JPH11211479A - 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. SOLUTION: This device is formed of gyroscopes 5, 6, 7 for detecting the angle speeds around three mutually orthogonal axes, a moving angle arithmetic device 31 for calculating the moving angle per unit time on the basis of the output according to the angle speed of each gyroscope, three acceleration sensors 10, 11, 12 for detecting the accelerations of the three axes, two geomagnetic sensors 8, 9 for detecting the geomagnetism of the two horizontal axes, an angle of repose arithmetic device 32 for calculating the angles of repose around the three axes, a judging device 33 for judging the justice of the operation result by the angle of repose arithmetic device 32, and an attitude angle arithmetic device 30 for calculating the attitude angle from 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.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Conventionally, as a posture angle detection method used in virtual reality to detect head movement, a weak AC magnetic field is generated from an externally provided AC magnetic field source.
A method using an AC magnetic field, which is detected by a sensor unit arranged in a head mounted display (hereinafter referred to as HMD) and a head operation is detected by a control operation unit, and an ultrasonic signal from an externally installed ultrasonic generation source There is a method of using an ultrasonic wave, which is detected by a sensor unit arranged on the HMD and detected by a control operation unit to detect a head movement.

[0003]

However, in the former method using an alternating magnetic field, since the signal generating source is a weak alternating magnetic field, the responsiveness is reduced by using a large number of filters to cancel noise, and the head is reduced. Compared to the movement of
The movement of the image of the HMD was slowed down, making the patient feel sick and causing sickness.

In the latter method using ultrasonic waves,
There is a possibility that the signal may not be detected due to malfunction due to various other ultrasonic signals, a shield between the signal source and the sensor, or there is an arm or hair in front of the sensor However, there is a problem that reception becomes impossible and malfunctions occur.

Accordingly, the present invention has solved the above problems,
It is an object of the present invention to provide a posture angle detection device used for posture control / detection of a movable body which can be used widely by alleviating restrictions on the place and environment of use.

[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 an axis; and first, for detecting accelerations of the three axes,
A second and third acceleration sensor and a geomagnetic sensor for detecting two axes of geomagnetism orthogonal to each other are arranged, and a movement angle (movement angle) per unit time based on the angular velocities output by the three gyroscopes. Motion angle detecting means for detecting a static angle, a static angle detecting means for detecting a static angle based on acceleration and geomagnetism, a discriminating device for discriminating whether or not the detection result of the static angle detecting means is correct, and a discriminating result of this discriminating device And an attitude angle calculation device that calculates the attitude angle to be output using the calculation results of the motion angle detection means and the stationary angle detection means, and detects the attitude angle of the moving body without using an external signal source It is characterized by being made possible.

That is, the present invention provides an X-axis orthogonal to a plane,
In a posture angle detecting device for detecting rotation angles around three axes orthogonal to each other, with an axis orthogonal to the Y axis being a Z axis,
Three gyroscopes for detecting angular velocities around the axis, the Y-axis, and the Z-axis; a motion angle calculating device that calculates a moving angle per unit time based on an output corresponding to the angular speed of each of the gyroscopes; Three acceleration sensors for detecting the three-axis acceleration, two geomagnetic sensors for detecting the two-axis geomagnetism of the X-axis and the Y-axis, and the three-axis acceleration sensor based on the outputs of the acceleration sensor and the geomagnetic sensor. A static angle calculating device for calculating a surrounding static angle, a discriminating device for determining whether the result of calculation by the static angle calculating device is true or false, and a motion angle calculating device and a static angle calculating device according to the calculation result of the discriminating device. And a posture angle calculation device that calculates a posture angle from the calculation result of the device.

Further, according to the present invention, the gyroscope comprises a vibrator and a drive detecting circuit for operating the vibrator as a gyroscope, and the vibrator is made of a non-magnetic material. It is a detection device.

Further, the present invention is the above-described attitude angle detecting device, wherein a high-pass filter is connected to an output section of the gyroscope, and a movement angle per unit time is calculated using an output from the high-pass filter.

