WO2014125809A1

WO2014125809A1 - Attitude calculating apparatus, attitude calculating method, portable apparatus, and program

Info

Publication number: WO2014125809A1
Application number: PCT/JP2014/000704
Authority: WO
Inventors: 淑正鈴木; 剛志舛田; 崇弘北浦; 北村　徹
Original assignee: 旭化成エレクトロニクス株式会社
Priority date: 2013-02-13
Filing date: 2014-02-10
Publication date: 2014-08-21
Also published as: JP6209581B2; JPWO2014125809A1

Abstract

Provided is an attitude calculating apparatus that is provided with: a first attitude calculating section, which is mounted in an apparatus, and which calculates first attitude of the apparatus on the basis of an output from an angular velocity detecting section that detects an angular velocity of the apparatus; a second attitude calculating section that calculates second attitude of the apparatus using a means different from the first attitude calculating section; and a third attitude calculating section that calculates third attitude on the basis of the first attitude, the second attitude, and rotation information of the apparatus.

Description

Attitude calculation device, attitude calculation method, portable device, and program

The present invention relates to an attitude calculation device, an attitude calculation method, a portable device, and a program.

Conventionally, devices using an angular velocity sensor, an acceleration sensor, and a geomagnetic sensor are known as devices for detecting the attitude of an apparatus. As an example of the device, a motion angle calculation device that calculates a movement angle per unit time based on an output of an angular velocity sensor, a static angle calculation device that calculates a static angle based on outputs of an acceleration sensor and a geomagnetic sensor, A discriminating device that discriminates the truth of the calculation result by the static angle calculation device, and an attitude angle calculation that calculates an attitude angle from the calculation results of the motion angle calculation device and the static angle calculation device according to the calculation result of the discrimination device 2. Description of the Related Art An attitude angle detection device configured with a device is known (see, for example, Patent Document 1).
[Patent Document 1] Japanese Patent Application Laid-Open No. 11-211479

The posture angle calculation device of Patent Document 1 calculates the posture angle from the motion angle when it is estimated that the calculation result by the stationary angle calculation device is incorrect. In addition, the posture angle calculation device of Patent Document 1 preliminarily calculates the motion angle obtained from the motion angle calculation device and the static angle obtained from the static angle calculation device when the calculation result by the static angle calculation device is estimated to be correct. The posture angle is calculated by adding together at a predetermined ratio. That is, the posture angle calculation device of Patent Document 1 calculates a posture obtained by adding the motion angle and the stationary angle at a ratio of k: 1-k (k is a predetermined constant) as the posture angle.

However, the posture angle detection device of Patent Document 1 reduces the uncomfortable feeling given to the user of the device, and allows the posture angle to quickly follow the stationary angle when the output of the acceleration sensor or the geomagnetic sensor is estimated to be correct. There is a problem that the two cannot be made compatible. The reason will be described below.

In many scenes, devices equipped with posture angle calculation devices are moving with large accelerations, and large disturbance magnetic fields are generated around the posture angle calculation devices. For this reason, there are few scenes where the output of the acceleration sensor or the geomagnetic sensor is estimated to be correct. Therefore, in the posture angle detection device of Patent Document 1, in most cases, the posture angle is calculated based on the motion angle, and the posture angle is calculated based on the stationary angle and the motion angle. In Patent Document 1, when the value of k is small, the influence of the motion angle is small and the influence of the stationary angle is large. Therefore, when the output of the acceleration sensor or the geomagnetic sensor is estimated to be correct, the posture changes greatly. Become. If the posture changes greatly while the device is almost stationary, the user of the device will feel uncomfortable. On the other hand, when the value of k is large, the influence of the motion angle is large and the influence of the static angle is small, so that the feeling of discomfort given to the user of the device is reduced, but the static angle cannot be quickly followed. As described above, the posture angle detection device of Patent Document 1 reduces the uncomfortable feeling given to the user of the device and quickly follows the posture angle when the output of the acceleration sensor or the geomagnetic sensor is estimated to be correct. There is a problem that it is impossible to achieve both of the two.

In the first aspect of the present invention, a first attitude calculation unit that calculates the first attitude of the device based on the output of the angular velocity detection unit that is mounted on the device and detects the angular velocity of the device, and the first attitude The third posture is calculated based on the second posture calculation unit that calculates the second posture of the device by means different from the calculation unit, the first posture, the second posture, and the rotation information of the device. A posture calculation device including the third posture calculation unit, and a posture calculation method according to the device.

In the second aspect of the present invention, there is provided a portable device provided with the posture detection device in the first aspect. In a third aspect of the present invention, there is provided a program for causing a computer to function as the posture calculation device in the first aspect.

Note that the above summary of the invention does not enumerate all the necessary features of the present invention. In addition, a sub-combination of these feature groups can also be an invention.

