JP2009093440A - Portable terminal and program for complementing number of steps of pedestrian detected by acceleration sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a portable terminal which counts the exact number of steps by complementing the number of steps derived by an acceleration sensor mounted to the portable terminal in consideration of an influence of hand shaking even if a pedestrian walks while carrying the portable terminal in hand, and a program. <P>SOLUTION: The portable terminal has a walk timing determination means for counting the number of steps of the pedestrian. The means includes: a synthetic acceleration computing means for computing a synthetic acceleration value from acceleration data; a buffer means for storing a plurality of synthetic acceleration values at predetermined time intervals; a peak detection means which detects the number of maximum points when a difference of the subtraction of a first time synthetic acceleration value from a second time synthetic acceleration value is ≥0 in an increase tendency, and when the difference becomes <0 and shifts in a decrease tendency; and a complementary means of the number of steps which complements the number of steps by adding the number of sloping shoulders when the difference is increased and after the difference of the synthetic acceleration value approaches zero, and when increasing again, to the number of maximum points. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a portable terminal and a program that complement the number of steps of a pedestrian detected by an acceleration sensor. In particular, the present invention relates to an autonomous navigation technique for deriving a current position and a traveling direction in real time.

  Conventionally, there is an autonomous navigation technique that derives a current position and a traveling direction in real time using an acceleration sensor and a direction sensor. Autonomous navigation technology is combined with GPS (Global Positioning System) technology and is mainly used for a car navigation system. The car navigation system displays, on a display, an accurate current position and traveling direction and a travel route guide to a destination for a driver of a car.

  The car navigation system corrects the current position information measured by the GPS by an autonomous navigation technique such as a vehicle speed pulse or a gyro. Further, the road map information is read out as necessary, and the current position and the traveling direction are corrected so that the current travel route coincides with the road (map matching technique based on a projection method, for example, see Patent Document 1). As a result, it is possible to prevent the current position from being a position not on the road due to a sensor error.

  On the other hand, there is a system in which such navigation technology is applied to a portable terminal possessed by a pedestrian. Specifically, a cumulative current position from the starting point is derived using the detected “number of steps” of the pedestrian and the “step length” of the pedestrian (see, for example, Patent Document 2). When the autonomous navigation technology is applied to a pedestrian, acceleration components other than horizontal movement are also detected. Thus, the measured distance is derived from the number of steps and the step length, rather than simply integrating the output of the acceleration sensor.

  “Number of steps” is the sum of squares of the accelerations detected for each axis detected by the acceleration sensor in the portable terminal, and the peak-to-peak interval is detected as one step (see, for example, Patent Document 3). The “step length” is preset by the user or estimated from the height of the user. Alternatively, according to another technique, there is a technique of calibrating the stride by causing a pedestrian to walk a specified distance (see, for example, Non-Patent Document 1).

  The “traveling direction” is detected by the “direction sensor”. As the direction sensor, a geomagnetic sensor is generally used. There is also a technique for three-dimensionally displaying the orientation and direction of a terminal detected using a geomagnetic sensor on a display (see, for example, Patent Document 4). In addition, when there are a plurality of roads through an intersection in the traveling direction, there is a technique in which the intersection is the current position (see, for example, Patent Document 5).

  A technology to determine the current position using autonomous navigation technology, in order to prevent the influence of the cumulative error of sensor data, when the right turn or left turn at the intersection is detected, the intersection is the starting point for specifying the current position (See, for example, Patent Document 6). That is, every time a turn is detected, the cumulative error of the sensor data is reset, and the previous cumulative error does not affect the subsequent specification of the current position.

  However, according to the above-described technique, unless an accurate “step count” can be counted, a large error is caused in specifying the current position.

  FIG. 1 is an explanatory diagram showing counting of the number of steps using an acceleration sensor in the prior art.

  According to FIG. 1, a pedestrian is walking while holding a portable terminal and shaking his / her hand back and forth. The mobile terminal includes an acceleration sensor. FIG. 1 also shows a graph in which the relationship between the combined acceleration G detected by the acceleration sensor and the number of steps (elapsed time) is plotted. The combined acceleration G is a value obtained by summing squares of accelerations for each axis obtained from the acceleration sensor of the mobile terminal.

