Portable terminal, walking robot, storage medium, and position calculation support method

Abstract

The present invention provides a portable terminal, a walking robot, a storage medium, and a position calculation support method capable of improving the accuracy of detecting changes in posture. The portable terminal includes: a housing portion; a walking motion detection portion that detects a walking motion when the housing portion is moved by walking; a posture estimation portion that estimates the posture of the housing portion; and a posture change detection portion that, when the posture of the housing portion has changed significantly between a first time when the walking motion detection portion detects a first walking motion and a second time when the walking motion detection portion detects a second walking motion after the first walking motion, detects that the posture of the housing portion has changed between the first walking motion and the second walking motion based on the amount of change in the posture of the housing portion estimated by the posture estimation portion between the first time and the second time.

Description

Technical Field

[0001] The present disclosure relates to a portable terminal, a walking robot, a storage medium, and a position calculation support method. Background Art

[0002] Patent Document 1 discloses a portable terminal. This portable terminal can estimate the traveling direction using the detected value of the angular velocity corrected according to the posture.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2016-057205 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] However, in the portable terminal described in Patent Document 1, for example, when the posture of the portable terminal changes according to a person's walking motion, the detection errors of the portable terminal overlap. Therefore, the estimation accuracy of the traveling direction decreases.

[0008] The present disclosure has been made to solve the above problems. An object of the present disclosure is to provide a portable terminal, a walking robot, a storage medium, and a position calculation support method capable of improving the accuracy of detecting changes in posture.

[0009] Means for Solving the Problems

[0010] The portable terminal of the present disclosure includes: a housing portion; a walking motion detection portion that detects a walking motion when the housing portion is moved by walking; a posture estimation portion that estimates the posture of the housing portion; and a posture change detection portion that, when the posture of the housing portion has changed significantly between a first time when the walking motion detection portion detects a first walking motion and a second time when the walking motion detection portion detects a second walking motion after the first walking motion, the posture change detection portion detects that the posture of the housing portion has changed between the first walking motion and the second walking motion based on the amount of change in the posture of the housing portion estimated by the posture estimation portion between the first time and the second time.

[0011] The walking robot of the present disclosure includes: a walking housing portion that moves by walking using a plurality of legs;

[0012] A walking motion detection unit that detects a walking motion when the walking housing unit moves; a posture estimation unit that estimates the posture of the walking housing unit; and a posture change detection unit that, when the posture of the walking housing unit has changed significantly between a first time when the walking motion detection unit detects a first walking motion and a second time when the walking motion detection unit detects a second walking motion after the first walking motion, the posture change detection unit detects that the posture of the walking housing unit has changed between the first walking motion and the second walking motion based on the amount of change in the posture of the walking housing unit estimated by the posture estimation unit between the first time and the second time.

[0013] A computer-readable storage medium of the present disclosure stores a computer program. The computer is provided in a housing. When the computer program is executed by a processor, the following steps are performed: a walking detection step of detecting a walking motion when the housing is moved by walking; a posture estimation step of estimating the posture of the housing; and a posture change detection step of, when the posture of the housing has changed significantly between a first time when the first walking motion is detected in the walking detection step and a second time when a second walking motion after the first walking motion is detected in the walking detection step, detecting that the posture of the housing has changed between the first walking motion and the second walking motion based on the amount of change in the posture of the housing estimated in the posture estimation step between the first time and the second time.

[0014] A position calculation support method of the present disclosure includes: a first walking detection process in which a processing circuit provided in a housing detects a first walking motion when the housing is moved by walking; a posture estimation process that is performed after the first walking detection process, and in which the processing circuit estimates the posture of the housing; a second walking detection process that is performed after the posture estimation process, and in which the processing circuit detects a second walking motion after the first walking motion; and a posture change detection process that is performed after the second walking detection process, and in which, when the posture of the housing has changed significantly between the first walking motion and the second walking motion, the processing circuit detects that the posture of the housing has changed between the first walking motion and the second walking motion based on the amount of change in the posture of the housing estimated in the posture estimation process.

[0015] Effects of the Invention

[0016] According to the present disclosure, a change in posture between walking motions is detected, so that the accuracy of detecting the change in posture can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram showing a situation in which a portable terminal is held by a person in Embodiment 1.

[0018] Figure 2 This is a block diagram of the portable terminal in Implementation Example 1.

[0019] Figure 3 This is a flowchart for explaining the outline of the operation of the portable terminal determining the traveling direction in the first embodiment.

[0020] Figure 4 This is a flowchart for explaining the outline of the operation of estimating the posture of the portable terminal in the first embodiment.

[0021] Figure 5 This is a hardware configuration diagram of the portable terminal in Implementation Example 1.

[0022] Figure 6 This is a block diagram of a portable terminal in Implementation Example 2.

[0023] Figure 7 This is a diagram showing the azimuth angle calculated by the portable terminal in the second embodiment.

[0024] Figure 8 This is a diagram showing the azimuth angle calculated by the portable terminal in the second embodiment.

[0025] Description of symbols

[0026] 1 portable terminal, 2 housing, 2a reference surface, 3 acceleration sensor, 4 gyro sensor, 5 computing unit, 6 walking motion detection unit, 7 posture estimation unit, 8 posture change detection unit, 9 moving direction estimation unit, 10 moving direction output unit, 11 position computing unit, 20 geomagnetic sensor, 21 azimuth computing unit, 100a processor, 100b memory, 200 hardware. DETAILED DESCRIPTION

[0027] The mode for implementing the present disclosure is described with reference to the accompanying drawings. In addition, in each figure, the same reference numerals are given to the same or corresponding parts, and the repeated description of the parts is appropriately simplified or omitted.

[0028] Implementation method 1.

[0029] Figure 1 This is a schematic diagram showing a situation in which a portable terminal is held by a person in Embodiment 1.

[0030] exist Figure 1Among them, for example, the portable terminal 1 is a smart phone. The portable terminal 1 includes a housing portion 2. The housing portion 2 houses a plurality of devices included in the portable terminal 1 inside. For example, the housing portion 2 houses an inertial sensor (not shown) inside. The housing portion 2 has a reference plane 2a. For example, the reference plane 2a is the display screen of the smart phone.

[0031] As Figure 1 shown in (A) of FIG., for example, the portable terminal 1 is held by a person. When the person walks while holding the portable terminal 1, the portable terminal 1 uses the detection value of the inertial sensor to detect the walking motion of the person. Specifically, the portable terminal 1 uses the tendency that the detection value of the inertial sensor changes periodically along with the walking motion of the person to detect the motion of taking one step by the person as one walking motion. The portable terminal 1 uses the detection value of the inertial sensor to estimate the posture of the housing portion 2 and the direction in which the housing portion 2 moves.