It is a figure which shows the outline | summary of the portable apparatus which concerns on embodiment of this invention. It is a figure which shows the structural example of an attitude | position calculation apparatus. It is a figure which shows the structural example of an attitude | position calculation part. It is a figure explaining the outline | summary of operation | movement of an attitude | position calculation part. It is a flowchart which shows the operation example of an attitude | position calculation apparatus. It is a figure which shows the other structural example of an attitude | position calculation part. It is a figure explaining the outline | summary of operation | movement of the attitude | position calculation part shown in FIG. It is a flowchart which shows the operation example of the attitude | position calculation apparatus using the attitude | position calculation part of FIG. It is a figure which shows an example of the hardware constitutions of the computer 1900 which concerns on this embodiment.

Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention.

FIG. 1 is a diagram showing an outline of a portable device 200 according to an embodiment of the present invention. The portable device 200 refers to a portable device such as a mobile phone, a tablet-type terminal, a portable personal computer, a camera, a wristwatch, a head-mounted display, and a game machine. The mobile device 200 includes an attitude calculation device 100. The attitude calculation device 100 detects the attitude of the mobile device 200 in a reference coordinate system having orthogonal axes X, Y, and Z. The posture of the device can be defined using Euler angles or quaternions.

The posture calculation device 100 calculates a first posture in which the rotation of the mobile device 200 from the past to the current time is accumulated and a second posture based on information on the mobile device 200 at the current time.

FIG. 2 is a diagram illustrating a configuration example of the posture calculation apparatus 100. The posture calculation device 100 of this example includes a geomagnetism detection unit 10, an acceleration detection unit 12, an angular velocity detection unit 14, an offset removal unit 16, a stillness determination unit 18, and a posture calculation unit 20.

The angular velocity detection unit 14 detects the angular velocity of the mobile device 200. The angular velocity detection unit 14 is provided for each of three orthogonal axes (roll, pitch, yaw), and detects the rotation of the mobile device 200 by separating it into rotation components centered on each axis.

The stationary determination unit 18 determines whether or not the mobile device 200 is stationary. The stationary determination unit 18 determines the stationary state based on the data detected by each detection unit. For example, the stillness determination unit 18 determines that the state is still when the angular velocity detected by the angular velocity detection unit 14 is equal to or less than a predetermined threshold.

The offset removal unit 16 detects an offset component in the output of the angular velocity detection unit 14. The offset component refers to an angular velocity component that appears in the output of the angular velocity detector 14 even though the mobile device 200 is actually stationary, for example. The offset removal unit 16 may detect the offset component by averaging the outputs of the angular velocity detection unit 14 while the stationary determination unit 18 determines that the stationary state. The offset removing unit 16 removes the offset component from the angular velocity data output from the angular velocity detecting unit 14. The offset removal unit 16 preferably detects the offset component periodically.

The posture calculation unit 20 calculates the first posture of the mobile device 200 based on the angular velocity data from which the offset component has been removed. The posture calculation unit 20 calculates the first posture of the mobile device 200 by accumulating posture changes according to the angular velocity data detected sequentially. In addition, the posture calculation unit 20 calculates rotation information of the mobile device 200 based on the angular velocity data from which the offset component has been removed. The rotation information is not particularly limited as long as it is information indicating the rotation state of the mobile device 200. Examples of the rotation information include a rotation amount of the mobile device 200 per unit time and an angular velocity of the mobile device 200 at a predetermined time.

The geomagnetism detection unit 10 is provided for each of three orthogonal axes (roll, pitch, yaw) and detects a magnetic component parallel to each axis. Thereby, the direction of geomagnetism with respect to the mobile device 200 is detected. The acceleration detection unit 12 is provided for each of three orthogonal axes (roll, pitch, yaw) and detects an acceleration component parallel to each axis. Thereby, the direction of the gravitational acceleration with respect to the portable device 200 is detected.

The posture calculation unit 20 detects the second posture of the mobile device 200 based on the magnetic data and acceleration data output from the geomagnetism detection unit 10 and the acceleration detection unit 12. Since the first posture is calculated by accumulating data from the past to the present time, an error is accumulated, whereas the second posture is detected from the current data without using the past data. Errors are not accumulated.

Note that the magnetic data and acceleration data include magnetic and acceleration components due to other factors of geomagnetism and gravitational acceleration. For this reason, the posture calculation unit 20 calculates the second posture from the magnetic data and the acceleration data only when a predetermined condition is satisfied. In general, the frequency with which the posture calculation unit 20 can calculate the second posture is less than the frequency with which the first posture is calculated. By the way, the angular velocity detector 14 generally has a drift in offset due to the influence of temperature or the like. Therefore, if angular velocity data is accumulated for a long time, errors are accumulated, and the first posture is not correct.

When calculating the second attitude, the attitude calculating unit 20 calculates a new third attitude based on the first attitude, the second attitude, and the rotation information of the device obtained from the output of the angular velocity detection unit. To do. The posture calculation unit 20 may use the third posture as the first posture at the present time and accumulate subsequent rotations of the mobile device 200. By regularly calculating the third posture and outputting it as the posture of the device, it is possible to prevent errors from being accumulated in the first posture.

FIG. 3 is a diagram illustrating a configuration example of the posture calculation unit 20 according to the embodiment of the present invention. The posture calculation unit 20 of this example includes a second posture calculation unit 22, a first posture calculation unit 24, a difference calculation unit 26, a coefficient calculation unit 28, a third posture calculation unit 30, and a determination unit 32.

