JP4839975B2 - Azimuth and tilt angle detection device, azimuth and tilt angle detection method, program, and portable terminal device - Google Patents

Description

  The present invention relates to a technique for detecting an azimuth and an inclination angle of a center line of a target device in a ground coordinate system by detecting a geomagnetic component and a gravity component, and particularly to a technique for improving detection accuracy.

  2. Description of the Related Art In recent years, mobile terminals such as mobile phones have been improved in functionality, and those equipped with a magnetic sensor for detecting geomagnetism and an acceleration sensor for detecting the inclination of the apparatus main body have been developed to measure the direction. This type of apparatus has an advantage that it is possible to perform processing for improving the direction detection accuracy by adding correction based on the inclination of the apparatus main body.

Conventional techniques of this type include techniques described in Patent Documents 1 and 2, for example. Both of these technologies use both a geomagnetic sensor and an acceleration sensor, and improve detection accuracy by cooperative operation of both sensors.
JP-A-10-185608 JP 2003-172633 A

  When this type of detection device is mounted on a portable terminal such as a cellular phone, the acceleration sensor picks up the acceleration component generated by the movement of the portable terminal, causing an error in the inclination of the detected portable terminal, and the orientation There is a problem in that an error occurs in the correction amount of this and the detection accuracy deteriorates. Such a problem cannot be solved even with the techniques described in Patent Documents 1 and 2.

  In view of such circumstances, the present invention detects the azimuth component in the ground coordinate system of the center line of the target device by detecting the geomagnetic component and the gravitational component. It is an object of the present invention to provide a technique in which detection accuracy is improved by improving the detection accuracy.

In order to solve the above problems, the invention described in claim 1 includes an azimuth sensor that detects a geomagnetic component in a coordinate system fixed to the apparatus and an acceleration sensor that detects a gravity component in the coordinate system fixed to the apparatus . a azimuth and tilt angle detection device for generating a detection value of the azimuth and tilt angle of the device against the ground coordinate system, and reference information by calculating the inclination oblique angle using the geomagnetism component and the gravity component It is defined by the geomagnetic depression angle from the relationship between the first computing means, the geomagnetic depression angle obtaining means for obtaining the geomagnetic depression angle that is an angle formed by the horizontal plane and the geomagnetic direction, and the geomagnetic component in the coordinate system fixed to the device and the ground coordinate system. is the calculated the azimuth and the calculation result of the inclination angle by solving the simultaneous equations of the azimuth and tilt angle, and a second arithmetic means to the detected value of the operation result when the operation result plurality Street Providing azimuth and tilt angle detection device, characterized in that Ru and a selection means to the detected value by selecting the operation result with the inclination angle closer to the tilt angle which is the reference information.

According to a second aspect of the present invention, in the azimuth and inclination angle detection device according to the first aspect, the first calculation means calculates a twist angle of the device, and the twist angle is within a predetermined range. An azimuth and tilt angle detection device is provided in which the reference information is the detection value.

According to a third aspect of the present invention, in the azimuth and inclination angle detection device according to the first aspect, the geomagnetic dip angle acquisition means corresponds to the geomagnetic dip angle by performing coordinate conversion of the geomagnetic component using the gravity component. Bearing and inclination angle detection means, comprising: a geomagnetic dip angle calculating means for calculating a value to be calculated; and an averaging means for accumulating a value corresponding to the geomagnetic dip angle and taking an average value to set the geomagnetic dip angle. Providing equipment.

According to a fourth aspect of the present invention, in the azimuth and tilt angle detection device according to the first aspect, the geomagnetic dip angle acquisition means includes position information acquisition means for acquiring at least the latitude as the current position information among the current latitude and longitude. There is provided an azimuth and tilt angle detecting device comprising a geomagnetic dip angle generating means for generating a geomagnetic dip angle from the current position information.

According to claim 5, wherein also invention detects a geomagnetic components in the coordinate system of the device fixed, also detects the gravity component in the coordinate system of the apparatus fixation, the device against the ground coordinate system of azimuth and inclination angle a azimuth and inclination angle detection method in an apparatus for generating a detection value, the first calculation means of the device, and the geomagnetic components and reference information by calculating the inclination oblique angle with the gravity component, The geomagnetic depression angle acquisition means of the device acquires a geomagnetic depression angle that is an angle formed by a horizontal plane and a geomagnetic direction, and the second calculation means of the device calculates the geomagnetic component in the coordinate system fixed to the device and the ground coordinate system. The calculation result of the azimuth and the inclination angle is obtained by solving the simultaneous equations of the azimuth and the inclination angle defined by the geomagnetic dip from the relationship, the calculation result is set as the detection value, and the selection unit of the device includes The operation result is duplicated When the streets, providing azimuth and inclination angle detection method comprising said reference the detected value information is a Select operation result with the inclination angle closer to the angle of inclination and to Turkey.

