JP5564065B2 - Setting apparatus and method for three-dimensional motion analysis system with force plate - Google Patents

Description

The present invention relates to a setting apparatus and method for a three-dimensional motion analysis system provided with a force plate, and a displacement information acquisition apparatus for a force plate used for the setting.

Analyzing the three-dimensional movement of a person is useful in the medical field, the care and welfare field, the sports field, robotics, computer graphics, and the like. A motion capture system is known as means for measuring a three-dimensional motion of a person or an object. In an optical motion capture system, subjects having markers attached to a plurality of predetermined points are photographed by a plurality of cameras, each marker is identified in the camera image, and time-series data of the three-dimensional coordinates of each marker is acquired. Is done. A three-dimensional motion analysis apparatus using optical motion capture is described in Patent Document 1, for example.

In a three-dimensional motion analysis apparatus using optical motion capture, camera parameters (DLT coefficient in the DLT method) for reconstructing three-dimensional data from two-dimensional data are acquired prior to actual motion measurement. For example, in order to obtain the DLT coefficient, a calibration tool (having six or more reference points whose relative positional relationships are known) is actually installed in the space, and the calibration tool is photographed with a plurality of cameras. Done in In calibration in the DLT method, camera parameters (DLT coefficients) are estimated from correspondence between real space coordinates of known reference points of the calibration tool and reference points in an image acquired by the camera. The camera parameter (DLT coefficient) is a coefficient that defines the correspondence between the coordinate value of the reference point in the two-dimensional image acquired by each camera and the coordinate value of the reference point in the three-dimensional space. Using the parameter (DLT coefficient), the real space coordinates (x, y, z) of the measurement points are restored from the camera coordinates (u, v) of a plurality of cameras. The DLT coefficient is described in Patent Documents 2 and 3, for example.

In a three-dimensional motion analysis system, it is useful to acquire floor reaction force data during motion in addition to data obtained using motion capture. By using the floor reaction force data obtained from the force plate (floor reaction force meter) and the posture / position data of the subject obtained by the 3D motion measurement device at the same time, it is possible to calculate the force and moment applied to the joint. Known to traders.

Some 3D motion analysis systems that can acquire floor reaction force include studios equipped with multiple cameras and floor reaction force sensors embedded in the floor surface. There is also a need for a comparatively simple system that can be set on the spot as needed using a portable force plate.

Conventionally, in order to calibrate a system using a 3D motion measurement device and a force plate, it is necessary to perform calibration after adjusting the direction of the camera and create a new camera parameter. The coordinate system of the force plate was matched. Further, when installing a plurality of force plates, it is necessary to change the setting file in accordance with the way of placing the force plates. As will be described in detail below, it is practically difficult to perform these tasks alone, and it takes time and effort.

The direction adjustment of the camera is to adjust the direction of the camera and the position of the plate so that space data necessary for motion analysis can be acquired. Conventionally, adjustment of the direction of the camera has been performed by moving the camera or the plate while the operator looks at the monitor on which the image acquired by the camera is actually displayed. However, depending on the installation location of the three-dimensional motion analysis apparatus, the operator may not always be able to see the monitor. In such a case, an instruction is given while looking at the monitor with the operator adjusting the position of the apparatus. An operator is required. Therefore, there is a demand for adjusting the direction of the camera without looking at the monitor.

In order to calculate the joint moment using the data from the three-dimensional motion measurement system and the force plate, the coordinates of the floor reaction force and the value of the floor reaction force are required. Since it is necessary to know where the COP (Center of Pressure), which is the center of action of the floor reaction force, is located in the coordinate system for motion analysis, the coordinate system for 3D motion analysis and the coordinate system for the force plate are matched. There is a need. Conventionally, when the direction of the camera is adjusted and the position of the force plate is determined, the origin and XY axes of the coordinates of the calibration tool (calibrator) are set to the origin and XY axes of the coordinates based on the force plate. A calibration tool was installed so as to match each other (see FIG. 4), and camera parameters (DLT coefficients in the DLT method) were acquired using the calibration tool. However, each time the position of the force plate changes, it is complicated to obtain the camera parameters by aligning and installing the calibration tool each time.

In a system using a three-dimensional motion measurement device and a force plate, a plurality of force plates may be installed in the same space. For example, there are a case where two left and right force plates are installed so that the left and right feet of the subject are placed, or a case where a plurality of force plates are laid so as to acquire the walking motion of the subject. Conventionally, for example, when two force plates are installed, the position of the force plate is set in the following procedure. First, the installation method of the force plate is determined, and a setting file for specifying the position of the force plate is created for each force plate. In the setting file, parallel movement information and rotation information with respect to the reference position of the force plate are set, and the position of the force plate in the force plate coordinate system is specified by the parallel movement information and rotation information with respect to the reference position of the force plate. Then, two force plates are installed so as to have the same positional relationship as the setting file, and calibration is performed by placing a calibration tool (calibrator) so that the force plate coordinate system and the motion analysis coordinate system coincide. In this work process, it took time and effort to create a setting file and adjust the plate position in accordance with the setting file (which involves actually measuring the position of the force plate and manually inputting the setting file).

JP 2004-344418 A JP-A-10-149445 JP2009-268584A

Although it is understood that three-dimensional motion analysis using a force plate is useful, the complexity of setting work before measurement is a bottleneck in the spread of such a three-dimensional motion analysis system.
The present invention seeks to solve this problem by more easily setting a three-dimensional motion analysis system having a force plate.
The present invention makes it easier to set a three-dimensional motion analysis system including a force plate by using displacement information of the force plate.

The first technical means adopted by the present invention is:
One or more force plates,
Recognizing means provided on the force plate and capable of specifying the position of the force plate;
A plurality of cameras that photograph the force plate and obtain a camera image of the force plate;
Means for setting first position information of the force plate in the force plate coordinate system when the force plate is placed at the first position in the first space;
Means for storing first position information of a means for recognizing the force plate when the force plate is placed at a first position in the first space;
Means for acquiring second position information of the means for recognizing the force plate from the camera image of the force plate when the force plate is placed at the second position in the second space;
Means for acquiring displacement information between the first position information and the second position information of the recognition means;
An apparatus used for setting a three-dimensional motion analysis system having a force plate.

  The recognition means used in the present invention can detect position information of the recognition means by image processing using a camera image, and can specify the position of the force plate by the detected recognition means. In addition, when a plurality of force plates are included in one camera image, the plurality of recognition units need to be distinguishable from each other.

  In this specification, the first space and the second space are used to distinguish the space where the force plate is placed at different times, and the first position is the first space. The position where the force plate is placed and the second position refer to the position where the force plate is placed in the second space. For example, the space where the force plate is placed at the time of calibration is the first space, and the space where the force plate is placed at the time of measurement is the second space. The first space and the second space may be the same room.

  In one aspect, the first position information of the recognition means is acquired from a camera image of a force plate placed at a first position in a first space. The coordinates of the recognition means can be calculated using a plurality of camera images and camera parameters. Further, the position information of the recognition means when the force plate is placed at a specific position in the first space may be acquired in advance and stored in the storage unit. For example, the position information of the recognition means corresponding to the position information of the force plate may be stored in a database, and the position information of the recognition means corresponding to the first position of the selected force plate may be acquired from the database.

In one aspect,
In the first space, the coordinate system of the three-dimensional motion analysis coincides with the coordinate system of the force plate,
In the second space, the coordinate system of the three-dimensional motion analysis and the coordinate system of the force plate are inconsistent,
The displacement information is used to make the coordinate system of the three-dimensional motion analysis in the second space coincide with the coordinate system of the force plate.