The second attitude calculation unit 22 calculates the second attitude of the mobile device 200 based on the magnetic data and acceleration data detected by the geomagnetism detection unit 10 and the acceleration detection unit 12. The parameters used for calculating the second posture are not limited to the geomagnetic direction and the gravitational direction. The second attitude calculation unit 22 can calculate the second attitude based on various parameters whose directions are known (for example, the direction of the sun, the direction of an external known marker, GPS, and network positioning). .

For example, the second posture calculation unit 22 calculates how much the mobile device 200 is tilted with respect to the direction of gravity based on the acceleration data. And based on the said inclination and geomagnetic data, the azimuth | direction which the portable apparatus 200 faces in a horizontal surface is calculated. Thereby, the 2nd attitude | position of the portable apparatus 200 is computable. In the present example, the second posture of the mobile device 200 at the current time t is determined based on the roll angle R (t), pitch angle P (t), and yaw angle Y (t ).

Note that when motion acceleration occurs in the mobile device 200, the direction of gravity cannot be calculated accurately from the acceleration data. Therefore, the second posture calculation unit 22 compares the magnitude of the vector obtained by combining the accelerations in the three-axis directions detected by the acceleration detection unit 12 with the magnitude corresponding to 1G that is the gravitational acceleration, and the difference is predetermined. The second posture is calculated when it is equal to or less than the threshold value.

The first attitude calculation unit 24 calculates the first attitude of the mobile device 200 based on the angular velocity data detected by the angular velocity detection unit 14. The first posture calculation unit 24 of this example calculates the first posture based on the angular velocity data from which the offset component has been removed by the offset removal unit 16. In this example, the first posture of the mobile device 200 at time t is represented by a roll angle r (t), a pitch angle p (t), and a yaw angle y (t) at time t. The roll angle r (t), pitch angle p (t), and yaw angle y (t) are given by the following equations.
r (t) = r (t−1) + Δr (t)
p (t) = p (t−1) + Δp (t)
y (t) = y (t−1) + Δy (t)
Here, t−1 indicates a time one unit time before the time t. In addition, Δr (t), Δp (t), and Δy (t) indicate the amount of rotation of the mobile device 200 during the period from time t−1 to time t. In the present specification, the rotation amount may be referred to as a current rotation amount. The amount of rotation is calculated, for example, by multiplying the angular velocity at time t by one unit time. One unit time may be the same as the angular velocity detection interval in the angular velocity detector 14.

The difference calculation unit 26 calculates the difference between the first posture and the second posture. The difference calculation unit 26 of this example uses the differences r (t) −R (t), p (t) −P (t), y (t) −Y (t) for the roll angle, pitch angle, and yaw angle. Is calculated.

The determination unit 32 dynamically determines a ratio of combining the first posture and the second posture based on the rotation information of the mobile device 200. Dynamically determining the ratio does not mean that the ratio is always constant, but means that the ratio is changed according to the situation. For example, every time the second attitude calculation unit 22 calculates the second attitude. The operation of determining the ratio based on the rotation information of the mobile device 200 at the time point. The determination unit 32 of this example dynamically calculates a proportional constant to be multiplied by the above-described difference based on the angular velocity at the time t of the mobile device 200. The determination unit 32 generates a proportional constant k that is larger as the angular velocity is larger and smaller as the angular velocity is smaller. The determination unit 32 may generate a common proportionality constant k for the roll angle, the pitch angle, and the yaw angle based on the square sum of the angular velocity of the roll angle, the pitch angle, and the yaw angle. The determination unit 32 may generate proportional constants kr, kp, and ky for the roll angle, the pitch angle, and the yaw angle based on the absolute values of the angular velocity of the roll angle, the pitch angle, and the yaw angle. . The proportionality constant is greater than 0 and less than 1.

The coefficient calculation unit 28 calculates a difference coefficient obtained by multiplying the difference calculated by the difference calculation unit 26 by the proportionality constant calculated by the determination unit 32. The coefficient calculation unit 28 of this example calculates the following difference coefficient.
Roll angle: kr (r (t) -R (t))
Pitch angle: kp (p (t) -P (t))
Yaw angle: ky (y (t) -Y (t))

The third posture calculation unit 30 calculates a new third posture based on the first posture, the second posture, and the rotation information of the mobile device 200. That is, the third posture calculation unit 30 further uses the rotation information of the mobile device 200 in addition to the rotation information used to calculate the first posture and the second posture. Further, the rotation information used may be a content partially or entirely overlapped with the rotation information used to calculate the first posture or the second posture.