According to a sixth aspect of the present invention, there is provided an apparatus for detecting a geomagnetic component in a coordinate system fixed to the apparatus and an acceleration sensor for detecting a gravitational component in the coordinate system fixed to the apparatus. the computer of azimuth and tilt angle detection device for generating a detection value of the azimuth and tilt angle, the steps of the reference information by calculating the inclination oblique angle using the geomagnetism component and the gravity component, and the horizontal plane and the geomagnetic direction Obtaining the geomagnetic dip angle which is an angle formed by the system, and solving the simultaneous equations of the azimuth and tilt angle defined by the geomagnetic dip angle from the relationship between the geomagnetic component in the coordinate system fixed to the device and the ground coordinate system. obtains the operation result of the azimuth and tilt angle, the steps of the calculation result and the detected value, when the operation result plurality of ways, closer to the tilt angle which is the reference information A step of said detected value by selecting the operation result with the inclination angle Urn, the providing Help program is executed.

Invention or請 Motomeko 7 described, an azimuth sensor for detecting the terrestrial magnetism components in the coordinate system of the device fixed, likewise in pairs locations coordinate system including an acceleration sensor for detecting the gravity component in the coordinate system of the device fixing a portable terminal apparatus having a means for generating a detection value of the azimuth and inclination angle of the apparatus, the geomagnetic components and first calculating means for the reference information by calculating the inclination oblique angle with the gravity component And a geomagnetic dip angle acquisition means for acquiring a geomagnetic dip angle which is an angle formed by a horizontal plane and a geomagnetic direction, and the orientation defined by the geomagnetic dip angle from the relationship between the geomagnetic component in the coordinate system fixed to the device and the ground coordinate system, and obtains an operation result of the inclination angle and the azimuth by solving the simultaneous equations of the inclination angle, a second calculating means for the calculation result and the detected value, when the operation result plurality of ways, in the reference information is there To provide a mobile terminal device for the selection means to the detected value by selecting the operation result with the inclination angle closer to the serial inclination angle, characterized in that Ru comprising a.

  According to the present invention, since the azimuth and the inclination angle are calculated by solving the simultaneous equations of the azimuth and the inclination angle defined by the geomagnetic component, a detection value that is not affected by the error of the gravity component can be obtained, and the detection is performed. There is an advantage that accuracy is improved. Moreover, by calculating the azimuth component from the geomagnetic component and the gravity component as reference information, and selecting one of a plurality of solutions using this reference information, the above simultaneous equations may have a plurality of solutions. A problem is solved. Because of such advantages, the present invention is extremely effective when applied to a portable azimuth and tilt angle detection device, particularly an azimuth and tilt angle detection device built in a portable terminal such as a mobile phone.

  In addition, the geomagnetic depression angle acquisition means calculates a value corresponding to the geomagnetic depression angle by, for example, converting the geomagnetic component using the gravity component, accumulates this value, and averages the error component of the acceleration sensor. If it is removed and used as a geomagnetic depression, there is an advantage that a highly reliable calculation using the measured value of the geomagnetic depression at the local point is possible.

  Further, for example, if the geomagnetic depression angle acquisition unit acquires at least the latitude as the current position information from the current latitude and longitude, and generates the geomagnetic depression angle from the current position information, it is completely affected by the error of the gravity component. There is an advantage that the geomagnetic dip angle can be acquired as a non-existent value and the detection accuracy can be improved.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing an outline of a mobile phone according to an embodiment of the present invention.

  As shown in the figure, the mobile phone 1 is a foldable mobile terminal including two housings of terminal units 1-1 and 1-2. The antenna 201 is an antenna for transmitting and receiving radio signals with a radio base station (not shown). An RF (Radio Frequency) unit 202 converts a received signal received by the antenna 201 into a received signal having an intermediate frequency and outputs the received signal to the modem unit 203. Further, the RF unit 202 modulates a transmission signal input from the modulation / demodulation unit 203 into a signal having a transmission frequency, and outputs the signal to the antenna 201 for transmission.

