JP5092279B2 - Head motion tracker device and method of using the same - Google Patents

Description

  The present invention relates to a head motion tracker device for measuring an occupant's head angle, head position, and the like with respect to a reference direction set for a moving body, and a method of using the head motion tracker device.

  For example, in a rescue operation by a rescue flying boat, locking is performed by locking when the aiming image displayed by the head-mounted display device corresponds to the rescue target so that the discovered rescue target is not lost. The position of the rescue target that has been made is calculated. At this time, in order to calculate the position of the rescue target, in addition to the latitude, longitude, altitude and attitude of the flying object, the head information of the crew (head angle and head) with respect to the reference direction set for the flying object Position).

As such a conventional head motion tracker device (hereinafter also referred to as HMT), for example, an AC magnetic type HMT can be cited (for example, see Patent Document 1). FIG. 8 is a diagram showing a schematic configuration of an AC magnetic HMT mounted on a flying object. The HMT 100 is fixed to a magnetic source 102 that generates an alternating magnetic field, a helmet 110 with a head-mounted display device that a pilot 103 sitting on a seat 104 wears on the head, and a helmet 110 with a head-mounted display device. The magnetic sensor 107 includes a control unit 120 that controls the magnetic source 102 and the magnetic sensor 107 and has a function of calculating the position and angle of the magnetic sensor 107 based on magnetic data detected by the magnetic sensor 107. .
That is, according to the HMT 100, an alternating magnetic field generated by the magnetic source 102 causes a magnetic change (magnetic data having a magnitude and a direction) unique to each position at each point in the space. At this time, coordinates serving as a reference for the position with respect to the flying object and a reference direction serving as a reference for the direction with respect to the flying object are determined in advance. For example, it is assumed that the XYZ coordinates are determined with the position of the magnetic source 102 as the origin, and the X-axis direction is determined as the reference direction (for example, the model direction is the X-axis).

  By comparing the magnetic data detected by the magnetic sensor 107 with the magnetic data possessed by each point in the space, the positional information of the current position of the magnetic sensor 107 X, Y, Z, and the reference direction of the magnetic sensor 107 The pilot 103 wearing the head-mounted display-equipped helmet 110 is obtained by obtaining angle information of azimuth angle (rotation with respect to the X axis), elevation angle (rotation with respect to the Y axis), and roll angle (rotation with respect to the Z axis). The head position and head angle with respect to the origin of the head and the reference direction are calculated.

Further, an optical HMT is disclosed that monitors reflected light with a camera device when a plurality of reflectors are attached to a helmet and light is emitted from a light source (see, for example, Patent Document 2). There is also an HMT filed by the present applicant (Japanese Patent Application No. 2005-106418). Specifically, on the outer peripheral surface of the helmet with a head-mounted display device, LEDs are attached to the three locations so as to be separated from each other, and the positional relationship between these three markers is determined in advance. These three markers are photographed simultaneously with two camera devices that can be viewed in stereo and the installation location is fixed, thereby measuring the current positional relationship of the three markers based on the so-called triangulation principle. doing. Thereby, the position and angle of the helmet with a head-mounted display device are specified by associating the current positional relationship of the markers with the predetermined positional relationship of the markers for the three marker positional relationships.
JP 2002-81904 A JP-T 9-506194

  However, in the AC magnetic HMT 100, when a conductive material such as a metal is present around the magnetic source 102 or the magnetic sensor 107, the magnetic field is generated in the AC magnetic field due to the influence of the eddy current generated in the conductive material. Distortion occurred, making it difficult to specify a position and angle with high accuracy.

  On the other hand, in an optical HMT, it is necessary to continue to observe a marker with a camera. However, if the position and angle of the helmet with a head-mounted display device change greatly, the relationship between the marker position and the camera installation location In some cases, the marker may be out of the field of view of the camera device, making measurement impossible in stereo.

Therefore, the present invention provides a head for a reference direction set for a moving body even when magnetostriction occurs in an AC magnetic field in an AC magnetic HMT, or stereo measurement cannot be performed in an optical HMT. It is an object of the present invention to provide a head motion tracker device including an auxiliary mechanism that can accurately calculate a component angle.
Another object of the present invention is to provide a head motion tracker device having an auxiliary mechanism that does not require precise adjustment work and a method of using the head motion tracker device.

The head motion tracker of the present invention, which has been made to solve the above-mentioned problems, has a passenger motion with respect to a reference axis set on a moving body by a measurement method of either a magnetic motion tracker or an optical motion tracker. A motion tracker that detects head movement, and a main head information calculation unit that calculates first relative head information including at least the head angle of the passenger based on the head movement detected by the motion tracker. In the head motion tracker apparatus, the moving body sensor that is attached to the moving body and detects at least the angular velocity and the absolute moving body information that calculates the absolute moving body information that represents the movement of the moving body based on the output signal of the moving body sensor A calculation unit, a head sensor that is mounted on the head of the passenger and detects at least the angular velocity, and an output signal of the head sensor Absolute head information calculation unit movement of the moving body and head to calculate a synthesized absolute head information based on a first relative calculation of the first relative head information is calculated immediately before entering the inappropriate region A sub head information calculation unit that calculates second relative head information corresponding to the first relative head information including at least the head angle of the passenger based on the head information, the absolute moving body information, and the absolute head information. And a switching unit that switches from the first relative head information to the second relative head information calculated by the sub head information calculation unit in an area where the calculation of the first relative head information by the main head information calculation unit is inappropriate And so on.

Here, the magnetic motion tracker is a magnetic sensor attached to an object (for example, a helmet) whose movement is to be detected, and a magnetic field is generated by a magnetic source in a space within the movement range of the object. This is a motion tracker that tracks the movement of an object by detecting the magnetism determined for each point in the space with an attached magnetic sensor to determine the position and orientation (angle) of the magnetic sensor.
In addition, an optical motion tracker is an object whose motion is to be detected by placing a marker such as a light emitter (lamp, LED, etc.), reflector, phosphor, etc. in the space of the movement range of the object. It refers to a type of motion tracker that tracks the movement of an object by arranging optical detection means such as a camera that can optically detect the marker and sequentially detecting the movement of the marker.

  In addition, the mobile body sensor and the head sensor have three axes defined in the sensor itself, and by attaching the sensor to a measurement object, the angular velocity or the acceleration in the three-axis direction based on the three axes can be obtained. It can be detected. Specifically, a gyro sensor or an acceleration sensor is used to detect movement information with respect to an absolute space of an object (that is, a head-mounted helmet attached with a head sensor or a moving body attached with a moving body sensor). The head sensor detects movement information obtained by combining the movement of the head and the movement of the moving body in the moving body.

  The “region where calculation of the first relative head information is inappropriate” means a region where accurate head information cannot be obtained for the first head information to be obtained, or the first head to be obtained. An area where information cannot be measured. Specifically, for example, in the case of a magnetic motion tracker, an area where accurate magnetic data cannot be measured due to magnetostriction (this area is preset and stored), and in the case of an optical motion tracker, the marker is an optical such as a camera. An area outside the field of view of the detection means and incapable of optical measurement.

According to the head motion tracker device of the present invention, the main head information calculation unit detects the movement of the passenger's head relative to the reference axis set on the moving body by the magnetic motion tracker or the optical motion tracker. Then, the first relative head information including at least the passenger's head angle is calculated based on the detected head movement. Further, the moving body sensor attached to the moving body detects the angular velocity, and the absolute moving body information calculation unit calculates absolute moving body information representing the movement of the moving body based on the detection result. Also, the head sensor attached to the passenger's head detects the angular velocity, and the absolute head information calculation unit combines the movement of the moving body and the movement of the passenger's head based on the detection result. Calculate information.
Then, the sub head information calculation unit, based on the absolute moving body information and the absolute head information, from these differences, the second relative corresponding to the first relative head information including at least the head angle of the passenger Head information is calculated. Then, the switching unit becomes a region in which magnetostriction is generated in the AC magnetic field in the magnetic motion tracker (previously set and stored region), or the optical motion tracker cannot measure by stereo vision, Second relative head information including a head angle with respect to a reference direction set by the sub head information calculation unit when the main head information calculation unit cannot calculate the first relative head information. Is calculated.
In this way, head information such as head angle with respect to the reference direction set for the moving body is always calculated.