The third posture calculation unit 30 of this example is based on at least one of the first posture and the second posture, the difference between the first posture and the second posture, and the ratio determined by the determination unit 32. The third posture is calculated. In a more specific example, the third posture calculation unit 30 calculates the first posture (r (t), p (t), y (t)) calculated by the first posture calculation unit 24, and coefficient calculation. A new third posture is calculated using the difference coefficient calculated by the unit 28. As described above, the difference coefficient includes at least the information on the second posture and the proportionality constant according to the rotation information of the mobile device 200. The third posture calculation unit 30 in this example calculates the third posture as in the following equation.
Roll angle: r (t) -kr (r (t) -R (t))
Pitch angle: p (t) -kp (p (t) -P (t))
Yaw angle: y (t) -ky (y (t) -Y (t))

The coefficient calculation unit 28 may determine the difference coefficient so that the difference coefficient is equal to or smaller than the current rotation amount of the mobile device 200. For example, in the range where the calculated difference coefficient is larger than the rotation amount, the coefficient calculation unit 28 matches the magnitude of the difference coefficient with the rotation amount.

When the proportionality constant k is smaller than 1, the difference between the second posture and the first posture does not become zero in one calculation process. Therefore, the attitude calculation unit 20 may divide the difference detected at time t into a plurality of timings such as times t, t + 1,... And use them for calculating the third attitude at each timing. . The determination unit 32 calculates a proportionality constant at each timing according to the angular velocity of the mobile device 200 at each timing. The posture calculation unit 20 may calculate, for example, the third posture at time t + 1 using the difference at time t as follows.
Roll angle: r (t + 1) −kr (t + 1) · (r (t) −R (t))
Pitch angle: p (t + 1) −kp (t + 1) · (p (t) −P (t))
Yaw angle: y (t + 1) −ky (t + 1) · (y (t) −Y (t))

The posture calculation unit 20 newly uses the difference detected at time t until the sum of proportional constants for each axis at each timing (for example, kr (t) + kr (t + 1) +...) Is substantially equal to 1. The third posture may be calculated. Accordingly, the third posture can be calculated so that the detected difference is almost eliminated. However, when the difference detected at time t is divided into a plurality of timings and the third posture at each timing is calculated, the second posture is newly calculated. It is preferable to calculate the third posture by using the difference between the new second posture and the first posture. Thereby, even when the interval for calculating the second posture is long, the third posture can be calculated so that the difference between the second posture and the first posture is eliminated. Note that the third attitude calculation method that can be used in the present invention can use a method such as linear spherical interpolation using quaternions, linear interpolation, or the like in addition to the method using the Euler angle difference described above.

According to the posture calculation unit 20 of this example, since the third posture is calculated based on the first posture, the second posture, and the rotation information of the mobile device 200, it is possible to reduce discomfort given to the user. it can. For example, when the mobile device 200 is close to a stationary state, the posture information close to the first posture is calculated to reduce a sense of incongruity when the posture changes, and when the mobile device 200 moves greatly, the second By calculating posture information close to the posture, posture tracking can be performed efficiently. That is, the posture calculation unit 20 calculates the third posture such that the difference with respect to the first posture is smaller as the amount of rotation of the mobile device 200 per unit time is smaller. Further, the third posture is calculated such that the difference with respect to the second posture becomes smaller as the amount of rotation of the portable device per unit time is larger. The difference in posture may be the sum of the absolute value of the difference in the roll angle, the absolute value of the difference in the pitch angle, and the absolute value of the difference in the yaw angle.

FIG. 4 is a diagram for explaining the outline of the operation of the posture calculation unit 20. FIG. 4 shows an example of the first posture and the second posture at time t. As described above, since errors are accumulated in the first posture, the first posture and the second posture do not necessarily match. The posture calculation unit 20 calculates a difference coefficient obtained by multiplying the difference between the first posture and the second posture by a proportional constant according to the angular velocity at time t.

FIG. 5 is a flowchart showing an operation example of the posture calculation apparatus 100. The posture calculation apparatus 100 detects the angular velocity of the portable device 200 at a predetermined cycle by the angular velocity detector 14 (S300). The first posture calculation unit 24 accumulates the posture changes according to the angular velocity data sequentially detected, and calculates the first posture of the mobile device 200 (S302). The posture calculation apparatus 100 calculates the first posture at a predetermined cycle by repeating the processes of S300 and S302.

The second posture calculation unit 22 calculates the second posture of the mobile device 200 in parallel with the first posture calculation unit 24 (S304). The second posture calculation unit 22 calculates the second posture when the detection results of the geomagnetism detection unit 10 and the acceleration detection unit 12 satisfy a predetermined condition. For example, the second posture calculation unit 22 compares the magnitude of the vector obtained by combining the accelerations in the three-axis directions detected by the acceleration detection unit 12 with the magnitude corresponding to 1G that is the gravitational acceleration, and the difference is a predetermined threshold value. The second posture is calculated when:

Further, when the first posture is calculated, there is an advantage that, as the calculation cycle is shorter, the accuracy of reproducing the continuous smooth motion of the posture of the mobile device 200 is improved. In this example, the cycle in which the first posture calculation unit 24 calculates the first posture is shorter than the cycle in which the second posture calculation unit 22 calculates the second posture. The posture calculation unit 20 calculates a third posture when the second posture calculation unit 22 calculates the second posture.

