JPH0797295B2 - Target tracking system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Object of the Invention 1) Field of Industrial Application The present invention relates to a target tracking system for tracking (detecting) a displacement of a target which is displaced within a predetermined spatial region.

Such a target tracking system can be used for tracking the displacement of the target mounted on the head of the manipulator operator or the head-up display user.

2) Conventional technology Conventionally, when performing work in a nuclear reactor or in an unsanitary working environment,
A manipulator is used. This manipulator is composed of a work manipulator arranged in a work environment isolated by a shield wall or a shield window, and an operation manipulator arranged in an operation room. And
The operator of the manipulator is provided with visual information imaged by the imaging camera on the side of the manipulator for work (reference example, Japanese Patent Laid-Open No. 61-209889).

As described above, the visual information is given to the manipulator operator by displacing the imaging camera in accordance with the displacement of the operator's head (positional displacement and rotational angle displacement). (A feeling that the operator is actually operating on the spot) can be given. For that purpose, it is necessary to track the displacement (movement) of the operator's head at high speed.

As a method for tracking the displacement of the head, a mechanical method using a mechanical link mechanism, a magnetic method that uses a change in the surrounding magnetic field accompanying the movement of the head by attaching a device that generates a magnetic field to the head There is an optical system in which a target attached to a person's head is imaged by a plurality of cameras and image data is processed.

3) Problem to be Solved by the Invention However, the mechanical system is not comfortable because it gives the operator a feeling of wearing. Further, the magnetic type is easily influenced by environmental conditions, and the conventional optical type requires a long time to process the image data. Therefore, it is possible to detect displacements in three orthogonal directions and angular displacements around the axes at high speed. Was difficult.

In view of the above circumstances, it is an object of the present invention to make it possible to track the displacement of the operator's head at high speed without giving the operator a feeling of wearing, being less susceptible to environmental conditions.

B. Configuration of the Invention 1) Means for Solving the Problems In order to solve the above problems, the target tracking system of the present invention includes a target that is displaced within a predetermined space region, and a target that is placed in the field of view. And a head motion calculation unit that calculates displacements of the target in the directions of three axes orthogonal to each other and angular displacements around these axes from the image data of the target captured by the plurality of imaging units. In a target tracking system provided with, an angular displacement sensor for directly detecting an angular displacement of a target around two predetermined axes among the three axes is fixed to the target,
The target tracking system is characterized in that only the angular displacement about one axis other than the predetermined two axes is calculated by the head motion calculation unit.

2) Operation In the target tracking system of the present invention having the above-mentioned characteristics, since the angular displacement around the predetermined two axes is detected by the angular displacement sensor fixed to the target, the angular displacement around the predetermined two axes is detected. Need not be obtained by image data processing. For this reason, the time required for image data processing is shortened, and the displacement of the target can be detected at high speed.

3) Examples Hereinafter, examples of the present invention will be described with reference to the drawings.

FIG. 1 is an overall view of the target tracking system of the present invention, and FIG. 2 is a functional explanatory view of the system.

In FIG. 1, a helmet H is attached to the head of an operator M of a manipulator (not shown), and a target T is attached to the helmet H. The target T has a rod-shaped portion extending in the front-rear direction (X-axis direction), and a detection point T composed of a light emitting diode at the front-rear end thereof.
1, T2 are provided. Further, inside the target T, a biaxial gimbal mechanism and an angular displacement sensor S1 (see FIG. 2) for detecting angular displacement around the axes thereof are incorporated. The angular displacement sensor S1 includes a sensor (not shown) for detecting an angle signal (that is, roll angular displacement φ) around the X axis (roll axis) and a sensor for detecting the Y axis (pitch axis, that is, the axis in the left-right direction). A sensor (not shown) for detecting the angle signal (that is, the pitch displacement θ). The pitch / roll displacement processing unit S2 amplifies the angle signals θ and φ to appropriate magnitudes and outputs the pitch angle displacement θ and roll angle displacement φ of the target T.

In FIG. 1, detection points T1 and T of the target T are shown.
The CCD cameras A and B that capture the image of 2 are arranged apart in the X-axis direction. The image data obtained by these CCD cameras is input to the head motion calculation unit S3. The head motion calculation section S3 calculates X from the captured image data.
Displacement X, Y and Z along the axis, Y axis and Z axis (vertical axis)
And yaw displacement ψ are calculated.

As mentioned above, the coordinate system (X, Y, Z coordinate system) of the space where the object is placed from the image data obtained by the two imaging cameras.
The technique for calculating the displacement of the target in (1) is conventionally known, and is also described in, for example, "Modern Automatic Control Sosho 10, Robotics" (First Edition, 1977, Corona Publishing, P94-97). Therefore, the initial value (value at time t = 0) of the coordinates of the detection points T1, T2 of the target T and the value at time t = t can be calculated. The yaw displacement ψ is t = when the map of the line segment connecting the detection points T1 and T2 of the target T on the XY plane is t = 0.
It is represented by how much it is rotating at t.
Therefore, the yaw displacement ψ can be calculated from the coordinates of the detection points T1 and T2 of the target T.

