JP2010112854A - Navigation device for pedestrian, and moving direction detection method in the navigation device for pedestrian - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect accurately the direction of movement of a navigation device for a pedestrian held by the pedestrian, while suppressing power consumption. <P>SOLUTION: A coordinate conversion part 103 converts an acceleration vector into a coordinate based on the navigation device 100 for the pedestrian, and a BPF (Band Pass Filter) 105 allows transmission of a walking frequency component of the pedestrian in frequency components of the acceleration vector after coordinate conversion. A moving direction (based on the navigation device for the pedestrian) detection part 106 and a direction-of-movement (based on the navigation device for the pedestrian) detection part 107 detect the moving direction and the direction of movement of the navigation device 100 for the pedestrian on coordinates based on the navigation device 100 for the pedestrian, and a direction-of-movement (based on the earth) calculation part 109 calculates the direction of movement of the navigation device 100 for the pedestrian on coordinates based on the earth. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a pedestrian navigation device and a moving direction detection method in a pedestrian navigation device.

  In recent years, mobile communication terminal devices equipped with SPS receivers such as in-vehicle navigation devices equipped with satellite positioning system (SPS) receivers such as GPS (Global Positioning System) and mobile phone devices with SPS reception functions have been developed. It has been put into practical use.

  In-vehicle navigation devices use autonomous navigation technology so that positioning can be performed even in GPS insensitive zones. In autonomous navigation, the current position is generally calculated by adding the sequentially detected movement vector to the immediately preceding position information. For calculating the direction and magnitude of the movement vector, a vehicle speed pulse output in accordance with the rotation of the gyroscope and the axle is often used.

  Since the vehicle-mounted navigation device is fixed to the vehicle, the relationship between the installation direction of the vehicle-mounted navigation device with respect to the vehicle and the vehicle movement direction is fixed. In other words, the relationship between the coordinate axis based on the navigation device and the coordinate axis based on the vehicle is fixed. Therefore, in the in-vehicle navigation device, the movement vector (direction of movement and magnitude of movement speed) can be calculated using the gyroscope and the vehicle speed pulse output according to the rotation of the axle.

  On the other hand, since the method of holding the pedestrian navigation device carried by the pedestrian is not always constant, the relationship between the direction of the pedestrian navigation device relative to the pedestrian and the direction of movement of the pedestrian is not fixed. . That is, the relationship between the coordinate axis based on the pedestrian navigation device and the coordinate axis based on the pedestrian is not fixed and varies. Therefore, when applying autonomous navigation to a pedestrian navigation device, it is necessary to determine the relationship between the direction of the pedestrian navigation device relative to the pedestrian and the direction of movement of the pedestrian.

In the case of applying autonomous navigation to a pedestrian navigation device, there are the following conventional methods for obtaining the relationship between the direction of movement of the pedestrian navigation device and the direction of movement of the pedestrian. That is, the acceleration vector is detected, and the timing at which the vertical component of the acceleration vector (hereinafter referred to as “vertical acceleration”) shows the maximum value and the minimum value is detected. Then, the timing at which the horizontal component of the acceleration vector (hereinafter referred to as “horizontal acceleration”) exhibits a maximum value during the period in which the vertical acceleration shifts from the maximum value to the minimum value is obtained. Then, an acceleration vector at a timing when the horizontal acceleration shows a maximum value is obtained, and the direction of the acceleration vector is set as the direction of movement of the pedestrian navigation device (see Patent Document 1). Thus, by obtaining the direction of movement of the pedestrian navigation device, autonomous navigation in the pedestrian navigation device is enabled.
JP 2003-302419 A

  However, in the above conventional method, the direction of movement of the pedestrian navigation device held by the pedestrian is not always obtained with good accuracy. In the above-described conventional method, the direction of movement of the pedestrian navigation device is determined using only the acceleration vector at the timing at which the horizontal acceleration shows the maximum value during the period in which the vertical acceleration changes from the maximum value to the minimum value. . That is, in the above conventional method, since the direction of movement of the pedestrian navigation apparatus is determined by an extremely small amount of information, there is a problem that the detection accuracy of the direction of movement of the pedestrian navigation apparatus is poor.

  In addition, when walking, humans move while swinging left and right, so if the sampling rate for detecting the acceleration vector is low, there is an error between the timing at which the horizontal acceleration actually reaches the maximum value and the detected timing. May occur, and an error in the left-right direction may occur in the detected direction of movement of the pedestrian navigation device. On the other hand, if the sampling rate of the acceleration sensor is increased in order to avoid the occurrence of this error, there is a problem that the power consumption of the pedestrian navigation device increases.

  The present invention has been made in view of the above points, and a pedestrian navigation apparatus and a pedestrian capable of accurately detecting the direction of movement of the pedestrian navigation apparatus held by the pedestrian while suppressing power consumption. An object of the present invention is to provide a moving direction detection method in a navigation apparatus for a vehicle.