In one aspect,
In the first space and the second space, the coordinate system of the three-dimensional motion analysis and the coordinate system of the force plate are the same,
The displacement information is used for obtaining the second position information of the force plate placed at the second position in the second space together with the first position information of the force plate.
In one aspect, the first position information of the force plate is defined by the rotation angle / translation amount of the force plate with respect to the reference position (see FIG. 5) (including the case where the translation amount = 0 and the rotation angle = 0). Is done.

The second technical means adopted by the present invention is an apparatus and method for matching the coordinate system of the three-dimensional motion analysis with the coordinate system of the force plate in the setting of the three-dimensional motion analysis system provided with the force plate.
A device that matches the coordinate system of 3D motion analysis with the coordinate system of the force plate
A plurality of cameras in which the distance between cameras and the direction of each camera are determined;
Recognizing means provided on the force plate and capable of specifying the position of the force plate;
Means for storing the first camera parameters obtained by performing calibration so that the coordinate system of the three-dimensional motion analysis matches the coordinate system of the force plate installed in the first space;
In the first space after the calibration in which the coordinate system of the three-dimensional motion analysis and the coordinate system of the force plate coincide with each other, the first plurality of camera images of the force plate installed in the first space and the first plate Means for storing the coordinates of the means for recognizing the force plate acquired using the camera parameters as a first coordinate value;
Using the second plurality of camera images of the force plate installed in the second space where the coordinate system of the three-dimensional motion analysis and the coordinate system of the force plate do not match, and the first camera parameter, Means for acquiring the coordinates of the means for recognizing the force plate as a second coordinate value;
Means for matching the coordinate system of the three-dimensional motion analysis with the coordinate system of the force plate in the second space using the displacement information of the first coordinate value and the second coordinate value of the recognition means;
Consists of.

The method of matching the coordinate system of 3D motion analysis with the coordinate system of the force plate is as follows:
The first camera parameter is acquired and stored by performing calibration so that the coordinate system of the three-dimensional motion analysis matches the coordinate system of the force plate installed in the first space,
In the first space after the calibration in which the coordinate system of the three-dimensional motion analysis and the coordinate system of the force plate coincide with each other, the first plurality of camera images of the force plate installed in the first space and the first plate Using the camera parameters, the coordinates of the force plate recognition means are acquired and stored as first coordinate values,
Using the second plurality of camera images of the force plate installed in the second space where the coordinate system of the three-dimensional motion analysis and the coordinate system of the force plate do not match, and the first camera parameter, The coordinate of the recognition means of the force plate is acquired as the second coordinate value,
Using the displacement information of the first coordinate value and the second coordinate value of the recognition means, the coordinate system of the three-dimensional motion analysis is matched with the coordinate system of the force plate in the second space.
Is.

In one aspect, the means for matching the coordinate system of the three-dimensional motion analysis with the coordinate system of the force plate is:
The first camera parameter is set to a second value so that the coordinate value of the force plate recognition means calculated using the second plurality of camera images and the second camera parameter matches the first coordinate value. Converts to camera parameters.

In one aspect, a plurality of force plates are installed in the second space,
The second camera parameter is acquired based on the first force plate,
When the second and subsequent force plates are at the first position in the force plate coordinate system, the position information of the second and subsequent force plates is the first position information, and the second and subsequent force plates are the first position information. The coordinates of the plate recognition means are stored as the first coordinate value,
The coordinates of the recognition means of the second and subsequent force plates are acquired as second coordinate values using the second camera parameter,
Based on the displacement information from the first coordinate value to the second coordinate value of the second and subsequent force plate recognition means and the first position information, the second and subsequent forces in the second coordinate system. Get the position information of the plate.

In one aspect, each of the plurality of cameras includes a camera unit including a plurality of cameras that are individually mounted so that the direction can be adjusted, and one or a plurality of visible light emitting units that are mounted so that the directions can be adjusted. And
The force plate is provided with a target of visible light emitted from the one or more visible light emitting parts,
Prior to calibration in the first space, visible light emitted from one or more visible light emitting units in a state determined by adjusting the direction of each camera so as to photograph the space including the force plate. Determine the direction of the visible light emitting portion so that the target hits the target of the force plate,
Prior to imaging of the force plate in the second space, the camera unit is positioned so that visible light emitted from one or a plurality of visible light emitting units hits the target of the force plate.
According to the method and the method for adjusting the direction of the camera according to the present invention, an appropriate camera position can be determined without looking at the monitor on which the camera image is displayed.
The plurality of cameras in the present invention is not limited to such a camera unit, and may be a plurality of cameras fixed to a space (for example, a ceiling).

The third technical means adopted by the present invention is an apparatus and method for automatically setting the position information of the force plate in the setting of the three-dimensional motion analysis system provided with the force plate.
The device that automatically sets the position information of the force plate
A plurality of cameras in which the distance between cameras and the direction of each camera are determined;
Recognizing means provided on the force plate and capable of specifying the position of the force plate;
In the first space in which the coordinate system of the three-dimensional motion analysis and the coordinate system of the force plate coincide, when the force plate is at the first position of the force plate coordinate system, the position information of the force plate is first Means for storing the coordinates of the means for recognizing the force plate as the first coordinate value,
Means for acquiring, as a second coordinate value, the coordinates of the means for recognizing the force plate placed in the second space in the second space in which the coordinate system of the three-dimensional motion analysis and the coordinate system of the force plate coincide with each other; ,
Based on displacement information from the first coordinate value to the second coordinate value and the first position information of the force plate recognition means, second position information of the force plate in the second space is acquired. Means to
Consists of.

To automatically set the force plate position information,
In the first space where the coordinate system of the three-dimensional motion analysis and the coordinate system of the force plate coincide with each other, when the force plate is at the first position of the force plate coordinate system, the position information of the force plate is the first. As the position information, the coordinates of the recognition means of the force plate are stored as the first coordinate value,
In the second space where the coordinate system of the three-dimensional motion analysis and the coordinate system of the force plate coincide with each other, the coordinate of the recognition means of the force plate placed in the second space is acquired as a second coordinate value,
Obtaining second position information of the force plate in the second space based on displacement information from the first coordinate value to the second coordinate value of the force plate recognition means and the first position information. Then, the position information of the force plate in the second space is automatically set.
Is.

In the above technical means, the following modes can be adopted.
In one aspect, a plate cover is detachably attached to the force plate, and the recognition means is provided on the plate cover.
In one aspect, the recognition means is provided directly on the force plate.
In one aspect, the said recognition means is three markers from which the distance between markers differs from each other.
In one aspect, the recognition means provided in each force plate of the plurality of force plates can be distinguished from each other.
Taking the case of using two force plates and a plate cover as an example,
A first plate cover is detachably attached to the first force plate, and first recognition means is provided on the first plate cover,
A second plate cover is detachably attached to the second force plate, and second recognition means is provided on the second plate cover,
The first recognizing unit and the second recognizing unit are distinguishable from each other.
In a more specific aspect,
The first identification means is three markers having different distances between markers,
The second identification means is three markers having different distances between the markers,
The lengths of at least one side of the three line segments connecting the three markers of the first identification unit and the three line segments connecting the three markers of the second identification unit are different.

According to the first technical means of the present invention, by using the displacement information of the force plate, the setting of the three-dimensional motion analysis system including the force plate (coincidence between the coordinate system of the three-dimensional motion analysis and the force plate, the position of the force plate, etc. (Automatic setting of information) can be performed more easily.

According to the second technical means of the present invention, it is possible to perform the three-dimensional motion analysis at the time of measurement and the alignment of the coordinate system of the force plate by converting the already acquired camera parameters by calculation. There is no need to recalibrate and recreate the camera parameters when aligning the coordinate system. Therefore, it is not necessary to perform a calibration work that has been conventionally performed at the time of measurement. Also, let the computer execute the processing (acquisition of second coordinate value, acquisition of displacement information, conversion of camera parameters) at the time of measurement (when the force plate is placed in the second space) with one input (click) Thus, the calibration work can be easily performed.