When the second posture calculation unit 22 calculates the second posture, the difference calculation unit 26 calculates the difference between the first posture and the second posture at the current time (S306). Next, the determination unit 32 and the coefficient calculation unit 28 calculate a difference coefficient according to the current angular velocity (S308). Then, the third posture calculation unit 30 calculates the current third posture based on the difference coefficient (S310). By such processing, it is possible to reduce a sense of incongruity when outputting postures calculated by different methods, and to calculate postures efficiently.

The first posture calculation unit 24 calculates the subsequent first posture using the third posture calculated by the third posture calculation unit 30. In this example, the first posture calculation unit 24 adds the rotation amounts Δr (t + 1), Δp (t + 1), Δy at the next time t + 1 to the third posture at the time t calculated by the third posture calculation unit 30. (T + 1) is added to calculate the first posture at time t + 1.

FIG. 6 is a diagram illustrating a configuration example of the posture calculation unit 20 according to the embodiment of the present invention. The posture calculation unit 20 of this example includes a second posture calculation unit 22, a rotation axis calculation unit 34, a rotation amount calculation unit 36, a first posture calculation unit 38, and a third posture calculation unit 40. The second posture calculation unit 22 has the same function as the second posture calculation unit 22 described with reference to FIGS. 3 to 5. The first posture calculation unit 38 calculates the first posture described with reference to FIGS. 1 to 5. The third posture calculation unit 40 calculates the third posture described with reference to FIGS. 1 to 5. The first posture calculation unit 38 may have the same function as the first posture calculation unit 24. The rotation amount calculation unit 36 calculates the current rotation amount of the mobile device 200 based on the angular velocity data. The current rotation amount may be calculated by multiplying the current angular velocity by one unit time. The rotation amount calculation unit 36 of this example calculates the rotation amount for each axis.

The rotation axis calculation unit 34 calculates the rotation axis from the first posture one unit time before the current time to the second posture at the current time. The rotation axis calculation unit 34 converts the first posture one unit time ago through the origin of the orthogonal axes X, Y, and Z into the second posture at the present time when rotating around the rotation axis. The possible rotation axis is calculated.

Generally, rotation between two postures can be expressed using a quaternion, a rotation matrix, or Euler angles. In this embodiment, rotation between two postures when using a quaternion is described as an example, but rotation between the two postures in the present invention uses a rotation matrix, Euler angles, etc. as described above. Methods can also be used. The rotation axis calculation unit 34 of this example calculates a quaternion indicating the rotation based on the first posture one unit time ago and the second posture at the present time.

Here, the quaternion is expressed in the form of q = w + xi + yj + zk. I, j, and k are basis vectors that satisfy the following relationship.
i ・ i = j ・ j = k ・ k = -1
i · j = k, j · k = i, k · i = j
j · i = −k, k · j = −i, i · k = −j

The relationship between the second posture at the present time and the first posture one unit time ago is expressed using a quaternion q indicating rotation.
P _R (t) = qP _r (t−1) q ⁻¹
Where P _R (t) is a vector indicating the current second attitude, P _r (t−1) is a vector indicating the first attitude one unit time ago, and q is a quaternion indicating rotation. . P _R (t) and P _r (t−1) may be obtained by converting the expression of the attitude angle by the Euler angle described in relation to FIGS. 3 to 5 into the expression of the quaternion. Further, P _R (t) may be a position vector indicating the position of a certain point A of the mobile device 200 in the second posture. In addition, P _r (t−1) may be a position vector indicating the position of the same point A in the mobile device 200 in the first posture. If the rotation between the second posture and the first posture is calculated for one specific point, the rotation of the entire posture can be specified.

The quaternion q indicating the rotation of θ with the vector (α, β, γ) as the rotation axis is expressed as follows.
q = cos (θ / 2) + αsin (θ / 2) · i + βsin (θ / 2) · j + γsin (θ / 2) · k
Then, the rotation axis from the first posture to the second posture one unit time before can be calculated from the vector outer product P _R × P _{r as} follows.
(Α, β, γ) = (P _R × P _r ) / (| P _R × P _r |)
The rotation amount from the first position before one unit time to the second position can be calculated by the following equation from the inner product P _R · P _r of the vector.
cos θ = (P _R · P _r ) / (| P _R | · | P _r |)

The third posture calculation unit 40 uses the rotation axes (α, β, γ) calculated by the rotation axis calculation unit 34 with respect to the first posture one unit time before calculated by the first posture calculation unit 38. The current rotation amount θ ′ detected by the rotation amount calculation unit 36 is applied. The rotation amount θ ′ indicates the magnitude of rotation and does not have information on the rotation axis. That is, the first posture one unit time before is rotated around the rotation axis by the rotation amount θ ′. Thereby, the third posture calculation unit 40 calculates the current third posture. Specifically, the current first posture P _r (t) is calculated based on the following equation.
P _r (t) = q′P _r (t−1) q ′ ⁻¹
q ′ = cos (θ ′ / 2) + αsin (θ ′ / 2) · i + βsin (θ ′ / 2) · j + γsin (θ ′ / 2) · k
The first posture calculation unit 38 may use the third posture calculated by the third posture calculation unit 40 as the first posture at the current time and accumulate subsequent rotations of the mobile device 200.

