JPH11211474A - Attitude angle detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a widely usable attitude angle detecting device used for attitude control and detection of a mobile, moderated with limitation for the place or environment to use. SOLUTION: This device is provided with three gyroscopes 5, 6, 7, two acceleration sensors 10, 11, two geomagnetic sensors 8, 9, a moving angle arithmetic device 31 for detecting a moving angle on the basis of the angle speed outputted by the three gyroscopes 5, 6, 7, an angle of repose arithmetic device 32 for detecting the attitude angle on the basis of acceleration and geomagnetism, a judging device 33 for judging the justice of the angle of repose detection result, and an attitude posture angle arithmetic device 30 for calculating the attitude angle to be outputted by use of the operation results of the moving angle arithmetic device 31 and the angle of repose arithmetic device 32 according to the operation result of the judging device 33. This device detects the attitude angle of a mobile without using an external signal generating source.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional space such as a tracker for detecting a head posture angle, a 3D game pad, etc., among head mounted displays used for posture detection, posture control, virtual reality, etc. of a moving body. In particular, the present invention relates to a posture angle detection device particularly suitable for detecting a posture angle (a rotation angle of three axes) of an object to be measured.

[0002]

2. Description of the Related Art Conventionally, as a posture angle detection method for detecting head movement, which is used in virtual reality, a weak AC magnetic field is generated from an externally provided AC magnetic field generation source, and a head mounted display (hereinafter, HMD) is used. The method uses an AC magnetic field that detects with the sensor unit located in the HMD and the head operation is detected by the control calculation unit. There is a method of using ultrasonic waves for detecting and detecting the head movement in the control calculation unit.

[0003]

However, in the former method using an alternating magnetic field, since the signal generating source is a weak alternating magnetic field, responsiveness is reduced by using a large number of filters to cancel noise, and the head is reduced. H compared to the movement of
The movement of the MD image may be slowed down, resulting in sickness or sickness.

In the latter method using ultrasonic waves,
Signals may not be detected due to malfunctions due to the effects of various other ultrasonic signals or obstacles between the signal source and the sensor.Received only with the arm or hair in front of the sensor Since it becomes impossible, there is a problem that a measure for preventing a malfunction is required.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides a posture angle detecting apparatus for use in posture control / detection of a moving body which can be used widely, alleviating restrictions on places and environments when used.

[0006]

In order to solve the above-mentioned problems, a posture angle detecting device according to the present invention comprises:
First, second, and third gyroscopes for detecting angular velocities around axes, first and second acceleration sensors for detecting two-axis accelerations orthogonal to each other, and detecting two-axis geomagnetism orthogonal to each other First and second terrestrial magnetism sensors arranged to detect a motion angle based on an angular velocity output by the gyroscope; and a stationary angle detection means detecting a posture angle based on acceleration and terrestrial magnetism. A discriminating device for discriminating whether or not the detection result of the static angle detecting means is correct, and calculating a posture angle to be output by using the discriminating result of the discriminating device and the calculation results of the motion angle detecting means and the static angle detecting means. The apparatus is characterized in that the apparatus is provided with an attitude angle calculating device for detecting the attitude angle of the moving body without using an external signal generation source.

That is, according to the present invention, when an axis orthogonal to a horizontal plane is an X axis and a Y axis, and an axis orthogonal to the X axis and the Y axis is a Z axis, the X axis, the Y axis, In a posture angle detection device that detects rotation angles around three axes orthogonal to each other in a reference coordinate system formed by the Z axis, an X axis, a Y axis,
Three gyroscopes for detecting angular velocities around the axis and the Z axis, a motion angle computing device for computing an angle moved per unit time based on an output corresponding to the angular velocity of the gyroscope, and an XY plane. An acceleration sensor arranged to detect two-axis acceleration orthogonal to each other, a geomagnetic sensor arranged to detect two-axis geomagnetism orthogonal to each other on the XY plane, and an acceleration sensor and a geomagnetic sensor. A static angle computing device that computes rotation angles about the X, Y, and Z axes based on the output; a discriminating device that determines whether the computation result by the static angle computing device is true or false; Accordingly, the attitude angle detection device includes an attitude angle calculation device that calculates an attitude angle to be output from the calculation result of the motion angle calculation device and the calculation result of the stationary angle calculation device.

Further, according to the present invention, the gyroscope of the attitude angle detecting device comprises a piezoelectric vibrating gyroscope vibrator and a drive detecting circuit for operating the vibrator as a gyroscope. This is a posture angle detection device made of a magnetic material.