  The modem unit 203 performs a demodulation process on the received signal input from the RF unit 202 and a modulation process on the transmission signal input from the CDMA (Code Division Multiple Access) unit 204. The CDMA unit 204 performs transmission signal encoding processing and reception signal decoding processing. The audio processing unit 205 converts the audio signal input from the microphone 301 into a digital signal and outputs the digital signal to the CDMA unit 204. Also, the audio processing unit 205 inputs the digital audio signal from the CDMA unit 204 and converts it into an analog audio signal. The sound is output to the speaker 302 and sounded.

  The antenna 401 is an antenna for receiving a radio signal from a GPS (Global Positioning System) satellite. The GPS receiving unit 402 demodulates a radio signal received from a GPS satellite, and calculates a position represented by the latitude / longitude of the mobile terminal 1 (more altitude in the case of the three-dimensional mode) based on the radio signal. is there.

  The acceleration sensor unit 510 detects the acceleration of the terminal unit 1-1, and is integrated into one package to form a single chip. Here, FIG. 2 is a front view when the terminal units 1-1 and 1-2 of the mobile phone 1 are opened, and the Y-axis indicates the terminal unit 1-1 of the terminal unit 1-1 to the terminal. It is an axis parallel to the side surface in the direction toward the unit 1-2. On the other hand, the X axis is an axis on the surface of the terminal unit 1-1 and is an axis orthogonal to the Y axis. The Z axis is set in a direction perpendicular to the plane including the X axis and the Y axis and from the back side to the front side in FIG. Returning to FIG. 1 and continuing the description, the acceleration detected by the acceleration sensor unit 510 is used, for example, to detect the movement and tilt of the terminal unit 1-1.

  The magnetic sensor unit 520 includes magnetic sensors 521-1 to 521-3, a temperature sensor 522, and a magnetic sensor control unit 523. The magnetic sensor unit 520 is incorporated into one package and formed into one chip. The magnetic sensors 521-1 to 521-3 detect magnetism (magnetic field) in the axial directions of the X, Y, and Z axes orthogonal to each other and output the magnetic field data. Here, it is assumed that the X, Y, and Z axes are adjusted to be the same as the acceleration sensor. The temperature sensor 522 detects the ambient temperature in order to perform temperature compensation of the magnetic sensors 521-1 to 521-3. The magnetic sensor control unit 523 performs predetermined data processing on the detection outputs of the magnetic sensors 521-1 to 521-3, the temperature sensor 522, and the acceleration sensor unit 510 and outputs the result.

  The main control unit 601 manages the main control of the mobile terminal 1, and is configured using a CPU (Central Processing Unit). A ROM (Read Only Memory) 602 and a RAM (Random Access Memory) 603 are memories constituting a main memory of the CPU. The ROM 602 holds programs executed by the CPU and various data. The RAM 603 provides a work area and the like for use in data storage or the like while the CPU is operating.

  The notification unit 303 includes a speaker, a vibrator, a light emitting diode, and the like, and notifies the user of an incoming call or mail reception by sound, vibration, light, or the like. The clock unit 304 is a time measuring function unit used by the main control unit 601. The main operation unit 305 takes in the user's instruction input and gives it to the main control unit 601.

  The electronic imaging unit 306 converts the subject image into a digital signal and outputs the digital signal to the main control unit 601. The display unit 307 is a liquid crystal display (LCD) that displays images, characters, and the like based on display signals input from the main control unit. The touch panel 308 is incorporated in the surface of the liquid crystal display of the display unit 307, and outputs a signal representing the input content by the user's contact operation to the main control unit 601. The sub operation unit 309 is a push switch used for display switching.

  In the above configuration, the main control unit 601 activates the upper program read from the ROM 602 by the CPU and selects and executes various application programs from the upper program. When data is required, a measurement trigger is activated as the application program is executed. In response to this measurement trigger, the main control unit 601 activates the azimuth and tilt angle detection process to acquire the azimuth angle α and elevation angle β, which are azimuth components in the ground coordinate system.

  FIG. 3 is a block diagram showing an outline of functions realized in the azimuth and tilt angle detection processing. As shown in the figure, the measurement trigger means 701 generates a measurement instruction. The measurement data capturing unit 702 captures the measurement data g and h from the acceleration sensor unit 510 and the magnetic sensor unit 520. The first azimuth and tilt angle calculation means 703 executes a first calculation described later, and calculates an azimuth angle α, an elevation angle β, a torsion angle γ, and a geomagnetic depression angle θ from the measurement data g and h. The azimuth angle α and elevation angle β will be described in detail later. Note that the azimuth angle α and elevation angle β obtained in the first calculation are treated as reference values α0 and β0, and the geomagnetic depression angle θ is treated as a rough value θ0 including an error. The averaging means 704 accumulates the geomagnetic depression angle θ0, takes the average value of the accumulated geomagnetic depression angle θ0, and removes the error to obtain the geomagnetic depression angle θ.