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

The present invention also provides an output Ax (n) from the x-axis and y-axis acceleration sensors of the three-axis acceleration sensor.
Roll angle calculation means and pitch angle calculation means for calculating a provisional roll angle R (n) and a provisional pitch angle P (n) from Ay (n), an x-direction component Mx (n) of the geomagnetism, and a y-direction component My
A two-axis geomagnetic sensor for measuring (n), a backup memory for storing the azimuth angle calculation result Φ (n-1) one unit time in the past for the unit time for calculation, and an output Ax ( n), determined from Ay (n) and a backup memory contents Φ (n-1), the north component inclination angle calculating means for calculating a north component theta ₂ of the inclination angle, the sign of the geomagnetism in the Z-direction component Mz Mz code discriminating means, Z-direction component geomagnetism Mz absolute value calculating means, geomagnetic Mz sign discriminating means, and geomagnetic Mz calculating means for calculating Z-axis component geomagnetism Mz from the geomagnetic Mz absolute value calculating means From the geomagnetics Mx, My, Mz,
X, Y, Z components HX, HY, H of geomagnetism in the reference coordinate system
The geomagnetic sensor 2 includes a coordinate transformation calculating means for calculating Z and an azimuth calculating means for calculating an azimuth angle Φ based on the HX and HY in the reference coordinate system. The above attitude angle detecting device can measure the azimuth angle Φ (n) only by the axis.

Further, according to the present invention, in the northern component tilt angle calculating device and the geomagnetic Mz code discriminating means of the attitude angle detecting device, the northward component tilt angle θ ₂ , the magnetic field dip angle θ ₀ at the origin, the backup memory The output is Φ (n-1), and the outputs of the two axes of the acceleration sensor are Ax (n) and Ay (n), respectively.
, The north component inclination angle θ ₂ is θ ₂ = sin ⁻¹ [A
x (n) · cos (−Φ (n−1)) + Ay (n) · s
in (−Φ (n−1))], and −90 degrees ≦
If θ ₂ ≦ θ ₀ , the geomagnetic Mz sign is minus and θ ₀ <
If θ ₂ ≦ 90 degrees, the above-described attitude angle detection device determines that the geomagnetic Mz sign is positive.

Further, the present invention provides a method for detecting a temporary yaw angle Φ, a temporary pitch angle P, and a temporary roll angle R, which are obtained by a static angle detecting means comprising the three-axis acceleration sensor and the two-axis geomagnetic sensor. As a means for determining whether the result is correct, since the combined level of the three-axis acceleration sensor is approximately 1 G, the current output Ax (n),
The above attitude angle detection device determines that the attitude angle information from the static angle detection means is correct when the algorithm performed by Ay (n) and Az (n) is Equation 1.

[0014]

(Equation 1)

Further, according to the present invention, the output to be obtained by the attitude angle detecting device is a roll angle α (n), a pitch angle β (n),
The yaw angle γ (n), the motion angles obtained from the motion angle detecting means are ヨ ー X (n), △ Y (n), △ Z (n), the static angle obtained from the static angle detecting means is R (n), P (n), Φ
(N) Assuming that the constants are C ₁ , C ₂ , and C ₃ , α (n) = α (n− 1) + △ X
(N) −C ₁ , β (n) = β (n−1) + ΔY (n) −
When C ₂ , γ (n) = γ (n−1) + △ Z (n) −C ₃ , 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) + ΔZ (n) is the above-described attitude angle detection device that calculates an attitude angle.

Further, according to the present invention, the output to be obtained by the attitude angle detecting device is a roll angle α (n), a pitch angle β (n),
The yaw angle γ (n), 運動 X (n), △ Y (n), △ Z (n) are the motion angles obtained from the motion angle detecting means, R (n) is the attitude angle obtained from the stationary angle detecting means, P (n), Φ
(N), when a following proportionality constant and _{k 1, k 2, 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) + △ 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
The above attitude angle detection device calculates the attitude angle by Y (n), γ (n) = γ (n−1) + △ Z (n).

[0017]

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

The coordinate conversion operation from the sensor coordinate system to the reference coordinate system described here will be described as being performed in the order of yaw angle Φ → pitch angle R → roll angle P.