Further, according to the present invention, a high-pass filter is connected to an output section of the gyroscope of the attitude angle detecting apparatus, and the output section of the high-pass filter is input to an arithmetic unit, and the motion angle is calculated using the output of the high-pass filter. It is a posture angle detecting device for calculating.

Further, the present invention is the attitude angle detecting device, wherein the high-pass filter has a cut-off frequency varying means.

Further, according to the present invention, in the posture angle detecting device, a two-axis acceleration sensor and an output Ax of the acceleration sensor are provided.
(N), a roll angle calculating means for calculating a temporary roll angle R (n) and a temporary pitch angle P (n) from Ay (n), a pitch angle calculating means, and an x-direction component Mx (n) of geomagnetism; A two-axis geomagnetic sensor that measures the y-direction component My (n), and an azimuth angle calculation result Φ (n−
Calculating a backup memory for storing 1), the output Ax of the acceleration sensor (n), from Ay (n) and a backup memory contents [Phi (n-1), the north direction component theta ₂ of the inclination angle North component tilt angle calculating means, geomagnetic Mz code determining means for determining the sign of the geomagnetic Z direction component Mz, geomagnetic Z direction component geomagnetic Mz absolute value calculating means, the geomagnetic Mz code determining means, geomagnetic Mz Geomagnetic Mz calculating means for calculating the geomagnetism Mz of the Z-axis direction component from the absolute value calculating means, and the X, Y, Z components HX, H of the geomagnetism in the reference coordinate system from the geomagnetics Mx, My, Mz
It is composed of a coordinate transformation calculating means for calculating Y and HZ, and an azimuth calculating means for calculating an azimuth angle Φ based on the aforementioned HX and HY in the reference coordinate system. This is an attitude angle detection device that measures an azimuth angle Φ (n) using two sensor axes.

Further, according to the present invention, in the above attitude angle detecting device, the north component tilt angle θ ₂ , the geomagnetic dip θ ₀ at the origin, the backup, The output of the memory is Φ (n−
1) The outputs of the two axes of the acceleration sensor are Ax (n),
When Ay (n), the north component inclination angle θ ₂ is θ ₂ = s
in ⁻¹ [Ax (n) · cos (−Φ (n−1)) + Ay
(N) · sin (−Φ (n−1))], −9
If 0 degree ≦ θ ₂ ≦ θ ₀ , the geomagnetic Mz sign is minus,
If θ ₀ <θ ₂ ≦ 90 degrees, the geomagnetic Mz sign is a posture angle detection device that determines that the sign is positive.

Further, according to the present invention, in the above attitude angle detecting device, the provisional yaw angle Φ obtained from the stationary angle detecting means comprising a two-axis acceleration sensor and a two-axis geomagnetic sensor by the discriminating device; As a means for determining whether or not the detection results of the pitch angle P and the provisional roll angle R are correct, the provisional roll angle obtained from the current output Ax (n) of the acceleration sensor is calculated by R (n). The tentative roll angle calculation result obtained from the output Ax (n-1) one unit time in the past in unit time is R (n-1), and similarly calculated from the current output Ay (n) of the acceleration sensor. The temporary pitch angle obtained from the output Ay (n-1), which is one unit time in the past, is P (n).
Assuming that 1), the attitude angle detection device determines that the attitude angle information from the stationary angle detection means is correct when at least one of the values of the expression 1 or 2 is within a certain value.

[0014]

(Equation 1)

[0015]

(Equation 2)

Further, according to the present invention, in the above-mentioned attitude angle detecting device, the output to be obtained is a roll angle α (n), a pitch angle β
(N), the yaw angle γ (n), and the motion angle obtained by the motion angle detecting means are calculated as a temporary roll angle change {X (n), a temporary pitch angle change {Y (n), a temporary yaw angle change}. Z (n), the stationary angle obtained by the stationary angle detecting means is a temporary roll angle R
(N), provisional pitch angle P (n), provisional yaw angle Φ (n),
Assuming that the constants that are not larger than the errors are C ₁ , C ₂ , and C ₃ , α (n) = α (n
−1) + ΔX (n) −C ₁ , β (n) = β (n−1) +
ΔY (n) −C ₂ , γ (n) = γ (n−1) + ΔZ
The (n) -C _3, also the attitude angle information from the static angle detecting means if it is determined that the error, α (n) = α ( n-
1) + △ X (n), β (n) = β (n−1) + △ Y
(N), γ (n) = γ (n−1) + △ Z (n),
This is a posture angle detection device that calculates a posture angle.