[0032] When the portable terminal 1 is in an environment such as an underground shopping mall where satellite positioning represented by GPS cannot be used, the portable terminal 1 uses pedestrian inertial navigation (PDR: Pedestrian Dead Reckoning), which is one of the indoor positioning technologies, to estimate the position. Specifically, the portable terminal 1 uses the detection value of the inertial sensor, the information on the estimated posture of the housing portion 2, the information on the direction in which the housing portion 2 moves, etc. to estimate the position of the housing portion 2. The portable terminal 1 calculates the movement trajectory of the housing portion 2 by accumulating the history of the estimated position of the housing portion 2. The portable terminal 1 uses the information on the calculated movement trajectory for the operation of estimating the current position of the housing portion 2.

[0033] As Figure 1 shown in (B) of FIG., when the holding method of the portable terminal 1 is changed between the time point of the first step motion by the walking person and the time point of the second step motion as the next step, the portable terminal 1 detects that the holding method has changed. Specifically, the portable terminal 1 detects that the holding method has changed by detecting that the amount of change in the posture of the housing portion 2 at each time is larger than a specified value. In this case, the portable terminal 1 regards the first traveling direction of the housing portion 2 at the time point of the first step motion as the second traveling direction of the housing portion 2 at the time point of the second step motion. After that, the portable terminal 1 uses the information on the second traveling direction as the information on the traveling direction to estimate the position of the housing portion 2.

[0034] Next, Figure 2 the portable terminal 1 will be described.

[0035] Figure 2 is a block diagram of the portable terminal in Embodiment 1.

[0036] As Figure 2As shown, the portable terminal 1 includes an acceleration sensor 3, a gyro sensor 4, and an arithmetic unit 5 inside the housing unit 2.

[0037] The acceleration sensor 3, as an inertial sensor, detects the acceleration generated in the housing unit 2. The acceleration sensor 3 transmits information on the detected value of the acceleration when a predetermined period has elapsed or when a acquisition instruction is received.

[0038] The gyro sensor 4, as an inertial sensor, detects the angular velocity generated in the housing unit 2. The gyro sensor 4 transmits information on the detected value of the angular velocity when a predetermined period has elapsed or when a acquisition instruction is received.

[0039] The arithmetic unit 5 receives information on the detected value of the acceleration from the acceleration sensor 3. The arithmetic unit 5 receives information on the detected value of the angular velocity from the gyro sensor 4. The arithmetic unit 5 includes a walking motion detection unit 6, a posture estimation unit 7, a posture change detection unit 8, a traveling direction estimation unit 9, a traveling direction output unit 10, and a position calculation unit 11.

[0040] The walking motion detection unit 6 detects the walking motion of the person holding the portable terminal 1 based on the information on the detected value of the acceleration received from the acceleration sensor 3. The walking motion detection unit 6 detects the walking motion every time the person takes a step. Specifically, when the detected value of the acceleration changes from a value other than 0 to 0, the walking motion detection unit 6 detects one walking motion.

[0041] The posture estimation unit 7 estimates the posture of the housing unit 2 using the information on the detected value of the acceleration received from the acceleration sensor 3 and the information on the angular velocity received from the gyro sensor 4. At this time, the posture estimation unit 7 estimates the posture of the housing unit 2 by estimating the normal direction of a reference plane 2a (not shown) in the Figure 2 housing unit 2. When estimating the terminal posture, the posture estimation unit 7 sends an acquisition instruction to the acceleration sensor 3 and the gyro sensor 4, thereby acquiring the detected value of the acceleration and the detected value of the angular velocity.

[0042] The posture estimation unit 7 extracts the gravitational acceleration component vector f included in the detected value of the acceleration by applying a low-pass filter to the detected value of the acceleration. b . Here, in the gravitational acceleration component vector f b , the x component, y component, and z component are represented by f x , f y , and f z , respectively.

[0043] The posture estimation unit 7 determines the gravitational acceleration component vector f at a certain moment bWhether the specified conditions are satisfied. Specifically, the posture estimation unit 7 determines the gravitational acceleration component vector f at a certain moment b whether the conditions shown in the following formula (1) are satisfied and the conditions shown in formula (2) are satisfied.

[0044] [Equation 1]

[0045] ||||f b ||-g||<δg (1)

[0046] [Equation 2]

[0047]

[0048] In Equation (1), g is the value of gravitational acceleration. δg is the first threshold of gravitational acceleration. For example, when the first threshold δg is set to a small value, the condition shown in Equation (1) becomes the following condition: the absolute value of the gravitational acceleration component vector f b becomes a value close to g.

[0049] In Equation (2), Δg is the second threshold of gravitational acceleration. For example, when the second threshold Δg is set to a small value, the condition shown in Equation (2) becomes the following condition: the gravitational acceleration component vector f b represents a value that is continuous and approximately the same over time.

[0050] When the posture estimation unit 7 determines that the gravitational acceleration component vector f at a certain moment b satisfies the specified conditions, it calculates the initial terminal posture based on the gravitational acceleration component vector f at that moment b Therefore, the posture estimation unit 7 can reduce the influence of the acceleration error component that cannot be removed by the low-pass filter included in the gravitational acceleration component vector f b on the calculation result of the initial terminal posture.

[0051] When estimating the initial terminal posture, the posture estimation unit 7 applies the gravitational acceleration component vector f b to the following formulas (3) and (4) to respectively obtain the value of the pitch angle p and the value of the roll angle r of the housing unit 2.

[0052] [Equation 3]

[0053]

[0054] [Equation 4]

[0055]

[0056] The pose estimation unit 7 uses the detected values of the angular velocity received from the gyro sensor 4, the value of the pitch angle p, and the value of the roll angle r to calculate the initial terminal pose q0 as a quaternion. When the pose estimation unit 7 calculates the initial terminal pose q0, it sets this initial terminal pose q0 as the immediately preceding terminal pose p as a quaternion. k .

[0057] The pose estimation unit 7 generates the quaternion shown in the following equation (5) for the operation of using the detected values of the angular velocity (ω x , ω y , ω z ) for pose estimation.

[0058] [Equation 5]

[0059]

[0060] The pose estimation unit 7 calculates the latest terminal pose q as a quaternion by reflecting the detected value of the angular velocity to the immediately preceding terminal pose q k as shown in the following equation (6). k+1 .

[0061] [Equation 6]

[0062]

[0063] In Equation (5), Δt is the time from the moment when the immediately preceding terminal pose q k is calculated to the moment when the latest terminal pose q k+1 is calculated.

[0064] When the pose estimation unit 7 calculates the latest terminal pose q k+1 , it sets this latest terminal pose q k+1 as the immediately preceding terminal pose q k . The pose estimation unit 7 calculates the latest terminal pose q k+1 at a prescribed period Δt. When the pose estimation unit 7 calculates the latest terminal pose q k+1 , it sends the information of this latest terminal pose q k+1 .