Thereby, an appropriate posture can be calculated according to the amount of rotation of the mobile device 200. For this reason, the error accumulated in the first posture can be corrected without causing the user to feel uncomfortable. Specifically, since accumulation of errors in the first posture can be prevented, for example, the calculated posture gradually changes even though the mobile device 200 is actually stationary, This can be prevented without giving the user a sense of incongruity. In addition, since the rotation axis from the first attitude to the second attitude is calculated, and the rotation amount of the mobile device 200 is applied to the calculated rotation axis, the third attitude is calculated for the first attitude. The third posture can be prevented from drifting due to the drift of the first posture. This effect is significant when stationary.

Even when the mobile device 200 rotates slowly, the first posture following the rotation can be calculated instantaneously. As the rotation amount in the present invention, for example, a physical quantity relating to rotation obtained by angular velocity, acceleration, geomagnetism, image data, or a combination thereof can be used. Here, when acceleration is used, the rotation amount for each axis can be obtained from the rotation amount of the pitch angle and roll angle per unit time. Similarly, when geomagnetism is used, the rotation amount for each axis can be obtained from the rotation amount of the yaw angle per unit time. When image data is used, the rotation amount for each axis can be obtained from the amount of change per unit time.

Note that, when the current angular velocity detected by the angular velocity detection unit 14 is equal to or less than a predetermined threshold, the posture calculation unit 20 uses the rotation axis to perform the third posture when the angular velocity is equal to or less than a predetermined threshold. May be calculated. For example, the posture calculation unit 20 calculates the third posture using the rotation axis when the angular velocity is small enough to determine that the mobile device 200 is stationary by the stillness determination unit 18. In addition, when the current angular velocity is larger than the above-described threshold, the posture calculation unit 20 may calculate the third posture as described with reference to FIGS.

FIG. 7 is a diagram for explaining the outline of the operation of the posture calculation unit 20 shown in FIG. FIG. 7 shows an example of the first posture one unit time ago and the current second posture. Since errors are accumulated in the first posture, for example, even if the mobile device 200 is stationary for a long time, a difference between the first posture one unit time ago and the current second posture is obtained. May occur.

The rotation axis calculation unit 34 calculates a rotation axis that changes to the current second attitude when the first attitude one unit time ago is rotated around a predetermined rotation axis. That is, a rotation axis is calculated such that any attitude obtained when the first attitude is rotated around the rotation axis coincides with the second attitude. The rotation axis calculation unit 34 may calculate the rotation axis from the current first posture to the current second posture.

The third posture calculation unit 40 uses the rotation axis calculated by the rotation axis calculation unit 34 to rotate the first posture one unit time ago with the current rotation amount of the mobile device 200, and Calculate the posture. Thereby, the error accumulated in the first posture can be corrected according to the rotation amount of the mobile device 200.

FIG. 8 is a flowchart showing an operation example of the posture calculation apparatus 100 using the posture calculation unit 20 of FIG. The processing from S300 to S304 is the same as the flowchart shown in FIG.

When the second posture calculation unit 22 calculates the second posture, the rotation axis calculation unit 34 calculates the rotation axis from the first posture one unit time ago to the current second posture (S312). ). The rotation amount calculation unit 36 calculates the current rotation amount of the mobile device 200 from the current angular velocity data (S314). The processes of S312 and S314 may be performed in parallel.

Then, the third attitude calculation unit 40 calculates the current third attitude by applying the rotation amount calculated in S314 to the rotation axis calculated in S312 (S316). The first attitude calculation unit 38 calculates the subsequent first attitude using the third attitude calculated by the third attitude calculation unit 40 in S316. By such processing, it is possible to reduce a sense of incongruity during error correction. Even if the terminal is stationary for a long time, it is possible to prevent a change in posture due to accumulation of errors.

FIG. 9 shows an example of a hardware configuration of a computer 1900 according to the present embodiment. A computer 1900 according to this embodiment is connected to a CPU peripheral unit having a CPU 2000, a RAM 2020, a graphic controller 2075, and a display device 2080 that are connected to each other by a host controller 2082, and to the host controller 2082 by an input / output controller 2084. Input / output unit having communication interface 2030, hard disk drive 2040, and CD-ROM drive 2060, and legacy input / output unit having ROM 2010, flexible disk drive 2050, and input / output chip 2070 connected to input / output controller 2084 With.

The host controller 2082 connects the RAM 2020 to the CPU 2000 and the graphic controller 2075 that access the RAM 2020 at a high transfer rate. The CPU 2000 operates based on programs stored in the ROM 2010 and the RAM 2020 and controls each unit. The graphic controller 2075 acquires image data generated by the CPU 2000 or the like on a frame buffer provided in the RAM 2020 and displays it on the display device 2080. Instead of this, the graphic controller 2075 may include a frame buffer for storing image data generated by the CPU 2000 or the like.