Further, according to the present invention, in the attitude angle detecting device, the output to be obtained is a roll angle α (n), a pitch angle β
(N), the yaw angle γ (n), the motion angle obtained from the dynamic motion angle detection means are calculated as a temporary roll angle change △ X (n), a temporary pitch angle change △ Y (n), and a temporary yaw change. Angle change △ Z (n),
The posture angles obtained from the static stationary angle detecting means are a provisional roll angle R (n), a provisional pitch angle P (n), and a provisional yaw angle Φ.
(N) Assuming that the proportionality constants equal to or smaller than ₁ are k ₁ , k ₂ , and k ₃ , α (n) = α (n) = when it is determined that the posture angle information from the static angle detecting means is correct based on the determination result of the determination device. α (n-
1) + ΔX (n) −k ₁ [α (n−1) + ΔX (n) −
R (n)], β (n) = β (n−1) + △ Y (n) −k
₂ [β (n-1) + △ Y (n) -P (n)], γ (n)
= Γ (n-1) + {Z (n) -k ₃ [γ (n-1) +}
Z (n) −Φ (n)], and when the attitude angle information from the static angle detection means is determined to be incorrect, α (n) = α
(N-1) + {X (n), β (n) = β (n-1) + ｎ
This is an attitude angle detection device that calculates an attitude angle based on Y (n), γ (n) = γ (n−1) + △ Z (n).

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

It is assumed that the coordinate conversion operation from the sensor coordinate system to the reference coordinate system described here is performed in the order of yaw angle γ → pitch angle α → roll angle β.

Here, the following symbols are used as sensor outputs in the sensor coordinate system. Gyroscope output: Jx (n), Jy (n), J
z (n). Output of acceleration sensor: Ax (n), Ay (n). Output of geomagnetic sensor: Mx (n), My (n). Calculated value of geomagnetic sensor: Mz (n).

The following symbols are used as values obtained by converting the sensor output in the sensor coordinate system into the reference coordinate system. Reference coordinate system X, Y, Z obtained from gyroscope output
Motion angle around axis: ΔX (n), ΔY (n), ΔZ
(N). A rotation angle around the X axis (temporary roll angle) obtained from the output of the acceleration sensor (temporary roll angle): R (n), and a rotation angle around the Y axis (temporary pitch angle): P (n). A rotation angle (azimuth angle or temporary yaw angle) around the Z axis obtained from the output of the geomagnetic sensor: Φ (n). The rotation angles around the X, Y, and Z axes, which are to be finally output and obtained from the above calculation results, are the roll angle α (n), the pitch angle β (n), and the yaw angle γ (n).

FIG. 1 shows a case where the reference coordinate system (XYZ system) and the sensor coordinate system (xyz system) match. As shown in FIG. 1, the axis orthogonal to the horizontal plane is X
When an axis orthogonal to each of the X axis and the Y axis is defined as a Z axis, the X axis, the Y axis, and the Z axis
In the reference coordinate system formed by the axes, the rotation angle about the X axis is referred to as a roll angle α, the rotation angle about the Y axis is referred to as a pitch angle β, and the rotation angle about the Z axis is referred to as a yaw angle γ.

FIG. 1 shows an arrangement of a gyroscope, an acceleration sensor, and a geomagnetic sensor in the attitude angle detecting device of the present invention. In the sensor coordinate system shown in FIG. 1, a first gyroscope 5, a second gyroscope 6, and a third gyroscope for detecting angular velocities around three axes (x axis, y axis, and z axis) orthogonal to each other. Gyroscope 7 has x,
They are arranged in parallel with the y and z axes, that is, perpendicular to each other. The first acceleration sensor 10 and the second acceleration sensor 11 are arranged parallel to two axes orthogonal to each other, the x axis, and the y axis. Similarly, the first geomagnetic sensor 8 and the second geomagnetic sensor 9 for detecting the yaw angle are arranged in parallel to two axes, the x axis and the y axis, which are orthogonal to each other.

FIG. 2 shows a case where the sensor coordinate system (xyz system) deviates from the reference coordinate system (XYZ system). A gyroscope, an acceleration sensor, and a geomagnetic sensor to be described in the sensor coordinate system are omitted. FIG. 2 shows that the gravitational acceleration acts in the −Z direction of the reference coordinate system, and the component forces in the x-axis and y-axis directions of the sensor coordinate system are Ax (n) and Ay (n). I have.