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), Az
(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. The reference coordinate system X obtained from the output of the gyroscope,
Motion angles around Y and Z axes: △ X (n), △ Y (n), △ Z
(N). Rotation angle around the X axis (temporary roll angle) obtained from the output of the acceleration sensor (temporary roll angle): R (n) Similarly, rotation angle around the Y axis (temporary pitch angle): P (n) Z
Rotation angle around axis (temporary yaw angle): Φ _m (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 reference coordinate systems X, Y, and Z axes to be finally output obtained from the above calculation results are roll angle α (n), pitch angle β (n), 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 second gyroscope 6 for detecting angular velocities around three axes (x axis, y axis, and z axis) orthogonal to each other. The gyroscope 7 of 3
They are arranged parallel to the x, y, and z axes, that is, perpendicular to each other. The three axes are the first acceleration sensor 1
0, a second acceleration sensor 11, and a third acceleration sensor 12 are arranged. Further, a first geomagnetic sensor 8 and a second geomagnetic sensor 9 are arranged on the x axis and the y axis, respectively, in parallel with the y axis.

FIG. 2 shows a case where the sensor coordinate system (xyz system) deviates from the reference coordinate system (XYZ system). 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. The gravitational acceleration is equal to the force Az (n) in the z-axis direction of the sensor coordinate system.

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 detecting device of the present invention includes three orthogonally arranged gyroscopes shown in FIG. 1, a high-pass filter connected to each of the gyroscopes, and a gyro through a high-pass filter. A motion angle calculator 31 for calculating a movement angle (movement angle) per unit time from an output of the scope, three acceleration sensors shown in FIG. 1, two geomagnetic sensors, and three acceleration sensors A temporary roll angle R is obtained from the first acceleration sensor 10 and a temporary pitch angle P is obtained from the second acceleration sensor 11, and a temporary yaw angle Φ is obtained from the temporary roll angle R and the temporary pitch angle P. The static angle computing device 32 to be obtained, a discriminating device 33 for discriminating whether the computation result of the static angle computing device 32 is true or false, and the motion angle computing device 31, the static angle computing device 32, and the discriminating device 33
And an attitude angle calculation device 30 that processes signals from the computer.

First, the contents of the gyroscope will be described. As the gyroscope 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 the present embodiment, a piezoelectric vibrating ceramic gyro manufactured by Tokin Co., Ltd. was 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, and the motion angle calculator 31 is connected to the outputs of the high-pass filters. Is connected. In the case of a gyroscope, the smaller and cheaper the gyroscope, the larger the variation and fluctuation of the output (offset) when the gyroscope is stationary, but using a stabilized gyroscope makes the posture detection device expensive and large. I will.

The high-pass filter cancels the offset of the gyroscope. By using the output after using the high-pass filter, an inexpensive, compact, and highly accurate attitude angle detecting device can be obtained. Usually, it is set to a low frequency of 0.1 Hz or less. Each high-pass filter has a cut-off frequency varying unit. In addition, 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 needed. After increasing the cutoff frequency and obtaining a stable output,
The cutoff frequency is immediately returned to a low state (measurement state).

The outputs Jx (n), Jy (n) and Jz (n) of each gyroscope according to the rotational angular velocity of the attitude angle detecting device (measured object) mounted on the moving body are calculated by the motion angle calculating device 31. From the output β (n−1) one unit time past the unit time calculated by performing coordinate transformation, the following equation is obtained:
It is converted into the current movement angle (movement angle) per unit time in the reference coordinate system △ X (n).

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 calculating device will be described with reference to FIG. 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.

The outputs Ax (n) and Ay of the 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 represented by Φ (n) = tan ^-1 [HX (n) / HY (n)] using the geomagnetic component in the reference coordinate system. It is. The yaw angle Φ _m (n) based on the output Az (n) of the acceleration sensor is compared with the yaw angle Φ (n) to calculate the yaw angle with high accuracy. When the attitude angle detector rotates on a horizontal plane, the outputs Mx (n) and My (n) of the geomagnetic sensor are equal to HX (n) and HY (n), respectively, and Φ (n) = tan ⁻¹ [Mx (n) / My (n)] holds.