  According to the graph of FIG. 1, when the hand of the pedestrian is directly below (the lowest point), the combined acceleration of the handheld portable terminal becomes a maximum (maximum). Conversely, when the hand of the pedestrian is at the highest position (top point), the resultant acceleration is minimal (minimum).

  If it does so, the frequency | count of a hand gesture will be derived | led-out by counting the frequency | count (number of times between peak-peak) that the synthetic | combination acceleration will become the maximum or the minimum about the portable terminal held by the pedestrian. One hand gesture corresponds to one step of a pedestrian. In this way, the resultant acceleration G is first-order differentiated, and the maximum point (or minimum point) is counted, thereby counting the lowest point and consequently counting “steps”.

JP-A-5-061408 Japanese Patent Laid-Open No. 9-089584 Japanese Patent Laying-Open No. 2005-038018 JP 2004-046006 A JP-A-3-099399 JP 63-011813 A "Nike + iPod User's Guide", page 27, "online", [searched August 31, 2007], Internet <URL: http://manuals.info.apple.com/en/nikeipod_users_guide.pdf>

  However, although the technique described in Patent Document 3 detects a local maximum point for each step, when actually counting the number of steps by a portable terminal held by the pedestrian, It is not always the maximum point. Therefore, the number of steps detected by the acceleration sensor is smaller than the actual number of steps. The reason is based on the fact that the waveform detected by the acceleration sensor is disturbed due to the hand-held state. In particular, when the pedestrian shakes his / her hand forward and backward, the magnitude of the combined acceleration is different.

  Therefore, in the present invention, even when a pedestrian is walking with a portable terminal handheld, the number of steps derived by the acceleration sensor mounted on the portable terminal is supplemented in consideration of the influence of camera shake. An object of the present invention is to provide a portable terminal and a program for counting the correct number of steps.

According to the present invention, the portable terminal has an acceleration sensor that is carried by a pedestrian and outputs acceleration data, and a walking timing determination unit that counts the number of steps of the pedestrian from the acceleration data,
The walking timing determination means
A combined acceleration calculating means for calculating a combined acceleration value from the acceleration data;
Buffer means for storing a plurality of combined acceleration values at predetermined time intervals;
When the difference obtained by subtracting the composite acceleration value at the first time point from the composite acceleration value at the second time point tends to be zero or positive (≧ 0), the difference tends to be negative (<0). Peak detection means for detecting the number of local maximum points when transitioned,
When there is a tendency to increase, the difference in the resultant acceleration value approaches zero, and then has step number complementing means that complements the number of shoulder sections when it increases again by adding to the number of maximum points. Features.

  According to another embodiment of the portable terminal of the present invention, the step number complementing means, when the difference in the combined acceleration value becomes equal to or smaller than the second threshold value θ2 after being less than or equal to the first threshold value θ1. It is also preferable to determine the shoulder section.

  According to another embodiment of the portable terminal of the present invention, the acceleration sensor is of a uniaxial, biaxial or triaxial type, and the resultant acceleration value is a sum of squares of acceleration values of all axes. It is also preferable.

According to another embodiment of the mobile terminal of the present invention,
Stride determination means for outputting the stride of each step of the pedestrian,
A movement amount integrating means for calculating a movement amount by adding the step output from the step determining means to the number of steps output from the walking timing determining means;
It is also preferable to have current position determining means for determining the current position from the start point according to the amount of movement.

According to the present invention, there is provided a program for causing a computer mounted on a portable terminal carried by a pedestrian to function, having an acceleration sensor that outputs acceleration data, and counting the number of steps of the pedestrian from the acceleration data. A program for a portable terminal that causes a computer to function as timing determination means,
The walking timing determination means
A combined acceleration calculating means for calculating a combined acceleration value from the acceleration data;
Buffer means for storing a plurality of combined acceleration values at predetermined time intervals;
When the difference obtained by subtracting the composite acceleration value at the first time point from the composite acceleration value at the second time point tends to be zero or positive (≧ 0), the difference tends to be negative (<0). Peak detection means for detecting the number of local maximum points when transitioned,
When there is an increasing trend, let the computer function as a step-complementing means that complements the number of shoulder sections when the difference between the combined acceleration values approaches zero and then increases again, adding to the number of maximum points It is characterized by that.