  The pedestrian navigation device of the present invention includes an acceleration sensor that detects an acceleration vector generated by a person walking, an absolute direction detection unit that detects an orientation of the pedestrian navigation device with respect to the earth, and the acceleration vector A first movement direction detection unit that detects a direction in which the aspect ratio of the amplitude of the horizontal plane component is maximum as a movement direction based on the navigation device for pedestrians, a direction detected by the absolute direction detection unit, and A second movement direction detection unit that detects the movement direction of the pedestrian navigation device based on the movement direction detected by the first movement direction detection unit is employed.

  The moving direction detection method of the present invention is a moving direction calculation method in a pedestrian navigation apparatus, which detects an acceleration vector generated by a person walking and detects the direction of the pedestrian navigation apparatus with respect to the earth. The direction in which the aspect ratio of the amplitude of the component in the horizontal plane of the acceleration vector is maximized is detected as the movement direction with reference to the navigation device for pedestrians, and the direction of the navigation device for pedestrians with reference to the earth And the movement direction of the said pedestrian navigation apparatus was detected based on the movement direction on the basis of the said pedestrian navigation apparatus.

  ADVANTAGE OF THE INVENTION According to this invention, the direction of a movement of the navigation apparatus for pedestrians which a pedestrian hold | maintains can be detected accurately, suppressing power consumption. Therefore, according to the present invention, for example, the accuracy of position detection by autonomous navigation can be improved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  In FIG. 1, the principal part structure of the navigation apparatus 100 for pedestrians concerning one embodiment of this invention is shown. 1 is mounted on, for example, a mobile communication terminal device (hereinafter referred to as “terminal”) held by a pedestrian.

  The acceleration sensor 101 detects an acceleration vector (synthetic acceleration vector) in which the acceleration vector generated by the movement of the pedestrian and the gravitational acceleration vector of the pedestrian navigation apparatus 100 are combined, and the detected combined acceleration vector is used as the posture detection unit. 102, the coordinate conversion unit 103, the walking frequency detection unit 104, and the movement speed calculation unit 110.

  The posture detection unit 102 detects the inclination of the pedestrian navigation device 100 with respect to gravity, that is, the posture of the pedestrian navigation device 100 by detecting the direction of the gravitational acceleration vector. At this time, since the combined acceleration vector is a combination of the acceleration due to movement and the gravitational acceleration, the posture detection unit 102 performs processing such as averaging the sampling data of the combined acceleration vector, It is possible to extract only the gravitational acceleration vector by removing the influence of acceleration due to movement during walking from the combined acceleration vector.

  The coordinate conversion unit 103 regards the direction of the gravitational acceleration vector as the vertical direction, and converts the resultant acceleration vector into coordinates with the z axis as the vertical direction and the xy plane as the horizontal plane. Specifically, for example, a rotation matrix is obtained such that the gravitational acceleration vector is in the z-axis direction, and the resultant acceleration matrix is multiplied by the resultant acceleration vector to coordinate-convert the resultant acceleration vector. However, the coordinate transformation may not necessarily be such that the gravitational acceleration vector is in the z-axis direction, and may be coordinate transformation in which the gravitational acceleration vector is in the x-axis or y-axis direction, for example.

  The walking frequency detection unit 104 detects the walking frequency using information on the combined acceleration vector. Here, the walking frequency is the reciprocal of the time from when one foot touches the ground until the other foot touches the ground. As a method for calculating the walking frequency, (1) obtaining the reciprocal of the time from the peak of the z-axis component of the composite acceleration vector coordinate-converted by the coordinate conversion unit 103 to the next peak, or (2) the composite acceleration There are methods such as performing Fourier transform on vectors. The method for calculating the walking frequency is not limited to these methods.

  The BPF (Band Pass Filter) 105 is configured by a filter that transmits the walking frequency calculated by the walking frequency detection unit 104, and transmits only the walking frequency component of the composite acceleration vector. This transmission process attenuates the gravitational acceleration component, which is a direct current, and the left / right swing component having a frequency half that of the walking frequency, and an acceleration vector in which the swing in the moving direction is dominant can be obtained. The direction detection accuracy can be improved. Note that the method of removing the gravitational acceleration component is not limited to the method using BPF. For example, the gravity acceleration component may be removed from the combined acceleration vector by subtracting the gravity acceleration vector detected by the posture detection unit 102 from the combined acceleration vector detected by the acceleration sensor 101.

  The moving direction (pedestrian navigation device reference) detection unit 106 detects the moving direction of the pedestrian navigation device 100 from the acceleration vector transmitted through the BPF 105. At this time, since the absolute azimuth is not calculated, the detected coordinate system of the moving direction of the pedestrian navigation device 100 is a coordinate system based on the pedestrian navigation device 100. A detection method in the moving direction (pedestrian navigation device reference) detection unit 106 will be described later.