  Here, the sub head information calculation unit calculates the second relative head information based on the absolute head information calculated from the output of the head sensor and the absolute moving body information calculated from the output of the moving body sensor. Although calculated, an error due to a drift phenomenon may occur with time due to the nature of a sensor (such as a gyro sensor) that detects angular velocity. However, when the first relative head information including the head angle is calculated by the main head information calculation unit that does not cause drift, and the calculation of the first relative head information by the main head information calculation unit is inappropriate As a temporary aid, the second relative head information including the head angle is calculated by the sub head information calculation unit. The second relative head information is obtained by adding the change measured by the mobile body sensor and the head sensor to the immediately preceding first relative head information. There is almost no. When the first relative head information can be calculated again by the main head information calculation unit, the first relative head information is referred to.

  According to the present invention, when accurate first relative head information cannot be obtained, accurate head information based on second relative head information can be temporarily obtained. At this time, the period of using the second relative head information can be set to a short time after the first relative head information cannot be calculated. As a result, the head angle with respect to the reference direction set for the moving body can always be calculated with high accuracy.

(Means and effects for solving other problems)
In the above invention, the sub head information calculation unit detects the sensor axis direction of the head sensor based on the absolute head information and the first relative head information obtained simultaneously with the moving body stopped. A sensor axis detection unit, and a moving body sensor axis calculation unit that calculates the sensor axis direction of the moving body sensor based on the absolute head information, the first relative head information, and the absolute moving body information simultaneously obtained while the moving body is moving And a conversion data storage unit for storing conversion data for axis alignment for adjusting the sensor axis direction of the head sensor and the sensor axis direction of the moving body sensor to the reference axis direction set in the moving body, The sub head information calculation unit may correct the absolute head information and the absolute moving body information based on the axis alignment conversion data.

According to this, the head sensor axis detection unit detects the absolute head information while the moving body is stopped. The head sensor originally detects a movement that combines the movement of the head and the movement of the moving body. However, when the moving body is stopped, the absolute head information includes only the movement of the head. Will be included.
In addition, as described above, the head sensor (for example, gyro sensor) has a triaxial direction defined in the sensor itself, and by attaching the sensor to an object to be measured, an angular velocity with respect to the triaxial axis is set. Although detected, these three axes and the reference axis direction of the motion tracker do not coincide with each other unless an adjustment operation is actively performed in advance, and an axis deviation occurs.
Therefore, in parallel with the measurement by the head sensor in a state where the moving body is stopped (the head sensor detects only the movement of the head at this time), the magnetic head or the optical motion tracker is used at the same time. The head angle is calculated as the first relative head information. From this first relative head information, accurate head information that does not include an axis deviation is obtained. Therefore, by comparing the absolute head information (including the axis deviation) measured by the head sensor with the moving body stopped and the first relative head information, Since the deviation amount of the sensor axis can be calculated, the sensor axis direction of the head sensor with respect to the reference axis direction set for the moving body is detected by obtaining the deviation amount.

Subsequently, in consideration of the amount of deviation between the detected sensor axis direction of the head sensor and the reference axis of the motion tracker, the moving body sensor axis detector further detects the axis deviation of the moving body sensor.
That is, the moving body sensor axis detection unit simultaneously detects the absolute head information and the absolute moving body information by the head sensor and the moving body sensor while the moving body is moving. As described above, while the moving body is moving, the absolute head information measured by the head sensor detects the combined motion of the head and the flying object, while it is measured by the moving body sensor. The movement of the flying object is detected in the absolute head information.
In parallel with these detections, the movement of the head is detected by a magnetic or optical motion tracker, and the head angle is calculated as first relative head information. From this first relative head information, accurate head information (head angle) with respect to the reference axis set for the moving body is obtained.
Therefore, the absolute head information (including the head movement and the movement of the moving body) measured by the head sensor and the first relative head information (only the head movement is measured while the moving body is moving). Information) including only the movement of the moving body excluding the head movement from the absolute head information (also referred to as reference moving body information) is calculated.

On the other hand, only the movement of the moving body is detected from the absolute moving body information measured by the moving body sensor, but this sensor is the same as the case of the head sensor unless adjustment work is actively performed. In addition, the amount of axial deviation between the sensor axis of the moving body sensor and the reference axis set for the moving body is included.
Therefore, the sensor axis direction of the mobile body sensor with respect to the reference axis direction set for the mobile body is calculated by taking the difference between the previously obtained reference mobile body information and the absolute mobile body information.

Then, the sub head information calculation unit calculates conversion data for axis alignment for alignment with the reference axis direction set for the moving body from the calculated sensor axis direction of the head sensor and the sensor axis direction of the moving body sensor. Then, the conversion data for axis alignment is stored in the conversion data storage unit. In addition, the sub head information calculation unit corrects the absolute head information and the absolute moving body information based on the axis alignment conversion data.
Thereby, when attaching a head sensor to a passenger | crew's head, or attaching a mobile body sensor to a mobile body, the necessity of performing a precise adjustment operation | work is eliminated.

In the first invention, the mobile body sensor and the head sensor further detect acceleration, and the main head information calculation unit includes first relative head information including the head angle and head position of the occupant. The sub head information calculation unit may calculate second relative head information including the head angle and head position of the passenger.
According to this, the head position can be calculated together with the head angle.

In the above invention, the sub head information calculation unit calculates the sensor axis direction of the head sensor and the sensor axis center based on the absolute head information and the first relative head information obtained simultaneously with the moving body stopped. Based on the absolute head information, the first relative head information, and the absolute moving body information that are simultaneously obtained while the moving body is moving, the sensor axis direction and the sensor axis center of the moving body sensor are detected. A moving body sensor axis calculating unit for calculating, and further, a sensor axis direction of the head sensor, a sensor axis center, and a sensor axis direction of the moving body sensor, a reference axis direction in which the sensor axis center is set to the moving body, A conversion data storage unit for storing axis alignment conversion data for alignment with the center of the reference axis is provided, and the sub head information calculation unit corrects the absolute head information and the absolute moving body information based on the axis alignment conversion data. Yo It may be.
According to this, when attaching the head sensor to the occupant's head or attaching the moving body sensor to the moving body, there is no need to perform precise adjustment work.

In each of the above inventions, the magnetic motion tracker may include a magnetic source that is attached to the moving body and generates an alternating magnetic field, and a magnetic sensor that is attached to the head and detects the alternating magnetic field.
According to the present invention, the head angle and head position can be obtained by the main head information calculation unit near the place where the magnetic source is attached in the moving body, and the sub head information calculation unit can be obtained at a place away from this. Information on the head angle and head position can be obtained.

In each of the above inventions, the optical motion tracker may be provided with an optical marker that is mounted on the head and emits a light beam, and a camera that is attached to the moving body and detects the light beam from the optical marker.
According to the present invention, the head angle and head position can be obtained by the main head information calculation unit near the camera installation location in the moving body, and the head information calculation unit can obtain the head angle at a location where the camera is blind spot. Information on the part angle and head position can be obtained.