According to the third technical means of the present invention, the position of the force plate can be set by calculation, and it is not necessary to actually measure the position and angle of the actually placed force plate and manually change the setting file. According to the present invention, the information in the setting file can be automatically adjusted based on the position information of the actually placed force plate without placing the force plate at the position set in the setting file.

It is the schematic of the three-dimensional motion analysis system provided with the force plate. It is a front view of the camera unit which concerns on this embodiment. It is a figure which shows the laser pointer of the camera unit which concerns on this embodiment. It is a camera image with the calibrator placed so that the force plate coordinate system and the three-dimensional motion analysis coordinate system coincide. It is a figure which shows the reference position of the force plate in the force plate coordinate system which concerns on this embodiment. At the reference position, the center of the force plate is located at the origin of the force plate coordinate system, and the vertex opposite to the midpoint of the base of the isosceles triangle of the force plate is located on the X axis. It is a figure which shows a force plate coordinate system. It is a figure which shows a force plate coordinate system. The pattern when the left and right sides of the force plate are shifted is shown. It is a figure which shows a force plate coordinate system. The pattern when the left and right sides of the force plate are shifted is shown. It is a figure which shows the plate cover which concerns on this embodiment, an upper figure shows a plate cover and a lower figure shows the force plate which adhered the plate cover. 2 shows two force plates formed by respectively attaching plate covers according to the present embodiment. It is the schematic of the force plate which adhered the camera unit and plate cover which concern on this embodiment. It is a figure which shows the state which the laser beam radiate | emitted from the laser pointer of the camera unit which concerns on this embodiment hit the target on a plate cover. It is the schematic of the force plate which adhered the camera unit and plate cover which concern on other embodiment. In the camera unit, one laser pointer is provided corresponding to one camera. It is a figure which shows the state which the laser beam radiate | emitted from the laser pointer of the camera unit which concerns on other embodiment hits the target on a plate cover. Three laser beams are emitted from the three laser pointers. The coordinate system of the three-dimensional motion analysis at the time of measurement and the positions of the three marker sets of the two force plates are displayed. The triangular lines in FIG. 15 indicate the default position of the force plate when the origin and coordinate axes of the coordinate system of the three-dimensional motion analysis coincide with the origin and coordinate axes of the coordinate system of the force plate. It does not show the force plate placed in the. The actually placed force plates shown in the left figure in the figure are each defined by three markers. 15 is an enlarged view of the right side of FIG. 15, and as apparent from a comparison between the origin and XYZ axes in FIG. 15A and the three marker positions on the right side force plate, in this state, the three-dimensional motion is performed. The analysis coordinate system and the force plate coordinate system do not match. FIG. 15 shows a state in which the coordinate system of the three-dimensional motion analysis and the coordinate system of the force plate are matched with each other from the state of FIG. Also, the position of the left force plate is adjusted. 16 is an enlarged view of the right side of FIG. 16, and as apparent from a comparison between the origin and XYZ axes in FIG. 16A and the three marker positions on the right side force plate, in this state, the three-dimensional operation is performed. The coordinate system of the analysis and the coordinate system of the force plate are the same. It is a block diagram explaining the conversion of a coordinate system using the displacement information of the marker coordinate on a force plate, and the automatic setting of a setting file. It is a flowchart which shows the procedure which matches the direction of a camera without looking at a monitor. It is a flowchart which shows the procedure which matches the coordinate system of a force plate, and the coordinate system of a three-dimensional motion analysis. It is a flowchart which shows the procedure which performs the automatic adjustment of the setting file which prescribes | regulates a force plate position.

[A] Configuration of 3D Motion Analysis System with Force Plate [A-1] A schematic diagram of a 3D motion analysis system with a motion capture system force plate is shown in FIG. In the three-dimensional motion analysis system provided with the force plate, the three-dimensional motion of the subject can be acquired by an optical motion capture system. In general, an optical motion capture system includes a plurality of optical markers (for example, infrared reflection markers) attached to a plurality of predetermined parts of a subject and a plurality of cameras that simultaneously photograph a subject wearing the optical markers from a plurality of angles. And the 2D position of the marker in the image information of the marker obtained by each camera is reconstructed to calculate the 3D position of the marker, and the body is determined from the 3D position of the optical marker and the 3D model of the body. And a display unit for displaying the result of the processing unit (exercise data acquired as time-series data of the posture of the subject). As a technique for calculating three-dimensional position coordinates using a plurality of cameras, the DLT method is well known to those skilled in the art.

[A-2] Camera Unit In this embodiment, a plurality of cameras used in the motion capture system are provided by a camera unit. The camera unit includes two or more motion analysis cameras in which the relationship between the cameras (inter-camera distance / camera direction) is fixed, and a laser pointer in which the relationship between the cameras (distance / direction) is fixed. Device.

As shown in FIG. 2, the camera unit includes a support 1, a leg 2 provided at a lower portion of the support 1, and a plate-like camera in which the position of the support 1 can be adjusted in the height direction and the angle is variable. And a support part 3. Three cameras 4 are arranged on the camera support unit 3 so as to be spaced apart from each other so as to be located at the vertices of an isosceles triangle (a regular triangle in the illustrated embodiment). The distance between the cameras 4 is fixed (the distance between the cameras may be variable). Each camera 4 is variable in angle and direction independently for each camera. As shown in FIG. 3, the support 1 is provided with a laser pointer 5 so that the angle can be changed and fixed. After adjusting the angle of the laser pointer 5 appropriately, the adjusted angle can be fixed. The laser pointer 5 may be provided on the camera support unit 3. Each camera 4 is electrically connected to a power source and electrically connected to the computer so as to output image data to a computer (data processing apparatus). Electrical wiring and components are housed in the central part of the camera support 3. A roller 20 is rotatably mounted on the leg 2, and the camera unit can move as a unit on the floor surface while maintaining a constant relationship between the cameras 4. The positional relationship between the three cameras is not limited to an isosceles triangle, and the number of cameras is not limited to three as long as it is a plurality.

[A-3] Force Plate The force plate 6 according to the present embodiment is a portable force plate having an isosceles triangular shape in plan view. The force plate 6 includes an isosceles triangle-shaped step platform in plan view, and three load cells (load detection sensors) disposed below the three apexes of the step platform. The load cell is a 3-component force sensor that detects load outputs in the X-axis direction, the Y-axis direction, and the Z-axis direction. In the local coordinates of the force plate, the position (XY coordinate) of each load cell is known. A center of pressure (COP) is obtained from the values obtained by the three load sensors. The coordinates of the COP are acquired in the XY coordinates as the XY plane in the surface direction of the platform (floor surface). In one aspect, the three-dimensional motion analysis system includes a first force plate on which one foot of the subject rests and a second force plate on which the other foot rests. Moreover, the floor reaction force at the time of walking can be acquired by laying a plurality of force plate pairs corresponding to the left and right feet continuously in a certain direction. Load information (z, y, z direction) acquired by each load cell is sequentially transmitted to the computer, and the COP is obtained sequentially (per unit time such as 0.01 second, 0.001 second, etc.) by the computing means of the computer. Thus, time series data of COP (XY coordinate values) can be acquired. The shape of the force plate and the number of load sensors are not limited. For example, a force plate that includes a substantially rectangular tread plate and four load cells arranged at four corners of the tread plate may be used.