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

However, when the attitude angle detecting device 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
+ Cos [R (n)] × cos [P (n)] × Mz, the temporary roll angle R (n) and the temporary 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, the attitude angle detection device (measured object) is tilted by 90 degrees so that the magnetic sensor 10 or the magnetic sensor 11 faces the Z axis of the reference coordinate system. Then, for example, a signal such as pressing a key or a button is sent, 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) and My (n) are changed to Mx (0) and Myx.
(0) is stored in the memory. These Mx (0), M
Ht is obtained from Equation 2 using y (0) and Mz (0).

[0041]

(Equation 2)

Further, in order to calculate the sign of Mz, it can be determined from the inclination angle of the north component of the geomagnetic field of the attitude angle detecting device (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
From the values of the acceleration sensor outputs Ax (n) and Ay (n), the north component inclination angle calculation means calculates the geomagnetic north component θ ₂ of the inclination angle of the attitude angle detection device (measured object) as follows. It is calculated by the formula.

Θ ₂ = sin ⁻¹ [Ax (n) × cosΦ (n−
1) + Ay (n) × sin Φ (n−1)]. If −90 degrees ≦ θ ₂ ≦ θ ₀ , the geomagnetic Mz sign is minus, and if θ ₀ <θ ₂ ≦ 90 degrees, the geomagnetic Mz sign is negative. The Mz code is determined to be positive.

Next, in the attitude angle detecting device of the present invention,
An algorithm performed when the combined vector of the three-axis acceleration sensor is approximately 1 G, that is, when the expression 1 is used, the tentative roll angle R (n) and the tentative pitch angle P calculated by the static angle detection device are calculated. (N) The determination device 33 that determines whether the temporary yaw angle Φ (n) is correct will be described.

[0046]

(Equation 1)

The discriminating device 33 calculates the acceleration Ax (n) in the X-axis direction and the acceleration A
From y (n), the roll angle R = sin ⁻¹ (Ax / cos
P) and the pitch angle P = sin ^-1 Ay.

However, here, Ax (n), Ay (n)
Is a composite vector of the inclination angle component of the gravitational acceleration and the X- and Y-axis components of the motion acceleration. Therefore, if there is a motion acceleration, the roll angle and the pitch angle will not be correct. Therefore,
The magnitude of the composite vector A of the three-axis acceleration sensor is obtained by Expression 3, and if this value is near 1 G, it is determined that there is no motion acceleration in the axial direction, that is, the roll angle R and the pitch angle P are correct. And enter static mode. Otherwise, it is determined that there is a motion acceleration in the axial direction, the calculation result from the static angle detection means is not correct, and the dynamic mode is set.

[0049]

(Equation 3)

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 static 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, the final outputs from the motion angle calculating device 31 and the static angle calculating device 32 for calculating the output of the motion angle detecting means and the output of the static angle detecting means in accordance with the result of the discrimination by the discriminating device 33. A calculation method performed by the obtained attitude angle calculation device 30 will be described.

The basis of this calculation is that when the determination device 33 determines that the output of the static angle detection means is incorrect, the current attitude angle detection result is obtained by comparing the attitude angle detection result one unit time past with the motion angle. The result is the sum of the values,
When it is determined that the output of the static angle detecting means is correct, the current posture angle detection result is obtained by subtracting the correction value from the sum of the posture angle detection result one unit past and the motion angle. The correction value is a value obtained by multiplying the error by a proportional constant or a constant. Here, the error is obtained by subtracting the current detection result by the stationary angle detection means from the sum of the posture angle detection result in the past unit time and the current motion angle.

When this is expressed by an equation, in the present embodiment, the output to be obtained by the attitude angle detecting device of the present invention is α
(N), β (n), γ (n), 運動 X (n), △ Y (n), △ Z (n), the motion angle obtained from the motion angle detecting means, The corner 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) −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 errors arbitrarily selected. When the sign of the error is plus, when the sign of the error is plus, and when the sign is 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.