  The second azimuth and inclination angle calculation means 705 executes a second calculation described later, and calculates the azimuth angle α and the elevation angle β from the measurement data h and the geomagnetic dip angle θ. If a plurality of solutions exist as the values of the azimuth angle α and the elevation angle β, the respective solutions are output as candidate values (α1, β1) (α2, β2). The selection means 706 uses (α0, β0) obtained by the first azimuth and tilt angle calculation means 703 as a reference value, and selects one of the candidate values (α1, β1) (α2, β2). Are output as detected values (α, β).

  FIG. 4 is a diagram showing data used in the first and second calculations and its coordinate system. In the figure, x, y and z axes are orthogonal coordinate axes (see FIG. 2) set on the mobile phone. The x0, y0, and z0 axes are orthogonal coordinate axes in which the x0 and y0 axes are located on the horizontal plane and the y0 axis faces the magnetic north direction N. The z0 axis is an axis extending vertically upward with respect to the horizontal plane. Hereinafter, the coordinate system represented by the x0, y0, and z0 axes is referred to as a ground coordinate system. A vector V is a vector indicating the direction of the center line of the mobile phone, and is parallel to the y-axis. The vector V0 is obtained by projecting the vector V onto the x0y0 plane (horizontal plane) from above the z0 axis, and is a vector on the x0y0 plane. The azimuth angle α corresponds to an angle formed by the y0 axis and the vector V0. The elevation angle β corresponds to an angle formed by the vector V0 and the vector V. The direction of the vector V is determined by the azimuth angle α and the elevation angle β. The torsion angle γ is an angle of torsion about the y axis in the x and y planes, and corresponds to the intersection angle between the yz0 plane and the yz plane. The vector H is a vector indicating the direction of geomagnetism, and faces the magnetic pole N0. The geomagnetic depression angle θ is an angle formed by the horizontal plane and the direction of geomagnetism, and corresponds to an angle formed by the y0 axis (magnetic north direction N) and the vector H (magnetic north N0).

  FIG. 5 is a flowchart showing an outline of the azimuth and tilt angle detection processing. 1 and 5, the main control unit 601 takes in the detected gravity g from the acceleration sensor unit 510 and takes in the detected geomagnetism h from the magnetic sensor unit 520 (S101). Here, the detected gravity g is acquired as a gravity component (gx, gy, gz) in the coordinate (x, y, z-axis coordinate) system on the mobile phone 1 described above as shown in Equation (1). Here, gx, gy, and gz correspond to detection outputs of the acceleration sensors 510-1 to 510-3.

  The main control unit 601 first executes a first calculation using the detected gravity g and the detected geomagnetism h (S102). In this first calculation, first the first angle calculation is executed to calculate the elevation angle β and the twist angle γ from the detected gravity g, and then the second angle calculation is executed to detect the detected geomagnetism h, the elevation angle β, and the twist. The azimuth angle α is calculated from the angle γ.

  Here, in describing the first angle calculation, the relationship between the detected gravity g and the gravity G in the ground coordinate system will be described. Gravity G in the ground coordinate system can be grasped as (Gx0, Gy0, Gz0), and Gx0 = 0 and Gy0 = 0. Gx0, Gy0, and Gz0 are gravity components on the above-described x0, y0, and z0 axes.

  At this time, the relationship between them is as shown in Equation 3.

  However, B is a conversion formula for rotationally converting only the elevation angle β, and is a determinant represented by Equation 4.

  C is a conversion formula for rotational conversion by the torsion angle γ, and is a determinant represented by Formula 5.

  From Equations 4 and 5, the composite transformation equation BC that rotationally transforms by the elevation angle β and the torsion angle γ is a determinant expressed by Equation 6,

  Substituting Equation 6 and Equation 2 into Equation 3 for rearrangement results in Equation 7.

  By rearranging Equation 7, as shown in Equation 8, the relational expression between the elevation angle β and the gravity components gx, gy, gz is determined, and

  As shown in Equation 9, a relational expression between the twist angle γ and the gravity components gx, gy, gz is determined.

  In the first angle calculation, the elevation angle β and the torsion angle γ are calculated from the gravity components gx, gy, gz using the relational expressions of equations 8 and 9.