In addition, the method of using the head motion tracker device of the present invention from another point of view is to board the reference axis set on the moving body by the measurement method of either the magnetic motion tracker or the optical motion tracker. A motion tracker that detects the movement of the head of the person, and a main head information calculation unit that calculates first relative head information including at least the head angle of the passenger based on the movement of the head detected by the motion tracker A moving body sensor that is attached to the moving body and detects an angular velocity, an absolute moving body information calculating unit that calculates absolute moving body information that represents the movement of the moving body based on an output signal of the moving body sensor, and a passenger's head The head sensor that is mounted on the head and detects the angular velocity, and the absolute head information that combines the movement of the moving body and the head based on the output signal of the head sensor is calculated. A pair head information calculation section, at least the rider on the basis of the first relative head information and absolute mobile body information and the absolute head information calculation of the first relative head information is calculated immediately before entering the inappropriate region A head motion tracker device comprising: a sub head information calculation unit that calculates second relative head information corresponding to the first relative head information including the head angle of: Calculate absolute head information consisting only of head movement based on the output of the head sensor when the body is stopped, and calculate the first relative head information by detecting head movement using a motion tracker. And a head sensor axis detecting step for detecting the sensor axis direction of the head sensor based on the absolute head information and the first relative head information obtained simultaneously, and (b) a head sensor in which the moving body is moving Output of the head and the moving body The absolute moving body consisting of the movement of the moving body is calculated by calculating the absolute head information by synthesizing the head and calculating the first relative head information by detecting the movement of the head by the motion tracker. A moving body sensor axis detecting step of detecting information and further detecting a sensor axis of the moving body sensor based on the absolute head information, the first relative head information, and the absolute moving body information is provided.
According to the present invention, the head sensor and the moving body sensor can be used only by attaching them to the moving body without performing complicated adjustment work for axis alignment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments described below, and it goes without saying that various aspects are included without departing from the spirit of the present invention.

(Embodiment 1)
FIG. 1 is a diagram showing a schematic configuration of a head motion tracker apparatus according to an embodiment of the present invention. In this embodiment, the head angle of the flying pilot is calculated.
The head motion tracker device 1 is composed of a helmet 10 with a head-mounted display device attached to the head of a pilot 3, a magnetic source 2 and a flying object side three-axis gyro sensor 4 attached to the flying object, and a computer. And a control unit 20.

  The magnetic source 2 generates an alternating magnetic field, and driving the magnetic source 2 causes a magnetic change (magnetic data having a magnitude and a direction) unique to each position at each point in the space. It will be. XYZ coordinates are determined with the position of the magnetic source 2 as the origin, and further, the X-axis direction is determined as the reference direction. This XYZ coordinate system is set as a flying object and becomes a coordinate system (also referred to as a flying object coordinate system) that moves with the flying object.

The flying object side three-axis gyro sensor 4 detects an angular velocity of the flying object. It should be noted that x ₁ y ₁ z ₁ coordinates are defined for the aircraft side 3-axis gyro sensor 4 itself, and further, the x ₁ axis direction is defined as a reference direction. In other words, as the absolute mobile body information, azimuth direction (rotation relative to _{x 1} axis), (rotating with respect to _{y 1} axis) elevation direction, the angular velocity (.theta.1 is the movement amount in the roll direction (rotation relative to _{z 1} axis), .phi.1, .psi.1 ) Is detected. In addition, the aircraft-side three-axis gyro sensor 4 is attached to the XYZ coordinate system (aircraft coordinate system) without being accurately aligned.

  The helmet 10 with a head-mounted display device includes a display (not shown), a combiner 8 that leads the eyes of the pilot 3 by reflecting image display light emitted from the display, a magnetic sensor 7, It has a head side three-axis gyro sensor 6. The head-mounted display-equipped helmet 10 itself has a coordinate system (helmet coordinate system) and a reference direction. However, in order to use it as a part of the motion tracker, the pilot 3 uses the magnetic source 2. It is necessary to match with the XYZ axis directions in the XYZ coordinate system (aircraft coordinate system) with the position of the origin as the origin. After the alignment, the angle of the helmet 10 with the head mounted display device is XYZ as with the aircraft. Expressed in coordinate system. Regarding the method of aligning the reference direction of the helmet 10 with a head-mounted display device itself and the XYZ coordinate system, a widely used general method (for example, to face a specific direction to a pilot wearing the helmet). The axis is adjusted by instructing and storing the position at that time). In addition, the pilot 3 wearing the helmet 10 with a head-mounted display device can visually recognize the display image by the display and the front actual thing of the combiner 8.

  The magnetic sensor 7 has a three-axis pickup coil, and detects the magnitude and direction of the magnetism specific to the position where the magnetic sensor 7 exists. The detected magnetic data is used for calculating the first relative head information.

The head side 3-axis gyro sensor 6 detects the angular velocity of the head. Note that x ₂ y ₂ z ₂ coordinates are determined for the head-side three-axis gyro sensor 6 itself, and further, the x ₂ axis direction is determined as the reference direction. That is, as the absolute head information, angular velocities (θ2, φ2, ψ2) that are movement amounts in the azimuth direction, the elevation direction, and the roll direction are detected. At this time, since the pilot 3 is on the flying object and the flying object itself is moving, the angular velocity (θ2, φ2, ψ2) includes not only the angular velocity of the pilot 3's head but also the angular velocity of the flying object. It will be a thing.

  Further, the head-side three-axis gyro sensor 6 is not necessarily adjusted accurately with respect to the XYZ axes and the reference direction (X-axis direction) set in the helmet 10 with a head-mounted display device. It attaches to the helmet 10 with a type | mold display apparatus.

  The control unit 20 is configured by a computer including a CPU 21, a memory 41, and the like, and performs various controls and arithmetic processes. The process executed by the CPU of the control unit 20 will be described separately for each functional block. The motion tracker driving unit 28, the main head information calculating unit 22, the absolute moving body information calculating unit 23, the absolute head information calculating unit 24, It consists of a sub head information calculation unit 25 and a switching unit 29. The sub head information calculation unit 25 includes a head sensor axis calculation unit 26 and a moving body sensor axis calculation unit 27 in more detail.

Further, the memory 41 is formed with an area for storing various data necessary for the control unit 20 to execute processing, and one of them is a head sensor axis conversion matrix A and a moving body sensor axis conversion, which will be described later. A conversion data storage area 42 for accumulating the matrix B is included.
In addition, a boundary information storage area 43 that stores boundary information between an area where magnetostriction is generated and an area where no magnetostriction is generated for the magnetic field generated by the magnetic source 2 is included. This region is determined in advance by collecting magnetic data at each position by the magnetic sensor 7 and creating a magnetic distribution.

The motion tracker driving unit 28 outputs a command signal that causes the magnetic source 2 to generate an alternating magnetic field, and controls the magnetic sensor 7 to detect magnetic data.
The main head information calculation unit 22 applies the magnetic data output from the magnetic sensor 7 to a theoretical calculation formula (Biosavart's law, etc.), thereby position information (Xa, Ya in the XYZ coordinate system (aircraft coordinate system)). , Za) and the angle information (Θa, Φa, Ψa) of the azimuth angle, the elevation angle, and the roll angle, which are angles with respect to the reference axis direction (XYZ coordinate axes). That is, the first relative head information including the head position (Xa, Ya, Za) and the head angle (Θa, Φa, Ψa) is calculated. The first relative head information including the head position (Xa, Ya, Za) and the head angle (Θa, Φa, Ψa) is stored in the memory 41.

Based on the angular velocity (θ1, φ1, ψ1) output from the moving body sensor 4, the absolute moving body information calculation unit 23 calculates the absolute flying body angle (θh, φh, ψh), which is absolute moving body information, by integral calculation. calculate. The absolute flying object angles (θh, φh, ψh) are calculated with respect to the reference direction (x ₁ axis direction) of the x ₁ y ₁ z ₁ coordinate system set in the flying object side 3 axis gyro sensor 4.

Based on the angular velocity (θ2, φ2, ψ2) output from the head-side three-axis gyro sensor 6, the absolute head information calculation unit 24 performs absolute calculation to calculate the absolute head angle (θt, φt) that is absolute head information. , Ψt).
The absolute head angle ([theta] t, .phi.t, .psi.t) is calculated relative to the head side triaxial gyro sensor 6 to the set _{x 2 y} 2 _z 2 coordinate system of the reference direction _{(x 2} axial direction).