As 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), the motion angles obtained from the motion angle detecting means are △ X (n), △ Y (n), △ Z (n), and the static angle obtained from the static angle detecting means is R (n ), P (n), Φ
(N)

If it is determined that the posture 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 a proportional constant of 1 or less that can be arbitrarily selected.

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 example of an HMD to which the attitude angle detecting device according to the embodiment of the present invention is applied. The HMD is provided so that the image displayed on the display 1 in front of the HMD changes in conjunction with the movement of the head and allows the user to experience a virtual space. , The head posture angle measured by the posture angle detection device 2 is transmitted to the video generation device 4 via the signal cable 3, and the video generation device 4
Since the image corresponding to the attitude angle is transmitted to the HMD, the image developed to the right is displayed, and the image is provided so that a 360-degree image of the entire space can be realized by the movement of the head.

[0061]

As described above, when the attitude angle detecting device according to the present invention is applied to the HMD, a high-performance high-speed response-free angle information with no accumulated error can be obtained without using an external signal. An HMD can be configured.

Further, according to the attitude angle detecting device of the present invention, since the gyroscope is mounted as an element, it is possible to reduce the size and weight, and since the ceramic vibrator is used, there is no magnetic noise. Even if it is close to the magnetic sensor, the function will not be impaired. Also, by using a high-pass filter, miniaturization, low cost, and high accuracy can be achieved.

Further, according to the present invention, the three acceleration sensors and the two terrestrial magnetism sensors can perform the determination / correction processing of the presence / absence of an error component with high accuracy only by a simple calculation, and provide a high-speed response. Thus, a highly accurate attitude angle detecting 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 coordinate system in which a reference coordinate system (XYZ system) and a sensor coordinate system (xyz system) do not match.

FIG. 3 is a diagram showing a configuration of a posture angle detection device of 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 2 Attitude angle detection apparatus (DUT) 3 Signal cable 4 Image generator 5 (First) gyroscope 6 (Second) gyroscope 7 (Third) gyroscope 8 (First) geomagnetism Sensor 9 (second) geomagnetic sensor 10 (first) acceleration sensor 11 (second) acceleration sensor 12 (third) acceleration sensor 30 attitude angle calculator 31 motion angle calculator 32 static angle calculator 33 discrimination Device 36 (first) high-pass filter 37 (second) high-pass filter 38 (third) high-pass filter

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI G01V 3/40 G01V 3/40 // G01R 33/02 G01R 33/02 L

Claims (9)