[0065] The pose estimation unit 7 measures the elapsed time. When it determines that the measured value of the elapsed time is larger than the prescribed value, it recalculates the initial terminal pose. When the pose estimation unit 7 recalculates the initial terminal pose, it resets the measured value of the elapsed time and starts measuring from the measured value 0.

[0066] The posture change detection unit 8 receives information on the detection result of the walking motion from the walking motion detection unit 6. The posture change detection unit 8 receives information on the latest terminal posture from the posture estimation unit 7. The posture change detection unit 8 detects whether there is a large change in the posture of the housing unit 2 based on the detection result of the walking motion and the information on the latest terminal posture.

[0067] Specifically, when the posture change detection unit 8 receives the detection result of the 0th walking motion as a certain walking motion, it detects the 0th moment when the 0th walking motion is detected. After that, when the posture change detection unit 8 receives the detection result of the walking motion detected following the 0th walking motion, that is, the detection result of the 1st walking motion, it detects the 1st moment when the 1st walking motion is detected.

[0068] The posture change detection unit 8 calculates the average value and the variance value for the pitch angle values of the housing unit 2 included in the information on a plurality of latest terminal postures received during the period from the 0th moment to the 1st moment. When the posture change detection unit 8 determines that at least one of the average value and the variance value of the pitch angle value as the variation amount of the terminal posture is larger than a specified threshold value, it detects that there is a large change in the posture of the housing unit 2. The posture change detection unit 8 performs the same calculation as in the case of the pitch angle value based on the yaw angle value and the roll angle value of the housing unit 2 included in the information on a plurality of latest terminal postures received during the period from the 0th moment to the 1st moment, thereby detecting whether there is a large change in the posture of the housing unit 2.

[0069] The traveling direction estimation unit 9 receives information on the detection result of the walking motion from the walking motion detection unit 6. The traveling direction estimation unit 9 receives information on the latest terminal posture from the posture estimation unit 7. The traveling direction estimation unit 9 estimates the traveling direction of the housing unit 2 using the detected value of the acceleration, the information on the detection result of the walking motion, and the information on the latest terminal posture.

[0070] Specifically, first, the traveling direction estimation unit 9 performs an operation of rotating the detected value of the acceleration (a x , a y , a z ) by the latest terminal posture q as shown in the following formula (7), thereby calculating the acceleration component values a n and a e in the horizontal direction.

[0071] [Equation 7]

[0072]

[0073] In formula (7), a n is the acceleration component value in the reference direction n on the horizontal plane. a eis the acceleration component value of the normal direction e on the horizontal plane with respect to the reference direction n. a u is the acceleration component value of the vertical direction u with respect to the horizontal plane. q ＊ is the conjugate quaternion of q.

[0074] For the information of a plurality of latest terminal postures received during the period from the 0th moment when the 0th step action is detected to the 1st moment when the 1st step action is detected, the traveling direction estimation unit 9 calculates the acceleration component value a in the horizontal direction n and a e .

[0075] The traveling direction estimation unit 9 performs principal component analysis on the acceleration component values a n and a e calculated during the period from the 0th moment to the 1st moment. The traveling direction estimation unit 9 estimates the direction indicated by the first component calculated by this principal component analysis as the first traveling direction moved by the first step action.

[0076] The traveling direction output unit 10 receives the information of the detection result of the step action from the step action detection unit 6. The traveling direction output unit 10 receives the information of the holding method detection result indicating whether a large change has occurred in the posture of the terminal from the posture estimation unit 7. The traveling direction output unit 10 receives the information of the estimated traveling direction of the housing unit 2 from the traveling direction estimation unit 9.

[0077] The traveling direction output unit 10 stores the information of the traveling direction flag. The traveling direction output unit 10 sets the traveling direction flag to either "0" or "1". The information of the traveling direction flag "0" indicates that the traveling direction estimation unit 9 has not estimated the traveling direction after the traveling direction output unit 10 outputs the traveling direction. The information of the traveling direction flag "1" corresponds to the information of the traveling direction estimated by the traveling direction estimation unit 9 after the traveling direction output unit 10 outputs the traveling direction.

[0078] When the traveling direction output unit 10 receives the information of the traveling direction of the housing unit 2, it determines whether the posture change detection unit 8 has detected a large change in the posture of the housing unit 2.

[0079] When the traveling direction output unit 10 determines that the posture change detection unit 8 has detected a large change in the posture of the housing unit 2 when receiving the information on the traveling direction of the housing unit 2, it determines whether the traveling direction flag is "1". When the traveling direction output unit 10 determines that the traveling direction flag is "1", it outputs the information on the traveling direction corresponding to the information of this traveling direction flag "1". When the traveling direction output unit 10 determines that the traveling direction flag is not "1", it outputs the received information on the traveling direction. After the traveling direction output unit 10 outputs the information on the traveling direction, it sets the traveling direction flag to "0".

[0080] When the traveling direction output unit 10 receives the information on the first traveling direction of the housing unit 2 and determines that the posture change detection unit 8 has not detected a large change in the posture of the housing unit 2, it associates the information on this traveling direction with the information of "1" of the traveling direction flag.

[0081] For example, the traveling direction output unit 10 receives the information on the first traveling direction corresponding to the first step motion. When no large change in the posture of the housing unit 2 is detected immediately before the first step motion, the traveling direction output unit 10 associates the information on the first step motion with the information of the traveling direction flag "1".

[0082] After that, the traveling direction output unit 10 receives the information on the second traveling direction corresponding to the second step motion following the first step motion. When no large change in the posture of the housing unit 2 is detected during the period from the first step motion to the second step motion, the traveling direction output unit 10 outputs the information on the second traveling direction. When a large change in the posture of the housing unit 2 is detected during the period from the first step motion to the second step motion, the traveling direction output unit 10 outputs the information on the first traveling direction corresponding to the information of the traveling direction flag "1".

[0083] The position calculation unit 11 receives the input of the information on the traveling direction from the traveling direction output unit 10. For example, the position calculation unit 11 calculates the position of the housing unit 2 using PDR. The position calculation unit 11 calculates the position of the housing unit 2 using information such as the detection value information of acceleration, the detection value information of angular velocity, and the information on the traveling direction of the housing unit 2.

[0084] Next, use Figure 3 to illustrate the operation of the portable terminal 1 for determining the traveling direction of the housing unit 2.

[0085] Figure 3 is a flowchart for illustrating the outline of the operation of the portable terminal in Embodiment 1 for determining the traveling direction.

[0086] For example, when the portable terminal 1 detects that it cannot receive GPS radio waves, it starts the operation of determining the traveling direction using PDR.

