JP2011069633A - Portable device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a portable device which can detect fluctuations in the attitude angle of the portable device having various kinds of sensors during its use with high precision and accurately correct the output from the sensors. <P>SOLUTION: The portable device includes: an acceleration sensor 131 for detecting the triaxial acceleration of the portable device; a rotation axis detector 182 for detecting the rotation axis of the portable device on the basis of the triaxial acceleration components; a rotation angle calculator 183 for calculating the rotation angle of the portable device about the detected rotation axis; and an axis exchange means 133 for exchanging the logical values of the triaxial acceleration components in accordance with the magnitude of the calculated rotation angle. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a portable device that can be carried around, and more particularly to a portable device that is used as pedestrian navigation by being carried or used as car navigation by being installed in a vehicle or the like.

  In recent years, a simple navigation device called PND (Portable Navigation Device) that is portable by simplifying functions and reducing the size and weight of the main body of the navigation device has become widespread.

  In addition to detecting the current position of the PND by receiving the GPS signal, the PND provides a more accurate current position than the GPS by incorporating an acceleration sensor and a gyro sensor as an auxiliary means when the GPS signal cannot be acquired. It is possible to detect.

  Further, since the PND can be easily attached to and detached from the dashboard inside the vehicle, the attachment work is performed by the user himself. However, if an acceleration sensor, a gyro sensor, or the like used in the self-contained navigation system is not attached in a correct posture so as to face a predetermined direction, the current position cannot be accurately detected due to an error caused by each attachment angle.

  Therefore, as a conventional technique for detecting the attitude angle of a mobile terminal device using this type of sensor, for example, it is disclosed in the following Patent Document 1 (Japanese Patent Laid-Open No. 2002-164987). In this Patent Document 1, the mounting angle of a posture angle detecting device including a posture angle sensor (gyro sensor, acceleration sensor, geomagnetic sensor, etc.) having only one axis or two axes is 45 ° ± 20 with respect to the angle detection reference plane. By mounting at a degree, it is possible to relax the limitation on the tilt when using the mobile terminal device.

JP 2002-164987 (paragraph [0018] to paragraph [0019], FIG. 2)

  By the way, even if the PND is correctly attached to the vehicle once, the mounting angle varies during use due to an input operation to the PND or the vibration of the vehicle, or the posture angle varies when carrying the PND while being used. In order to accurately detect the current position and moving distance, it is necessary to accurately detect the change in the attitude angle of the PND and correct the output error of the sensor due to the change in the attitude angle.

  Therefore, it is conceivable to detect the attitude angle by using the attitude angle detection device as shown in Patent Document 1, but the detection device is attached to a terminal device such as a mobile phone so as to be suitable when using the mobile phone. Since there is a restriction that it must be mounted at a predetermined angle, there is a problem that it is difficult to apply to a device that can be installed in a vehicle such as a PND in which it is unclear how the posture angle changes during use. Moreover, in the said patent document 1, the point which detects the fluctuation | variation of this attitude angle correctly was not considered.

  Accordingly, an object of the present invention is to eliminate the above-described problems, and to accurately detect a change in posture angle when using a portable device having various sensors, and to accurately correct the output from the sensor. The object is to provide a portable device that can be used.

In order to solve the above-mentioned problem, the invention according to claim 1 of the present application is
A mobile device that corrects the attitude angle of the mobile device based on acceleration applied to the mobile device,
Acceleration detecting means for detecting acceleration in the three-axis direction of the portable device (for example, acceleration sensor 131 in the following embodiment);
Based on the acceleration components in the three-axis directions detected by the acceleration detection means, a rotation axis detection means (for example, a rotation axis detection unit 182 in the following embodiment) that detects a rotation axis that the portable device has rotated;
A rotation angle calculation means for calculating the rotation angle of the portable device around the rotation axis detected by the rotation axis detection means (for example, in the following embodiment, a rotation angle calculation unit 183);
Axis exchanging means (for example, axis exchanging means 133 in the following embodiment) for exchanging logical values of acceleration components in the three-axis directions according to the magnitude of the rotation angle calculated by the rotation angle calculating means;
It is provided with.

The invention according to claim 2 of the present application is the portable device according to claim 1,
An angular velocity detection means (for example, gyro sensor 132 in the following embodiment) for detecting an angular velocity around three axes of the portable device;
The axis exchanging means exchanges logical values of angular velocities around the three axes in accordance with the magnitude of the rotation angle.