  At this stage, the direction of movement of the pedestrian navigation device 100 is not detected while the direction of movement is detected from the shaking of the acceleration vector before and after. That is, for example, it has been found that the terminal on which the pedestrian navigation device 100 is mounted has moved to the front of the terminal or the back of the terminal, but whether the terminal has moved to the front of the terminal, It is unknown whether it has moved to the back of the.

  The moving direction (pedestrian navigation device reference) detection unit 107 detects the z-axis direction (vertical direction) component of the acceleration vector after passing through the BPF 105 and the moving direction of the pedestrian navigation device 100 of the acceleration vector after passing through the BPF 105. The phase difference with the component is calculated, and the direction of movement of the pedestrian navigation device 100 (reference to the pedestrian navigation device) is detected from the sign of this phase difference. A detection method in the moving direction (pedestrian navigation device reference) detection unit 107 will be described later. The movement direction (pedestrian navigation apparatus reference) detection unit 107 outputs the movement direction (pedestrian navigation apparatus reference) of the pedestrian navigation apparatus 100 to the movement direction (earth reference) calculation unit 109.

  The absolute azimuth detecting unit 108 detects an absolute azimuth (earth reference) that the pedestrian navigation device 100 is facing. As a method for detecting the absolute direction, a method of calculating the absolute direction by measuring the earth's magnetic field using a magnetic sensor is not limited to this method.

  The movement direction (earth reference) calculation unit 109 includes a movement direction (pedestrian navigation apparatus reference) detected by the movement direction (pedestrian navigation apparatus reference) detection unit 107, and The direction of movement of the pedestrian navigation device 100 (earth reference) is calculated from the absolute azimuth (earth reference) that the navigation device 100 for pedestrians detected by the absolute azimuth detection unit 108 faces.

  The movement speed calculation unit 110 calculates the movement speed of the pedestrian navigation apparatus 100 using the acceleration vector. As a method for calculating the moving speed, for example, a method for obtaining the number of steps from an acceleration vector is conceivable. Note that the method for calculating the moving speed is not limited to this.

  The movement vector calculation unit 111 includes the movement speed of the pedestrian navigation device 100 calculated by the movement speed calculation unit 110 and the movement direction of the pedestrian navigation device 100 calculated by the movement direction (earth reference) calculation unit 109 ( The movement vector is calculated using the (global reference) and output to the position calculation unit 112.

  The position calculation unit 112 calculates the current position of the pedestrian navigation device 100 by adding a movement vector to the position information of the pedestrian navigation device 100 stored in the position storage unit 113. Then, the position calculation unit 112 updates the position information of the pedestrian navigation device 100 stored in the position storage unit 113 to the calculated position information of the current pedestrian navigation device 100.

  Hereinafter, with respect to the operation of the pedestrian navigation device 100 configured as described above, the movement direction (pedestrian navigation device reference) detection unit 106 and the movement direction (pedestrian navigation device reference) detection unit 107 are mainly described. The operation will be mainly described.

  First, a method of detecting the moving direction (standard of pedestrian navigation apparatus) of the pedestrian navigation apparatus 100 by the moving direction (pedestrian navigation apparatus standard) detection unit 106 will be described.

  The moving direction (pedestrian navigation device reference) detection unit 106 executes the following processing using a plurality of acceleration vectors collected while the pedestrian walks a plurality of steps (for example, while walking two steps) as a set of data sets.

  The movement direction (pedestrian navigation device reference) detection unit 106 uses a rotation vector that rotates the acceleration vector by a predetermined rotation angle about the z-axis (vertical direction) as an xy plane by the coordinate conversion unit 103. This acceleration vector is sequentially rotated by multiplying the acceleration vector that has been coordinate-transformed so that Then, the moving direction (pedestrian navigation device reference) detection unit 106 determines the rotation angle at which the evaluation value (hereinafter referred to as “moving direction evaluation value”) indicating the likelihood of the moving direction of the pedestrian navigation device 100 is maximized. To detect.

  As the movement direction evaluation value, for example, the ratio of the x-coordinate amplitude and the y-coordinate amplitude of the acceleration vector is used. FIG. 2 shows an example of the relationship between the rotation angle [deg] and the ratio between the x-coordinate amplitude and the y-coordinate amplitude of the acceleration vector. 2 that the ratio between the amplitude of the x coordinate and the amplitude of the y coordinate becomes maximum when the moving direction and the rotation angle coincide. Therefore, the ratio between the amplitude of the x coordinate and the amplitude of the y coordinate is used as the movement direction evaluation value, and the movement direction (pedestrian navigation device reference) detection unit 106 detects the rotation angle at which the value of this ratio is maximum. That's fine.