[0087] As Figure 3 shown, in step S001, the portable terminal 1 sets the traveling direction flag to "0".

[0088] After that, the portable terminal 1 performs the operation of step S002. In step S002, the portable terminal 1 detects the first step operation as a single step walking operation.

[0089] After that, the portable terminal 1 performs the operation of step S003. In step S003, the portable terminal 1 estimates the first posture of the housing portion 2 when the first step operation is detected.

[0090] After that, the portable terminal 1 performs the operation of step S004. In step S004, the portable terminal 1 estimates the first traveling direction of the housing portion 2 when the first step operation is detected.

[0091] After that, the portable terminal 1 performs the operation of step S005. In step S005, the portable terminal 1 determines whether the second step operation after the first step operation is detected.

[0092] If it is determined in step S005 that the second step operation is not detected, the portable terminal 1 repeats the operation of step S005.

[0093] If it is determined in step S005 that the second step operation is detected, the portable terminal 1 performs the operation of step S006. In step S006, the portable terminal 1 determines whether a large change in the posture of the housing portion 2 is detected.

[0094] If it is determined in step S006 that the holding method has not changed, the portable terminal 1 performs the operation of step S007. In step S007, the portable terminal 1 sets the traveling direction flag to "1". At this time, the portable terminal 1 associates the "1" of the traveling direction flag with the first traveling direction.

[0095] After performing the operation of step S007, the portable terminal 1 repeats the operations after step S002.

[0096] If it is determined in step S006 that the holding method has changed, the portable terminal 1 performs the operation of step S008. In step S008, the portable terminal 1 determines whether the traveling direction flag is "1".

[0097] When it is determined in step S008 that the traveling direction flag is "1", the portable terminal 1 performs the operation of step S009. In step S009, the portable terminal 1 outputs the first traveling direction corresponding to the "1" of the traveling direction flag as the traveling direction in the second step operation. After that, the portable terminal 1 performs the operations after step S001.

[0098] When it is determined in step S008 that the traveling direction flag is not "1", the portable terminal 1 performs the operation of step S010. In step S010, the portable terminal 1 estimates the information of the second traveling direction in the second step operation.

[0099] After that, the portable terminal 1 performs the operation of step S011. In step S011, the portable terminal 1 outputs the second traveling direction estimated in step S010 as the traveling direction in the second step operation. After that, the portable terminal 1 performs the operations after step S001.

[0100] Next, Figure 4 is used to illustrate the operation of the arithmetic unit 5 for estimating the posture of the housing unit 2.

[0101] Figure 4 is a flowchart for explaining the outline of the operation of the portable terminal for estimating the posture in Embodiment 1.

[0102] As Figure 4 shown, in step S101, the arithmetic unit 5 obtains the information of the detection values from the acceleration sensor 3 and the gyro sensor 4.

[0103] After that, the arithmetic unit 5 performs the operation of step S102. In step S102, the arithmetic unit 5 determines whether the gravitational acceleration component vector satisfies a specified condition.

[0104] When it is determined in step S102 that the gravitational acceleration component vector does not satisfy the specified condition, the arithmetic unit 5 performs the operations after step S101.

[0105] When it is determined in step S102 that the gravitational acceleration component vector satisfies the specified condition, the arithmetic unit 5 performs the operation of step S103. In step S103, the arithmetic unit 5 estimates the initial terminal posture.

[0106] After that, the arithmetic unit 5 performs the operation of step S104. In step S104, the arithmetic unit 5 starts measuring the elapsed time.

[0107] After that, the arithmetic unit 5 performs the operation of step S105. In step S105, the arithmetic unit 5 obtains the information of the detection values from the acceleration sensor 3 and the gyro sensor 4.

[0108] After that, the arithmetic unit 5 performs the operation of step S106. In step S106, the arithmetic unit 5 determines whether the measured value of the elapsed time is equal to or less than a specified value.

[0109] When it is determined in step S106 that the measured value of the elapsed time is equal to or less than the specified value, the arithmetic unit 5 performs the operation of step S107. In step S107, the arithmetic unit 5 calculates and outputs the latest terminal posture that reflects the detection value of the inertial sensor in the immediately preceding terminal posture. After that, the arithmetic unit 5 performs the operations after step S105.

[0110] When it is determined in step S106 that the measured value of the elapsed time is greater than the specified value, the arithmetic unit 5 performs the operation of step S108. In step S108, the arithmetic unit 5 determines whether the gravitational acceleration component vector satisfies a specified condition.

[0111] When it is determined in step S108 that the gravitational acceleration component vector does not satisfy the specified condition, the arithmetic unit 5 performs the operations after step S107.

[0112] When it is determined in step S108 that the gravitational acceleration component vector satisfies the specified condition, the arithmetic unit 5 performs the operation of step S109. In step S109, the arithmetic unit 5 re-estimates the initial terminal posture and sets the initial terminal posture as the immediately preceding terminal posture.

[0113] After that, the arithmetic unit 5 performs the operation of step S110. In step S110, the arithmetic unit 5 resets the measured value of the elapsed time and starts measuring from the state where the measured value is 0. After that, the arithmetic unit 5 performs the operations after step S107.

[0114] According to the first embodiment described above, the portable terminal 1 includes a housing unit 2, a walking motion detection unit 6, a posture estimation unit 7, and a posture change detection unit 8. When the holding method of the portable terminal 1 changes between the first walking motion and the second walking motion, the portable terminal 1 detects whether a large change has occurred in the posture of the housing unit 2 by calculating the change in the posture of the housing unit 2 between the first walking motion and the second walking motion. Therefore, the accuracy of detecting the change in the posture of the portable terminal 1 can be improved. As a result, it is possible to suppress an error caused by a change in posture from overlapping when the position of the portable terminal 1 is calculated using PDR.

[0115] In addition, since the portable terminal 1 can more accurately detect changes in posture, when obtaining various types of information, the portable terminal 1 can improve the accuracy of the obtained information. For example, when the portable terminal 1 obtains the radio wave intensity (RSSI), it can correct the radio wave intensities of the x, y, and z axes based on the change in the posture of the housing unit 2. When the portable terminal 1 obtains the intensity of sound waves (sound pressure), it can correct the sound wave intensities of the x, y, and z axes based on the change in the posture of the housing unit 2. In addition, since the portable terminal 1 can more accurately detect changes in posture, when a map is displayed on the screen of the portable terminal 1, the direction of the displayed map can be corrected.

[0116] In addition, the portable terminal 1 calculates the average pitch angle, the variance value of the pitch angle, the average yaw angle, the variance value of the yaw angle, the average roll angle, and the variance value of the roll angle of the housing unit 2. When the portable terminal 1 determines that at least one of the calculated multiple average values and variance values is larger than the corresponding threshold value, it detects that a large change in posture has occurred. Therefore, the change in the posture of the portable terminal 1 can be detected more accurately.