FIG. 3 is a diagram showing the overall configuration of the attitude angle detecting device according to one embodiment of the present invention. As shown in FIG. 3, the attitude angle detection device of the present invention includes three orthogonally arranged gyroscopes, a high-pass filter connected to each of the gyroscopes, and a high-pass filter as shown in FIG. A movement angle calculator 31 for calculating a movement angle (movement angle) per unit time from the output of the gyroscope, two acceleration sensors, two geomagnetic sensors arranged as shown in FIG. A static angle calculation device 32 for obtaining a temporary roll angle R and a temporary pitch angle P from the two acceleration sensors, and further obtaining a temporary yaw angle Φ from the temporary roll angle R and the temporary pitch angle P; Determination device 3 for determining whether the calculation result of calculation device 32 is true or false
3 and an attitude angle computing device 30 that processes signals from the motion angle computing device 31, the stationary angle computing device 32, and the discriminating device 33.

First, the contents of the motion angle detecting device 31 will be described. As the motion angle detecting device in the attitude angle detecting device of the present invention, a vibrator made of a nonmagnetic material such as piezoelectric ceramic, piezoelectric single crystal, or silicon can be used. In this embodiment, a case will be described in which a piezoelectric vibrating ceramic gyro manufactured by Tokin Co., Ltd. is used.

As shown in FIG. 3, high-pass filters 36, 37, and 38 are connected to the outputs of the three-axis gyroscopes 5, 6, and 7, respectively. Is connected. In a gyroscope, the smaller and cheaper the gyroscope, the larger the variation and the fluctuation of the output (offset) when the gyroscope is stationary, but using a stable gyroscope results in an expensive and large posture detection device.

The high-pass filter cancels the offset of the piezoelectric vibrating gyroscope. By using the output after using the high-pass filter, an inexpensive, compact and highly accurate attitude angle detecting device can be obtained. so,
Usually, it is set to a low frequency of 0.1 Hz or less. Also,
Each high-pass filter has a variable cutoff frequency. Since the low-frequency high-pass filter takes time from power-on to stabilization, a stable output can be obtained in a short time by increasing the cut-off frequency of the high-pass filter as necessary. After the cutoff frequency is increased and a stable output is obtained, the cutoff frequency is immediately returned to a low state (measurement state).

The motion angle calculator 31 performs coordinate conversion on the outputs Jx (n), Jy (n) and Jz (n) of each gyroscope corresponding to the rotational angular velocity of the attitude angle detector (measured object). Then, the output β (n−1), which is one unit time past in the unit time to be calculated, is converted into the current movement angle (movement angle) △ X (n) in the reference coordinate system as in the following equation.

ΔX (n) = cos [β (n-1)] × Jx (n) + sin [β (n-1)] × Jz (n) ΔY (n) = sin [α (n-1) ] × sin [β (n-1)] × Jx (n) + cos [α
(n-1)] × Jy (n) -sin [α (n-1)] × cos [β (n-1)] × Jz (n) ΔZ (n) = -cos [α (n-1) ] × sin [β (n-1)] × Jx (n) + sin [α
(n-1)] × Jy (n) + cos [α (n-1)] × cos [β (n-1)] × Jz (n)

Next, the static angle calculation device shown in FIG. 4 will be described. As described above, the static angle calculation device outputs the temporary roll angle R, the temporary pitch angle P, and the temporary yaw angle Φ which are the attitude angles during the static operation of the attitude angle detection device. is there.

As shown in FIG. 2, the acceleration sensors 10 and 11 shown in FIG. 1 respectively have x and y component components Ax (n) and Ay of the gravitational acceleration on the x and y axes in the sensor coordinate system.
(N). The geomagnetic sensors 8 and 9 shown in FIG. 1 are arranged to detect geomagnetic component forces Mx (n) and My (n) on the x and y axes, respectively.

Outputs Ax (n), Ay of acceleration sensor
(N) is a tentative roll angle R (n) and a tentative pitch angle P which are inclination angles with respect to the horizontal plane (XY plane) of the reference coordinate system, respectively, by the roll angle calculating means and the pitch angle calculating means by the following equations.
(N) is calculated.