The sub head information calculation unit 25 is configured in advance with the x ₁ y ₁ z ₁ coordinate system set in the flying object side three-axis gyro sensor 4 and the x ₂ y ₂ z ₂ coordinates set in the head side three axis gyro sensor 6. The contents to be processed differ depending on whether or not the axis alignment for matching the system to the XYZ coordinate system (aircraft coordinate system) is performed.
When accurate axis alignment between coordinate systems has already been performed, by calculating the difference between the absolute head angle (θt, φt, ψt) and the absolute flying object angle (θh, φh, ψh) Since the head angle of the passenger is obtained immediately, this is calculated as the second relative head information.

However, in general, it takes time and effort to align the x ₁ y ₁ z ₁ coordinate system and the x ₂ y ₂ z ₂ coordinate system with the XYZ coordinate system (aircraft coordinate system). Therefore, instead of performing the axis alignment operation, the sub head information calculation unit 25 performs coordinate conversion from the x ₁ y ₁ z ₁ coordinate system and the x ₂ y ₂ z ₂ coordinate system to the XYZ coordinate system (aircraft coordinate system). By obtaining conversion data (conversion matrix) for axis alignment to be performed, the axial directions can be made to coincide with each other by arithmetic processing. This calculation method will be described later.

  The switching unit 29 refers to the boundary information storage area 43 and performs control to switch between calculation by the main head information calculation unit 22 and calculation by the sub head information calculation unit 25. Specifically, it is determined whether or not the magnetic sensor 7 is in an area without magnetostriction, and when it is determined that the magnetic sensor 7 is in an area without magnetostriction, the first relative head information is output. On the other hand, when it is determined that the magnetostriction is in a certain region, control is performed so as to output the second relative head information.

(Calculation of conversion data (conversion matrix) for axis alignment by the sub head information calculation unit)
Next, calculation of the sub head information calculation unit 25 in the case of obtaining conversion data (conversion matrix) for axis alignment and matching the axial direction by calculation will be described. In this case, the head sensor axis calculation unit 26 and the moving body sensor axis calculation unit 27 of the sub head information calculation unit 25 perform the arithmetic processing described below.
FIG. 2 is a diagram for explaining the flow of arithmetic processing executed when the head motion tracker apparatus collects conversion data for axis alignment.

First, the head sensor axis calculation unit 26 performs an operation for calculating the sensor axis direction of the head side three-axis gyro sensor 6 with respect to the axial direction of the XYZ coordinate system (aircraft coordinate system).
That is, the head sensor axis calculation unit 26 detects angular velocity data (θ2, φ2, ψ2) detected by the head side three-axis gyro sensor 6 when the flying object is stopped and only the movement of the head is detected. ) And the head angle (Θa, Φa, ψa) calculated by the main head information calculation unit 22 in parallel with the absolute head angle (θt, φt, ψt) calculated using based on calculated head angle difference is an axial difference between the x ₂ axis direction and the X-axis direction of the head side triaxial gyro sensor 6 (Δθt, Δφt, Δψt) a.
When the calculation for obtaining the angle difference is expressed as “˜” for convenience, the head angle differences (Δθt, Δφt, Δψt) can be expressed by the equation (1).

(Δθt, Δφt, Δψt) = (θt, φt, ψt) to (Θa, Φa, ψa) (1)

Further, the head sensor axis calculation unit 26 performs head sensor axis conversion for matching the sensor axis direction of the head side three-axis gyro sensor 6 with the X axis direction from the head angle difference (Δθt, Δφt, Δψt). A process of obtaining the matrix A and storing it in the converted data storage area 42 of the memory 41 is performed. The head sensor axis conversion matrix A satisfies the relationship of the expression (2) and is used for subsequent calculations by the absolute head information calculation unit 24.

(Θa, Φa, ψa) = A · (θt, φt, ψt) (2)

Subsequently, the moving body sensor axis calculation unit 27 performs an operation for calculating the sensor axis direction of the aircraft side triaxial gyro sensor 4 with respect to the XYZ coordinate system and the X axis direction.
For this calculation, (1) absolute head angle in flight (θt, φt, ψt) ′ (coordinate-transformed by the transformation matrix, aligned with the XYZ coordinate system using the head sensor axis transformation matrix A For convenience, (2) head angle in flight (Θa, Φa, Ψa) calculated by the main head information calculation unit 22 (first relative head information) ) And (3) absolute flying object angles (θh, φh, ψh) in flight calculated by the absolute moving object information calculation unit 23 are used.

That is, the head sensor axis calculation unit 26 first calculates the absolute head angle (θt, φt, ψt) ′ (combined angle of the flying object and the head) calculated using the measurement data during the flight, The angle of the flying object is calculated by calculating a difference from the head angle (Θa, Φa, Ψa) (only the head angle) calculated by the head information calculation unit 22. This flying object angle is defined as a reference flying object angle (θs, φs, ψs).
If the calculation for obtaining the angle difference is described as “˜” for the sake of convenience, the reference aircraft angle (θs, φs, ψs) can be expressed by the following equation (3).

(Θs, φs, ψs) = (θt, φt, ψt) ′ to (Θa, Φa, ψa) (3)

Subsequently, the moving body sensor axis calculation unit 27 calculates the reference flying body angle (θs, φs, ψs) and the absolute flying body angle (θh, φh, ψh) in flight calculated by the absolute moving body information calculation unit 23. The aircraft angle difference (Δθh, Δφh, Δψh) is calculated.
Specifically, the reference flight calculated by the head side three-axis gyro sensor 6 and the main head information calculation unit 22 from the absolute flying object angle (θh, φh, ψh) by the calculation formula (4) described below. By calculating the difference between the body angles (θs, φs, ψs), the flying object angle differences (Δθh, Δφh, Δψh) are calculated.

(Δθh, Δφh, Δψh) = (θh, φh, ψh) to (θs, φs, ψs) (4)

That is, the reference flying object angle (θs, φs, ψs) and the absolute flying object angle (θh, φh, ψh) indicate the flying object angle, but the reference flying object angle (θs, φs, ψs). ) Is an angle with respect to the XYZ coordinate system, and absolute aircraft angle (θh, φh, ψh) is an angle with respect to the x ₁ y ₁ z ₁ coordinate system set in the aircraft-side three-axis gyro sensor 4. Accordingly, the aircraft angle difference (Δθh, Δφh, Δψh), which is the difference between them, corresponds to an axial difference (axial deviation amount) between the XYZ coordinate system and the x ₁ y ₁ z ₁ coordinate system.

Further, the moving body sensor axis calculation unit 27 obtains a moving body sensor axis conversion matrix B for making the calculated sensor axis direction coincide with the X axis direction, and stores this in the conversion data storage area 42 of the memory 41. I do.
This moving body sensor axis conversion matrix B satisfies the relationship of equation (5), and is used for subsequent calculations by the absolute head information calculation unit 23.

(Θs, φs, ψs) = B · (θh, φh, ψh) (5)

  By these calculation processes by the head sensor axis calculation unit 26 and the moving body sensor axis calculation unit 27, for example, the head side three-axis gyro sensor 6 and the aircraft side three-axis gyro sensor 4 and the XYZ coordinate system (aircraft coordinate system). Even if accurate axis alignment is not performed between the sub head information calculating unit 25 and the sub head information calculating unit 25, the absolute moving body information calculating unit 23 and the absolute head information calculating unit 24 However, the absolute flying object angle (θh, φh, ψh) ′ and the absolute head angle (θt, φt, ψt) ′ adjusted to the XYZ coordinate system can be calculated using these transformation matrices thereafter. To do.

(Head angle calculation by sub head information calculation unit)
Next, calculation of the head angle by the sub head information calculation unit 25 after the conversion matrices A and B are obtained will be described.
The sub-head information calculation unit 25 includes the angular velocities (θ1, φ1, ψ1) detected by the aircraft-side three-axis gyro sensor 4 and the angular velocities (θ2, φ2, ψ2) detected by the head-side three-axis gyro sensor 6. Based on the transformation matrices A and B, control is performed to calculate angle information (Θb, Φb, Ψb) of the azimuth angle, the elevation angle, and the roll angle, which are angles with respect to the XYZ axes that are the reference axis directions.