[0117] In addition, the portable terminal 1 includes a traveling direction estimation unit 9 and a traveling direction output unit 10. When the holding method of the portable terminal 1 changes between the first step motion and the second step motion, the portable terminal 1 outputs the first traveling direction immediately before the posture of the housing unit 2 is about to change significantly as the second traveling direction immediately after the posture has changed significantly. Therefore, the influence of the error caused by the change in the posture of the housing unit 2 when estimating the traveling direction using inertial navigation can be reduced. As a result, the accuracy of position detection using PDR can be improved. In addition, compared with conventional positioning methods such as map matching, position detection can be performed with a simple structure. In addition, accurate position detection can also be performed in a wide space such as a square.

[0118] In addition, the inertial sensor and the arithmetic unit 5 of the present application can be applied to a walking robot that moves by performing a periodic motion such as a walking motion. Specifically, the walking robot may also include a walking housing unit that moves by walking using multiple legs, an inertial sensor, and an arithmetic unit 5. The walking robot can also detect whether a significant change in the posture of the walking housing unit has occurred in the same manner as the portable terminal 1. Therefore, the walking robot can improve the accuracy of detecting changes in its own posture.

[0119] In addition, the portable terminal 1 detects whether a significant change in the posture of the housing unit 2 has occurred by means of a position calculation support method including a first step detection process, a posture estimation process, a second step detection process, and a posture change detection process. Therefore, the change in the posture of the housing unit 2 can be detected more accurately.

[0120] In addition, regarding the method for the walking motion detection unit 6 to detect a walking motion, it is only necessary to utilize the fact that the detection values of the inertial sensors change periodically, and a method other than the method described in Embodiment 1 may also be adopted. For example, the walking motion detection unit 6 may also detect the walking motion by detecting peaks that change periodically in the detection values of the acceleration. The walking motion detection unit 6 may also use the measured values of the angular velocity received from the gyro sensor 4 to detect the walking motion. When the acceleration sensor 3 detects the acceleration of three axes, the walking motion detection unit 6 may also detect the walking motion by detecting whether the absolute value of the detection value of the acceleration exceeds a specified value. When the acceleration sensor 3 detects the acceleration of three axes, the walking motion detection unit 6 may also detect the walking motion by detecting peaks that change periodically in the detection values of the acceleration related to each axis. When the acceleration sensor 3 detects the acceleration of three axes, the walking motion detection unit 6 may also calculate the acceleration in the vertical direction based on the detection values of the acceleration, and use the acceleration in the vertical direction to detect the walking motion.

[0121] In addition, the posture estimation unit 7 may also use filters such as a Kalman filter and a Madgwic filter to synthesize the detection values of the acceleration and the angular velocity, and thereby estimate the latest terminal posture based on the immediately preceding terminal posture.

[0122] In addition, the posture change detection unit 8 may also compare the first terminal posture at the first moment with the second terminal posture at the second moment to detect whether the second terminal posture has changed by a specified degree or more relative to the first terminal posture.

[0123] In addition, the traveling direction estimation unit 9 may also calculate a time-averaged vector obtained by time-averaging each component of the normal vector with respect to the reference plane 2a during the period from the first moment to the second moment. The traveling direction estimation unit 9 may also regard the vector direction obtained by projecting the time-averaged vector onto the horizontal plane as the first traveling direction after moving through the first walking motion.

[0124] In addition, the posture change detection unit 8 may also detect whether the holding method of the housing unit 2 has changed when it detects that the posture of the housing unit 2 has changed significantly.

[0125] Next, Figure 5 An example of the hardware constituting the portable terminal 1 will be described.

[0126] Figure 5 is the hardware configuration diagram of the portable terminal in Embodiment 1.

[0127] Each function of the portable terminal 1 can be implemented by a processing circuit. For example, the processing circuit includes at least one processor 100a and at least one memory 100b. For example, the processing circuit includes at least one dedicated hardware 200.

[0128] When the processing circuit includes at least one processor 100a and at least one memory 100b, each function of the portable terminal 1 is implemented by software, firmware, or a combination of software and firmware. At least one of the software and the firmware is described in the form of a program. At least one of the software and the firmware is stored in at least one memory 100b. At least one processor 100a implements each function of the portable terminal 1 by reading and executing the program stored in at least one memory 100b. At least one processor 100a is also referred to as a central processing unit, a processing unit, an arithmetic unit, a microprocessor, a microcomputer, or a DSP. For example, at least one memory 100b is a non-volatile or volatile semiconductor memory such as a RAM, a ROM, a flash memory, an EPROM, or an EEPROM, a magnetic disk, a floppy disk, an optical disk, a high-density disk, a mini disk, or a DVD.

[0129] When the processing circuit includes at least one dedicated hardware 200, the processing circuit is implemented, for example, by a single circuit, a composite circuit, a programmed processor, a parallel-programmed processor, an ASIC, an FPGA, or a combination thereof. For example, each function of the portable terminal 1 is implemented by the processing circuit respectively. For example, each function of the portable terminal 1 is implemented by the processing circuit uniformly.

[0130] Regarding each function of the portable terminal 1, a part can also be implemented by the dedicated hardware 200, and the other part can be implemented by software or firmware. For example, it can also be that, regarding the function of detecting the walking motion, it is implemented by the processing circuit as the dedicated hardware 200, and regarding the functions other than the function of detecting the walking motion, they are implemented by at least one processor 100a reading and executing the program stored in at least one memory 100b.

[0131] In this way, the processing circuit implements each function of the portable terminal 1 through the hardware 200, software, firmware, or a combination thereof.

[0132] Embodiment 2.

[0133] Figure 6 It is a block diagram of the portable terminal in Embodiment 2. In addition, the same reference numerals are given to the parts that are the same as or equivalent to the parts in Embodiment 1. The description of this part is omitted.

[0134] In Embodiment 2, the portable terminal 1 includes a geomagnetic sensor 20.

[0135] The geomagnetic sensor 20 detects the geomagnetic direction relative to the housing unit 2 as an inertial sensor. When a predetermined period has elapsed or when an acquisition instruction is received, the geomagnetic sensor 20 transmits information on the detected value of the geomagnetic direction to the arithmetic unit 5.

[0136] The arithmetic unit 5 includes an azimuth angle arithmetic unit 21.