R (n) = sin ⁻¹ [Ax (n) / cosP (n)]
P (n) = sin ^-1 Ay (n)

The provisional yaw angle Φ (n) in the reference coordinate system is calculated using the geomagnetic component in the reference coordinate system, Φ (n) = tan ⁻¹
[HX (n) / HY (n)]. When the attitude angle detector rotates on a horizontal plane, the outputs Mx (n) and My (n) of the geomagnetic sensor are HX (n) and HY (HY), respectively.
(N), and Φ (n) = tan ^-1 [Mx (n) / My (n)].

Assuming that the azimuth at the origin is Φ (0), the yaw angle γ (n) is γ (n) = Φ (n) -Φ (0).

However, when the attitude angle detector has a roll angle R and a pitch angle P and is not horizontal, HX = cos [P (n)] × Mx + sin [P (n)]
× Mz, HY = sin [R (n)] × sin [P (n)] × Mx
From the relational expression of + cos [R (n)] × cos [P (n)] × Mz, the provisional roll angle R (n) and the provisional pitch angle P
Coordinate conversion is performed using (n), a geomagnetic component in the reference coordinate system is obtained, and the result is substituted into Φ (n) = tan ^-1 [HX (n) / HY (n)].

At this time, a component Zz (n) in the geomagnetic Z direction is required.

Mz is virtually calculated by the following method.

First, the geomagnetism Ht is determined by the following procedure.
First, tilt the attitude angle detection device (measured object) by 90 degrees,
The magnetic sensor 10 or the magnetic sensor 11 in FIG. 1 is directed to the Z axis of the reference coordinate system. Then, a signal is sent, for example, a key or button is pressed, and the value of the sensor facing the Z axis at that time is stored in the memory as Mz (0).

Next, the attitude angle detecting device (measured object) is returned to the origin position, a signal is sent again, and the values of the magnetic sensors Mx (n), My (n) are changed to Mx (0), My.
(0) is stored in the memory. These Mx (0), M
Ht is obtained from Expression 3 using y (0) and Mz (0).

[0042]

(Equation 3)

Further, the sign of Mz is determined from the inclination angle of the north component of the geomagnetic field of the attitude angle detector (measured object). For this purpose, a backup memory and a north component inclination angle calculating means are provided.

The temporary yaw angle Φ (n-1), which is one unit time past in the unit time to be calculated, calculated in the arithmetic processing, is stored in the backup memory, and this temporary yaw angle Φ (n-
Following formula 1) and the acceleration sensor output Ax (n), from the value of Ay (n), the north direction component inclination angle calculating means, the geomagnetic north direction component theta ₂ of the inclination angle of the attitude-angle detecting apparatus (object to be measured) It is calculated by:

Θ ₂ = sin ⁻¹ [Ax (n) × cosΦ (n−
1) + Ay (n) × sinΦ (n−1)]

If −90 degrees ≦ θ ₂ ≦ θ ₀ , the geomagnetic Mz sign is determined to be minus, and if θ ₀ <θ ₂ ≦ 90 degrees, the geomagnetic Mz sign is determined to be positive.

Next, in the attitude angle detecting device of the present invention,
The provisional roll angle R calculated by the static angle detection device
(N), a determination device for determining whether the provisional pitch angle P (n) and the provisional yaw angle Φ (n) are substantially correct will be described.

Ax (n), A in the stationary angle detecting means
Since y (n) is a composite vector of the x and y axis components of the gravitational acceleration and the x and y axis components of the motion acceleration,
If there is motion acceleration, the correct roll angle and pitch angle will not be obtained. Therefore, the value obtained by subtracting R (n-1) from R (n) is close to 0, within a certain value, or
(N) minus P (n-1) is near 0,
If it is within a certain value, it is determined that there is no motion acceleration, that is, the provisional roll angle R (n) and the provisional pitch angle P (n) calculated by the stationary angle detection means are correct. Otherwise, it is determined that there is a motion acceleration, and the calculation result from the static angle detection means is not correct. That is, Equation 1 or Equation 2
At least one of the values is approximately 0 within a certain value.
Is provided, a determination device for determining that the posture angle information from the stationary angle detection means is correct.

[0049]

(Equation 1)

[0050]

(Equation 2)

Although the method of calculating and determining the output of the acceleration sensor has been described above, it is determined that the output of the stationary angle detecting means is not correct even when an error occurs in the output of the magnetic sensor and the output fluctuates greatly. I do.

Next, according to the discrimination result of the discrimination device,
A description will be given of a calculation method performed by the attitude angle calculation device for obtaining the final output by calculating the output of the motion angle detection means and the output of the stationary angle detection means.