The force plate coordinate system indicating the position of the force plate is illustrated in FIGS. The coordinate system of the force plate and the position of the force plate on the coordinate can be displayed on the display device of the computer. In FIG. 6, two force plates are shown. The base of each isosceles triangular force plate is on the X axis, and the bisector of the apex angle is on the Y axis. In one aspect, this state is the default position for placing the two force plates, with one foot of the subject resting on one force plate and the other foot resting on the other force plate. The position of the force plate is defined by a configuration file on the computer. More specifically, the position of each force plate is defined by the rotation angle with respect to the reference position of the force plate and the amount of translation. In one embodiment, the reference position of the force plate is as shown in FIG. 5, where the center of the force plate is located at the origin of the force plate coordinate system, and the vertex opposite the midpoint of the base of the isosceles triangle of the force plate is Located on the X axis. 6 to 8, Ox to Oz are parallel movements in the respective axial directions, and Rot is a rotation angle around the origin. 7, FIG. 8 shows the pattern when placing offset from one another left and right force plate in the X-axis direction. In the setting files shown in FIGS. 6 to 8, eight force plates can be set, but the number of force plates used in the present invention is not limited, and an arbitrary number of force plates can be set. .

[A-4] The plate cover plate cover 7 is a cover that covers the upper surface of the force plate 6 and has a planar shape of an isosceles half-angle in accordance with the planar shape of the force plate 6 as shown in FIG. . Three markers 8a, 8b and 8c are attached to the upper surface of the plate cover 7 so as to be separated from each other. The sides of the triangle connecting the three markers 8a, 8b, 8c have different lengths, that is, the distance between the three markers is different from each other. The set of three marker distances is stored in the storage unit of the data processing device. By making the distance between the three markers different, the posture of the triangle formed by the three markers (that is, the posture of the force plate) can be specified. The markers 8a, 8b, and 8c are optical markers that can be detected from a camera image, for example, infrared reflection markers.

A handle 70 is provided at the central portion of the upper surface of the plate cover 7, and positioning pieces 71 are provided at the respective peripheral edges. The mounting direction of the plate cover 7 with respect to the force plate 6 is determined, and in one aspect, the handle 70 is mounted so that the length direction of the handle 70 is aligned with the bisector of the apex angle. The plate cover 7 is always attached to the force plate 6 at the same position by gripping the handle 70 and placing the plate cover 7 on the upper surface of the force plate 6 so that the positioning piece 71 contacts the periphery of the force plate 6. The Therefore, by attaching the plate cover 7 to the force plate 6, the markers 8a, 8b, and 8c can always be positioned at the same position on the force plate 6. Four circular openings 72 formed on the upper surface of the plate cover 7 are air holes for easily removing the plate cover 7 attached to the force plate 6. The shape of the plate cover is not necessarily limited to the shape of the force plate as long as the marker can always be positioned at the same position on the force plate when the plate cover is attached to the force plate. There is no.

The handle 70 can be provided with a target of the laser beam emitted from the laser pointer 5. The handle 70 can be provided with a target of the laser beam emitted from the laser pointer 5. The target needs to be visible by the operator. In one aspect, the target has a circular shape with a diameter of about 1 cm and has a color that can be visually recognized by the operator. The part where the target is provided is not limited to the handle 9 and may be provided directly on the upper surface of the plate cover or the force plate.

FIG. 10 shows two plate covers attached to the upper surfaces of the two force plates. The two plate covers are the same size and shape, but the positions of the three markers 8a, 8b, 8c on the first plate cover and the three markers 8a ', 8b', 8c on the second plate cover. It is different from the position of ′. That is, the triangle formed by the line connecting the three markers 8a, 8b, and 8c and the triangle formed by the line connecting the three markers 8a ′, 8b ′, and 8c ′ have different shapes and can be distinguished from each other. It is. When installing multiple plates and plate covers, each plate cover (force plate) can be identified in the camera image acquired by each camera of the camera unit by changing the distance between the markers for each plate cover. ing. More specifically, each plate cover (force plate) is identified by making the length of at least one of the three sides connecting the three markers different between the plate covers at a distance between the markers between the plurality of plate covers. . A set of three marker distances provided on each plate cover is stored in the storage unit of the data processing device.

In the above-described embodiment, the plate cover provided with the recognition means capable of specifying the position of the force plate is used, but a force plate incorporating the function of the plate cover on the upper surface may be used. Specifically, a marker may be provided on the upper surface of the force plate (for example, an LED is incorporated flush with the upper surface as a marker), or a recognition means is formed by a figure (number etc.) drawn on the plate, You may recognize using pattern recognition. A laser pointer target may be provided directly on the upper surface of the force plate. It will be understood by those skilled in the art that when a plurality of force plates are used at the same time, the recognition means provided on each force plate can be distinguished from each other (by image processing of the camera image). The recognition means such as a marker is typically provided on the upper surface of the force plate or the plate cover, but the portion on which the recognition means is provided does not necessarily have to be the upper surface, and the recognition means can be detected by a camera image. For example, the part where the recognition means is provided is not limited, and may be the side surface of the force plate or the plate cover, or the bottom surface of the force plate (place the force plate on a transparent base and photograph from below).

[Appendix]
A force plate with a recognition means on the upper surface that can identify the position of the force plate.
A force plate with a visible light target on the top.
A plate cover, which is detachably attached to a force plate, wherein the plate cover is provided with a recognition means capable of specifying the position of the force plate.
In one embodiment, the plate cover is provided with a visible light target.
In one aspect, the said recognition means is three markers from which the distance between markers differs from each other.

[A-6] Data Processing Device Various calculations in the motion capture system and the force plate can be executed by a data processing device constituted by a computer. Specifically, an image input unit that captures image information acquired by the camera, a storage unit that stores the captured image information and information calculated by the image processing unit, the image information, measurement results, and analysis results are displayed. A display unit, an image processing unit for performing image processing on the image information, and a calculation unit for calculating time-series data of the three-dimensional position of the marker are provided. A processing unit that performs data processing using various measured data and a display unit that displays input camera images and processing results are a general-purpose computer (an input device for inputting data, for outputting processed data). Output device, display device for displaying data, arithmetic device mainly composed of CPU, storage device such as ROM, RAM, hard disk, bus connecting them, stored in the storage device so that the computer can execute predetermined processing A predetermined program, etc.). Similarly, the load cell of the force plate is electrically connected to the data processing device via an amplifier. The load information of the subject measured by the load cell is amplified by the amplifier and output to the data processing device. By sequentially obtaining the COP, time series data of the COP can be acquired.

[B] A method for easily matching the coordinate system of the three-dimensional motion analysis device and the force plate [B-1] Overview In one embodiment, the three-dimensional motion analysis system includes a three-dimensional motion measurement device, a portable plural A force plate and a plate cover corresponding to each force plate. The three-dimensional motion measurement apparatus includes a camera unit including three cameras that are individually mounted so that the direction can be adjusted, and a visible light emitting unit (laser pointer) that can be adjusted in the direction. Three markers (infrared reflective markers) and a target of the red laser beam emitted from the laser pointer are provided on the upper surface of the force plate (in the following description, the upper surface of the plate cover). In one plate cover, the distance between the three markers is different. Further, at least one marker distance (length of one side connecting the markers) is made different between the plate covers.

Using these devices, the coordinate system of the three-dimensional motion measurement device and the force plate is matched by the following procedure.
(1) Before installing the three-dimensional motion analysis system on the measurement site, the direction of each camera and the direction of the laser pointer of the camera unit are determined so that an image of a desired space can be acquired. In addition to acquiring camera parameters, three marker coordinates on the plate cover of the first force plate are acquired and stored.
(2) At the measurement site, use a laser pointer to adjust the direction of the camera without looking at the monitor.
(3) At the measurement site, the coordinate system of the force plate and the coordinate system of the three-dimensional motion measuring device are matched by converting the camera parameters by calculation using the marker coordinates on the plate cover of the first force plate. There is no need to recreate the camera calibration parameters when aligning the coordinate system.
(4) At the measurement site, the position and rotation after the second force plate are used, and the coordinates of the markers on the plate cover attached after the second force plate are used, and then the force after the second force plate. Performs automatic plate position adjustment. It is not necessary to actually measure the movement distance and rotation angle of the force plate after the second force plate and manually change the setting file.