Further, the invention according to claim 3 of the present application is the portable device according to claim 1 or 2,
The rotation angle calculation means calculates the magnitude of the rotation angle to be calculated from acceleration components related to a predetermined axis among the acceleration components in the three-axis directions detected by the acceleration detection means.

The invention according to claim 4 of the present application is the portable device according to claim 3,
An attitude angle correction unit (for example, an attitude angle correction unit 184 in the following embodiment) that corrects the attitude angle based on the rotation angle calculated by the rotation angle calculation unit is provided.

  With the above configuration, the present invention has the following excellent effects. That is, in the invention according to claim 1, the portable device detects the rotation axis of the rotation of the portable device based on the acceleration components in the triaxial directions detected by the acceleration detection means, and the detected rotation axis is detected. The rotation angle of the portable device is calculated, and the logical values of the acceleration components in the three-axis directions are exchanged according to the calculated rotation angle.

  According to such a configuration, it is possible to provide a portable device that can easily grasp the output value related to the acceleration component in the three-axis directions detected by the acceleration detecting means regardless of the rotation angle of the portable device.

  Further, in the invention according to claim 2, in the portable device according to claim 1, the output from the angular velocity detecting means for detecting the angular velocity around the three axes of the portable device also depends on the magnitude of the rotation angle. The logical values of the angular velocities around the three axes are exchanged. According to such a configuration, it is possible to provide a portable device that can easily grasp the output values related to the angular velocity components around the three axes detected by the angular velocity detecting means regardless of the rotation angle of the portable device.

  In the invention according to claim 3, in the portable device according to claim 1 or 2, the magnitude of the rotation angle to be calculated is predetermined among the acceleration components in the three-axis directions detected by the acceleration detecting means. It is calculated from the acceleration component related to the axis. According to such a configuration, the rotation angle around the rotation axis around which the portable device is rotated is detected with the most accurate rotation angle change rate among the acceleration components in the three-axis directions detected by the acceleration detection means. Therefore, the rotation angle can be calculated using an acceleration component related to a predetermined axis, and a portable device capable of accurately correcting the posture angle of the portable device can be provided.

  In the invention according to claim 4, in the portable device according to claim 3, the attitude angle of the portable device is corrected based on the calculated rotation angle. According to such a configuration, the change rate of the rotation angle is most accurately determined from the acceleration components in the three-axis directions detected by the acceleration detecting unit according to the magnitude of the rotation angle around the rotation axis around which the portable device is rotated. Thus, it is possible to calculate the rotation angle using the acceleration component related to the predetermined axis that can be detected, and it is possible to provide a portable device that can accurately correct the attitude angle of the portable device.

It is a block diagram which shows the structure of the navigation apparatus in the Example of this invention. It is a figure for demonstrating the output of the sensor when the navigation apparatus in the Example of this invention rotates around the Y-axis, and is an example which shows the state in which the navigation apparatus was installed with the correct attitude | position. It is a figure for demonstrating the output of the sensor when the navigation apparatus in the Example of this invention rotates around the Y-axis, and has shown the state which the navigation apparatus in FIG. 2 rotated only (theta) around the Y-axis. FIG. 4 is a diagram for explaining the output of the sensor when the navigation device in the embodiment of the present invention rotates around the Y axis, and shows the state where the navigation device in FIG. 2 rotates by θ = 90 ° around the Y axis. Yes. It is the figure which each displayed the X-axis component and Z-axis component of the acceleration sensor with respect to angle (theta) in the case of detecting the rotation around the Y-axis in the Example of this invention.

  Hereinafter, specific examples of the present invention will be described in detail with reference to examples and drawings. However, the embodiment described below exemplifies a navigation device that can be mounted on a vehicle body as a portable device for embodying the technical idea of the present invention, and is intended to specify the present invention as this navigation device. However, the present invention is equally applicable to portable devices of other embodiments included in the technical idea shown in the claims.

  First, with reference to FIG. 1, the structure of the navigation apparatus based on the Example of this invention is demonstrated. FIG. 1 is a block diagram showing a configuration of a navigation device according to an embodiment of the present invention. The navigation device 10 includes a control unit 100, a communication unit 110, a GPS positioning unit 120, a self-contained navigation positioning unit 130, a route search unit 140, a route guidance unit 150, a display unit 160, an input unit 170, an attitude angle correction unit 180, and a storage unit. 190 is comprised.