The input / output controller 2084 connects the host controller 2082 to the communication interface 2030, the hard disk drive 2040, and the CD-ROM drive 2060, which are relatively high-speed input / output devices. The communication interface 2030 communicates with other devices via a network. The hard disk drive 2040 stores programs and data used by the CPU 2000 in the computer 1900. The CD-ROM drive 2060 reads a program or data from the CD-ROM 2095 and provides it to the hard disk drive 2040 via the RAM 2020.

Also, the ROM 2010, the flexible disk drive 2050, and the relatively low-speed input / output device of the input / output chip 2070 are connected to the input / output controller 2084. The ROM 2010 stores a boot program that the computer 1900 executes at startup and / or a program that depends on the hardware of the computer 1900. The flexible disk drive 2050 reads a program or data from the flexible disk 2090 and provides it to the hard disk drive 2040 via the RAM 2020. The input / output chip 2070 connects the flexible disk drive 2050 to the input / output controller 2084 and inputs / outputs various input / output devices via, for example, a parallel port, a serial port, a keyboard port, a mouse port, and the like. Connect to controller 2084.

The program provided to the hard disk drive 2040 via the RAM 2020 is stored in a recording medium such as the flexible disk 2090, the CD-ROM 2095, or an IC card and provided by the user. The program is read from the recording medium, installed in the hard disk drive 2040 in the computer 1900 via the RAM 2020, and executed by the CPU 2000.

A program installed in the computer 1900 and causing the computer 1900 to function as an attitude calculation device includes a first attitude calculation module, a second attitude calculation module, a third attitude calculation module, a determination module, a difference calculation module, and a rotation axis calculation module. And a rotation amount calculation module. These programs or modules work on the CPU 2000 or the like to cause the computer 1900 to function as an attitude calculation device.

The information processing described in these programs is read into the computer 1900, whereby the first posture calculation unit 24, the second posture, which are specific means in which the software and the various hardware resources described above cooperate. As the posture calculation unit 22, the third posture calculation unit 30, the first posture calculation unit 38, the third posture calculation unit 40, the determination unit 32, the difference calculation unit 26, the rotation axis calculation unit 34, and the rotation amount calculation unit 36 Function. And by these specific means, the calculation or processing of information according to the purpose of use of the computer 1900 in the present embodiment is realized, so that a unique stillness determination device according to the purpose of use is constructed.

As an example, when communication is performed between the computer 1900 and an external device or the like, the CPU 2000 executes a communication program loaded on the RAM 2020 and executes a communication interface based on the processing content described in the communication program. A communication process is instructed to 2030. Under the control of the CPU 2000, the communication interface 2030 reads transmission data stored in a transmission buffer area or the like provided on a storage device such as the RAM 2020, the hard disk drive 2040, the flexible disk 2090, or the CD-ROM 2095, and sends it to the network. The reception data transmitted or received from the network is written into a reception buffer area or the like provided on the storage device. As described above, the communication interface 2030 may transfer transmission / reception data to / from the storage device by a DMA (direct memory access) method. Instead, the CPU 2000 transfers the storage device or the communication interface 2030 as a transfer source. The transmission / reception data may be transferred by reading the data from the data and writing the data to the communication interface 2030 or the storage device of the transfer destination.

The CPU 2000 is all or necessary from among files or databases stored in an external storage device such as a hard disk drive 2040, a CD-ROM drive 2060 (CD-ROM 2095), and a flexible disk drive 2050 (flexible disk 2090). This portion is read into the RAM 2020 by DMA transfer or the like, and various processes are performed on the data on the RAM 2020. Then, CPU 2000 writes the processed data back to the external storage device by DMA transfer or the like. In such processing, since the RAM 2020 can be regarded as temporarily holding the contents of the external storage device, in the present embodiment, the RAM 2020 and the external storage device are collectively referred to as a memory, a storage unit, or a storage device. Various types of information such as various programs, data, tables, and databases in the present embodiment are stored on such a storage device and are subjected to information processing. Note that the CPU 2000 can also store a part of the RAM 2020 in the cache memory and perform reading and writing on the cache memory. Even in such a form, the cache memory bears a part of the function of the RAM 2020. Therefore, in the present embodiment, the cache memory is also included in the RAM 2020, the memory, and / or the storage device unless otherwise indicated. To do.

In addition, the CPU 2000 performs various operations, such as various operations, information processing, condition determination, information search / replacement, etc., described in the present embodiment, specified for the data read from the RAM 2020 by the instruction sequence of the program. Is written back to the RAM 2020. For example, when performing the condition determination, the CPU 2000 determines whether or not the various variables shown in the present embodiment satisfy the conditions such as large, small, above, below, equal, etc., compared to other variables or constants. When the condition is satisfied (or not satisfied), the program branches to a different instruction sequence or calls a subroutine.

Further, the CPU 2000 can search for information stored in a file or database in the storage device. For example, in the case where a plurality of entries in which the attribute value of the second attribute is associated with the attribute value of the first attribute are stored in the storage device, the CPU 2000 displays the plurality of entries stored in the storage device. The entry that matches the condition in which the attribute value of the first attribute is specified is retrieved, and the attribute value of the second attribute that is stored in the entry is read, thereby associating with the first attribute that satisfies the predetermined condition The attribute value of the specified second attribute can be obtained.