  Furthermore, a method of detecting the moving direction of the pedestrian navigation device 100 (reference to the pedestrian navigation device) will be described in detail with reference to FIG.

  FIG. 3 is a flowchart for explaining the operation of the moving direction (pedestrian navigation device reference) detection unit 106.

  First, the rotation angle θ is initialized to 0 degree (step 201).

  Next, the horizontal component of the acceleration vector is rotated by θ degrees about the vertical vector (z axis) (step 202).

  Next, the ratio Pr between the x-coordinate amplitude and the y-coordinate amplitude of the rotated acceleration vector is calculated (step 203).

  Next, when the ratio Pr is the maximum among the Prs calculated so far, the rotation angle θ at this time is stored as θmax (step 204).

  Next, Δθ which is a step amount of the rotation angle is added to the rotation angle θ (step 205).

  Next, it is determined whether or not the rotation angle θ is 180 degrees or more (step 206). If the rotation angle θ is less than 180 degrees (step 206: No), the process returns to step 202, and steps 202 to 205 are executed again. On the other hand, when the rotation angle θ is 180 degrees or more (step 206: Yes), θmax at this point is set as the movement direction (reference to the pedestrian navigation device) (step 207).

  In the above description, the case where the initial value of the rotation angle θ is set to 0 degree and the rotation angle θ is sequentially increased every Δθ up to 180 degrees has been described as an example. However, the present invention is not limited to this. For example, the initial value of the rotation angle θ may be the immediately preceding movement direction (θmax), and the rotation angle θ that is the maximum of the rotation angles before and after that may be θmax.

  In the above description, the movement direction (pedestrian navigation apparatus standard) detection unit 106 uses the ratio Pr between the amplitude of the x coordinate and the amplitude of the y coordinate as the movement direction evaluation value, and walks θmax where Pr is maximum. The case where it detected as a moving direction (pedestrian navigation apparatus reference | standard) of the navigation apparatus 100 for people was demonstrated. However, it is not limited to this.

  For example, the x-coordinate amplitude may be used as the moving direction evaluation value, and the rotation angle at which the x-coordinate amplitude is maximized may be used as the moving direction of the pedestrian navigation device 100 (pedestrian navigation device reference). Alternatively, the y-coordinate amplitude may be used as the moving direction evaluation value, and the rotation angle at which the y-coordinate amplitude is minimized may be used as the moving direction of the pedestrian navigation device 100 (pedestrian navigation device reference). Alternatively, the y-coordinate amplitude may be used as the moving direction evaluation value, and the rotation angle at which the y-coordinate amplitude is maximized may be used as the moving direction of the pedestrian navigation device 100 (pedestrian navigation device reference). Alternatively, amplitudes other than the x-coordinate and y-coordinate may be used as the moving direction evaluation value, and the rotation angle at which the amplitude is maximized may be used as the moving direction of the pedestrian navigation device 100 (pedestrian navigation device reference). These differ only in the reference axis for calculating the rotation angle, and the rotation angle calculation method is the same.

  Alternatively, the effective value of the x-coordinate and y-coordinate (for example, RMS (Root Mean Square)) is used as the moving direction evaluation value, and the rotation angle at which the x-coordinate RMS is maximum or the y-coordinate RMS is minimum is used for pedestrians. It is good also as a movement direction (navigation apparatus reference | standard for pedestrians) of the navigation apparatus 100. FIG. Alternatively, the ratio of the RMS of the x coordinate and the RMS of the y coordinate may be used as the moving direction evaluation value, and the rotation angle at which this ratio is maximized may be used as the moving direction of the pedestrian navigation device 100 (pedestrian navigation device reference). . Alternatively, the arc tangent of the ratio of the amplitude of the x coordinate to the amplitude of the y coordinate, or the arc tangent of the ratio of the RMS of the x coordinate to the RMS of the y coordinate is set as the movement direction evaluation value, and the rotation angle at which these become the maximum is determined. The moving direction of the pedestrian navigation device 100 (based on the pedestrian navigation device) may be used. Also, instead of the x-coordinate RMS or the y-coordinate RMS, an integrated value of absolute values of acceleration vectors or an average value of acceleration may be used. By using the acceleration vector information at more timings, the RMS of the x coordinate, the RMS of the y coordinate, the absolute value of the acceleration, or the average value of the acceleration vector is calculated, and the moving direction of the pedestrian navigation device can be calculated. Detection accuracy can be improved.