The basis of this calculation is that when the discriminating device determines that the output of the static angle detecting means is incorrect,
Current attitude angle detection result = 1 attitude time detection result past unit time + motion angle, and when the discriminator determines that the output of the static angle detection means is correct, current attitude angle detection result = 1 attitude past one unit time Angle detection result + motion angle−correction value, and the correction value is error × proportional constant or constant. Here, error = (result of attitude angle detection in the past of one unit time + current motion angle) − (current detection result by stationary angle detecting means).

In the equation, the error on the X axis = α (n−1) +
ΔX (n) −R (n), Y-axis error = β (n−1) + △
Y (n) −P (n), error of Z axis = γ (n−1) + △ Z
(N) −Φ (n).

In the first embodiment, the outputs to be obtained by the attitude angle detecting device of the present invention are α (n), β (n), γ (n),
The motion angle obtained from the dynamic motion angle detection means is expressed as △ X
(N), △ Y (n), △ Z (n), and the static angles determined by static static angle detection means are R (n), P (n), Φ
(N)

When it is determined that the posture angle information from the stationary angle detecting means is correct, α (n) = α (n−1) + △ X (n) −C ₁ , β (n) = β (n−1) ) + ΔY (n) −C ₂ , γ (n) = γ (n−1) + ΔZ (n) −C ₃ , where C ₁ , C ₂ , and C ₃ are arbitrarily selected. Is a constant that is not greater than the error, and the sign is
At plus and minus, the attitude angle is calculated by minus.

When it is determined that the posture angle information from the stationary angle detecting means is wrong, α (n) = α (n−1) + △ X (n), β (n) = β (n−1) + △ Y (n), γ (n) = γ (n−1) + △ Z (n), and the attitude angle is calculated.

In another embodiment of the present invention, the outputs to be obtained by the attitude angle detecting device of the present invention are α (n), β
(N), γ (n), 運動 X (n), △ Y (n), △ Z (n), the motion angle obtained from the dynamic motion angle detection means, are obtained from the static static angle detection means. The static angle is R (n), P
(N), Φ (n),

When it is determined that the attitude angle information from the stationary angle detecting means is correct, α (n) = α (n−1) + {X (n) −k ₁ [α (n−1) +}
X (n) −R (n)], β (n) = β (n−1) + {Y (n) −k ₂ [β (n−1) +}
Y (n) −P (n)], γ (n) = γ (n−1) + {Z (n) −k ₃ [γ (n−1) +}
Z (n) −Φ (n)], and calculates the attitude angle. Here, k ₁ , k ₂ , and k ₃ are
It is an arbitrarily selected proportional constant of 1 or less.

When it is determined that the posture angle information from the stationary angle detecting means is wrong, α (n) = α (n−1) + △ X (n), β (n) = β (n−1) + △ Y (n), γ (n) = γ (n−1) + △ Z (n), and the attitude angle is calculated.

As described above, only when the output of the static angle detecting means is correct, the attitude angle is obtained by integrating the motion angles while correcting the error, thereby providing high-speed response, stability at rest, and reproducibility. Is a posture angle detection device which can satisfy the above at the same time.

FIG. 5 shows an HMD to which the attitude angle detecting device is applied.
An example is shown below. This HMD is provided so that the image displayed on the display in front of the user changes in conjunction with the movement of the head and can experience a virtual space. When turning to the right while wearing this HMD, , The head posture angle measured by the posture angle detection device is transmitted to the image generation device, and the image generation device transmits the image corresponding to the posture angle to the HMD, so that the image developed to the right is projected, and the motion of the head is It is provided so that a 360-degree image of the entire space can be realized.

As shown in FIG. 5, reference numeral 1 denotes an HMD main body. The HMD main body 1 includes a posture angle detecting device (measured object) 2 according to the present invention connected to a video generating device 4 through a signal cable 3. It is connected.

[0064]

According to the attitude angle detecting device of the present invention,
When applied to the above-described HMD, it is possible to obtain angle information with little accumulated error with a high-speed response without using an external signal, and to configure a high-performance HMD.

According to the attitude angle detecting device of the present invention, since the gyro is mounted as an element, it is possible to reduce the size and weight, and since the ceramic vibrator is used, no magnetic noise is received. The function is not impaired even if it is made to approach. Also, by using a high-pass filter, miniaturization, low cost, and high accuracy can be achieved.