  Next, the second angle calculation will be described. Here, the detected geomagnetism h is acquired as a geomagnetic component hx, hy, hz in a coordinate (x, y, z-axis coordinate) system on the mobile phone 1 as shown in Equation 10. Hx, hy, hz correspond to detection outputs of the magnetic sensors 521-1 to 521-3.

  The geomagnetism H in the ground coordinate (x0, y0, z0 axis coordinate) system can be regarded as (Hx0, Hy0, Hz0), and since Hx0 = 0, it is as shown in Equation 11. Hx0, Hy0, and Hz0 are geomagnetic components on the x0, y0, and z0 axes.

  At this time, the relationship between the two is as shown in Equation 12.

  However, A is a conversion formula for rotational conversion by the azimuth angle α, and is a determinant expressed by Equation 13.

  When Expression 12 is transformed, Expression 14 is obtained. This equation is an identity of (hx1, hy1, hz1). Here, hx1, hy1, and hz1 are geomagnetic components at coordinates based on coordinate axes x1, y1, and z1 (not shown) obtained by rotationally converting the x0, y0, and z0 axes around the z0 axis by an azimuth angle α.

  When formula 14 is rearranged, formula 15 is obtained.

  From Equation 15, a relational expression between the azimuth angle α and the geomagnetic components hx1 and hy1 is obtained as shown in Equation 16.

  Similarly, the relational expression between the geomagnetic depression angle θ and the geomagnetic components hx1, hy1, hz1 is as shown in Expression 17.

  In the second angle calculation, the azimuth angle α is calculated from the geomagnetic components hx, hy, hz using the relational expressions of Expressions 14 and 16.

  In this way, the main control unit 601 determines the azimuth angle α and the elevation angle β by executing the first and second angle calculations. However, since the azimuth angle α and the elevation angle β obtained here are values calculated based on the detected gravity g and are values with low accuracy affected by errors due to the movement of the mobile phone 1, the main control is performed. The unit 601 registers the obtained azimuth angle α and elevation angle β as reference values (α0, β0), and ends step S102. Here, if the calculated twist angle γ is within a range of −10 degrees to +10 degrees, (α0, β0) may be set as a final detection value, and steps S102 and after may be omitted.

  Next, the main control unit 601 executes a second calculation (S103). In this second calculation, an azimuth angle α and an elevation angle β are calculated from the detected geomagnetism h captured in step 101 and the separately acquired geomagnetic dip angle θ.

  Here, in describing the second calculation, when the horizontal and vertical components of the geomagnetism H are expressed using the geomagnetic intensity Hg and the geomagnetic depression angle θ, the following formula 18 is obtained.

  Here, the relationship between the geomagnetism H and the detected geomagnetism h is as shown in Equation 19.

  However, AB is a composite conversion equation for conversion between the x, y, z-axis coordinate system and the x0, y0, z0-axis coordinate system, and is a determinant expressed by equations 4-13.

  From Equations 18 and 19, the equation shown in Equation 21 is derived.

  That is, when the geomagnetic depression angle θ and the geomagnetic components hx, hy, hz are given, simultaneous equations of the azimuth angle α and the elevation angle β can be obtained from Equations 20 and 21.

  In the second calculation, the main control unit 601 obtains simultaneous equations of the azimuth angle α and the elevation angle β from the geomagnetic depression angle θ and the geomagnetic components hx, hy, hz, and solves the simultaneous equations to obtain the azimuth angle α. The elevation angle β is calculated. However, the solution of the simultaneous equations is not necessarily one, and a plurality of solutions may be obtained.

  Therefore, when a plurality of solutions are obtained, the main control unit 601 registers the plurality of solutions as candidate values (α1, β1) (α2, β2), and ends step S103. If there is one solution obtained as a result of the second calculation (S104: No), the solution is registered as the detected values α and β, and the process ends. If there are a plurality of obtained solutions (S104: Yes), the main control unit 601 executes a comparison / selection process (S105).

  In this comparison and selection process, the reference values (α0, β0) and the candidate values (α1, β1) (α2, β2) are compared, and a candidate value having an elevation angle closer to the reference value elevation angle β0 is selected. And registered as detected values (α, β). The detection values α and β obtained in this way are values obtained based on the geomagnetic dip angle θ and the geomagnetic components hx, hy, hz, and thus do not include the influence of errors due to the movement of the mobile phone 1. A highly accurate value can be obtained.