  According to another embodiment of the program for a portable terminal of the present invention, the step count complementing means has an increase difference in the combined acceleration value that is greater than the second threshold value θ2 after the difference is less than or equal to the first threshold value θ1. It is also preferable to make the computer function so as to determine that the shoulder section is determined.

  According to another embodiment of the program for the portable terminal of the present invention, the acceleration sensor is of a uniaxial, biaxial or triaxial type, and the resultant acceleration value is the square of the acceleration values of all axes. It is also preferable to make the computer function so that it is the sum.

According to another embodiment of the portable terminal program of the present invention,
Stride determination means for outputting the stride of each step of the pedestrian,
A movement amount integrating means for calculating a movement amount by adding the step output from the step determining means to the number of steps output from the walking timing determining means;
It is also preferable to cause the computer to function as current position determining means for determining the current position from the start point according to the amount of movement.

  According to the mobile terminal and the program of the present invention, even when a pedestrian is walking with the mobile terminal held by hand, the number of steps derived by the acceleration sensor mounted on the mobile terminal is affected by the hand shake. Complemented by taking into account and counting the exact number of steps.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 2 is a functional configuration diagram of the portable terminal according to the present invention.

  According to FIG. 2, the mobile terminal 1 includes a microprocessor unit 10, a geomagnetic sensor 11, an acceleration sensor 12, a GPS unit 13, a map information storage unit 14, and a display unit 15.

  The geomagnetic sensor 11 measures the direction of geomagnetism in the front-rear direction and the left-right direction (and the up-down direction). The geomagnetic sensor 11 separates the detection coils and obtains the azimuth angle of the geomagnetism using the output values detected from the separated detection coils. For example, even if the portable terminal including the geomagnetic sensor is tilted, the horizontal direction geomagnetism can be calculated by subtracting the tilt and the direction can be detected.

  The acceleration sensor 12 detects acceleration, that is, a change in speed per unit time. The type includes one axis, two axes, or three axes. In the case of the three-axis type that can detect the tilt of the mobile terminal, three-dimensional acceleration can be detected, and measurement of the gravity (static acceleration) of the earth can be supported.

  The map information storage unit 14 stores map information representing a travel route such as a road map. Further, the display unit 15 displays the current position and the traveling direction output from the microprocessor unit 10 together with the map information. This provides a navigation function for pedestrians.

  The microprocessor unit 10 functions as a walking timing determination unit 101, a traveling direction determination unit 102, a direction change determination unit 103, a stride determination unit 104, a movement amount integration unit 105, and a current position determination unit 106. Run the program. Here, the characteristic function of the present invention resides in the walking timing determination unit 101.

  The walking timing determination unit 101 counts the number of steps of the pedestrian from the acceleration for each axis output from the acceleration sensor 12. Then, the acceleration for each number of steps is output to the traveling direction determination unit 102 and the stride determination unit 104.

  The walking timing determination unit 101 includes a combined acceleration calculation unit 1011, a buffer unit 1012, a peak detection unit 1013, and a step number complementation unit 1014.

The combined acceleration calculation unit 1011 calculates a combined acceleration value G from the acceleration for each axis output from the acceleration sensor 12. The combined acceleration value G is the sum of squares of acceleration values of all axes. For example, in the case of a triaxial acceleration sensor, when the acceleration of each axis is Gx, Gy, and Gz, the combined acceleration value G is obtained by the following equation.
Composite acceleration value G = Gx ² + Gy ² + Gz ²

  The buffer unit 1012 stores the composite acceleration value G at a predetermined time interval in time series. The buffer unit 1012 stores a number (for example, 16) of synthesized accelerations G corresponding to at least two steps of a pedestrian.

  When the difference obtained by subtracting the composite acceleration value at the first time point from the composite acceleration value at the second time point tends to be zero or positive (≧ 0), the peak detection unit 1013 has a negative (<0) difference. ) Is detected, and the number of local maximum points is detected. That is, the peak detection unit 1013 detects, as a maximum point, a point at which the difference for each of the two combined accelerations shifts from an increasing tendency to a decreasing tendency for the plurality of combined accelerations G stored in the buffer unit 1012.