[B-2] Method and apparatus for aligning the direction of the camera without looking at the monitor In the present embodiment, two or more motion analysis cameras 4 and cameras that fix the relationship between the cameras (inter-camera distance / camera direction). The direction of the camera for motion analysis is monitored using a device composed of a laser pointer 5 with a fixed relationship (distance / direction) and a target 9 for a laser pointer provided on the upper surface of the force plate 6 or the plate cover 7. Adjust without looking at it. In FIGS. 11 and 12, a target 9 is provided on the upper surface of the plate cover 7 attached to the upper surface of the force plate 6. The procedure for aligning the direction of the camera without looking at the monitor is shown in FIG.

(1) After adjusting the direction of each camera 4 and the position of the force plate 6 so that the data of the space necessary for the three-dimensional motion analysis can be acquired at the time of manufacturing (for example, before the system is brought into the measurement site) The direction of the laser pointer 5 is adjusted so that a visible laser beam (typically a red laser beam) hits the target 9 on the plate cover (force plate). More specifically, the force plate 6 is arranged on the floor surface of the space (for example, the experiment space on the manufacturer side), and a desired space including the force plate 6 is photographed by each camera 4 of the camera unit and displayed on the monitor. To do. Adjust the direction of each camera 4 while looking at the monitor. With the direction of each camera 4 determined, the direction of the laser pointer 5 is adjusted so that the laser beam strikes the target on the force plate (the target 9 on the plate cover 7 in the illustrated embodiment). Thus, in the camera unit, the direction of each camera 4 and the direction of the laser pointer 5 are determined and fixed.

(2) The position of the camera unit is adjusted so that the laser beam emitted from the laser pointer 5 strikes the target 9 at the time of measurement (when the system is carried into the measurement site). More specifically, the force plate 6 is disposed at a predetermined portion of the floor surface of the measurement space, and the plate cover 7 is attached, so that the laser beam from the laser pointer 5 strikes the target 9 on the plate cover 7. Position the camera unit.

Since the operator only has to move the camera unit while looking at the target 9 on the laser beam and the force plate (plate cover 7), it is not necessary to see the monitor screen acquired by the camera of the camera unit. Therefore, it is possible to match the directions of a plurality of cameras without looking at the image displayed on the monitor.

11 and 12, one laser pointer 5 is provided for the camera unit, but a plurality of laser pointers 5 may be used. For example, as shown in FIGS. 13 and 14, a laser pointer 5 may be provided separately for each camera 4, and the direction of the camera may be adjusted using the laser pointer 5 for each camera. 13 and 14, one laser pointer 5 is associated with one camera, but one laser pointer 5 is associated with two cameras, and the other laser pointer 5 is associated with the remaining camera. You may let them. In FIG. 13 and FIG. 14, one common target is shown as the target 9 of the three laser pointers 5, but a different target may be used for each laser pointer.

The method and apparatus for aligning the direction of the camera without looking at the monitor can be regarded as a technical idea independent of the three-dimensional motion analysis system provided with the force plate, and the camera when photographing a certain object with a plurality of cameras. It can be applied to the position setting.
[Appendix]
A camera unit comprising a plurality of cameras that are individually adjustable in direction and one or a plurality of visible light emitting parts that are attached in a direction-adjustable manner;
The target is provided with a target of visible light emitted from the visible light emitting part,
In the first space, the visible light emitted from the visible light emitting unit hits the target on the object in a state determined by adjusting the direction of each camera so as to photograph the space including the object. , Determine the direction of the visible light emitting part,
A camera unit positioning method or system for positioning the camera unit so that visible light emitted from a visible light emitting unit hits a target on an object in the second space.
In one aspect, the object is a force plate.
In one aspect, the target is provided directly on the upper surface of the force plate.
In one aspect, the target is provided on a cover member that is detachably attached to the force plate.
In one aspect, the camera unit includes one visible light emitting unit.
In one aspect, the camera unit includes a plurality of visible light emitting units. In a more specific aspect, one visible light emitting unit is provided for each camera, and the direction of the corresponding visible light emitting unit is determined for each camera.
In one aspect, the visible light emitting part is a laser pointer.
In one aspect, the target is provided with one target.
In one aspect, the target is provided with a plurality of targets.
In one aspect, the target is detachably provided on the object.
In one aspect, the target is provided on a cover member that is detachably provided on the object.

[B-3] Coordination of the coordinate system of the three-dimensional motion measurement apparatus and the coordinate system of the plate In this embodiment, two or more motion analysis cameras in which the relationship between the cameras (inter-camera distance / camera direction) is fixed And a plate cover on which three markers are attached (the distance between the markers is not equal) and the marker can be placed at the same position on the force plate. Match the coordinate system of the system and the force plate. When installing a plurality of force plates, the coordinates of the coordinate system of the three-dimensional motion measuring device and the coordinate system of the first force plate are adjusted here. Adjustment of the positions of the second and subsequent force plates is as follows. Note that it is calculated in the “automatic adjustment of positional relationship between plates” part. The procedure for matching the coordinate system of the force plate with the coordinate system of the three-dimensional motion analysis is shown in FIG. If the coordinate system of the three-dimensional motion analysis and the coordinate system of the force plate are the same, it is not necessary to align the coordinate system.

(1) Camera parameters are created with the relationship between cameras fixed at the time of manufacture. Specifically, in a state where the positional relationship between two or more cameras in which the relationship between the cameras (inter-camera distance / camera direction) is fixed and the force plate position is determined, the coordinate system of the force plate is adjusted. The calibration tool is installed, and the calibration tool is photographed with a plurality of cameras to create camera parameters (DLT coefficients).

At this time, three marker coordinates on the plate cover attached to the force plate, which is a reference for setting the calibration tool, are recorded in the storage unit. That is, the plate cover attached to the force plate when calibrated at the time of manufacture (the origin and coordinate axes of the coordinate system of the three-dimensional motion measurement system coincide with the origin and coordinate axes of the coordinate system of the force plate) The coordinate values of the above three markers are stored. The coordinate values of the three markers on the plate cover can be calculated based on marker positions and camera parameters in a plurality of camera images at the time of calibration.

(2) Since the relationship between cameras is fixed at the time of measurement, three-dimensional calculation is possible using camera parameters at the time of manufacture. At the time of measurement, three-dimensional coordinates can be calculated from images acquired by a plurality of cameras using this camera parameter.

(3) At the time of measurement, the position of the force plate in the coordinate system of the three-dimensional motion measuring apparatus obtained by calibration at the time of manufacture is different from the position at the time of manufacture (at the time of calibration). At the time of measurement, the force plate with the plate cover attached is photographed by a plurality of cameras, and the obtained camera image is searched for a marker that is equal to the distance between the markers stored in the storage unit, The three markers are searched to obtain the coordinate values of the three markers.

(4) A calculation for matching the coordinate system of the three-dimensional motion measuring apparatus with the coordinate system of the plate is performed using three markers on the plate cover. A specific calculation method will be described later.

(5) By using the camera parameters converted by calculation in (4), it is possible to match the coordinate system of the three-dimensional motion measuring apparatus and the coordinate system of the force plate.
The operations (3) and (4) at the time of measurement can be performed automatically by clicking on the computer screen. Specifically, a program for causing the computer to execute a calculation for matching the coordinate system of the three-dimensional motion measuring device with the coordinate system of the plate is stored in the storage unit, and by clicking the simple calibration button on the screen, Such a program is executed.