Next, the acquisition process of the geomagnetic depression angle θ will be described.
FIG. 6 is a flowchart showing an example of the acquisition process of the geomagnetic depression angle θ. 1 and 6, the main control unit 601 starts up the acquisition process of the geomagnetic depression angle θ with an arbitrarily set trigger. In this process, the main control unit 601 first captures the detected gravity g from the acceleration sensor unit 510 and also captures the detected geomagnetism h from the magnetic sensor unit 520 (S201), similarly to the above-described azimuth and tilt angle detection process. Then, the geomagnetic depression angle θ is obtained from the gravity components gx, gy, gz and the geomagnetic components hx, hy, hz using the relational expressions of Expressions 8 and 9 and Expressions 14 and 17 (S202). The main control unit 601 registers and accumulates the obtained geomagnetic depression angle θ as a rough value θ0 including an error of the acceleration sensor unit 510 (S203).

  Thereafter, the main control unit 601 selects an average value calculation process with a trigger such as accumulation of a predetermined amount of accumulated data (S204). In this average value calculation process, the average value of the accumulated geomagnetic dip angle θ0 is taken, and the error of the acceleration sensor unit 510 caused by the movement of the mobile phone 1 is averaged out (S205). At this time, for example, only the value θ0 within a certain deviation range from the current average value θ can be discriminated, and only the discriminated value θ0 can be used as target data for the average value calculation. According to this embodiment, there is an advantage that a more accurate geomagnetic depression angle θ can be obtained by eliminating θ0 where the error of the acceleration sensor unit 510 is significant.

Here, an example of a method for accumulating the geomagnetic depression angle θ will be shown. When accumulating θ0 in step S203, the main control unit 601 obtains date / time data indicating the current date / time from the clock unit 304, and writes the date / time data in the table together with θ0. FIG. 7 is a diagram showing an example of a geomagnetic depression table in which the geomagnetic depression angle θ0 and date / time data are accumulated. When the predetermined number n of data is accumulated in the geomagnetic dip table, the main control unit 601 acquires date / time data indicating the current date / time from the clock unit 304 again.

  Subsequently, the main control unit 601 compares the date and time data indicating the current date and time of income with the date and time data stored together with θ0 in the geomagnetic depression table, and data that is more than a predetermined time away from the current date and time is accumulated in the geomagnetic depression table. Judge whether or not. If data that is more than a predetermined time away from the current date and time is not accumulated, the main control unit 601 proceeds to the process of step S204 and performs an average value calculation process of θ0.

  On the other hand, if data that is longer than the predetermined time from the current date and time is accumulated, the main control unit 601 deletes θ0 corresponding to the data from the geomagnetic depression table, and returns to step S201 again to continue taking in data. . Even when the processing proceeds to step S204, the main control unit 601 does not clear the data of the geomagnetic depression table. As a result, it is possible to effectively use the geomagnetic dip data acquired in the past, and it is possible to use only the data within a predetermined time from the current date and time by performing the determination process using the date and time data described above. Thus, the detection accuracy of the geomagnetic depression can be improved.

  As another form regarding the accumulation method of the geomagnetic depression angle θ, the main control unit 601 may acquire the current position information (latitude / longitude) from the GPS reception unit 402 and accumulate it in the geomagnetic depression table together with θ0. In this case, the current position information is compared with the position information stored in the geomagnetic depression table in the same manner as described in the determination process using the date / time data, and data that is more than a predetermined distance away from the current position is obtained. It may be deleted or not used. FIG. 8 shows an example of a geomagnetic dip table when position information is accumulated together with date / time data.

Next, another example of the processing for obtaining the geomagnetic depression angle θ will be described with reference to FIG.
The main control unit 601 executes the acquisition process of the geomagnetic depression angle θ, for example, at the start of step S103 (see FIG. 5) in the azimuth and tilt angle detection process. In this acquisition process, the main control unit 601 first acquires the current position information φ, λ from the GPS receiving unit 402. Where φ is latitude and λ is longitude. Then, using Equation 22, the geomagnetic depression angle θ is calculated from the position information φ, λ.

  Note that this equation is an equation for 2000, Δφ is Δφ = φ−37 ° N, and Δλ is Δλ = λ−138 ° E.

  This equation 22 is an expression obtained by approximating the distribution of the geomagnetic dip with a quadratic expression of latitude and longitude. Since the coefficients of each term in Equation 22 change with the movement of the magnetic pole, they are updated periodically (for example, the data of each coefficient is downloaded from the server to the portable terminal) every year or the like. Should be maintained. Further, depending on the accuracy required for obtaining the geomagnetic depression angle θ, it is also possible to use a form up to the second term of Equation 22, that is, an expression that linearly approximates the geomagnetic depression angle θ by the latitude φ.