  When the difference obtained by subtracting the composite acceleration value at the first time point from the composite acceleration value at the second time point tends to be zero or positive (≧ 0), the step number complementing unit 1014 approaches the difference to zero. After that, the number of shoulder sections when increased again is added to the number of local maximum points to complement. That is, the step number complementing unit 1014 detects a predetermined shoulder section as a maximum point of one step. Specifically, the step number complementation unit 1014 determines that the step is a shoulder section when the increase difference in the combined acceleration value becomes equal to or smaller than the first threshold value θ1 and then becomes larger than the second threshold value θ2.

  FIG. 3 is an explanatory diagram for complementing counting of steps in the present invention.

  FIG. 3 shows a graph of the relationship between the combined acceleration and the number of steps when the number of steps is actually counted by the portable terminal held by the pedestrian. In reality, as shown in FIG. 1, an ideal graph in which the lowest point of the hand is the maximum point is not obtained. As shown in FIG. 3, even the lowest point does not become a local maximum point, but occurs as a shoulder section. According to the present invention, this “shoulder shoulder section” is detected, and the number of steps is complemented by adding the number to the number of maximum points.

  The “shoulder shoulder section” means a section between the two maximum points, where the slope of increase in the combined acceleration once becomes gentle and then the slope increases suddenly again. The “shoulder shoulder section” is a section that is actually the lowest point of hand shaking but cannot be detected as a maximum point.

In FIG. 3, two threshold values θ1 and θ2 are shown to determine the shoulder section. The section to be determined is a section in which the difference (slope) of the composite acceleration is 0 or more (uphill slope from the minimum point to the maximum point).
(S301) It is detected that the difference between the combined accelerations that are temporally adjacent (later combined acceleration−previous combined acceleration) ω is greater than the second threshold θ2.
(S302) Thereafter, it is detected that the difference ω of the combined acceleration is equal to or less than the first threshold value θ1.
(S303) Thereafter, it is detected that the difference ω of the combined acceleration is larger than the second threshold value θ2. At this time, it is determined that a “shoulder shoulder section” has occurred.

  FIG. 4 is a numerical example of counting the number of steps in the present invention.

The graph of FIG. 4 represents the relationship between the combined acceleration and the number of steps that occur when a pedestrian holding the mobile terminal actually walks.
In the third to fourth items, the difference in the combined acceleration is larger than the second threshold (80).
In the fifth to sixth items, the difference of the composite acceleration becomes equal to or less than the first threshold (40), and the start of the “shoulder shoulder section” is detected.
In the ninth to tenth pieces, the difference of the composite acceleration becomes larger than the second threshold (80), and the end of the “shoulder shoulder section” is detected. At this point, it is determined as one step.
Since the 11th-12th thirteenth and the thirteenth thirteenth tend to decrease the difference, the maximum point of the difference of the composite acceleration is detected for the twelfth. At this point, it is determined as one step.

  With reference to FIG. 2 again, other functional components of the mobile terminal will be described.

  The traveling direction determination unit 102 determines the traveling direction from the azimuth information from the geomagnetic sensor 11 and the acceleration data for each step from the walking timing determination unit 101 at predetermined time intervals. The direction change determination unit 103 determines whether or not a direction change has been made for the traveling direction output from the traveling direction determination unit 102.

  The stride determination unit 104 receives the acceleration data for one step from the walking timing determination unit 101 and determines the stride for each step. The movement amount accumulation unit 105 accumulates the traveling direction and step length for one step at the current position. The current position determination unit 106 acquires map information from the map information storage unit 14 and identifies the current position from the accumulated movement amount. If the current position determination unit 106 determines that the direction change determination unit 103 has changed direction, the current position determination unit 106 determines the position of a nearby intersection in the map information as the current position. If it is determined that the direction has not changed (if it is determined that the vehicle has moved straight), the position projected by map matching is determined as the current position.

  As described above in detail, according to the mobile terminal and the program of the present invention, even when a pedestrian is walking with the mobile terminal held by hand, it is derived by an acceleration sensor mounted on the mobile terminal. The number of steps taken is complemented in view of the effects of camera shake, and the exact number of steps is counted.