[0137] The azimuth angle arithmetic unit 21 receives information on the latest terminal posture transmitted from the posture estimation unit 7. The azimuth angle arithmetic unit 21 receives information on the detected value of the geomagnetic direction from the geomagnetic sensor 20. The azimuth angle arithmetic unit 21 uses the information on the latest terminal posture and the information on the detected value of the geomagnetic direction to calculate a projection vector obtained by projecting onto the normal vector of the reference plane 2a (not shown) with respect to the horizontal plane. At this time, the azimuth angle arithmetic unit 21 uses the time-averaged vector of the normal vectors between the (n - 1)-th time when the (n - 1)-th action is performed and the n-th time when the n-th action is performed as the n-th normal vector in the n-th action. Figure 6 The azimuth angle arithmetic unit 21 sets the detected value of the geomagnetic direction as the reference direction on the horizontal plane. The azimuth angle arithmetic unit 21 calculates the angle between the projection vector and the reference direction on the horizontal plane, that is, the azimuth angle. For example, the n-th azimuth angle of the normal vector is the azimuth angle calculated using the n-th normal vector in the n-th action.

[0138] The azimuth angle arithmetic unit 21 receives information on the traveling direction from the traveling direction estimation unit 9. The azimuth angle arithmetic unit 21 calculates the azimuth angle between the traveling direction vector, which is the traveling direction estimated by the traveling direction estimation unit 9, and the reference direction on the horizontal plane. For example, the n-th azimuth angle of the traveling direction vector is the azimuth angle of the n-th traveling direction.

[0139]

[0140] In the case where no significant change in the posture is detected in the second and third actions after a significant change in the posture of the housing unit 2 is detected, the traveling direction output unit 10 calculates the third traveling direction in the third action based on the geomagnetic sensor 20.

[0141] ​Specifically, when it is determined that a large change in the posture of the housing unit 2 is detected between the first movement action and the second movement action and no large change in the posture of the housing unit 2 is detected in the second movement action and the third movement action, the traveling direction output unit 10 receives information on the value α of the first azimuth angle of the normal vector in the first movement action and information on the value β of the third azimuth angle of the normal vector in the third movement action from the azimuth angle calculation unit 21. In addition, the traveling direction output unit 10 receives information on the value A′ of the first azimuth angle of the first traveling direction vector in the first movement action from the azimuth angle calculation unit 21. The traveling direction output unit 10 uses the detected value of the geomagnetic direction as the reference direction and outputs the direction of the traveling direction estimation vector whose azimuth angle value B′ as the corrected azimuth angle satisfies the following formula (8) as the third traveling direction.

[0142] B′ = A′ + (β - α) (8)

[0143] Next, using Figure 7 and Figure 8 , the estimation method of the traveling direction using the geomagnetic sensor 20 will be described using the vector space.

[0144] Figure 7 is a diagram showing the azimuth angles calculated by the portable terminal in Embodiment 2. Figure 8 is a diagram showing the azimuth angles calculated by the portable terminal in Embodiment 2.

[0145] In Figure 7 and Figure 8 , an orthogonal coordinate system representing a three-dimensional vector space is shown. The direction of the n-axis is the direction indicated by the detected value of the geomagnetic direction as the reference direction. The direction of the e-axis is the direction orthogonal to the n-axis on the horizontal plane. The direction of the u-axis is the direction perpendicular to the horizontal plane.

[0146] Figure 7 shows the first traveling direction vector v A , the first normal vector v n1 in the first movement action, and the first projection vector v p1 of the first normal vector. The value of the first azimuth angle of the first traveling direction vector v A is A′. The value of the azimuth angle of the first normal vector v n1 is α.

[0147] Figure 8 shows the third normal vector v n3 in the third movement action, the third projection vector v p3 of the third normal vector, and the third traveling direction vector v B . The value of the azimuth angle of the third normal vector v n3 is β.

[0148] The traveling direction output unit 10 calculates the value of the azimuth angle relative to the reference direction as A'+(β-α) for the third traveling direction vector v B . The traveling direction output unit 10 outputs the third traveling direction vector v as a correction vector B in the direction as the estimated third traveling direction.

[0149] According to the second embodiment described above, the portable terminal 1 outputs a corrected traveling direction obtained by correcting the traveling direction immediately before the posture of the housing unit 2 changes using the detection value of the geomagnetic sensor. Generally, the spatial resolution of the geomagnetic sensor in an outdoor space is on the order of several meters. That is, within a range of several meters, the geomagnetic sensor outputs a substantially stable detection value. Therefore, for example, in an outdoor space, the portable terminal 1 can improve the accuracy of estimating the traveling direction. As a result, the accuracy of position measurement can be improved.

[0150] In addition, the portable terminal 1 calculates the azimuth angle using the geomagnetic direction as the reference direction, and corrects the first traveling direction using the azimuth angle, thereby outputting the third traveling direction as the corrected traveling direction. Therefore, it is possible to utilize the corrected traveling direction that reflects the change in the posture of the housing unit 2 in the traveling direction estimated by the traveling direction estimation unit 9 using the geomagnetic direction.

[0151] In addition, the portable terminal 1 may also determine the propriety of the traveling direction corrected by the geomagnetic sensor based on the traveling direction of the housing unit 2 obtained by using a positioning method other than PDR. The portable terminal may also determine that the traveling direction corrected by the geomagnetic sensor is proper when the difference between the traveling direction corrected by the geomagnetic sensor and the traveling direction obtained by using other positioning methods is less than a specified value. When the portable terminal 1 determines that the traveling direction corrected by the geomagnetic sensor is proper, the corrected traveling direction may also be output. For example, this other positioning method is a positioning method that utilizes the radio wave intensity of radio waves such as Bluetooth (registered trademark) Low Energy and Wi-Fi (registered trademark), a positioning method that utilizes the arrival time of radio waves of Ultra Wide Band, a positioning method that utilizes the image information captured by a camera, and the like.

Claims

1. A portable terminal, wherein, The portable terminal includes: a housing portion; a walking motion detection unit that detects a walking motion when the housing portion is moved by walking; a posture estimation unit that estimates the posture of the housing portion; a posture change detection unit that, when the posture of the housing portion has changed significantly between a first time when the walking motion detection unit detects a first walking motion and a second time when the walking motion detection unit detects a second walking motion after the first walking motion, detects that the posture of the housing portion has changed between the first walking motion and the second walking motion based on the amount of change in the posture of the housing portion estimated by the posture estimation unit between the first time when the first walking motion is detected and the second time when the second walking motion is detected; a traveling direction estimation unit that estimates the traveling direction in which the housing portion has moved by a walking motion using information on the walking motion detected by the walking motion detection unit; a traveling direction output unit that, when the posture change detection unit detects that the posture of the housing portion has changed between the first walking motion and the second walking motion, outputs the first traveling direction of the housing portion estimated by the traveling direction estimation unit based on the first walking motion as the traveling direction of the housing portion based on the second walking motion; and a position calculation unit that calculates the position of the housing portion based on information including the traveling direction of the housing portion output by the traveling direction output unit.