  The control unit 100 includes a processor including a CPU 100a, a RAM 100b, and a ROM 100c. The CPU 100a executes a program stored in the RAM 100b or the ROM 100c to control and control the operation of each unit of the navigation device 10.

  The communication unit 110 transmits / receives various information such as map data to / from an information providing server (not shown) that can communicate with the navigation device 10 under the control of the control unit 100.

  The GPS positioning means 120 receives radio waves including time information from a plurality of GPS satellites orbiting the earth, and calculates current position information of the vehicle body on which the navigation device 10 is mounted based on the received radio waves. .

  The self-contained navigation positioning unit 130 includes an acceleration sensor 131 and a gyro sensor 132. The acceleration sensor 131 detects the acceleration of the navigation device 10 in predetermined three-axis directions, and the gyro sensor 132 detects angular velocities around the X axis, the Y axis, and the Z axis of the navigation device 10. The acceleration sensor 131 and the gyro sensor 132 output the detected acceleration and angular velocity to the control means 100, respectively.

  When the acceleration sensor 131 is installed in the correct posture with respect to the vehicle body, as shown in FIG. 2A, the acceleration sensor 131 accelerates the acceleration X in the vehicle body traveling direction (X-axis direction in this embodiment). And the acceleration Y in a direction orthogonal to the traveling direction of the vehicle body in the horizontal plane (in this embodiment, the Y-axis direction), the traveling direction of the vehicle body (X-axis direction), and the direction orthogonal to the traveling direction in the horizontal plane An acceleration Z in a direction orthogonal to the (Y-axis direction) (in this embodiment, the Z-axis direction) is detected.

  When the gyro sensor 132 is installed in the correct posture with respect to the vehicle body, as shown in FIG. 2B, the angular velocity X (Roll angle θr) when the vehicle body rotates around the X axis is detected by the gyro sensor 132r. Then, the angular velocity Y (Pitch angle θp) when the vehicle body rotates around the Y axis is detected by the gyro sensor 132p, and the angular velocity Z (Yaw angle θy) when the vehicle body rotates around the Z axis is detected by the gyro sensor 132y. Detected.

  In addition, the self-contained navigation positioning means 130 outputs logic on each axis of the acceleration sensor 131 according to the rotation angle when the navigation device 10 installed in a correct posture with respect to the vehicle body rotates around a predetermined axis. A shaft exchanging means 133 for exchanging the value or the logical value of the output around each axis of the gyro sensor 132 is provided. The shaft exchanging method by the shaft exchanging means 133 will be described in detail later.

  When the departure point and the destination point are designated by the operation of the input unit 170, the route search unit 140 refers to the road data stored in the map storage unit 192 of the storage unit 190 and reaches the destination point from the departure point. The optimum route is searched and guide route data is created. The guidance route searched by the route searching means 140 is displayed on the display means 160 together with the map image around the current position by the control means 100 and used for guidance to the destination point.

  The route guidance means 150 compares the guidance route data searched by the route search means 140 with the current position detected by the GPS positioning means 120, and outputs the guidance required at the current position from a speaker or the like not shown. To do.

  The display unit 160 is a display unit having a display screen composed of a display panel such as an LCD, and displays a map image, a guide route, a current position, and the like.

  The input unit 170 includes operation buttons, a touch panel, and the like, and operates various functions of the navigation device 10 and inputs necessary numerical values and characters.

  The posture angle correction unit 180 includes a posture angle calculation unit 181, a rotation axis detection unit 182, a rotation angle calculation unit 183, and a posture angle correction unit 184.

  The posture angle calculation unit 181 calculates a posture angle (attachment angle) of the navigation device 10 with respect to the vehicle body or a posture angle when the navigation device 10 is carried and used based on outputs from the acceleration sensor 131 and the gyro sensor 132. And stored in the posture angle storage unit 191.

  Based on the gravitational acceleration component detected by the acceleration sensor 131, the rotation axis detection unit 182 is configured so that the navigation device 10 installed on the vehicle body has three axes (X axis, Y axis) orthogonal to each other from the predetermined position of the navigation device 10. , The Z axis), the rotation angle of the posture angle (attachment angle) is detected.

  The rotation angle calculation unit 183 calculates the rotation angle of the navigation device 10 around the rotation axis detected by the rotation axis detection unit 182 based on the triaxial acceleration components output from the acceleration sensor 131. At this time, the navigation apparatus uses the acceleration component in the axial direction that has the largest change rate of the rotation angle among the acceleration components in the three axis directions output from the acceleration sensor 131 and can be accurately detected even at a slight rotation angle. A rotation angle of 10 is calculated.