  Next, a method for detecting the direction of movement of the pedestrian navigation device 100 (reference to the pedestrian navigation device), which is different from the above method, will be described with reference to FIG. In FIG. 4, the vertical axis indicates the moving direction evaluation value, and the horizontal axis sequentially rotates the acceleration vector that has been coordinate-converted by the coordinate conversion unit 103 so that the xy plane becomes a horizontal plane, with the z-axis as an axis. The rotation angle when

Here, first, assume that φ ₀ (arbitrary) is selected as the initial angle value (initial angle). Then, angles away from phi ₀ only equal intervals [Delta] [phi in the direction of the positive and negative phi, _{i.e., φ = φ 0 -Δφ, φ} = φ 0 + movement direction evaluation value S _over the [Delta] [phi, seek S _+. At this time, when φ coincides with the moving direction, S ₋ and S ₊ have the same value, but when φ differs from the moving direction, S ₋ and S ₊ become different values and S ₋ and There is a difference with S ₊ .

Therefore, as shown in Expression (1), the moving direction φ is updated by a value obtained by multiplying the difference between S ₋ and S ₊ by a coefficient α. By sequentially updating the moving direction φ in this way, the moving direction φ gradually approaches the moving direction of the pedestrian navigation device 100.
φ = φ + α (S ₊ −S ₋ ) (1)

As a method of setting the coefficient α, a method of setting a constant or a method of using a function of S ₊ and S ₋ can be considered, but the method is not limited to these methods.

  Furthermore, the detection method of the moving direction (pedestrian navigation apparatus reference | standard) of the navigation apparatus 100 for pedestrians is demonstrated in detail using FIG.

  FIG. 5 is a flowchart for explaining the operation of the moving direction (pedestrian navigation device standard) detection unit 106.

First, the moving direction φ is initialized (step 301). The initial angle of the moving direction φ is, for example, the moving direction φ _{1 of} the pedestrian navigation device 100 obtained immediately before the processing described below is executed. However, the initialization method of the moving direction φ is not limited to this.

  Next, the horizontal component of the acceleration vector is rotated by φ−Δφ (step 302). Here, Δφ is a fixed value.

  Next, the ratio Prb between the x-coordinate amplitude and the y-coordinate amplitude of the rotated acceleration vector is calculated (step 303).

  Next, the horizontal component of the acceleration vector is rotated by φ + Δφ (step 304).

  Next, a ratio Prf between the x-coordinate amplitude and the y-coordinate amplitude of the rotated acceleration vector is calculated (step 305).

Here, when the movement direction φ initialized in step 301 is equal to the actual movement direction, Prb and Prf are substantially equal. On the other hand, when the movement direction φ initialized in step 301 is different from the actual movement direction, a difference is generated between Prb and Prf. Therefore, as shown in Expression (2), the moving direction φ is updated by a value obtained by multiplying the difference between Prb and Prf by a coefficient α (step 306).
φ = φ + α (Prb−Prf) (2)

  The steps 301 to 306 may be repeated until the moving direction φ converges, or the number of repetitions may be fixed and the steps 301 to 306 may be repeated a fixed number of times. Alternatively, assuming that the moving direction does not change greatly in a short period, the processing may be performed only once for a set of data.

  In the above description, the movement direction φ is updated so that the ratio Pr between the amplitude of the x coordinate and the amplitude of the y coordinate is maximized. However, the present invention is not limited to this. For example, the movement direction φ may be updated so that the amplitude of the x coordinate becomes maximum, or the movement direction φ may be updated so that the amplitude of the y coordinate becomes minimum. Good. Alternatively, the moving direction φ may be updated so that the RMS of the x coordinate is the maximum or the RMS of the y coordinate is the minimum. Alternatively, the moving direction φ may be updated so that the ratio between the RMS of the x coordinate and the RMS of the y coordinate is maximized. Alternatively, the moving direction φ may be updated so that the arc tangent of the ratio between the amplitude of the x coordinate and the amplitude of the y coordinate, or the arc tangent of the ratio of the RMS of the x coordinate and the RMS of the y coordinate is maximized. . Further, instead of RMS, an integrated value of absolute values of acceleration vectors or an average value of acceleration vectors may be used.

  Next, a method of detecting the direction of movement of the pedestrian navigation device 100 (based on the pedestrian navigation device) in the movement direction (standard of pedestrian navigation device) detection unit 107 will be described. As described above, the movement direction (pedestrian navigation apparatus reference) detection unit 106 detects the movement direction of the pedestrian navigation apparatus 100, but does not detect the direction of movement of the pedestrian navigation apparatus 100. That is, for example, although it has been found that the terminal has moved to the front of the terminal or the back of the terminal by detecting the moving direction of the terminal on which the pedestrian navigation device 100 is mounted, I do n’t know where it ’s moving to the back. Therefore, the direction of movement (reference to the navigation device for pedestrians) detection unit 107 detects the direction of movement of the navigation device 100 for pedestrians. Hereinafter, a method for detecting the direction of movement of the pedestrian navigation device 100 (based on the pedestrian navigation device) will be described with reference to FIGS. 6A and 6B.