  According to the various embodiments of the present invention described above, those skilled in the art can easily make various changes, modifications and omissions within the scope of the technical idea and the viewpoint of the present invention. The above description is merely an example, and is not intended to be restrictive. The invention is limited only as defined in the following claims and the equivalents thereto.

It is explanatory drawing showing the count of the step count using the acceleration sensor in a prior art. It is a functional block diagram of the portable terminal in this invention. It is explanatory drawing which supplements the count of the step count in this invention. It is a numerical example of counting of the number of steps in the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Portable terminal 10 Microprocessor part 101 Walking timing determination part 102 Travel direction determination part 103 Direction change determination part 104 Stride determination part 105 Movement amount integration part 106 Current position determination part 11 Geomagnetic sensor 12 Acceleration sensor 13 GPS part 14 Map information storage part 15 Display section

Claims (8)

A portable terminal possessed by a pedestrian and having an acceleration sensor that outputs acceleration data, and walking timing determination means for counting the number of steps of the pedestrian from the acceleration data,
The walking timing determination means includes
A combined acceleration calculating means for calculating a combined acceleration value from the acceleration data;
Buffer means for storing a plurality of the resultant acceleration values at a predetermined time interval;
When the difference obtained by subtracting the composite acceleration value at the first time point from the composite acceleration value at the second time point tends to be zero or positive (≧ 0), the difference tends to be negative (<0). Peak detection means for detecting the number of local maximum points when moving to
Step supplement means for adding the number of shoulder sections when the difference between the combined acceleration values increases again after approaching zero when the difference is in the increasing trend, and adding to the number of local maxima. A portable terminal comprising:   The step number complementing means determines the shoulder section when the difference between the combined acceleration values becomes equal to or less than a first threshold value θ1 and then becomes larger than a second threshold value θ2. The mobile terminal according to claim 1.   The acceleration sensor is of a uniaxial, biaxial or triaxial type, and the combined acceleration value is a sum of squares of acceleration values of all axes. Mobile devices. Stride determination means for outputting the stride of each step of the pedestrian;
A moving amount integrating means for calculating a moving amount by adding the step output from the step determining means to the number of steps output from the walking timing determining means;
The mobile terminal according to any one of claims 1 to 3, further comprising a current position determining unit that determines a current position from a starting point according to the amount of movement. A program for causing a computer mounted on a portable terminal carried by a pedestrian to function, the computer having an acceleration sensor that outputs acceleration data, and a computer as a walking timing determining means for counting the number of steps of the pedestrian from the acceleration data Is a program for mobile devices that allows
The walking timing determination means includes
A combined acceleration calculating means for calculating a combined acceleration value from the acceleration data;
Buffer means for storing a plurality of the resultant acceleration values at a predetermined time interval;
When the difference obtained by subtracting the composite acceleration value at the first time point from the composite acceleration value at the second time point tends to be zero or positive (≧ 0), the difference tends to be negative (<0). Peak detection means for detecting the number of local maximum points when moving to
A computer as step number complementing means for adding the number of shoulder sections when the difference between the combined acceleration values increases again after approaching zero when the difference is in the increasing trend, and adding to the number of maximum points A program for a portable terminal characterized by causing the function to function.   The step number complementing means determines the computer to determine the shoulder section when the increase difference in the combined acceleration value becomes greater than the second threshold value θ2 after the increase difference becomes less than or equal to the first threshold value θ1. The program for a portable terminal according to claim 5, wherein the program is made to function.   The acceleration sensor is of a uniaxial, biaxial or triaxial type, and causes the computer to function so that the combined acceleration value is a sum of squares of acceleration values of all axes. Item 7. The portable terminal program according to Item 5 or 6. Stride determination means for outputting the stride of each step of the pedestrian;
A moving amount integrating means for calculating a moving amount by adding the step output from the step determining means to the number of steps output from the walking timing determining means;
The program for a mobile terminal according to any one of claims 5 to 7, wherein a computer is caused to function as current position determining means for determining a current position from a starting point according to the amount of movement.

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