  That is, as shown in FIG. 2, the three orthogonal axes of the navigation device 10 are the X axis, the Y axis, and the Z axis (where the X axis is the same axis as the traveling direction of the vehicle body, the Y axis is the horizontal axis of the vehicle body, Assuming that the Z axis is the vertical axis of the vehicle body and the acceleration sensor 131 is arranged coaxially with the three axes orthogonal to each other of the navigation device 10, the rotation angle calculation unit 183 rotates, for example, around the Y axis. Calculate the axis.

  2-4 is a figure for demonstrating the output of a sensor when a navigation apparatus rotates around the Y-axis. 2A to 4A show the case of the acceleration sensor, and FIGS. 2B to 4B show the case of the gyro sensor.

For example, when the navigation device 10 in a stationary state rotates around the Y axis from the correct posture shown in FIG. 2A as shown in FIG. 3A, if the rotation angle is θ, the acceleration sensor 131 The output of the X-axis component (acceleration X) and the Z-axis component (acceleration Z) is X = sin θ
Z = cos θ
It is expressed as However, the gravitational acceleration applied to the navigation device 10 is 1.

  FIG. 5 is a diagram displaying the X-axis component and the Z-axis component of the acceleration sensor with respect to the angle θ when rotation about the Y-axis is detected.

When the rotation angle is as small as 0 ° ≦ θ ≦ 45 ° (the inclination is small), cos θ is close to 1, and conversely sin θ changes greatly. Therefore, from the value of X = sin θ, which is the X-axis component of the acceleration sensor 131, the rotation angle θ is
θ = sin ⁻¹ X
Thus, θ can be accurately obtained according to the variation of the X-axis component. Therefore, the posture angle can be corrected with high accuracy.

Further, as shown in FIG. 4A, when the navigation apparatus 10 further rotates around the Y axis from the posture shown in FIG. 3A, sin θ is 1 when the rotation angle is 45 ° ≦ θ ≦ 90 °. On the contrary, cos θ changes greatly. Therefore, from the value of Z = cos θ, which is the Z-axis component of the acceleration sensor 131, the rotation angle θ is
θ = cos ^-1 Z
Thus, the posture angle can be corrected with high accuracy.

  Further, when the navigation device 10 rotates about the Y axis, sin θ is close to 1 and cos θ changes greatly when the rotation angle is 90 ° ≦ θ ≦ 135 °, and similarly, it is the Z axis component of the acceleration sensor 131. By obtaining θ from the value of Z = cos θ, the posture angle can be corrected with high accuracy.

Similarly, as shown in FIG.
When the rotation angle is 135 ° ≦ θ ≦ 225 °, θ = sin ⁻¹ X
When the rotation angle is 225 ° ≦ θ ≦ 315 °, θ = cos ⁻¹ Z
When the rotation angle is 315 ° ≦ θ ≦ 360 °, θ = sin ⁻¹ X
Can be obtained as follows.

  The posture angle correction unit 184 is based on the rotation angle calculated by the rotation angle calculation unit 183, or the posture angle (attachment angle) calculated by the posture angle calculation unit 181, or already calculated and stored in the posture angle storage unit 191. The stored posture angle (attachment angle) is corrected. The corrected posture angle is stored in the posture angle storage unit 191 again.

  The storage unit 190 includes an attitude angle storage unit 191 and a map storage unit 192. The posture angle storage unit 191 is configured by a non-volatile memory such as FRAM (registered trademark), and stores the posture angle (attachment angle) of the navigation device 10 with respect to the vehicle body calculated by the posture angle calculation unit 181. Further, the posture angle (attachment angle) corrected by the posture angle correction unit 184 is stored. The stored posture angle is used when calculating the travel distance and the current position of the vehicle body.

  The map storage unit 192 stores road node data including road node data and road link data in which nodes such as intersections and branch points of each road are nodes and links between the nodes are links. The road node data includes road node numbers, position coordinates, the number of connection links, intersection names, and the like. The road link data includes the number of road nodes as starting and ending points, road type, link length (link cost), required time, number of lanes, road width, and the like. Further, data such as bridges, tunnels, railroad crossings, and toll gates are added to the road link data as link attributes. The road type is information including a distinction between an expressway and a toll road and a distinction such as a national road or a prefectural road.