  FIG. 3 is a diagram for explaining a method of calculating the head angle with respect to the XYZ axes (X axis is a reference direction) set for the flying object. The sub head information calculating unit 25 calculates the absolute head angle (θt, φt, ψt) by integrating the angular velocities (θ2, φ2, ψ2) detected by the head side three-axis gyro sensor 6. Also, by integrating the angular velocities (θ1, φ1, ψ1) detected by the flying vehicle side three-axis gyro sensor 4, the absolute flying object angles (θh, φh, ψh) are calculated.

Subsequently, by using the transformation matrix A, the absolute head angle (θt, φt, ψt) is corrected by the following formula (6), and the absolute head angle (θt, φt, ψt) ′ on the XYZ axes is corrected. Is calculated.

(Θt, φt, ψt) ′ = A · (θt, φt, ψt) (6)

This is equivalent to:
(Θt, φt, ψt) ′ = (θt, φt, ψt) to (Δθt, Δφt, Δψt)

Similarly, using the transformation matrix B, the absolute aircraft angle (θh, φh, ψh) is corrected by the following equation (7), and the absolute head angle (θh, φh, ψh) ′ on the XYZ axes is corrected. Is calculated.

(Θh, φh, ψh) ′ = B · (θh, φh, ψh) (7)

This is equivalent to:
(Θh, φh, ψh) ′ = (θh, φh, ψh) to (Δθh, Δφh, Δψh)

Subsequently, the angular difference (θb, φb, ψb) is calculated in the XYZ coordinate system by the calculation formula (8) described below. That is, by calculating the difference between the absolute head angle and the absolute flying object angle, the flying object angle is eliminated, and the head angle with respect to the XYZ coordinate system (aircraft coordinate system) is obtained.

(Θb, φb, ψb) = (θt, φt, ψt) ′ to (θh, φh, ψh) ′ (8)

Subsequently, an initial value is added by the calculation formula (9) described below to calculate the head angle (Θb, Φb, Ψb) of the pilot 3 in the XYZ coordinate system. That is, the head angle obtained by integrating the angular velocities is calculated by changing the head angle from the initial value, and the initial values (Θ0, Φ0, Ψ0) are added. As the initial value, the output value of the main head information calculation unit 22 immediately before the operation is switched from the main head information calculation unit 22 to the sub head information calculation unit 25 by the switching unit 29 is used.

(Θb, Φb, ψb) = (θb, φb, ψb) + (Θ0, Φ0, ψ0) (9)

  Here, since drift occurs in the flying body side three-axis gyro sensor 4 and the head side three-axis gyro sensor 6, the calculated head angle of the pilot 3 and the actual pilot 3 head over time. Deviation occurs in the part angle. In order to prevent such a problem, the first relative head information including the head angle with respect to the reference direction set in the flying object is mainly output by the main head information calculation unit 22 and the auxiliary head information calculation unit is used as an auxiliary. The second relative head information including the head angle with respect to the reference direction set for the flying object in accordance with 75 is output. This switching is performed by the switching unit 29.

(Operation of the head motion tracker)
Next, a measurement operation for measuring the head angle by the head motion tracker device 1 will be described. FIG. 4 is a flowchart for explaining the measurement operation by the head motion tracker device 1. It is assumed that the measurement is performed in advance when the flying object is stopped and the transformation matrix A is obtained.

  First, in the process of step S101, it is determined whether or not the flying object is moving. When it is determined that the flying object is not moving, this flowchart is ended.

  On the other hand, when it is determined that the flying object is moving, in the process of step S102, the main head information calculation unit 22 uses the magnetic data output from the magnetic sensor 7 to determine the reference axis direction ( The head angle (Θa, Φa, Ψa) with respect to the XYZ axis direction is calculated. That is, first relative head information including head angles (Θa, Φa, Ψa) with respect to the reference axis direction set for the flying object is calculated.

Next, in the process of step S103, first relative head information including head angles (Θa, Φa, ψa) is output. That is, the head angle with respect to the reference direction set for the flying object is measured.
Next, in the process of step S <b> 104, first relative head information including the head angle (Θa, Φa, Ψa) is stored in the memory 41. At this time, the head angle (Θa, Φa, Ψa) stored in the memory 41 is updated every time the process of step S104 is executed.

  Next, in the process of step S105, the switching unit 27 refers to the boundary information in the boundary condition storage area 43 and determines whether or not the magnetic sensor 7 is in an area without magnetostriction. When it is determined that the magnetic sensor 7 exists in an area where no magnetostriction occurs (measurable area), the process returns to step S101. That is, the processes in steps S101 to S104 are repeated until it is determined that the magnetic sensor 7 is out of the measurable region of the first relative head information or that the flying object is not moving.

On the other hand, when it is determined that the magnetic sensor 7 is present in the region where the magnetostriction occurs (non-measurable region), in the process of step S106 (Θa, Φa, ψa), the head side 3-axis gyro sensor 6 is The angular velocity (θ2, φ2, ψ2) of the head is output.
Further, in the process of step S107, the flying vehicle side three-axis gyro sensor 4 outputs the angular velocity (θ1, φ1, ψ1) of the flying vehicle.
Note that the processes of steps S106 and S107 are performed simultaneously.

  Next, in the process of step S108, the sub head information calculation unit 25, the angular velocity (θ1, φ1, ψ1), the angular velocity (θ2, φ2, ψ2), and the stored head angle (Θa, Φa, Ψa) (used as initial values (Θ0, Φ0, Ψ0)) and stored transformation matrices A and B, by calculating the head angle (Θb, Φb, Ψb), The second relative head information including the angles (Θb, Φb, Ψb) is output. That is, the head angle with respect to the reference axis direction (XYZ axis direction) set for the flying object is measured.

  Next, in the process of step S109, the switching unit 27 determines whether or not the magnetic sensor 7 is in the measurable area. When it is determined that the region is a region where magnetostriction occurs (non-measurable region), the process returns to steps S106 and S109. That is, the processes in steps S106 to S108 are repeated until it is determined that the magnetic sensor 7 has entered the measurable area.

  On the other hand, when it is determined that the magnetic sensor 7 has returned to the region (measurable region) where there is no magnetostriction, the process returns to step S101.

As described above, according to the head motion tracker device 1 of the first embodiment, the sub head information calculation unit 25 performs the flight when the magnetic distortion occurs and the measurement is difficult in the main head information calculation unit 22. Since the second relative head information including the head angle with respect to the reference axis direction (XYZ axis) set for the body can be calculated, the head angle can always be calculated.
In addition, the sub head information calculation unit 25 is configured to perform the second operation based on the absolute head information detected by the head side triaxial gyro sensor 6 and the absolute moving body information detected by the aircraft side triaxial gyro sensor 4. Since the relative head information is calculated, a drift error may occur with time. The main head information calculation unit 22 mainly calculates the first relative head information including the head angle and the auxiliary head as an auxiliary. Since the second relative head information including the head angle is temporarily calculated by the head information calculation unit 25, the head angle with respect to the reference direction set for the flying object can be calculated with high accuracy.
Moreover, an accurate head angle can be calculated even if the flying object side three-axis gyro sensor 4 or the head side three-axis gyro sensor is attached to the head (helmet or the like) without axis alignment.

(Embodiment 2)
FIG. 5 is a diagram showing a schematic configuration of a head motion tracker device according to another embodiment of the present invention. In the present embodiment, the head position is calculated in addition to the head angle. An optical motion tracker is used. In addition, since the same calculation process as Embodiment 1 is performed about calculation of a head angle, description about calculation of a head angle is abbreviate | omitted here and calculation of a head position is demonstrated.

  The head motion tracker device 51 includes a head mounted display-equipped helmet 60 attached to the pilot 53 head, a pair of camera devices 52a and 52b attached to the flying object, a flying object side three-axis gyro sensor 54, and a flight. It is comprised from the body side acceleration sensor 55 and the control part 70 comprised with a computer.