[Claims] 1. An attitude angle detecting device for detecting rotation angles around three mutually orthogonal axes, with an axis orthogonal to an X axis and a Y axis orthogonal to each other in a plane as a Z axis. And Z
Three gyroscopes for detecting angular velocities around axes, a motion angle calculating device for calculating a moving angle per unit time based on an output corresponding to the angular velocities of the respective gyroscopes, and detecting the accelerations of the three axes Three acceleration sensors, two terrestrial magnetism sensors for detecting terrestrial magnetism in two axes of X-axis and Y-axis, and a static angle around the three axes is calculated based on outputs of the acceleration sensor and the terrestrial magnetism sensor. A static angle computing device, a discriminating device for discriminating whether the computation result by the static angle computing device is true or false, and an attitude angle based on the computation result of the motion angle computing device and the static angle computing device according to the computation result of the discriminating device. And a posture angle calculating device for calculating the following. 2. The gyroscope comprises a vibrator and a drive detection circuit for operating the vibrator as a gyroscope, wherein the vibrator is made of a non-magnetic material. The attitude angle detecting device as described in the above. 3. The attitude angle according to claim 1, wherein a high-pass filter is connected to an output unit of the gyroscope, and a movement angle per unit time is calculated using an output from the high-pass filter. Detection device. 4. The attitude angle detecting device according to claim 3, wherein the high-pass filter has a cut-off frequency variable unit. 5. A tentative roll angle R (n) and a tentative pitch angle P (n) based on outputs Ax (n) and Ay (n) from the x-axis and y-axis acceleration sensors of the three-axis acceleration sensor. ), A two-axis geomagnetic sensor for measuring the x-direction component Mx (n) and the y-direction component My (n) of the geomagnetism, and one unit time for the unit time to be calculated A backup memory for storing the past azimuth angle calculation result Φ (n-1), and an output A of the acceleration sensor
a north component tilt angle calculating means for calculating a north component θ ₂ of the tilt angle from x (n), Ay (n) and the contents Φ (n-1) of the backup memory;
a geomagnetic Mz code discriminating means for judging the sign of z, a geomagnetic Z-direction component geomagnetic Mz absolute value calculating means, the geomagnetic Mz code discriminating means, and a geomagnetic Mz absolute value calculating means.
Geomagnetic Mz calculating means for calculating an axial component geomagnetism Mz; coordinate conversion calculating means for calculating geomagnetic X, Y, Z components HX, HY, HZ in a reference coordinate system from the geomagnetism Mx, My, Mz; , HX, H in the reference coordinate system
An azimuth calculating means for calculating an azimuth angle Φ from Y, and a terrestrial magnetism Mz calculating means virtually obtains the terrestrial magnetism Mz.
The attitude angle detecting device according to any one of claims 1 to 4, wherein the attitude angle can be measured. 6. A north component tilt angle θ ₂ , a geomagnetic dip θ ₀ at the origin, and a backup memory output of Φ ( n-1), and when the outputs of the two axes of the acceleration sensor are Ax (n) and Ay (n), respectively, the north component inclination angle θ ₂ is θ ₂ = sin ⁻¹ [Ax (n) · cos
(−Φ (n−1)) + Ay (n) · sin (−Φ (n−
1))], if −90 degrees ≦ θ ₂ ≦ θ ₀ , the geomagnetic Mz sign is determined to be negative, and if θ ₀ <θ ₂ ≦ 90 degrees, the geomagnetic Mz sign is determined to be positive. The attitude angle detecting device according to any one of claims 1 to 5, wherein 7. The detection results of the provisional yaw angle Φ, the provisional pitch angle P, and the provisional roll angle R obtained by the static angle detection means including the three-axis acceleration sensor and the two-axis geomagnetic sensor are correct. As a means for determining whether or not the combined output of the three-axis acceleration sensor is approximately 1 G, the current outputs Ax (n), Ay (n), Az of the acceleration sensor
7. The attitude angle detecting device according to claim 1, wherein when the algorithm performed by (n) is Equation 1, the attitude angle information from the stationary angle detecting means is determined to be correct. (Equation 1) 8. An output to be obtained by the attitude angle detecting device is a roll angle α (n), a pitch angle β (n), and a yaw angle γ.
(N), the motion angle obtained from the motion angle detecting means is represented by ΔX
(N), △ Y (n), △ Z (n), R (n), P (n), Φ (n), and the fixed constants C ₁ , C ₂ , when C _3, the discrimination result of the discriminating device, to determine the attitude angle information from the static angle detecting means correct, α (n) = α ( n-1) + △ X (n) -C
₁ , β (n) = β (n−1) + ΔY (n) −C ₂ , γ
If (n) = γ (n−1) + ΔZ (n) −C ₃ , and if the attitude angle information from the static angle detection unit is determined to be incorrect, α (n) = α (n−1) ) + △ X (n), β
(N) = β (n−1) + △ Y (n), γ (n) = γ (n
The attitude angle detecting device according to any one of claims 1 to 7, wherein the attitude angle is calculated from -1) + △ Z (n). 9. An output to be obtained by the attitude angle detecting device is a roll angle α (n), a pitch angle β (n), and a yaw angle γ.
(N), the motion angle obtained from the motion angle detecting means is represented by ΔX
(N), △ Y (n), △ Z (n), and the attitude angles determined by the static angle detection means are R (n), P (n), Φ (n),
Assuming that the following proportional constants are k ₁ , k ₂ , and k ₃ , α (n) = α (n−1) when it is determined that the posture angle information from the static angle detection unit is correct based on the determination result of the determination device. ) + △ X
(N) −k ₁ [α (n−1) + ΔX (n) −R
(N)], β (n) = β (n−1) + ΔY (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
The attitude angle detecting device according to claim 1, wherein the attitude angle is calculated by Y (n), γ (n) = γ (n−1) + △ Z (n).