  In addition to road data, the map storage unit 192 may include background image data stored in a vector format so that a map image can be easily displayed. When the navigation device 10 is used by the control means 100, the map image data including the road data and the background image data is extracted from the map storage unit 192 and a predetermined range including the current position of the navigation device 10 is shown. The current position mark and the guide route image are superimposed and displayed on the display means 160.

  Next, with reference to FIG. 2 and FIG. 4, the axis | shaft exchange means 133 of the navigation apparatus 10 in the Example of this invention is demonstrated.

  As shown in FIG. 2A, when the navigation device 10 is installed in a correct posture with respect to the vehicle body, the output of the X-axis component (acceleration X) of the acceleration sensor 131 is the vehicle body to which the navigation device 10 is attached. When the vehicle body is accelerating, a positive value is output, and when the vehicle body is decelerating, a negative value is output.

  The output of the Y-axis component (acceleration Y) of the acceleration sensor 131 detects the acceleration when the vehicle turns right or left, and outputs a positive value when the vehicle turns left, and the vehicle turns right. When it is, a negative value is output. Further, the output of the Z-axis component (acceleration Z) of the acceleration sensor 131 detects gravitational acceleration and outputs a positive value.

  On the other hand, as shown in FIG. 4A, when the rotation angle θ around the Y axis is 90 °, the output of the X-axis component (acceleration X) of the acceleration sensor 131 detects the gravitational acceleration and is negative. A value is output, and the output of the Y-axis component (acceleration Y) of the acceleration sensor 131 is the same as when θ = 0 ° shown in FIG. 2A when the vehicle body to which the navigation device 10 is attached is turned right or left. The acceleration is detected, and a positive value is output when the vehicle is turning left, and a negative value is output when the vehicle is turning right.

  The output of the Z-axis component (acceleration Z) of the acceleration sensor 131 detects the acceleration of the vehicle body, outputs a positive value when the vehicle body is accelerating, and outputs a negative value when the vehicle body is decelerating. Is output.

  As described above, the X-axis component (acceleration X) and the Z-axis component (acceleration Z) of the three axes (physical axes) of the acceleration sensor 131 at the rotation angles θ = 0 ° and θ = 90 ° around the Y-axis. Since the output values are interchanged, it can be considered that the logical axes of the X axis and the Z axis are interchanged. Therefore, the axis exchanging means 133 determines a logical value (gravity, acceleration) suitable for the output value output from the acceleration sensor 131 according to the magnitude of the rotation angle θ around the Y axis calculated by the rotation angle calculation unit 183. Etc.).

  As shown in FIG. 2B, when the navigation device 10 is installed in a correct posture with respect to the vehicle body, the output of the X-axis component (gyro X) of the gyro sensor 132r is attached to the navigation device 10. The vehicle roll is detected and a positive value is output when the vehicle body is rotating clockwise, and a negative value is output when the vehicle body is rotating counterclockwise.

  The output of the Y-axis component (gyro Y) of the gyro sensor 132p detects the slope (pitch) of the road surface on which the vehicle body is traveling, and outputs a positive value when the vehicle body is traveling on a downward slope. However, a negative value is output when the vehicle body is traveling uphill. Further, the output of the Z-axis component (gyro Z) of the gyro sensor 132y detects the yaw angle when the vehicle body is turning right or left, and outputs a positive value when the vehicle body is turning right. When it is, a negative value is output.

  On the other hand, as shown in FIG. 4B, when the rotation angle θ around the Y axis is 90 °, the output of the X axis component (gyro X) of the gyro sensor 132r detects the yaw angle of the vehicle body, When the vehicle is turning right, a positive value is output. When the vehicle is turning left, a negative value is output. The output of the Y-axis component (gyro Y) of the gyro sensor 132p is shown in FIG. As in the case of θ = 0 °, the inclination (pitch) of the road surface on which the vehicle body is traveling is detected.

  The output of the Z-axis component (gyro Z) of the gyro sensor 132y detects the roll of the vehicle body, and outputs a positive value when the vehicle body rotates counterclockwise, and minus when the vehicle body rotates clockwise. The value of is output.