  The camera devices 52a and 52b are installed with a shooting direction directed to the helmet 60 with a head-mounted display device and at a distance allowing stereoscopic viewing of the helmet. And the position of each LED is calculated | required by detecting the position of the infrared light light-emitted from the LED group 57 mentioned later by stereoscopic vision, and the motion of a helmet is detected.

Since the flying object side three-axis gyro sensor 54 is the same as the flying object side three axis gyro sensor 4 (FIG. 1), description thereof is omitted.
The flying object side acceleration sensor 55 detects acceleration of the flying object. Note that x ₃ y ₃ z ₃ coordinates are determined for the flying object side acceleration sensor 55 itself, and further, the x ₃ axis direction is determined as the reference direction. That, _{x 3} axis, _{y 3} axes, acceleration with respect to _{z 3} axially (x1, y1, z1) is detected. Further, the flying object side acceleration sensor 55 is configured to determine the position and direction of the coordinate axes and the coordinate system (x ₄ y ₄ z ₄ coordinate system) set in the XYZ coordinate system set for the flying object, the head side acceleration sensor 59 described later. It is attached to the flying body without matching.

  The helmet 60 with a head-mounted display device includes a display (not shown), a combiner 58 that guides the eyes of the pilot 53 by reflecting image display light emitted from the display, an LED group 57, A head side three-axis gyro sensor 56 and a head side acceleration sensor 59 are provided. The pilot 53 wearing the head mounted display-equipped helmet 60 can visually recognize the display image by the display and the front actual thing of the combiner 58.

  The LED group 57 is attached so that three (or more) LEDs emitting infrared light having different wavelengths are separated from each other. By this LED group 57, XYZ coordinates are defined, and the X-axis direction is defined as a reference direction. That is, the position and angle of the helmet can be obtained by obtaining the coordinates of the three LEDs attached to the head-mounted display-equipped helmet 60 itself.

The head side triaxial gyro sensor 56 is the same as the head side triaxial gyro sensor 6 described above. The reference direction of the head side triaxial gyro sensor 56 (x ₂ axial direction), by the method described in Embodiment 1, assumed to be the X-axis direction and the alignment set by the LED group 57.

The head-side acceleration sensor 59 detects head acceleration. It should be noted that x ₄ y ₄ z ₄ coordinates are determined for the head-side acceleration sensor 59 itself, and the x ₄ axis direction is determined as the reference direction. That, _{x 4} axis, _{y 4} axis, the acceleration in the _{z 4} axially (x2, y2, z2) is detected. Since the pilot 53 is on the flying body and the flying body is also moving, the acceleration (x2, y2, z2) includes not only the acceleration of the pilot 53's head but also the acceleration of the flying body. Further, the head acceleration sensor 59 does not match the position and direction of the coordinate axis with the coordinate system (x ₃ y ₃ z ₃ coordinate system) set in the XYZ coordinate system and the aircraft-side acceleration sensor 55 described later. Is attached.

The control unit 70 is configured by a computer including a CPU 71, a memory 91, and the like, and performs various controls and arithmetic processes. The processing executed by the CPU of the control unit 70 will be described separately for each functional block. The switching unit 77, the motion tracker driving unit 78, the main head information calculating unit 72, the absolute moving body information calculating unit 73, and the absolute head information. A calculation unit 74, a sub head information calculation unit 75, a head sensor axis calculation unit 76, and a moving body sensor axis calculation unit 77 are included.
In addition, the memory 91 is formed with an area for storing various data necessary for the control unit 70 to execute processing, and one of them is a head sensor axis conversion matrix C and a moving body sensor axis conversion described later. A conversion data storage area 92 for storing the matrix D is provided.

    Of the control unit 70, a main head information calculation unit 72, an absolute moving body information calculation unit 73, an absolute head information calculation unit 74, a sub head information calculation unit 75, a head sensor axis calculation unit 76, a moving body sensor axis. The calculation unit 77 includes a main head information calculation unit 22, an absolute moving body information calculation unit 23, an absolute head information calculation unit 24, a sub head information calculation unit 25, and the like. A function similar to that of the head sensor axis calculation unit 26 and the moving body sensor axis calculation unit 27 is realized, and an additional function for calculating the head position is realized. Therefore, since the description regarding the calculation of the head angle is the same as that of the first embodiment, the description will be omitted, and the description regarding the calculation of the head position will be given below.

  The motion tracker driving unit 78 outputs a command signal for lighting the LED group 57, and performs control to detect position data of the LED group 57 by the camera devices 52a and 52b.

  The main head information calculation unit 72 calculates an angle with respect to position information (Xa, Ya, Za) and a reference axis direction (XYZ coordinate axis) in an XYZ coordinate system (aircraft coordinate system) from image data captured by the camera devices 52a and 52b. Are calculated to calculate angle information (Θa, Φa, Ψa) of azimuth angle, elevation angle, and roll angle. That is, the first relative head information including the head position (Xa, Ya, Za) and the head angle (Θa, Φa, Ψa) is calculated. The first relative head information including the head position (Xa, Ya, Za) and the head angle (Θa, Φa, Ψa) is stored in the memory 91.

Based on the acceleration (x1, y1, z1) output from the flying object side acceleration sensor 54, the absolute moving object information calculation unit 73 performs absolute calculation to obtain the absolute flying object position (xh, yh, zh) as absolute moving object information. Is calculated. This absolute flying object position (θh, φh, ψh) is calculated with respect to the x ₃ y ₃ z ₃ coordinate system set in the flying object side acceleration sensor 54.

Based on the acceleration (x2, y2, z2) output from the head-side acceleration sensor 56, the absolute head information calculation unit 74 integrates the absolute head position (xt, yt, zt) as absolute head information. ) Is calculated.
The absolute head position (xt, yt, zt) is calculated with respect to the x ₄ y ₄ z ₄ coordinate system set in the head-side acceleration sensor 56.

The sub-head information calculation unit 75 preliminarily converts the x ₃ y ₃ z ₃ coordinate system set in the flying object side acceleration sensor 54 and the x ₄ y ₄ z ₄ coordinate system set in the head side acceleration sensor 56 into XYZ. The processing contents differ depending on whether or not the axis alignment for matching the position and direction to the coordinate system (aircraft coordinate system) is performed.
_Already, x ₃ y _{3 z 3} coordinate _system, x ₄ y _{4 z 4} coordinate system of the sensor axis center, the sensor axis direction, if you combined axial with respect to the corresponding position and the axial direction of the XYZ coordinate system, By calculating the difference between the absolute head position (xt, yt, zt) and the absolute flying object angle (xh, yh, zh), the head position of the occupant is immediately obtained. Calculated as part information.

However, in _general, x ₃ y _{3 z 3} coordinate _system, the axis to align x ₄ y _{4 z 4} coordinate system of the sensor axis center, the sensor axis, the corresponding position or the axial direction on the XYZ coordinate system (aircraft coordinate system) The alignment work takes time. Therefore, instead of performing the coordinate alignment operation of the coordinate system, the sub-head information calculation unit 75 obtains conversion data (conversion matrix) for alignment to perform coordinate conversion, so that the calculation of the sensor axis center and The sensor axis direction can be matched. This calculation method will be described later.

  The switching unit 79 performs control to switch between calculation by the main head information calculation unit 22 and calculation by the sub head information calculation unit 25. Specifically, it is determined whether or not the LED group can be detected by the camera devices 52a and 52b. If the LED group can be detected, the first relative head information is output. If the LED group cannot be detected, the second relative head information is output. Control to switch as follows.

(Calculation of transformation matrix by sub head information calculation unit 75)
Next, calculation of the sub head information calculation unit 75 in the case of obtaining axis alignment conversion data (conversion matrix) and aligning the coordinate system by calculation will be described. In this case, the head sensor axis calculation unit 76 and the moving body sensor axis calculation unit 77 of the sub head information calculation unit 75 perform the arithmetic processing described below. Here, description of the calculation of the head angle conversion matrix will be omitted, and calculation of the head position conversion matrix will be described.
FIG. 6 is a diagram illustrating the flow of arithmetic processing executed when the head motion tracker device 51 collects conversion data for axis alignment.