Next, the operation of the above embodiment will be described.

As shown in FIG. 2, the angle signal (θ, φ) detected by the angular displacement sensor S1 is amplified to an appropriate magnitude by the pitch / roll displacement processing unit S2 and output as pitch displacement θ and roll displacement φ. It On the other hand, the initial positions of the detection points T1 and T2 of the target T imaged by the CCD cameras A and B (t = 0
Position P1 and P2 are displaced to P1 'and P2' at time t = t, the head motion calculation unit S3 performs three-dimensional coordinate calculation to detect the detection point T of the target T.
The coordinates of the positions P1, P2, P1 ', P2' of 1, T2 are calculated. It is assumed that the positions P1, P2, P1 ', P2' are as follows.

P1 (X1, Y1, Z1), P2 (X2, Y2, Z2), P1 '(X1', Y1 ', Z1'), P2 '(X2', Y2 ', Z2'), these detection points T1, From the coordinates of the positions P1, P2, P1 ', P2' of T2, the displacements X, Y, Z in the X, Y, Z directions of the positions intermediate the detection points T1, T2 of the target T (that is, the positions of the target T). Is calculated by the following formula.

Also, a line segment connecting the positions P1 and P2 of the detection points T1 and T2
The angle formed by the mapping on the XY plane and the mapping on the XY plane of the line segment connecting P1 'and P2' is the yaw displacement.
It is calculated from the coordinates of the positions P1, P2, P1 ', P2' of T1, T2.

Therefore, in this embodiment, the X, Y, Z displacement and the yaw displacement can be detected by processing the image data obtained by imaging the two detection points T1, T2 of the target T.

By the way, when both the CCD cameras A and B and the detection points T1 and T2 of the target T are arranged in the X-axis direction as in the above embodiment, a line segment connecting P1 and P2 and a line segment connecting P1 ′ and P2 ′ are provided. Although the length of the map on the XY plane is long, the calculation accuracy of the yaw displacement ψ is sufficient, but the length of the map on the YZ plane is small, so it is difficult or impossible to calculate the roll displacement. Be accurate. Further, if the arrangement directions of the CCD cameras A and B and the target T are changed, the pitch displacement will be inconveniently calculated. Therefore, all the displacements (X, Y, Z,
In order to calculate (θ, φ, ψ) with high accuracy, detection points T1 and T2 and detection points T3 and T4 orthogonal to the line segment connecting these T1 and T2 are provided on the target T, and this detection point T3,
It is necessary to calculate X, Y, Z displacements for T4 as well.

However, in this case, since the number of detection points is doubled, the processing time of image data is doubled, and high-speed processing becomes difficult.

From the above description, the optical target tracking system using the image pickup means can be classified into three types,
The advantages and disadvantages are as shown in the table in FIG. In the table of FIG. 4, Δ indicates that there is a problem.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the claims. Is possible.

For example, the present invention can be used for tracking a target other than the target mounted on the head of the manipulator operator. It is also possible to dispose the two image pickup means apart from each other in the axial direction other than the X-axis (front-rear axis) direction. In that case, the angular displacement directly detected by the angular displacement sensor can be a displacement other than the yaw displacement. Furthermore, it is also possible to adopt an imaging means other than the CCD camera.

C. Effect of the Invention In the target tracking system of the present invention described above,
Since the angular displacement around the predetermined axis is detected by the angular displacement sensor, it is not necessary to obtain the angular displacement around the predetermined axis by image data processing. For this reason, the time required for image data processing is shortened, and the displacement of the target can be detected at high speed.

Moreover, unlike a mechanical tracking system using a link, it does not give an uncomfortable feeling to the operator, and unlike a magnetic system, it does not depend on environmental conditions.

[Brief description of drawings]

FIG. 1 is an overall view of a target tracking system of the present invention, FIG. 2 is a functional explanatory view of the system, FIG. 3 is a functional explanatory view of a conventional system, and FIG. 4 is an embodiment of the present invention and a conventional example. 9 is a table for explaining a difference in function. A, B ... Imaging means (CCD camera), S1 ... Angular displacement sensor,
S3: Head motion calculation unit, T: Target,

Claims (1)

[Claims] 1. A target displacing within a predetermined spatial region, a plurality of image pickup means arranged so that the target is in the field of view, and image data of the target taken by the plurality of image pickup means, In a target tracking system including a head motion calculation unit that calculates displacements in three axial directions orthogonal to each other and angular displacements around those axes, the angular displacement of a target around predetermined two axes among the three axes is directly measured. An angular displacement sensor to detect is fixed to the target,
The target tracking system is characterized in that only the angular displacement about one axis other than the predetermined two axes is calculated by the head motion calculation unit.