  Thus, of the outputs around the three axes (physical axes) of the gyro sensor 132 at the rotation angles θ = 0 ° and θ = 90 ° around the Y axis, the X axis component (gyro X) and the Z axis component (gyro) Since the output value of Z) is interchanged, it can be considered that the logical axes of the X axis (roll axis) and the Z axis (yaw axis) are interchanged. Therefore, the axis exchanging means 133 is a logical value suitable for the output value output from the gyro sensor 132 according to the magnitude of the rotation angle θ around the Y axis calculated by the rotation angle calculation unit 183 (left and right rotation, Assign left and right folds.

  Similarly, at the rotation angles θ = 180 ° and θ = 270 ° around the Y axis, the X axis component (acceleration X) and the Z axis out of the three axes (physical axes) of the acceleration sensor 131 according to the rotation angle. The output value of the component (acceleration Z) is interchanged, and the output values of the X-axis component (gyro X) and the Z-axis component (gyro Z) among the outputs around the three axes (physical axes) of the gyro sensor 132 are interchanged. It will be.

  Further, not only the rotation around the Y axis but also the rotation around the Z axis or the X axis. In the rotation around the Z axis, the logical axes of the X axis (roll axis) and the Y axis (pitch axis) are the same. In rotation around the X axis, the logical axes of the Y axis (pitch axis) and the Z axis (yaw axis) can be regarded as exchanged.

  Therefore, the relationship between the physical axis and the logical axis with respect to the rotation angle around each axis can be arranged as shown in the table below.

よって、軸交換手段１３３は、加速度センサ１３１やジャイロセンサ１３２から出力される出力値に対して回転角算出部１８３によって算出された各軸周りの回転角度θの大きさに応じて適した論理値（重力、加速度等）を割り当てることが可能となる。

Therefore, the axis exchanging means 133 is a logical value suitable for the output value output from the acceleration sensor 131 or the gyro sensor 132 according to the magnitude of the rotation angle θ around each axis calculated by the rotation angle calculation unit 183. (Gravity, acceleration, etc.) can be assigned.

  As described above, according to the navigation device of the present invention, the logic of the acceleration component in the triaxial direction in the acceleration sensor according to the magnitude of the rotation angle around the rotation axis that the navigation device has rotated from the predetermined mounting position. Since the values or the logical values of the angular velocity components around the three axes in the gyro sensor are exchanged, the output values from the acceleration sensor and the gyro sensor can be easily grasped.

  Further, when calculating the rotation angle around each axis used for exchanging the logical value of the sensor output value around each axis, the change in the rotation angle is the most among the acceleration components in the three-axis directions detected by the acceleration sensor. It is possible to calculate the rotation angle using an acceleration component related to a predetermined axis capable of accurately detecting the rate, and it is possible to accurately correct the attitude angle of the navigation device.

  In the above embodiment, the navigation device 10 is used as a portable device. However, the present invention is not limited to this, and various electronic devices that calculate the moving distance of the moving body from the acceleration of the moving body are used. Is also applicable.

10. Navigation device 100 ... Control means 110 ... Communication means 120 ... GPS positioning means 130 ... Self-contained navigation positioning means 131 ... Acceleration sensor 132 ... Gyro sensor 133 ... Axis exchange means 140... Route search means 150... Route guidance means 160... Display means 170... Input means 180... Attitude angle correction means 181. Axis detection unit 183 ... rotation angle calculation unit 184 ... posture angle correction unit 190 ... storage means 191 ... posture angle storage unit 192 ... map storage unit

Claims (4)

A mobile device that corrects the attitude angle of the mobile device based on acceleration applied to the mobile device,
Acceleration detecting means for detecting acceleration in the three-axis direction of the portable device;
Rotation axis detection means for detecting a rotation axis that the portable device has rotated based on acceleration components in three axis directions detected by the acceleration detection means;
Rotation angle calculation means for calculating a rotation angle of the portable device around the rotation axis detected by the rotation axis detection means;
Axis exchanging means for exchanging logical values of acceleration components in the three-axis directions according to the magnitude of the rotation angle calculated by the rotation angle calculating means,
A portable device comprising: An angular velocity detecting means for detecting an angular velocity around three axes of the portable device;
The portable device according to claim 1, wherein the axis exchange unit exchanges logical values of angular velocities around the three axes according to the magnitude of the rotation angle.   The rotation angle calculation unit calculates the magnitude of the rotation angle to be calculated from an acceleration component related to a predetermined axis among the acceleration components in the three-axis directions detected by the acceleration detection unit. The mobile device according to claim 2.   The portable device according to claim 3, further comprising an attitude angle correction unit that corrects the attitude angle based on the rotation angle calculated by the rotation angle calculation unit.

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