2. The portable terminal according to claim 1, wherein, When the posture change detection unit does not detect that the posture of the housing portion has changed between the second walking motion and a third walking motion after the second walking motion, the traveling direction output unit calculates a corrected traveling direction and outputs the corrected traveling direction as the traveling direction based on the third walking motion, where the corrected traveling direction is obtained by correcting the first traveling direction of the housing portion based on information on the geomagnetic direction detected by a geomagnetic sensor.

3. The portable terminal according to claim 2, wherein, The portable terminal includes an azimuth angle calculation unit that calculates an average vector obtained by averaging the components of a normal vector of the housing portion with respect to a reference plane during a period from a walking motion to the next walking motion, and calculates an angle formed by a projection vector obtained by projecting the average vector onto a horizontal plane and the geomagnetic direction detected by the geomagnetic sensor as the azimuth angle of the normal vector in the next walking motion. The traveling direction output unit receives information on the value of the first azimuth angle of the normal vector in the first step motion and information on the value of the third azimuth angle of the normal vector in the third step motion from the azimuth angle calculation unit, calculates the angle formed by the first traveling direction estimated by the traveling direction estimation unit and the geomagnetic direction detected by the geomagnetic sensor as the azimuth angle of the first traveling direction, calculates the value of the corrected azimuth angle obtained by subtracting the value of the first azimuth angle of the normal vector from the sum of the value of the azimuth angle of the first traveling direction and the value of the third azimuth angle of the normal vector, and calculates the direction toward which the correction vector having the same azimuth angle as the value of the corrected azimuth angle with respect to the geomagnetic direction is oriented as the corrected traveling direction.

4. A portable terminal, wherein, The portable terminal includes: a housing unit; a step motion detection unit that detects a step motion when the housing unit is moved by walking; a posture estimation unit that estimates the posture of the housing unit; a posture change detection unit that, when the posture of the housing unit has changed significantly between the first moment when the step motion detection unit detects the first step motion and the second moment when the step motion detection unit detects the second step motion after the first step motion, detects that the posture of the housing unit has changed between the first step motion and the second step motion based on the amount of change in the posture of the housing unit estimated by the posture estimation unit between the first moment when the first step motion is detected and the second moment when the second step motion is detected; a traveling direction estimation unit that estimates the traveling direction in which the housing unit has moved by a step motion using information on the step motion detected by the step motion detection unit; and a traveling direction output unit that, when the posture change detection unit detects that the posture of the housing unit has changed between the first step motion and the second step motion, outputs the first traveling direction of the housing unit estimated by the traveling direction estimation unit based on the first step motion as the traveling direction of the housing unit based on the second step motion, and when the posture change detection unit does not detect that the posture of the housing unit has changed between the second step motion and the third step motion after the second step motion, the traveling direction output unit calculates a corrected traveling direction and outputs the corrected traveling direction as the traveling direction based on the third step motion, where the corrected traveling direction is obtained by correcting the first traveling direction of the housing unit based on information on the geomagnetic direction detected by the geomagnetic sensor.

5. The portable terminal according to claim 4, wherein, The portable terminal includes an azimuth angle calculation unit that calculates an average vector obtained by averaging the components of the normal vector of the housing unit with respect to a reference plane during a step motion to the next step motion, and calculates the angle formed by the projection vector obtained by projecting the average vector onto a horizontal plane and the geomagnetic direction detected by the geomagnetic sensor as the azimuth angle of the normal vector in the next step motion. The traveling direction output unit receives information on the value of the first azimuth angle of the normal vector in the first step motion and information on the value of the third azimuth angle of the normal vector in the third step motion from the azimuth angle calculation unit, calculates the angle formed by the first traveling direction estimated by the traveling direction estimation unit and the geomagnetic direction detected by the geomagnetic sensor as the azimuth angle of the first traveling direction, calculates the value of the corrected azimuth angle obtained by subtracting the value of the first azimuth angle of the normal vector from the sum of the value of the azimuth angle of the first traveling direction and the value of the third azimuth angle of the normal vector, and calculates the direction in which the corrected vector having the same azimuth angle as the value of the corrected azimuth angle with respect to the geomagnetic direction points as the corrected traveling direction.

6. The portable terminal according to any one of claims 1 to 5, wherein, The posture estimation unit estimates the posture of the housing unit at a plurality of times during the period from the first time to the second time, and thereby generates a plurality of posture information corresponding to the plurality of times respectively. Based on the plurality of posture information generated by the posture estimation unit, the posture change detection unit calculates the pitch angle average value and the pitch angle variance value for the pitch angle values of the housing unit at the plurality of times, calculates the yaw angle average value and the yaw angle variance value for the yaw angle values of the housing unit at the plurality of times, calculates the roll angle average value and the roll angle variance value for the roll angle values of the housing unit at the plurality of times, and detects that the posture of the housing unit has changed between the first step motion and the second step motion when it is determined that at least one of the pitch angle average value, the pitch angle variance value, the yaw angle average value, the yaw angle variance value, the roll angle average value, and the roll angle variance value is greater than the corresponding threshold value.

7. A walking robot, wherein, The walking robot includes: A walking housing unit that moves by walking using a plurality of legs; A step motion detection unit that detects the step motion when the walking housing unit moves; A posture estimation unit that estimates the posture of the walking housing unit; A posture change detection unit that, when the posture of the walking housing unit has changed significantly between the first time when the step motion detection unit detects the first step motion and the second time when the step motion detection unit detects the second step motion after the first step motion, detects that the posture of the walking housing unit has changed between the first step motion and the second step motion based on the amount of change in the posture of the walking housing unit estimated by the posture estimation unit between the first time when the first step motion is detected and the second time when the second step motion is detected. A traveling direction estimation unit that estimates the traveling direction in which the walking housing unit has moved by the step motion using the information on the step motion detected by the step motion detection unit. A traveling direction output unit that, when the posture change detection unit detects a change in the posture of the walking housing unit between the first step motion and the second step motion, outputs the first traveling direction of the walking housing unit based on the first step motion estimated by the traveling direction estimation unit as the traveling direction of the walking housing unit based on the second step motion; and A position calculation unit that calculates the position of the walking housing unit based on the information including the traveling direction of the walking housing unit output by the traveling direction output unit.