The program or module shown above may be stored in an external recording medium. As the recording medium, in addition to the flexible disk 2090 and the CD-ROM 2095, an optical recording medium such as DVD or CD, a magneto-optical recording medium such as MO, a tape medium, a semiconductor memory such as an IC card, and the like can be used. Further, a storage device such as a hard disk or RAM provided in a server system connected to a dedicated communication network or the Internet may be used as a recording medium, and the program may be provided to the computer 1900 via the network.

As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

The execution order of each process such as operations, procedures, steps, and stages in the apparatus, system, program, and method shown in the claims, the description, and the drawings is particularly “before” or “prior”. It should be noted that they can be implemented in any order unless the output of the previous process is used in the subsequent process. Regarding the operation flow in the claims, the description, and the drawings, even if it is described using “first”, “next”, etc. for the sake of convenience, it means that it is essential to carry out in this order. is not.

DESCRIPTION OF SYMBOLS 10 ... Geomagnetic detection part, 12 ... Acceleration detection part, 14 ... Angular velocity detection part, 16 ... Offset removal part, 18 ... Stillness determination part, 20 ... Attitude calculation part, 22. .. second posture calculation unit, 24... First posture calculation unit, 26... Difference calculation unit, 28... Coefficient calculation unit, 30.・ Determining unit 34... Rotating axis calculating unit 36... Rotation amount calculating unit 38... First posture calculating unit 40. 200, portable device, 1900 ... computer, 2000 ... CPU, 2010 ... ROM, 2020 ... RAM, 2030 ... communication interface, 2040 ... hard disk drive, 2050 ...・ Flexible disk drive, 2060 ・CD-ROM drive, 2070 ... input / output chip, 2075 ... graphic controller, 2080 ... display device, 2082 ... host controller, 2084 ... input / output controller, 2090 ... flexible Disc, 2095 ... CD-ROM

Claims

A first attitude calculation unit that is mounted on a device and calculates a first attitude of the device based on an output of an angular velocity detection unit that detects an angular velocity of the device;
A second attitude calculation unit that calculates a second attitude of the device by means different from the first attitude calculation unit;
A third attitude calculation unit that calculates a third attitude based on the first attitude, the second attitude, and the rotation information of the device;
An attitude calculation device comprising:
The third posture calculation unit
The third posture is calculated such that the difference with respect to the first posture is smaller as the rotation amount of the device per unit time is smaller, and the second posture is larger as the rotation amount of the device per unit time is larger. The posture calculation apparatus according to claim 1, wherein the third posture is calculated such that a difference with respect to is small.
The second posture calculation unit
The posture calculation apparatus according to claim 1, wherein the second posture is calculated based on an output of at least one of a geomagnetism detection unit and an acceleration detection unit mounted on the device.
The third posture output unit includes:
The system determines whether or not to output the third posture based on the output of the geomagnetism detection unit or the acceleration detection unit, and outputs the first posture when the third posture is not output. 4. The posture calculation apparatus according to 3.
The posture calculation apparatus according to any one of claims 1 to 4, wherein the first posture calculation unit calculates the posture of the device at a shorter cycle than the second posture calculation unit.
The posture calculation apparatus according to any one of claims 1 to 5, wherein the first posture calculation unit calculates the first posture by accumulating outputs of the angular velocity detection unit.
A determination unit that dynamically determines a ratio of combining the first posture and the second posture based on rotation information of the device;
The third posture calculation unit
The posture calculation device according to any one of claims 1 to 6, wherein a third posture is calculated based on the first posture, the second posture, and the ratio determined by the determination unit. .
The determination unit
The ratio of the second posture is larger as the amount of rotation of the device per unit time is larger, and the proportion of the second posture is smaller as the amount of rotation of the device per unit time is smaller. The posture calculation apparatus according to claim 7.
A difference calculation unit for calculating a difference between the first posture and the second posture;
The third posture calculation unit
The third posture based on at least one of the first posture and the second posture, a difference between the first posture and the second posture, and a ratio determined by the determination unit. The posture calculation apparatus according to claim 7 or 8.
A rotation axis calculator that calculates a rotation axis from the first attitude to the second attitude;
The third posture calculation unit
7. The third posture is calculated by applying a rotation amount of the device to the rotation axis calculated by the rotation axis calculation unit with respect to the first posture. The posture calculation device described in 1.
The third posture calculation unit
The third posture is calculated by applying a rotation amount of the device to the rotation axis calculated by the rotation axis calculation unit with respect to the first posture one unit time before. Attitude calculation device.
A portable device comprising the posture calculation device according to any one of claims 1 to 11.
A first posture calculating step of calculating a first posture of the device based on an output of an angular velocity detection unit mounted on the device and detecting an angular velocity of the device;
A second posture calculating step of calculating a second posture of the device by means different from the first posture calculating step;
A third posture calculating step for calculating a third posture based on the first posture, the second posture, and the rotation information of the device;
An attitude calculation method comprising:
A program that causes a computer to function as the posture calculation device according to any one of claims 1 to 11.