In the present embodiment, a calculation method when the DLT method is used will be described. Make decisions as unknowns to A ₁₁ -C ₁₃ for each of the equation below camera calibration of DLT method. (U ₁ , V ₁ ) is a two-dimensional coordinate value of the camera image, and (X, Y, Z) is a three-dimensional coordinate value in the three-dimensional motion analysis apparatus.
In the present embodiment, the coefficients A _{11 to} C ₁₃ are camera parameters acquired at the time of calibration.

At this time, it is assumed that three points (three marker coordinates in the present embodiment) on the force plate acquired at the time of calibration and set in the storage unit move as follows at the time of measurement.
By changing the coefficients A _{11 to} C ₁₃ to A ″ _{11 to} C ″ ₁₃ , the coordinate system of the three-dimensional motion measuring apparatus can be matched with the coordinate system of the plate.

However,
Also,
here
And

the unit vector from p ₁ to p ₂
The normal vector of the vector from p ₁ to p ₂ and the vector from p ₁ to p ₃
v ₁ and v ₂ normal vectors
And when

the unit vector from p ₁ 'to p ₂ '
Normal vector of p ₁ 'to p ₂ ' vector and p ₁ 'to p ₃ ' vector
normal vector of v ₁ 'and v ₂ '
And when

The calculation principle will be described.
An arbitrary marker coordinate value X calculated using the DLT parameter at the time of in-house calibration is converted to a coordinate value of the motion analysis coordinate system and the coordinate system of the plate, and the coordinate value moved is defined as X ′.
Also,
R ₁ : rotation matrix from the coordinate system of the world coordinate system to the coordinate system after the plate coordinate system and the motion analysis coordinate system are combined,
R ₂ : rotation matrix from the coordinate system of the world coordinate system to the motion analysis coordinate system at the time of in-house calibration,
C: parallel movement from the origin of the coordinate system of the world coordinate system to the origin of the coordinate system after fitting the plate coordinate system and the motion analysis coordinate system,
B: Translation from the origin of the coordinate system of the world coordinate system to the origin of the coordinate system for motion analysis during internal calibration,
Then,
The relationship between coordinate value X and coordinate value X ′ is as follows.

When the above equation is transformed,
It becomes. By replacing X ′ with (x, y, z) in equation (1), equation (1) becomes
It becomes. By transforming this equation, equation (2) is obtained.

[B-4] Automatic adjustment of the positional relationship of the relationship between the force plates Two or more motion analysis cameras in which the relationship between the cameras (inter-camera distance / camera direction) is fixed, two or more force plates, The positional relationship of the relationship between the force plates is automatically adjusted using an apparatus including two or more plate covers provided with three markers. Each plate cover can place a marker at the same position as the corresponding force plate, and in one plate cover, the distance between the three markers is different. Further, the plate covers can be distinguished from each other by making the distance between at least one marker (the length of one side connecting the markers) different between the plate covers. Three marker distance sets for each plate cover are stored in the storage unit. FIG. 20 shows a procedure for automatically adjusting the setting file that defines the force plate position.

(1) It is assumed that the coordinate system of the force plate and the coordinate system of the three-dimensional motion measuring apparatus are already in agreement. Further, marker position information on the force plate and position information of the force plate when calibrated in-house are stored in the storage unit. The position information of each force plate is defined by the rotation angle of the force plate when the force plate at the reference position (for example, FIG. 3) is rotated around the origin by a certain angle and then translated, and the vector of the translation. For example, when there are a first force plate and a second force plate, the first force plate and the second force plate are placed at the position preset in the setting file at the time of in-house calibration. In the setting file, the rotation angle and the parallel movement distance for specifying the position of the force plate are set, and these pieces of information are stored in the storage unit. The coordinates of the marker on the first force plate and the coordinates of the marker on the second force plate are calculated based on a plurality of images photographed by the camera unit and stored in the storage unit. Alternatively, when the coordinate system of the force plate and the coordinate system of the three-dimensional motion analysis coincide with each other, the marker coordinates on the force plate when the force plate is located at a predetermined position set in advance are acquired, and the marker The coordinates may be stored in the storage unit in advance.

(2) For the first first force plate, it is assumed that the coordinate system of the three-dimensional motion measuring apparatus matches the coordinate system of the plate.

(3) For the second second force plate, utilizing the fact that the coordinates between the markers of each plate cover are different, the marker of the plate cover of the second force plate is identified, and the plate of the second force plate Get the marker coordinate values of the three markers on the cover.

(4) By executing the calculation described below using this marker coordinate value and the set coordinate value (marker coordinate value acquired during in-house calibration), the reference position of the second force plate (see FIG. 3) The rotation angle and translation amount with respect to can be calculated.

(5) The third and subsequent force plates (third force plate, fourth force plate,...) Are also calculated in the same manner as the second force plate, and the rotation angle and translation vector are calculated. To do. In a more specific example, when there are four force plates, four plate covers are prepared corresponding to each force plate. Each plate cover is provided with three markers, and the markers on each plate cover are distinguishable from each other. In the camera image obtained by placing four force plates on the floor and photographing the state where the plate cover is attached to each force plate with a camera, the marker corresponding to each force plate is identified and identified, Get each marker coordinate. For each plate cover, the rotation angle and translation vector are acquired from the displacement amount of the marker coordinate (from the preset reference coordinate value).

A calculation method will be described. If X is a translation vector,
It becomes.
Also,
Then,
The rotation angle Rot is
It becomes.
here,
R ₁ : Rotation angle is 0 → Rotation matrix when executing force plate alignment R ₂ : Rotation angle is 0 → Rotation matrix during in-house calibration C: Origin of force plate coordinate system → Force plate during in-house calibration Translation vector B to position: origin of force plate coordinate system → translation vector to force plate position when executing force plate alignment.
At this time, it is assumed that the force plate is placed horizontally.

Specifically, it is assumed that the marker coordinates of three points on the plate set in the software have moved as follows at the time of measurement.

the unit vector from p ₁ to p ₂
The normal vector of the vector from p ₁ to p ₂ and the vector from p ₁ to p ₃
v ₁ and v ₂ normal vectors
And when

the unit vector from p ₁ 'to p ₂ '
Normal vector of p ₁ 'to p ₂ ' vector and p ₁ 'to p ₃ ' vector
normal vector of v ₁ 'and v ₂ '
And when

Also,
C: Origin of plate coordinate system → Parallel vector to plate position during internal calibration B: Origin of plate coordinate system → Parallel vector to plate position when executing plate alignment

[B-5] Use of marker coordinate displacement information in setting of three-dimensional motion analysis system The use mode of marker coordinate displacement information on the force plate will be described with reference to FIG. In the force plate coordinate system, the position of the force plate is defined by the setting items of the setting file. Specifically, the position of the force plate is determined by the rotation angle and the parallel movement amount with respect to the reference position (rotation angle 0, parallel movement amount 0). The reference position is illustrated in FIG. A force placed in the first space by placing the force plate at the first position so as to match the position (first rotation angle / translation amount) defined in the setting file in the first space. The position of the plate corresponds to the position on the setting file. In this state, the camera parameters are acquired by performing calibration so that the coordinate system of the three-dimensional measuring apparatus (motion analysis) matches the coordinate system of the force plate. The position information (first rotation angle / translation amount) of the first position of the force plate and the acquired camera parameters are stored in the storage unit.