Further, conventionally, as a posture angle detecting device,
If there are not three acceleration sensors, the error of the attitude angle cannot be determined,
Therefore, according to the present invention, the two acceleration sensors and the two geomagnetic sensors can be used to determine and correct the presence / absence of an error component by simple calculations. A high-speed response and high-accuracy attitude angle detection device can be provided.

[Brief description of the drawings]

FIG. 1 is a gyroscope of a posture angle detecting device according to the present invention;
The figure which shows arrangement | positioning of an acceleration sensor and a geomagnetic sensor, and shows the case where a reference coordinate system (XYZ system) and a sensor coordinate system (xyz system) correspond.

FIG. 2 is a diagram showing a case where a reference coordinate system (XYZ system) and a sensor coordinate system (xyz system) do not match.

FIG. 3 is a diagram showing an overall configuration of an embodiment of a posture angle detecting device according to the present invention.

FIG. 4 is a block diagram showing a configuration of a stationary angle calculation device in the posture angle detection device of the present invention.

FIG. 5 is an explanatory diagram of a usage state of a posture angle detection device in an HMD.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Display main body 2 Attitude angle detection apparatus (DUT) 3 Signal cable 4 Image generator 5 (1st) gyroscope 6 (2nd) gyroscope 7 (3rd) gyroscope 8 1st geomagnetic sensor Reference Signs List 9 second geomagnetic sensor 10 first acceleration sensor 11 second acceleration sensor 31 motion angle calculator 32 stationary angle calculator 33 discriminator 30 attitude angle calculator 36 (first) high-pass filter 37 (second) High Pass Filter 38 (Third) High Pass Filter

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification code FI G06F 3/033 310 G06F 3/033 310Y H04N 5/64 511 H04N 5/64 511A (72) Inventor Naoji Yamamoto Taishiro, Sendai City, Miyagi 6-7-1, Koriyama-ku, Tokin Co., Ltd.

Claims (9)

