The electronic device according to claim 1, further comprising a process of suppressing the request for the predetermined operation when it is determined that the condition is satisfied. The processor is
The process for calculating an offset using a measurement value of the magnetic sensor obtained within a period in which a change in posture is detected when it is determined that the condition is satisfied is further executed. Electronic equipment. In a computer equipped with a magnetic sensor that measures magnetism, including geomagnetism,
Detecting a change in the magnetic field environment based on the measurement value of the magnetic sensor,
When a change in the magnetic field environment is detected, it is determined whether only an azimuth-use application that uses the measurement value for azimuth estimation among applications that use the measurement value of the magnetic sensor is running.
As a result of the determination, when an application other than the direction use application is activated, a predetermined operation is requested to the user, while when only the direction utilization application is activated, the predetermined operation is not requested. ,
Using the measured value of the magnetic sensor obtained after requesting the predetermined operation, and executing a process of calculating an offset corresponding to the influence of the magnetic field inside the computer on the measured value of the magnetic sensor, Calibration program to do.

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