Using the camera image of the force plate placed at the first position and the obtained camera parameters, the position information of the marker on the force plate at the first position is obtained as the first coordinate value and stored in the storage unit To do. In the first space, the coordinate system of the three-dimensional measuring device (motion analysis) matches the coordinate system of the force plate, and the XY coordinate value of the first coordinate value is the coordinate of the three-dimensional measurement device (motion analysis). In the coordinate system of the system and force plate. In the first space, the position information (first rotation angle / parallel movement amount) of the force plate and the position information (first coordinate value) of the marker on the force plate correspond to each other.

A case will be described in which the coordinate system of the three-dimensional measuring device (motion analysis) and the coordinate system of the force plate match in the second space. In the second space, the force plate is placed in the second position. Using the camera image of the force plate placed at the second position and the obtained camera parameters, the position information of the marker on the force plate at the second position is obtained as the second coordinate value and stored in the storage unit To do.

From the displacement information of the first coordinate value at the first position in the first space and the second coordinate value at the second position in the second space, from the first position to the second position The rotation angle and parallel movement amount are acquired as adjustment amounts. The second rotation angle / translation amount at the second position in the second space from the first rotation angle / translation amount at the first position in the first space of the setting file and the acquired adjustment amount. Can be calculated and the configuration file can be set automatically.

A case will be described where the coordinate system of the three-dimensional measuring device (motion analysis) and the coordinate system of the force plate do not match in the second space. In the second space, the force plate is placed in the second position. Using the camera image of the force plate placed at the second position and the obtained camera parameters, the position information of the marker on the force plate at the second position is obtained as the second coordinate value and stored in the storage unit To do.

A first coordinate value in the first space (the coordinate system of the motion analysis and the coordinate system of the force plate match) and a second coordinate value in the second space (the coordinate system of the motion analysis and the coordinate system of the force plate do not match) Corresponds to a difference between the coordinate system of the motion analysis at that time in the second space and the coordinate system of the motion analysis when the coordinate system of the force plate coincides with the coordinate system of the force plate in the second space. Therefore, transforming the camera parameters acquired in the first space so that the second coordinate value calculated from the camera image of the force plate placed at the second position matches the first coordinate value. Thus, the coordinate system of the motion analysis in the second space can be made to coincide with the coordinate system of the force plate (as a result, the second rotation angle / translation amount at the second position in the setting file is (It is automatically set to be the same position as the first rotation angle and parallel movement amount at the position). When there are multiple force plates, the setting files for the second and subsequent force plates are automatically set using the displacement information between the second and first coordinate values obtained using the converted camera parameters. can do.

[B-6] Overall Flow The overall flow will be described based on one embodiment. At the time of manufacture, one camera unit, one force plate, one plate cover, and a calibration tool are prepared.

The first force plate with the first plate cover attached is placed on the floor surface and photographed with three cameras of the camera unit. Adjust the direction of each camera while viewing the camera image displayed on the monitor. After determining the direction of the camera, the angle of the laser pointer is determined so that the laser beam emitted from the laser pointer of the camera unit hits the target on the first cover plate. In this way, the orientation of each camera and laser pointer in the camera unit is determined and fixed.

A calibration tool is installed according to the position of the first force plate when the orientation of each camera and laser pointer in the camera unit is determined, and the calibration tool is photographed by each camera in which the relationship between the cameras is fixed. Thus, the camera parameter (DLT coefficient) is acquired from the position of the reference point on the calibration tool and the position of the reference point in the camera image, and stored in the storage unit. At this time, the coordinate system (first coordinate system) of the three-dimensional motion measuring apparatus and the coordinate system of the force plate are the same. Further, the coordinate values of the three markers on the plate cover are acquired and stored in the storage unit.

At the time of measurement, the camera unit in which the relationship between the cameras and the direction of the laser pointer are fixed, two force plates, and two plate covers are carried into the measurement site. The first force plate with the first plate cover attached is placed in the measurement space, and the position of the camera unit is determined so that the laser beam emitted from the laser pointer hits the target on the first plate cover. At this time, there is no need to look at the monitor that displays the camera image.

Three markers on the first plate cover are searched from the images photographed by the cameras of the camera units whose positions are determined, and the coordinates of the three markers are calculated and stored in the storage unit.

Using the three marker coordinates acquired at the time of manufacture and the three marker coordinates acquired at the time of measurement, the coordinate system (first coordinate system) at the time of manufacturing the three-dimensional motion measuring apparatus is changed to the coordinate system at the time of measurement (second Coordinate system). Specifically, camera parameters acquired at the time of manufacture are converted using marker coordinates at the time of manufacture and marker coordinates at the time of measurement. When aligning the coordinate system, it is not necessary to recreate the camera parameters acquired at the time of manufacture.

Further, the second force plate with the second cover plate attached is placed in the measurement space. The timing for placing the second force plate is not limited, and the first force plate and the second force plate may be placed simultaneously. Three markers on the second plate cover are searched from the images photographed by the cameras of the camera units whose positions are determined, and the coordinates of the three markers are calculated and stored in the storage unit. The three markers on the first plate cover and the three markers on the second plate cover are distinguishable from each other.

The storage unit stores the reference position information of the second force plate in the force plate coordinate system and the reference coordinates of the three markers on the second plate cover at that time, and the three marker coordinates actually placed The displacement information of the second force plate is acquired from the reference coordinates of the marker, and the position information of the second force plate is acquired from the reference position information of the second force plate and the displacement information. There is no need to actually measure the moving distance and rotation angle of the second force plate and manually change the setting file.

In the three-dimensional motion analysis system (including the three-dimensional motion measurement device and the force plate) according to the present embodiment, the coordinate system of the three-dimensional motion analysis and the force plate are adopted by employing one or more of the above-described methods and devices. The coordinate system can be easily aligned.

Claims (17)