Further, based on Equation 22, a conversion table for converting the position information φ, λ to the geomagnetic depression angle θ is created in advance and stored in the ROM 602, and the position information φ, λ is input to the conversion table to determine the geomagnetic depression angle θ. It can also take the form of acquisition. According to this example, detection because gravity g can acquire the geomagnetic dip θ without using the from the acceleration sensor unit 510, there is an advantage that high computing accuracy without the error of the acceleration sensor 510 becomes possible. Further, there is an advantage that the geomagnetic dip angle θ can be obtained only by simple calculation.

  The embodiment of the present invention has been described in detail above, but the specific configuration is not limited to this embodiment, and includes design changes and the like within a scope not departing from the gist of the present invention. For example, when the present invention is applied to a device having a communication function, such as a mobile phone, a function for notifying the position information φ, λ or the geomagnetic depression angle θ to a relay station or server or the like as a communication destination is installed. In response to the request, the requested information may be transmitted from the relay station side to the mobile phone. This form is particularly suitable in that the terminal can obtain a highly accurate geomagnetic dip angle θ in a narrow area wireless communication system such as PHS (registered trademark: Personal Handyphone System).

  Although the main control unit 601 has been described as a control unit using a CPU, specifically, a BBP (Base Band Processor) or a DSP (Digital Signal Processor) that performs modulation / demodulation processing of a call signal mainly using the BBP. It is possible to take a form that is constructed by combining as sub.

  The program incorporated in the BBP or DSP can be recorded and distributed on a computer-readable recording medium, and may be distributed in a form that realizes a part of the functions. For example, it may be distributed in the form of application software using basic functions provided by an OS (operation system). Further, it is possible to adopt a form in which a predetermined function can be realized in combination with a program of an existing system already recorded in a computer system, that is, a so-called differential program.

  The computer-readable recording medium includes a storage device such as a hard disk and other nonvolatile storage devices in addition to a storage medium such as a portable magnetic disk and a magneto-optical disk. Furthermore, the form provided from another computer system via arbitrary transmission media, such as the internet and other networks, may be sufficient. In this case, the “computer-readable recording medium” includes a medium that holds a program for a certain period of time in a transmission medium such as a volatile memory inside a computer system serving as a host or client on a network.

  In addition, although a configuration in which the control unit is constructed by a coprocessor method using BBP or DSP is mentioned, at least a part of the processor may be constructed by a hardware circuit such as an FPGA (Field Programmable Gate Array). The distribution of circuit program information to be incorporated into the FPGA can take various forms in the same manner as the distribution of the program.

It is a block diagram which shows the outline of the mobile telephone which concerns on one Embodiment of this invention. It is a front view when the terminal unit of a terminal portable telephone is made into the open state. It is a block diagram which shows the outline of the function implement | achieved in the detection process of this azimuth | direction and an inclination angle. It is a diagram which shows the data used by the 1st and 2nd calculation, and its coordinate system. It is a flowchart which shows the outline of the detection process of an azimuth | direction and an inclination angle. It is a flowchart which shows an example of the acquisition process of geomagnetic depression angle (theta). It is a figure which shows an example of the geomagnetic depression angle table in which the geomagnetic depression angle θ0 is accumulated. It is a figure which shows another example of the geomagnetic depression angle table in which geomagnetic depression angle (theta) 0 is accumulate | stored.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Cellular phone 1-1, 1-2 ... Terminal unit 201 ... Antenna 202 ... RF part 203 ... Modulator / demodulator 204 ... CDMA part 205 ... Voice processing part 301 ... Microphone 302 ... Speaker 303 ... Notification means 304 ... Clock part 305 ... Main operation unit 306 ... Electronic imaging unit 307 ... Display unit 308 ... Touch panel 309 ... Sub operation unit 401 ... Antenna 402 ... GPS reception unit 510 ... Acceleration sensor unit 520 ... Magnetic sensor unit 521-1 to 521-3 ... Magnetic sensor 522 ... Temperature sensor 523 ... Magnetic sensor control unit 601 ... Main control unit 602 ... ROM 603 ... RAM 701 ... Measurement trigger means 702 ... Measurement data fetching means 703 ... First calculation means 704 ... Averaging means 705 ... Second calculation means 706 ... selection means

Claims (7)