8. A walking robot, wherein, The walking robot includes: A walking housing unit that moves by walking using a plurality of legs; A step motion detection unit that detects the step motion when the walking housing unit moves; A posture estimation unit that estimates the posture of the walking housing unit; A posture change detection unit that, when the posture of the walking housing unit changes significantly between the first time when the step motion detection unit detects the first step motion and the second time when the step motion detection unit detects the second step motion after the first step motion, the posture change detection unit detects a change in the posture of the walking housing unit between the first step motion and the second step motion based on the amount of change in the posture of the walking housing unit estimated by the posture estimation unit between the first time when the first step motion is detected and the second time when the second step motion is detected; A traveling direction estimation unit that uses the information of the step motion detected by the step motion detection unit to estimate the traveling direction in which the walking housing unit has moved by the step motion; and A traveling direction output unit that, when the posture change detection unit detects a change in the posture of the walking housing unit between the first step motion and the second step motion, outputs the first traveling direction of the walking housing unit based on the first step motion estimated by the traveling direction estimation unit as the traveling direction of the walking housing unit based on the second step motion, When the posture change detection unit does not detect a change in the posture of the walking housing unit between the second step motion and the third step motion after the second step motion, the traveling direction output unit calculates and corrects the traveling direction, and outputs the corrected traveling direction as the traveling direction based on the third step motion, where the corrected traveling direction is obtained by correcting the first traveling direction of the walking housing unit based on the information of the geomagnetic direction detected by the geomagnetic sensor.

9. A computer-readable storage medium storing a computer program, wherein the computer is disposed in a housing, wherein, When this computer program is executed by a processor, the following steps are performed: A walking detection step of detecting the step motion when the housing is moved by walking; A posture estimation step of estimating the posture of the housing; Posture change detection step: When there is a significant change in the posture of the housing between the first moment of the first step action detected in the walking detection step and the second moment of the second step action detected after the first step action in the walking detection step, based on the amount of change in the posture of the housing estimated between the first moment and the second moment in the posture estimation step, detect that the posture of the housing has changed between the first step action when the first step action is detected and the second step action when the second step action is detected; Travel direction estimation step: Using the information of the walking action detected in the walking detection step, estimate the travel direction in which the housing has moved through the walking action; Travel direction output step: When it is detected in the posture change detection step that the posture of the housing has changed between the first step action and the second step action, output the first travel direction of the housing based on the first step action estimated in the travel direction estimation step as the travel direction of the housing based on the second step action; And Position calculation step: Calculate the position of the housing based on the information including the travel direction of the housing output in the travel direction output step.

10. A computer-readable storage medium storing a computer program, wherein the computer is disposed in a housing, wherein, When this computer program is executed by a processor, the following steps are performed: Walking detection step: Detect the walking action when the housing is moved by walking; Posture estimation step: Estimate the posture of the housing; Posture change detection step: When there is a significant change in the posture of the housing between the first moment of the first step action detected in the walking detection step and the second moment of the second step action detected after the first step action in the walking detection step, based on the amount of change in the posture of the housing estimated between the first moment when the first step action is detected and the second moment when the second step action is detected in the posture estimation step, detect that the posture of the housing has changed between the first step action and the second step action; Travel direction estimation step: Using the information of the walking action detected in the walking detection step, estimate the travel direction in which the housing has moved through the walking action; And Travel direction output step: When it is detected in the posture change detection step that the posture of the housing has changed between the first step action and the second step action, output the first travel direction of the housing based on the first step action estimated in the travel direction estimation step as the travel direction of the housing based on the second step action, The traveling direction output step includes the following steps: When it is not detected in the posture change detection step that the posture of the housing has changed between the second step motion and the third step motion after the second step motion, the traveling direction is calculated and corrected, and the corrected traveling direction is output as the traveling direction based on the third step motion, where the corrected traveling direction is obtained by correcting the first traveling direction of the housing based on the information of the geomagnetic direction detected by the geomagnetic sensor.

11. A position calculation support method, wherein, The position calculation support method includes: A first step motion detection process in which a processing circuit provided in the housing detects a first step motion when the housing is moved by walking. A posture estimation process that is performed after the first step motion detection process, and in which the processing circuit estimates the posture of the housing. A first traveling direction estimation process that is performed after the first step motion detection process, and in which the processing circuit estimates the moving direction of the housing based on the first step motion, that is, the first traveling direction. A second step motion detection process that is performed after the posture estimation process, and in which the processing circuit detects a second step motion after the first step motion. A posture change detection process that is performed after the second step motion detection process, and in which, when the posture of the housing has changed significantly between the first step motion and the second step motion, the processing circuit detects that the posture of the housing has changed between the first step motion and the second step motion based on the amount of change in the posture of the housing estimated in the posture estimation process between the first step motion and the second step motion. A traveling direction output process in which, when it is detected in the posture change detection process that the posture of the housing has changed between the first step motion and the second step motion, the processing circuit outputs the first traveling direction as the traveling direction of the housing based on the second step motion. And A position calculation process in which the processing circuit calculates the position of the housing based on the information including the traveling direction of the housing output in the traveling direction output process.

12. A method for supporting position operations, wherein, The position calculation support method includes: A first step motion detection process in which a processing circuit provided in the housing detects a first step motion when the housing is moved by walking. A first posture estimation process that is performed after the first step motion detection process, and in which the processing circuit estimates the first posture of the housing. A first traveling direction estimation process that is performed after the first step motion detection process, and in which the processing circuit estimates the moving direction of the housing based on the first step motion, that is, the first traveling direction. The second step detection process, which is performed after the first posture estimation process. In the second step detection process, the processing circuit detects a second step action after the first step action; The second posture estimation process, which is performed after the second step detection process. In the second posture estimation process, the processing circuit estimates a second posture of the housing; The first posture change detection process, which is performed after the second posture estimation process. In the first posture change detection process, when the posture of the housing has changed significantly between the first step action and the second step action, the processing circuit detects that the posture of the housing has changed between the first step action and the second step action based on the amount of change in the posture of the housing estimated in the first posture estimation process and the second posture estimation process between the first step action and the second step action; The traveling direction output process. When it is detected in the first posture change detection process that the posture of the housing has changed between the first step action and the second step action, the processing circuit outputs the first traveling direction as the traveling direction of the housing based on the second step action; The third step detection process, which is performed after the traveling direction output process. In the third step detection process, the processing circuit detects a third step action after the second step action; The third posture estimation process, which is performed after the third step detection process. In the third posture estimation process, the processing circuit estimates a third posture of the housing; The second posture change detection process, which is performed after the third posture estimation process. In the second posture change detection process, the processing circuit detects that the posture of the housing has changed between the second step action and the third step action based on the amount of change in the posture of the housing estimated in the second posture estimation process and the third posture estimation process; And The corrected traveling direction output process. When it is not detected in the second posture change detection process that the posture of the housing has changed between the second step action and the third step action, the processing circuit calculates a corrected traveling direction, and the processing circuit outputs the corrected traveling direction as the traveling direction based on the third step action, where the corrected traveling direction is obtained by correcting the first traveling direction of the housing based on information on the geomagnetic direction detected by a geomagnetic sensor provided in the housing.

Images