One or more force plates,
Provided on the force plate, positional information by image processing using a camera image is a recognition means can detect, and capable of specifying recognition means the position of the force plate from the recognition unit position information,
A plurality of cameras that photograph the force plate and obtain a camera image of the force plate;
Force plate coordinate system when the force plate is placed at the first position in the first space (in the first space, the coordinate system of the three-dimensional motion analysis and the coordinate system of the force plate coincide) Means for setting the first position information of the force plate at
Means for storing, as first recognition means position information , recognition means position information of the force plate when the force plate is placed at a first position in the first space;
A second recognizing means position information recognition means position information of the force plate from the force plates of the camera image in the coordinate system of the three-dimensional motion analysis when placed in the second position of the force plate is the second space Means to obtain,
Means for obtaining the displacement information of the first recognition means position information and the difference between the second recognition unit location information, the second recognition unit location information for said first recognition means position information,
A device used for setting a three-dimensional motion analysis system equipped with a force plate. In the second space, the coordinate system of the three-dimensional motion analysis and the coordinate system of the force plate are inconsistent,
The displacement information is used to match the coordinate system of the three-dimensional motion analysis in the second space with the coordinate system of the force plate.
The apparatus of claim 1. In the second space, the coordinate system of the three-dimensional motion analysis coincides with the coordinate system of the force plate,
The displacement information is used to acquire the second position information of the force plate placed at the second position in the second space together with the first position information of the force plate.
The apparatus of claim 1. A plurality of cameras in which the distance between cameras and the direction of each camera are determined;
Provided force plate, positional information by image processing using a camera image is a recognition means can detect, and capable of specifying recognition means the position of the force plate from the recognition unit position information,
Means for storing the first camera parameters obtained by performing calibration so that the coordinate system of the three-dimensional motion analysis matches the coordinate system of the force plate installed in the first space;
In the first space after the calibration in which the coordinate system of the three-dimensional motion analysis and the coordinate system of the force plate coincide with each other, the first plurality of camera images of the force plate installed in the first space and the first plate Means for storing the coordinates of the means for recognizing the force plate acquired using the camera parameters as a first coordinate value;
Using the second plurality of camera images of the force plate installed in the second space where the coordinate system of the three-dimensional motion analysis and the coordinate system of the force plate do not match, and the first camera parameter, Means for acquiring the coordinates of the means for recognizing the force plate as a second coordinate value;
Using the displacement information of the second coordinate value with respect to the first coordinate value acquired from the difference between the first coordinate value and the second coordinate value, a coordinate system for three-dimensional motion analysis in the second space is used as a force plate. Means to match the coordinate system of
A setting device for a 3D motion analysis system equipped with a force plate. Means for matching the coordinate system of the three-dimensional motion analysis with the coordinate system of the force plate,
The first camera parameter is set to a second value so that the coordinate value of the force plate recognition means calculated using the second plurality of camera images and the second camera parameter matches the first coordinate value. The apparatus according to claim 4, wherein the apparatus converts to camera parameters. It has multiple force plates,
The second camera parameter is acquired based on the first force plate,
When the second and subsequent force plates are at the first position in the force plate coordinate system, the position information of the second and subsequent force plates is used as the first position information, and the second and subsequent forces are displayed. Means for storing the coordinates of the plate recognition means as a first coordinate value;
Means for acquiring the coordinates of the recognition means of each of the second and subsequent force plates placed in the second space as the second coordinate value using the second camera parameter;
Wherein the displacement information to the second coordinate values from said first coordinate value of each force plate of the second and subsequent sheets based on the first position information, position information of each force plate of the second and subsequent sheets in the second space Means for obtaining
The apparatus of claim 5 comprising: The plurality of cameras is composed of a camera unit including a plurality of cameras mounted so as to be individually adjustable in direction and one or a plurality of visible light emitting units mounted so as to be adjusted in direction.
Wherein the force plate, Ri Ah provided with a visible light targets that are emitted from the visible light emitting portion,
Prior to calibration in the first space, visible light emitted from one or more visible light emitting units in a state determined by adjusting the direction of each camera so as to photograph the space including the force plate. Determine the direction of the visible light emitting portion so that the target of the force plate is hit, and prior to photographing the force plate in the second space, one or more visible light emitting portions are applied to the target of the force plate. The camera unit is positioned so that the visible light emitted from
The apparatus according to any one of claims 4 to 6.   The apparatus according to claim 7, wherein the target is provided on a plate cover that is detachably attached to the force plate.   The apparatus according to any one of claims 4 to 8, wherein the recognition means is provided on a plate cover that is detachably attached to the force plate. A plurality of cameras in which the distance between cameras and the direction of each camera are determined;
Recognizing means provided on the force plate and capable of detecting position information by image processing using a camera image, wherein the recognizing means can identify the position of the force plate from the recognizing means position information ;
In the first space in which the coordinate system of the three-dimensional motion analysis and the coordinate system of the force plate coincide, when the force plate is at the first position of the force plate coordinate system, the position information of the force plate is first Means for storing the coordinates of the means for recognizing the force plate as the first coordinate value,
Means for acquiring, as a second coordinate value, the coordinates of the means for recognizing the force plate in a second space in which the coordinate system of the three-dimensional motion analysis and the coordinate system of the force plate coincide with each other;
The force in the second space based on displacement information from the first coordinate value to the second coordinate value obtained from a difference between the first coordinate value and the second coordinate value and the first position information. Means for obtaining second position information of the plate;
A setting device for a 3D motion analysis system equipped with a force plate.   The apparatus according to claim 10, wherein the recognition means is provided on a plate cover that is detachably attached to the force plate. In the setting of a three-dimensional motion analysis system equipped with a force plate, a method of matching the coordinate system of the three-dimensional motion analysis with the coordinate system of the force plate,
The three-dimensional motion analysis system includes a plurality of cameras in which a distance between cameras and a direction of each camera are determined,
The force plate is a recognition unit capable of detecting position information by image processing using a camera image, and is provided with a recognition unit capable of specifying the position of the force plate from the recognition unit position information .
The first camera parameter is acquired and stored by performing calibration so that the coordinate system of the three-dimensional motion analysis matches the coordinate system of the force plate installed in the first space,
In the first space after the calibration in which the coordinate system of the three-dimensional motion analysis and the coordinate system of the force plate coincide with each other, the first plurality of camera images of the force plate installed in the first space and the first plate Using the camera parameters, the coordinates of the force plate recognition means are acquired and stored as first coordinate values,
Using the second plurality of camera images of the force plate installed in the second space where the coordinate system of the three-dimensional motion analysis and the coordinate system of the force plate do not match, and the first camera parameter, The coordinate of the recognition means of the force plate is acquired as the second coordinate value,
Using the displacement information of the first coordinate value obtained from the difference of the second coordinate value and the first coordinate values and the second coordinate value, in the second space, the coordinate system of the three-dimensional motion analysis Force Match the coordinate system of the plate,
Setting method of 3D motion analysis system with force plate. The step of matching the coordinate system of the three-dimensional motion analysis with the coordinate system of the force plate includes:
The first camera parameter is set to a second value so that the coordinate value of the force plate recognition means calculated using the second plurality of camera images and the second camera parameter matches the first coordinate value. 13. A method according to claim 12, wherein the method converts to camera parameters. In the second space, a plurality of force plates are installed,
The second camera parameter is acquired based on the first force plate,
When the second and subsequent force plates are at the first position in the force plate coordinate system, the position information of the second and subsequent force plates is the first position information, and the second and subsequent force plates are the first position information. The coordinates of the plate recognition means are stored as the first coordinate value,
The coordinates of the recognition means of the second and subsequent force plates are acquired as second coordinate values using the second camera parameter,
Based on the displacement information from the first coordinate value to the second coordinate value of the second and subsequent force plate recognition means and the first position information, the second and subsequent forces in the second coordinate system. The method according to claim 13, wherein the position information of the plate is obtained. The plurality of cameras is composed of a camera unit including a plurality of cameras mounted so as to be individually adjustable in direction and one or a plurality of visible light emitting units mounted so as to be adjusted in direction.
The force plate is provided with a target of visible light emitted from the one or more visible light emitting parts,
Prior to calibration in the first space, visible light emitted from one or more visible light emitting units in a state determined by adjusting the direction of each camera so as to photograph the space including the force plate. Determine the direction of the visible light emitting portion so that the target hits the target of the force plate,
The camera unit is positioned so that visible light emitted from one or a plurality of visible light emitting units hits a target of the force plate prior to imaging of the force plate in the second space. The method of any one of -14. In the setting of a three-dimensional motion analysis system equipped with a force plate, a method for automatically setting the position information of the force plate,
The three-dimensional motion analysis system includes a plurality of cameras in which a distance between cameras and a direction of each camera are determined,
The force plate is a recognition unit capable of detecting position information by image processing using a camera image, and is provided with a recognition unit capable of specifying the position of the force plate from the recognition unit position information .
In the first space where the coordinate system of the three-dimensional motion analysis and the coordinate system of the force plate coincide with each other, when the force plate is at the first position of the force plate coordinate system, the position information of the force plate is the first. As the position information, the coordinates of the recognition means of the force plate are stored as the first coordinate value,
In the second space where the coordinate system of the three-dimensional motion analysis and the coordinate system of the force plate coincide with each other, the coordinates of the recognition means of the force plate are acquired as second coordinate values,
Based on the displacement information from the first coordinate value to the second coordinate value acquired from the difference between the first coordinate value and the second coordinate value and the first position information, the force plate in the second space By acquiring the second position information, the position information of the force plate in the second space is automatically set.
Setting method of 3D motion analysis system with force plate.   The step of matching the coordinate system of the three-dimensional motion analysis with the coordinate system of the force plate is performed before obtaining the second coordinate value of the force plate recognition means in the second space. The method described.