  FIG. 6A schematically shows the coordinate axes of the terminal and the acceleration sensor when the pedestrian holds the terminal on which the pedestrian navigation device 100 is mounted facing the front and the direction of movement of the terminal is the front of the terminal. Yes. FIG. 6B schematically shows the coordinate axes of the terminal and the acceleration sensor when the pedestrian holds the terminal on which the pedestrian navigation device 100 is mounted facing the back and the direction of movement of the terminal is the back of the terminal. Show. Note that the pedestrian shown in FIG. 6A and the pedestrian shown in FIG. 6B have the same moving direction and moving direction. 6A and 6B, the vertical direction, that is, the direction of the z-axis is the same, and the direction of the axis of the moving direction is 180 degrees different.

  As can be seen from FIGS. 6A and 6B, there is no change in the component in the vertical direction (z-axis) of the acceleration vector depending on whether the terminal is facing the front or the back with respect to the moving direction of the terminal. On the other hand, the direction of the movement direction axis (y-axis) changes by 180 degrees depending on whether the terminal is facing the front or the back with respect to the movement direction of the terminal, so the sign of the acceleration vector in the movement direction is inverted. become. That is, depending on whether the terminal is facing the front or the back with respect to the moving direction of the terminal, the direction of the phase shift of the moving direction of the acceleration vector with respect to the vertical direction of the acceleration vector is reversed. Therefore, in order to detect the direction of movement of the navigation device 100 for pedestrians, the direction of phase shift between the vertical direction of the acceleration vector and the direction of movement of the acceleration vector (whether the phase is advanced or delayed) is detected. Good.

  FIG. 7 shows how the acceleration vector fluctuates in the pedestrian navigation apparatus 100 shown in FIGS. 6A and 6B. In FIG. 7, the vertical axis indicates the magnitude of the acceleration vector, and the horizontal axis indicates time. Moreover, in FIG. 7, S11 shows the component of the perpendicular direction of the acceleration vector of the navigation apparatus 100 for pedestrians. As described above, whether the terminal on which the pedestrian navigation device 100 is mounted faces the front or the back with respect to the moving direction of the terminal, the vertical direction of the acceleration vector of the pedestrian navigation device 100 The components of are the same. In FIG. 7, S12 indicates a component in the moving direction of the acceleration vector in FIG. 6A, and S13 indicates a component in the moving direction of the acceleration vector in FIG. 6B.

  The moving direction (pedestrian navigation device reference) detection unit 107 detects a phase difference between a vertical component of the acceleration vector of the pedestrian navigation device 100 and a moving direction component of the acceleration vector of the pedestrian navigation device 100. That is, the direction of movement of the pedestrian navigation device 100 is determined by detecting the direction of phase shift (whether the phase is advanced or delayed).

  By changing the direction of the phase shift, the sign of the moving direction component of the acceleration vector when the vertical direction component of the acceleration vector crosses zero varies depending on the moving direction. Therefore, the movement direction (pedestrian navigation apparatus reference) detection unit 107 detects the direction of movement of the pedestrian navigation apparatus 100 by detecting the sign of the acceleration vector movement direction component.

  For example, as shown in the region S21 in FIG. 7, when the vertical component of the acceleration vector crosses 0 from + to −, the moving direction component of the acceleration vector is positive. It is determined that the terminal to be mounted is moving in the direction of the front side of the terminal, and if negative, it is determined that the terminal on which the pedestrian navigation device 100 is mounted is moving in the direction of the back side of the terminal.

  Similarly, as shown in the region S22 of FIG. 7, when the vertical component of the acceleration vector crosses 0 from − to +, if the moving component of the acceleration vector is negative, the pedestrian navigation device It is determined that the terminal on which the terminal 100 is mounted is moving in the direction of the front surface of the terminal. If the terminal is positive, it is determined that the terminal on which the pedestrian navigation device 100 is mounted is moving in the direction of the rear surface of the terminal.

  In this way, the movement direction (pedestrian navigation device reference) detection unit 107 detects the phase difference between the vertical component of the acceleration vector and the component of the acceleration vector in the moving direction, that is, the direction of the phase shift (the phase is The direction of movement is determined by detecting whether the vehicle is moving forward or late.

  In the above description, in order to simplify the description, the direction of movement of the terminal on which the pedestrian navigation device 100 is mounted is described as the front of the terminal or the back of the terminal, but the pedestrian navigation device 100 is mounted. Even if the direction of movement of the terminal to be used is another surface, the direction of movement of the pedestrian navigation device 100 can be detected by the same method. When a person moves on foot, the vertical direction component of the acceleration vector and the movement direction component of the acceleration vector are out of phase at the walking frequency, so the direction of movement of the terminal on which the pedestrian navigation device 100 is mounted is changed. Even on other surfaces, the direction of movement of the pedestrian navigation device 100 can be detected by detecting the phase shift.