First, the head sensor axis calculation unit 76 performs an operation for calculating the sensor axis center of the head side acceleration sensor 56 with respect to the XYZ coordinate system (aircraft coordinate system).
That is, the head sensor axis calculation unit 76 uses the acceleration data (x2, y2, z2) detected by the head side acceleration sensor 56 when the flying object is stopped and only the movement of the head is detected. Based on the difference between the absolute head position (xt, yt, zt) calculated using the head position (Xa, Ya, Za) calculated by the main head information calculation unit 72 in parallel with the absolute head position (xt, yt, zt) Then, the head side coordinate position difference (Δxt, Δyt, Δzt), which is the difference between the x ₄ y ₄ z ₄ coordinate axis center of the head side acceleration sensor 56 and the XYZ coordinate axis center, is calculated.
If the calculation for obtaining the position difference is expressed by “˜” for convenience, the head side coordinate position difference (Δxt, Δyt, Δzt) can be expressed by the equation (10).

(Δxt, Δyt, Δzt) = (xt, yt, zt) to (Xa, Ya, Za) (10)

Further, the head sensor axis calculation unit 76 calculates a head sensor axis conversion matrix C for matching the sensor axis of the head side acceleration sensor 56 with the X axis from the head side coordinate position difference (Δxt, Δyt, Δzt). Is obtained and stored in the converted data storage area 92 of the memory 91. The head sensor axis conversion matrix C satisfies the relationship of the expression (11) and is used for subsequent calculations by the absolute head information calculation unit 74.

(Xa, Ya, Za) = C · (xt, yt, zt) (11)

Subsequently, the moving body sensor axis calculation unit 77 performs an operation for calculating the sensor axis center of the flying object side acceleration sensor 54 with respect to the XYZ coordinate system.
For this calculation, (1) absolute head position in flight (xt, yt, zt) ′ (coordinate-transformed by the transformation matrix with the coordinate axes coincided with the XYZ coordinate system using the head sensor axis transformation matrix C (') For convenience) (2) Head position in flight (Xa, Ya, Za) calculated by main head information calculation unit 72 (first relative head Information) and (3) the absolute flying object position (xh, yh, zh) in flight calculated by the absolute moving object information calculation unit 73 is used.

That is, the head sensor axis calculation unit 76 first calculates an absolute head position (xt, yt, zt) ′ (combined position of the flying object position and the head position) calculated using the measurement data during flight, and The difference from the head position (Xa, Ya, Za) (head position) calculated by the main head information calculation unit 72 is calculated.
Specifically, according to the calculation formula (12) described below, from the absolute head position (xt, yt, zt) ′ to the head position (Xa, Ya, By calculating the difference of Za), the reference aircraft position (xs, ys, zs) indicating the position of the aircraft is calculated.

(Xs, ys, zs) = (xt, yt, zt) ′ to (Xa, Ya, Za) (12)

This reference aircraft position (xs, ys, zs) is obtained by calculating only the head position in the XYZ coordinate system from the absolute head position represented by the XYZ coordinate system (the combined position of the aircraft position and the head position). Excluded flying object position.

Subsequently, the moving body sensor axis calculation unit 77 sets the reference flying body position (xs, ys, zs) and the absolute flying body position (xh, yh, zh) in flight calculated by the absolute moving body information calculation unit 73. The aircraft side coordinate position difference (Δxh, Δyh, Δzh), which is the difference, is calculated.
Specifically, the reference flying object position calculated by the head-side acceleration sensor 56 and the main head information calculation unit 72 from the absolute flying object position (xh, yh, zh) according to the calculation formula (13) described below. By calculating the difference of (xs, ys, zs), the aircraft side coordinate position difference (Δxh, Δyh, Δzh) is calculated.

(Δxh, Δyh, Δzh) = (xh, yh, zh) to (xs, ys, ψs) (13)

That is, the reference aircraft position (xs, ys, zs) and the absolute aircraft position (xh, yh, zh) both indicate the aircraft position, but the reference aircraft position (xs, ys, zs). ) Is a position with respect to the XYZ coordinate system, and absolute vehicle position (xh, yh, zh) is a position with respect to the x ₃ y ₃ z ₃ coordinate system set in the vehicle-side acceleration sensor 54. Therefore, the aircraft side coordinate position difference (Δxh, Δyh, Δzh), which is the difference between them, corresponds to the sensor axis center position difference between the XYZ coordinate system and the x ₃ y ₃ z ₃ coordinate system.

Further, the moving body sensor axis calculation unit 77 converts the flying body side sensor axis to match the sensor axis center of the moving body side acceleration sensor 54 with the XYZ coordinate axis center from the flying object side difference table position difference (Δxh, Δyh, Δzh). A process of obtaining the matrix D and storing it in the converted data storage area 92 of the memory 91 is performed.

This moving body sensor axis conversion matrix D satisfies the relationship of the equation (14), and is used for subsequent calculations by the absolute head information calculation unit 23.

(Xs, ys, zs) = D · (xh, yh, zh) (14)

  In this way, the head-side acceleration sensor 56, the flying object-side acceleration sensor 54, and the XYZ coordinates are calculated by the arithmetic processing by the head sensor axis calculation unit 76 and the moving body sensor axis calculation unit 77 of the sub head information calculation unit 75. Even when accurate sensor axis alignment is not performed with the system (aircraft coordinate system), the absolute moving body information calculation unit 73 and the absolute head information calculation unit are obtained by obtaining the transformation matrices C and D. 74 can calculate the absolute flying object position (xh, yh, zh) ′ and the absolute head position (xt, yt, zt) ′ in accordance with the XYZ coordinate system using these transformation matrices. .

(Calculation of head position by sub head information calculation unit 75)
Next, the calculation of the head angle by the sub head information calculation unit 75 after the conversion matrices C and D are obtained will be described.
The sub head information calculation unit 75 includes an acceleration (x1, y1, z1) detected from the flying object side acceleration sensor 54, an acceleration (x2, y2, z2) detected from the head side acceleration sensor 56, and a conversion matrix. Based on C and D, control for calculating position information (xb, yb, zb) with respect to the XYZ axes, which are reference axes, is performed.

  FIG. 7 is a diagram for explaining a method of calculating the head position with respect to the XYZ axes (reference axes) set for the flying object. The sub-head information calculation unit 75 calculates the absolute head position (xt, yt, zt) by integrating the acceleration (x2, y2, z2) detected by the head-side acceleration sensor 56, and the aircraft side By integrating the acceleration (x1, y1, z1) detected by the acceleration sensor 54, the absolute flying object position (xh, yh, zh) is calculated.

Subsequently, using the transformation matrix C, the absolute head position (xt, yt, zt) is corrected by the following formula (15), and the absolute head position (xt, yt, zt) ′ on the XYZ axes is corrected. Is calculated.

(Xt, yt, zt) ′ = C · (xt, yt, zt) (15)

This is equivalent to:
(Xt, yt, zt) ′ = (xt, yt, zt) to (Δxt, Δyt, Δzt)

Similarly, using the transformation matrix D, the absolute aircraft position (xh, yh, zh) is corrected by the following equation (16), and the absolute head position (xh, yh, zh) ′ on the XYZ axes is corrected. Is calculated.

(Xh, yh, zh) ′ = D · (xh, yh, zh) (16)

This is equivalent to:
(Xh, yh, zh) ′ = (xh, yh, zh) to (Δxh, Δyh, Δzh)

Subsequently, the position difference (xb, yb, zb) is calculated in the XYZ coordinate system by the calculation formula (17) described below. That is, by calculating the difference between the absolute head position and the absolute flying object position, the position of the flying object is deleted, and the position of the head with respect to the XYZ coordinate system (aircraft coordinate system) is obtained.