[Claims] An X-axis, a Y-axis, and an X-axis, a Y-axis, and a Z-axis, which are orthogonal to each other, are defined as an X-axis and a Y-axis. A gyroscope for detecting angular velocities around X-axis, Y-axis and Z-axis in a posture angle detecting device for detecting rotation angles around three axes orthogonal to each other in a reference coordinate system; A motion angle calculator for calculating an angle moved per unit time based on an output corresponding to the angular velocity of the X-axis;
An acceleration sensor arranged to detect two-axis acceleration orthogonal to each other on the Y plane; a geomagnetic sensor arranged to detect two-axis geomagnetism orthogonal to each other on the XY plane; A static angle computing device that computes a rotation angle about the X-axis, Y-axis, and Z-axis based on the output of the geomagnetic sensor; a discriminating device that discriminates whether the computation result by the static angle computing device is true or false; An attitude angle detection device, comprising: an attitude angle calculation device that calculates an attitude angle to be output from the calculation result of the motion angle calculation device and the calculation result of the stationary angle calculation device in accordance with the calculation result. 2. A gyroscope for an attitude angle detecting device according to claim 1, comprising a vibrator for a piezoelectric vibrating gyroscope and a drive detecting circuit for operating the vibrator as a gyroscope. An attitude angle detection device comprising a magnetic material. 3. A high-pass filter is connected to an output of the gyroscope of the attitude angle detecting device according to claim 1, and the output of the high-pass filter is input to an arithmetic unit, and the motion angle is calculated using the output of the high-pass filter. Is calculated. 4. The attitude angle detection device according to claim 3, wherein the high-pass filter has a cut-off frequency variable unit. 5. The posture angle detecting device according to claim 1, wherein a provisional roll angle R is calculated from a biaxial acceleration sensor and outputs Ax (n) and Ay (n) of the acceleration sensor. (N), roll angle calculating means for calculating a provisional pitch angle P (n), pitch angle calculating means, and two-axis geomagnetism for measuring x-direction component Mx (n) and y-direction component My (n) of geomagnetism A sensor, a backup memory for storing the azimuth angle calculation result Φ (n-1) one unit time in the past for the unit time to be calculated, and outputs Ax (n), A
y (n) and the contents of the backup memory Φ (n-1)
A north component inclination angle calculating means for calculating the north component θ ₂ of the tilt angle, a geomagnetic Mz code discriminating means for determining the sign of the geomagnetic Z direction component Mz, and a geomagnetic Z direction component geomagnetic Mz absolute value calculation Means, a terrestrial magnetism Mz code discriminating means, a terrestrial magnetism Mz calculating means for calculating a terrestrial magnetism Mz of a component in the Z-axis direction from a terrestrial magnetism Mz absolute value computing means, X,
Coordinate transformation computing means for computing the Y, Z components HX, HY, HZ, and azimuth computing means for computing the azimuth angle Φ from the HX, HY in the reference coordinate system,
An attitude angle detection apparatus characterized in that an azimuth angle Φ (n) is measured by two axes of a geomagnetic sensor by virtually obtaining geomagnetic Mz by an arithmetic means. 6. The attitude angle detecting device according to claim 5, wherein the north component tilt angle θ ₂ , the geomagnetic dip θ ₀ at the origin, the backup, The output of the memory is Φ (n−
1) The outputs of the two axes of the acceleration sensor are Ax (n),
When Ay (n), the north component inclination angle θ ₂ is θ ₂ = s
in ⁻¹ [Ax (n) · cos (−Φ (n−1)) + Ay
(N) · sin (−Φ (n−1))], −9
If 0 degree ≦ θ ₂ ≦ θ ₀ , the geomagnetic Mz sign is minus,
If θ ₀ <θ ₂ ≦ 90 degrees, the geomagnetic Mz code is determined to be positive, and the attitude angle detecting device is characterized in that it is determined. 7. The posture angle detecting device according to claim 1, wherein the discriminating device includes a two-axis acceleration sensor,
The present output of the acceleration sensor is used as a means for determining whether or not the detection results of the temporary yaw angle Φ, the temporary pitch angle P, and the temporary roll angle R obtained by the stationary angle detection means including the two-axis geomagnetic sensor are correct. R (n) is the provisional roll angle obtained from Ax (n), and R is the provisional roll angle calculation result obtained from output Ax (n-1) which is one unit time past the unit time for calculation. (N-1), a tentative pitch angle similarly calculated from the current output Ay (n) of the acceleration sensor is P (n), and the output A in the unit time to be calculated is one unit time in the past.
The tentative pitch angle obtained from y (n-1) is P (n-1)
Then, when at least one of Expression 1 and Expression 2 is within a certain value, the posture angle information from the stationary angle detection means is determined to be correct. (Equation 1) (Equation 2) 8. The attitude angle detecting device according to claim 1, wherein an output to be obtained is obtained from a roll angle α (n), a pitch angle β (n), a yaw angle γ (n), and a motion angle detecting means. The tentative roll angle change △ X (n), the tentative pitch angle change △ Y (n), the tentative yaw angle change △ Z (n), and the static angle determined by the static angle Roll angle R
(N), provisional pitch angle P (n), provisional yaw angle Φ (n),
Assuming that the constants that are not larger than the errors are C ₁ , C ₂ , and C ₃ , α (n) = α (n
−1) + ΔX (n) −C ₁ , β (n) = β (n−1) +
ΔY (n) −C ₂ , γ (n) = γ (n−1) + ΔZ
The (n) -C _3, also the attitude angle information from the static angle detecting means if it is determined that the error, α (n) = α ( n-
1) + △ X (n), β (n) = β (n−1) + △ Y
(N), γ (n) = γ (n−1) + △ Z (n),
An attitude angle detection device for calculating an attitude angle. 9. The attitude angle detecting device according to claim 1, wherein outputs to be obtained are a roll angle α (n), a pitch angle β (n), a yaw angle γ (n), and a dynamic motion angle detection. The motion angle obtained from the means is calculated as a tentative roll angle change ΔX (n),
Temporary pitch angle change ΔY (n), temporary yaw angle change ΔZ
(N), the attitude angle obtained from the static stationary angle detecting means is a temporary roll angle R (n), a temporary pitch angle P (n), a temporary yaw angle Φ (n), and a proportional constant of 1 or less. Are assumed to be k ₁ , k ₂ , and k ₃ , when it is determined that the posture angle information from the stationary angle detecting means is correct based on the determination result of the determination device, α (n) =
α (n−1) + ΔX (n) −k ₁ [α (n−1) + ΔX
(N) −R (n)], β (n) = β (n−1) + △ Y
(N) −k ₂ [β (n−1) + ΔY (n) −P
(N)], γ (n) = γ (n−1) + △ Z (n) −k ₃
[Γ (n−1) + △ Z (n) −Φ (n)], and when the attitude angle information from the static angle detection means is determined to be incorrect, α (n) = α (n−1) ) + △ X (n), β
(N) = β (n−1) + △ Y (n), γ (n) = γ (n
-1) An attitude angle detection device which calculates an attitude angle from + △ Z (n).