  As described above, in the present embodiment, the coordinate conversion unit 103 converts the acceleration vector to coordinates based on the pedestrian navigation device 100 based on the posture of the pedestrian navigation device 100 held by the pedestrian. Convert. The BPF 105 transmits the walking frequency component of the pedestrian among the frequency components of the acceleration vector after the coordinate conversion. The moving direction (pedestrian navigation device reference) detection unit 106 detects the moving direction of the pedestrian navigation device 100 at coordinates based on the pedestrian navigation device 100, using the acceleration vector transmitted through the BPF 105. The direction of movement (pedestrian navigation device reference) detection unit 107 detects the direction of movement of the pedestrian navigation device at coordinates based on the pedestrian navigation device, using the acceleration vector transmitted through the BPF 105. The movement direction (earth reference) calculation unit 109 is configured to move the pedestrian navigation device 100 in the coordinates with respect to the pedestrian navigation device 100 and the pedestrian navigation in the coordinates with respect to the pedestrian navigation device 100. Based on the direction of movement of the device 100 and the direction of the pedestrian navigation device 100 in the coordinates with respect to the earth, the direction of movement of the pedestrian navigation device 100 in the coordinates with respect to the earth is calculated.

  Thus, since the direction of movement of the pedestrian navigation device is detected using information on the acceleration vector of the pedestrian at a plurality of timings, the pedestrian can be accurately compared with the case where only the acceleration vector at one timing is used. The direction of movement of the navigation device can be detected. As described above, in the present embodiment, the acceleration vector information at a plurality of timings is used, so that the acceleration vector can be sampled at a low sampling rate, and thus the power consumption of the pedestrian navigation device can be reduced. Can be achieved.

  In the present embodiment, the BPF 105 transmits the walking frequency component among the frequency components of the acceleration vector after the coordinate conversion, and the moving direction (pedestrian navigation device reference) detection unit 106 transmits the acceleration vector after the BPF 105 transmission. Is used to detect the moving direction of the pedestrian navigation device 100 at the coordinates fixed to the pedestrian navigation device 100. As a result, it is possible to obtain an acceleration vector in which the fluctuation of the moving direction of the pedestrian navigation device 100 is dominant by attenuating the left and right shaking components in the acceleration vector, so that the detection of the moving direction of the pedestrian navigation device 100 is detected. Accuracy can be improved.

  When the moving direction (pedestrian navigation device reference) detection unit 106 uses RMS as the moving direction evaluation value, it becomes possible to use information on acceleration vectors at all sampling timings, and for pedestrians. The detection accuracy of the movement direction of the navigation device 100 can be further improved.

  The pedestrian navigation device and the movement direction detection method in the pedestrian navigation device according to the present invention can be widely applied to electronic devices that perform pedestrian navigation.

The block diagram which shows the principal part structure of the navigation apparatus for pedestrians concerning one embodiment of this invention. The figure which shows the relationship between the moving direction evaluation value and rotation angle which concern on the said embodiment. Flow chart for explaining the moving direction detection method according to the above embodiment The figure provided in order to demonstrate the principle of the moving direction detection method which concerns on the said embodiment Flow chart for explaining the moving direction detection method according to the above embodiment The figure which shows the coordinate axis of the acceleration sensor when holding the terminal toward the front The figure which shows the coordinate axis of the acceleration sensor when holding the terminal toward the back The figure which shows the mode of the fluctuation | variation of the acceleration vector shown to FIG. 6A and 6B

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Pedestrian navigation apparatus 101 Acceleration sensor 102 Posture detection part 103 Coordinate conversion part 104 Walking frequency detection part 105 BPF
106 Movement direction (pedestrian navigation device reference) detection unit 107 Movement direction (pedestrian navigation device reference) detection unit 108 Absolute orientation detection unit 109 Movement direction (earth reference) calculation unit 110 Movement speed calculation unit 111 Movement vector Calculation unit 112 Position calculation unit 113 Position storage unit

Claims (9)