(Xb, yb, zb) = (xt, yt, zt) ′ to (xh, yh, zh) ′ (17)

Subsequently, an initial value is added by a calculation formula (18) described below, and the head position (Xb, Yb, Zb) of the pilot 3 in the XYZ coordinate system is calculated. That is, since the head position obtained by integrating the acceleration is calculated from the initial value as a starting point, the initial position (X0, Y0, Z0) is added. As the initial value, the output value of the main head information calculation unit 72 immediately before the operation is switched from the main head information calculation unit 72 to the sub head information calculation unit 75 by the switching unit 79 is used.

(Xb, Yb, Zb) = (xb, yb, zb) + (X0, Y0, Z0) (18)

  Here, since drift occurs in the flying object side acceleration sensor 54 and the head side acceleration sensor 56, the calculated head position of the pilot 53 and the actual head position of the pilot 3 are changed with time. Deviation occurs. In order to prevent such a problem, the first relative head information including the head position with respect to the reference position set in the flying object is mainly output by the main head information calculation unit 72, and the auxiliary head information calculation unit is used as an auxiliary. The second relative head information including the head position with respect to the reference direction set in the flying object by 75 is output. This switching is performed by the switching unit 79.

(Operation of the head motion tracker)
The measurement operation for measuring the head position by the head motion tracker device 51 basically performs the same processing for “head position” as that described for “head angle” using FIG. Since there is, description is abbreviate | omitted.

  The present invention can be used for a head motion tracker device for measuring a head angle with respect to a reference direction set in a flying object such as a crew member.

1 is a diagram showing a schematic configuration of a head motion tracker device according to an embodiment of the present invention. The figure explaining the calculation method of the conversion matrix by the sub head information calculation part 25. FIG. The figure explaining the calculation method of the head angle by the sub head information calculation part 25. FIG. The flowchart for demonstrating the measurement operation | movement by the head motion tracker apparatus which is one Embodiment of this invention. The figure which shows schematic structure of the head motion tracker apparatus which is other one Embodiment of this invention. The figure explaining the calculation method of the conversion matrix by the sub head information calculation part 75. FIG. The figure explaining the calculation method of the head angle by the sub head information calculation part 75. FIG. The figure which shows schematic structure of the conventional AC magnetic type head motion tracker apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,51 Head motion tracker apparatus 2 Magnetic source 3, 53 Pilot 4, 54 Aircraft side 3 axis gyro sensor 6, 56 Head side 3 axis gyro sensor 7 Magnetic sensor 10, 60 Helmets 22 and 72 with head mounted display devices Main head information calculation unit 23, 73 Absolute moving body information calculation unit 24, 74 Absolute head information calculation unit 25, 75 Sub head information calculation unit 26, 76 Head sensor axis calculation unit.
27, 77 Moving body sensor axis calculation unit 28, 78 Motion tracker driving unit 29, 79 Switching unit 42, 92 Conversion data storage area 52 Camera device 57 LED group

Claims (8)

A motion tracker that detects the movement of the head of the passenger relative to the reference axis set on the moving object by the measurement method of either the magnetic motion tracker or the optical motion tracker, and the head detected by the motion tracker In a head motion tracker device comprising a main head information calculation unit that calculates first relative head information including at least the head angle of the passenger based on the movement of the unit,
A moving body sensor that is attached to the moving body and detects at least an angular velocity;
An absolute moving body information calculating unit that calculates absolute moving body information representing movement of the moving body based on an output signal of the moving body sensor;
A head sensor that is mounted on the head of the passenger and detects at least the angular velocity;
An absolute head information calculation unit that calculates absolute head information obtained by combining the movement of the moving body and the head based on the output signal of the head sensor;
First including at least the head angle of the passenger based on the first relative head information, the absolute moving body information, and the absolute head information calculated immediately before entering the area where the calculation of the first relative head information is inappropriate . A sub head information calculation unit for calculating second relative head information corresponding to the relative head information;
And a switching unit for switching to the second relative head information calculated by the sub head information calculation unit from the first relative head information in the calculation are inappropriate areas of the first relative head information primarily head information calculating section A head motion tracker device comprising: The sub-head information calculation unit calculates a sensor axis direction of the head sensor based on the absolute head information and the first relative head information obtained simultaneously with the moving body stopped. A moving body sensor axis calculation unit for calculating a sensor axis direction of the moving body sensor based on the absolute head information and the first relative head information and the absolute moving body information obtained simultaneously while the moving body is moving;
Furthermore, a conversion data storage unit for storing conversion data for axis alignment for adjusting the sensor axis direction of the head sensor and the sensor axis direction of the moving body sensor to the reference axis direction set in the moving body is provided,
The head motion tracker device according to claim 1, wherein the sub head information calculation unit corrects the absolute head information and the absolute moving body information based on the axis alignment conversion data. The moving body sensor and head sensor further detect acceleration,
The main head information calculation unit calculates first relative head information including the head angle and head position of the passenger,
The head motion tracker device according to claim 1, wherein the sub head information calculation unit calculates second relative head information including a head angle and a head position of the passenger. The sub head information calculation unit calculates the sensor axis direction of the head sensor and the sensor axis center based on the absolute head information and the first relative head information obtained simultaneously with the moving body stopped. A moving body sensor axis that calculates a sensor axis direction and a sensor axis center of the moving body sensor based on the absolute head information, the first relative head information, and the absolute moving body information that are simultaneously obtained while the moving body is moving. A calculation unit,
Furthermore, the sensor axis direction of the head sensor, the sensor axis center, and the sensor axis direction of the moving body sensor, the reference axis direction set to the moving body, and the axis alignment conversion data for aligning with the reference axis center A conversion data storage unit for storing
The head motion tracker device according to claim 3, wherein the sub head information calculation unit corrects the absolute head information and the absolute moving body information based on the axis alignment conversion data.   5. The magnetic motion tracker according to claim 1, further comprising: a magnetic source that is attached to a moving body and generates an alternating magnetic field; and a magnetic sensor that is attached to a head and detects the alternating magnetic field. The head motion tracker device according to any one of the above.   The optical type motion tracker includes an optical marker that is mounted on the head and emits a light beam, and an optical detection unit that is attached to the moving body and detects the light beam from the optical marker. Item 5. The head motion tracker device according to any one of Items 4 to 6. A magnetic motion tracker is used for the motion tracker, and a boundary information storage area for storing boundary information of an area where accurate magnetic data cannot be measured is provided.
The head motion tracker device according to claim 1, wherein the switching unit refers to the boundary information as an area where the calculation of the first relative head information is inappropriate. A motion tracker that detects the movement of the head of the passenger relative to the reference axis set on the moving object by the measurement method of either the magnetic motion tracker or the optical motion tracker, and the head detected by the motion tracker A main head information calculation unit that calculates first relative head information including at least the head angle of the passenger based on the movement of the unit, a mobile body sensor that is attached to the mobile body and detects an angular velocity, and a mobile body sensor An absolute moving body information calculation unit that calculates absolute moving body information representing movement of the moving body based on the output signal, a head sensor that is mounted on the head of the passenger and detects an angular velocity, and an output signal of the head sensor absolute head information calculation unit movement of the moving body and head to calculate a synthesized absolute head information, the calculation of the first relative head information calculated immediately before entering the inappropriate region based on Deputy head to calculate a second relative head information corresponding to the first relative head information and absolute mobile body information and the first relative head information including the head angle of at least occupant based absolutely and head information A head motion tracker device comprising a head information calculation unit,
(A) Absolute head information consisting only of head movement is calculated based on the output of the head sensor in a state where the moving body is stopped, and the head movement is detected by the motion tracker to detect the first relative head information. And a head sensor axis calculation step for calculating the sensor axis direction of the head sensor based on the absolute head information and the first relative head information obtained simultaneously.
(B) The absolute head information obtained by synthesizing the head movement and the movement of the moving body is calculated based on the output of the head sensor while the moving body is moving, and the head movement is detected by the motion tracker. Relative head information is calculated, absolute moving body information consisting of movement of the moving body is detected by the output of the moving body sensor, and further based on these absolute head information, first relative head information, and absolute moving body information A method of using a head motion tracker device, comprising: a moving body sensor axis calculation step of calculating a sensor axis of a moving body sensor.

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