An azimuth sensor for detecting the terrestrial magnetism components in the coordinate system of the device fixed, also the detection values of the azimuth and tilt angle of the device against the ground coordinate system including an acceleration sensor for detecting the gravity component in the coordinate system of the device fixing A azimuth and tilt angle detection device to generate,
First calculating means for said geomagnetic components and reference information by calculating the inclination oblique angle with the gravity component,
A geomagnetic depression obtaining means for obtaining a geomagnetic depression that is an angle formed by a horizontal plane and a geomagnetic direction;
The calculation result of the azimuth and the tilt angle is obtained by solving the simultaneous equations of the azimuth and the tilt angle defined by the geomagnetic dip from the relationship between the geomagnetic component in the coordinate system fixed to the device and the ground coordinate system, and the calculation result A second computing means having the detected value as the detection value;
If the operation result plurality of ways, and selection means to the detected value by selecting the operation result with the inclination angle closer to the tilt angle which is the reference information,
Azimuth and tilt angle detection apparatus characterized by Ru with a. 2. The azimuth and azimuth according to claim 1, wherein the first calculation means also calculates a twist angle of the device, and if the twist angle is within a predetermined range, the reference information is used as the detected value. Inclination angle detector. The geomagnetic dip angle acquisition means includes:
A geomagnetic dip calculation means for calculating a value corresponding to the geomagnetic dip by performing coordinate conversion of the geomagnetic component using the gravitational component;
An averaging means for accumulating a value corresponding to the geomagnetic depression and taking an average value to set the geomagnetic depression;
The azimuth and tilt angle detection device according to claim 1, wherein The geomagnetic dip angle acquisition means includes:
Position information acquisition means for acquiring at least latitude as current position information among current latitude and longitude;
A geomagnetic dip generating means for generating a geomagnetic dip from the current position information;
The azimuth and tilt angle detection device according to claim 1, wherein Detects the geomagnetism components in device fixed coordinate system, also detects the gravity component in the coordinate system of the device fixed orientation in apparatus for generating a detection value of the azimuth and tilt angle of the device against the ground coordinate system and An inclination angle detection method comprising:
First arithmetic means of the apparatus, the geomagnetic components and calculates the inclination oblique angle with the gravity component and reference information,
The geomagnetic depression obtaining means of the device obtains a geomagnetic depression that is an angle formed by a horizontal plane and a geomagnetic direction ,
The second calculation means of the apparatus solves the azimuth and inclination by solving simultaneous equations of the azimuth and inclination defined by the geomagnetic dip from the relationship between geomagnetic components in the coordinate system fixed to the apparatus and the ground coordinate system. Obtain the calculation result of the corner, the calculation result as the detection value ,
Selecting means of the device, when the operation result plurality of ways, you and the detection value by selecting the operation result with the inclination angle closer to the tilt angle which is the reference information
Azimuth and inclination angle detection method comprising the this. Generates azimuth sensor and azimuth angle detection values in ground coordinate system with azimuth sensor to detect geomagnetic component in device fixed coordinate system and acceleration sensor to detect gravitational component in device fixed coordinate system To the computer of the azimuth and tilt angle detection device
The method comprising the reference information by calculating the inclination oblique angle using the geomagnetism component and the gravity component,
Obtaining a geomagnetic dip angle which is an angle formed by a horizontal plane and a geomagnetic direction;
The calculation result of the azimuth and the tilt angle is obtained by solving the simultaneous equations of the azimuth and the tilt angle defined by the geomagnetic dip from the relationship between the geomagnetic component in the coordinate system fixed to the device and the ground coordinate system, and the calculation result Setting the detected value to
If the operation result plurality of ways, the steps of said detection value by selecting the operation result with the inclination angle closer to the tilt angle which is the reference information,
The Help program to run. An azimuth sensor for detecting the terrestrial magnetism components in the coordinate system of the device fixed, also the detection values of the azimuth and tilt angle of the device against the ground coordinate system including an acceleration sensor for detecting the gravity component in the coordinate system of the device fixing A portable terminal device having means for generating,
First calculating means for said geomagnetic components and reference information by calculating the inclination oblique angle with the gravity component,
A geomagnetic depression obtaining means for obtaining a geomagnetic depression that is an angle formed by a horizontal plane and a geomagnetic direction;
The calculation result of the azimuth and the tilt angle is obtained by solving the simultaneous equations of the azimuth and the tilt angle defined by the geomagnetic dip from the relationship between the geomagnetic component in the coordinate system fixed to the device and the ground coordinate system, and the calculation result A second computing means having the detected value as the detection value;
If the operation result plurality of ways, and selection means to the detected value by selecting the operation result with the inclination angle closer to the tilt angle which is the reference information,
Portable terminal device characterized by Ru with a.

Images