A pedestrian navigation device,
An acceleration sensor for detecting an acceleration vector generated by a person walking;
An absolute azimuth detector that detects the orientation of the navigation device for the pedestrian relative to the earth,
A first movement direction detection unit that detects a direction in which the aspect ratio of the amplitude of the component in the horizontal plane of the acceleration vector is maximum as a movement direction based on the navigation device for pedestrians;
A second movement direction detection unit that detects a movement direction of the navigation device for pedestrians based on the direction detected by the absolute azimuth detection unit and the movement direction detected by the first movement direction detection unit;
A pedestrian navigation device comprising: Based on the phase difference between the vertical component of the acceleration vector and the component of the acceleration vector in the moving direction of the pedestrian navigation device, the pedestrian navigation at coordinates based on the pedestrian navigation device. A third movement direction detection unit for detecting the direction of movement of the device;
The navigation device for pedestrians according to claim 1. A pedestrian navigation device,
An acceleration sensor for detecting an acceleration vector of the pedestrian navigation device caused by movement of the pedestrian navigation device;
A detection unit for detecting the posture of the pedestrian navigation device;
Based on the attitude of the pedestrian navigation device, the conversion unit that converts the acceleration vector into coordinates based on the pedestrian navigation device;
Among the frequency components of the acceleration vector after coordinate transformation, a filter that transmits the walking frequency component;
A first detection unit that detects a moving direction of the pedestrian navigation device at coordinates based on the pedestrian navigation device, using the acceleration vector after passing through the filter;
A second detection unit that detects the direction of movement of the pedestrian navigation device at coordinates based on the pedestrian navigation device, using the acceleration vector after passing through the filter;
A third detection unit that detects an absolute direction of the direction of the navigation device for the pedestrian in coordinates with respect to the earth;
The direction of movement of the pedestrian navigation device in coordinates based on the pedestrian navigation device, the direction of movement of the pedestrian navigation device in coordinates based on the pedestrian navigation device, and the absolute orientation A first calculation unit that calculates the direction of movement of the navigation device for pedestrians in coordinates with respect to the earth,
A moving speed calculator that calculates the moving speed of the pedestrian navigation device using the acceleration vector;
A second calculation unit that calculates a movement vector of the navigation device for pedestrians using a direction of movement of the navigation device for pedestrians and a movement speed of the navigation device for pedestrians in coordinates with respect to the earth;
A pedestrian navigation device comprising: The second detector is
Based on the phase difference between the vertical component of the acceleration vector after passing through the filter and the moving direction component of the acceleration vector after passing through the filter, the navigation device for pedestrian Detecting the direction of movement of the navigation device for the pedestrian in the reference coordinates;
The pedestrian navigation device according to claim 3. A position calculation unit that calculates the position of the navigation device for the pedestrian using the movement vector;
A position storage unit that stores the position of the navigation device for the pedestrian,
The pedestrian navigation device according to claim 3. The first detection unit includes:
Using the rotation angle that sequentially rotates the horizontal component of the acceleration vector after passing through the filter about the vertical direction and maximizes the amplitude of the rotated acceleration vector in a predetermined coordinate axis in the horizontal direction, Detecting the direction of movement of the pedestrian navigation device in coordinates based on the pedestrian navigation device;
The pedestrian navigation device according to claim 3. The first detection unit includes:
The component in the horizontal direction of the acceleration vector after passing through the filter is rotated positively or negatively by a predetermined angle with respect to the vertical direction as an axis, and based on the amplitude of the two acceleration vectors after rotation on a predetermined coordinate axis in the horizontal direction, Detecting the moving direction of the pedestrian navigation device in coordinates based on the pedestrian navigation device,
The pedestrian navigation device according to claim 3. A method of detecting a moving direction in a pedestrian navigation device,
Detects acceleration vector generated by human walking,
Detect the direction of the navigation device for pedestrians with respect to the earth,
A direction in which the aspect ratio of the amplitude of the component in the horizontal plane of the acceleration vector is maximized is detected as a moving direction based on the navigation device for pedestrians;
A moving direction detection method for detecting a moving direction of the pedestrian navigation device based on a direction of the pedestrian navigation device based on the earth and a moving direction based on the pedestrian navigation device. A movement vector measurement method for calculating a movement vector of a pedestrian navigation device,
Based on the posture of the pedestrian navigation device, the acceleration vector of the pedestrian navigation device generated by the movement of the pedestrian navigation device is converted into coordinates based on the pedestrian navigation device,
Among the frequency components of the acceleration vector after coordinate transformation, perform band limitation to transmit the walking frequency component,
Using the acceleration vector after the band limitation, the movement direction of the pedestrian navigation device in coordinates based on the pedestrian navigation device, and the walking in coordinates based on the pedestrian navigation device Detecting the direction of movement of the navigation device for the
The direction of movement of the pedestrian navigation device in coordinates based on the pedestrian navigation device, the direction of movement of the pedestrian navigation device in coordinates based on the pedestrian navigation device, and the earth Using the absolute azimuth of the direction of the navigation device for pedestrians in the coordinates determined, the direction of movement of the navigation device for pedestrians in the coordinates with respect to the earth is calculated,
Calculate the moving speed of the pedestrian navigation device using the acceleration vector,
Calculating a movement vector of the pedestrian navigation device using the direction of movement of the pedestrian navigation device and the movement speed of the pedestrian navigation device in coordinates with respect to the earth;
Moving vector measurement method.

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