JPH03286211A - Target tracking system - Google Patents

Abstract

PURPOSE:To quickly detect the displacement of a target, and to realize high- speed and correct target tracking by detecting angular displacement around the prescribed axis of three dimensional axes by an angular displacement sensor. CONSTITUTION:A helmet H is attached to the head part of the operator M of a manipulator, and the helmet H is provided with a rod-shaped target T extending toward the direction of X-axis, and detection points T1, T2 by an LED are arranged at both the ends of the target T, and each of the points T1, T2 is image-picked up by CCD cameras A, B. Then, three-dimensional coordinates varying together with time are computed by a head motion arithmetic part S3, and X, Y, Z-displacements and yaw angular displacement are determined. On the other hand, a biaxial gimbal mechanism and angle sensors to detect the angular displacement around its axes are arranged in the target T, and the angular displacements around X-axis of a rolling axis and Y-axis of a pitching axis are detected, and pitching angular displacement and rolling angular displacement are detected at high speed from a pitch/roll displacement processing part S2, and the high-speed and correct target tracking is executed on the basis of these detected results.

Description

DETAILED DESCRIPTION OF THE INVENTION A9 Object of the Invention 1> Industrial Application Field The present invention relates to a target tracking system for tracking (detecting) the displacement of a target displaced within a predetermined spatial region.

Such a target tracking system can be used to track the displacement of a target worn on the head of a manipulator operator, head-up display user, or the like.

2> Conventional technology Traditionally, when working inside a nuclear reactor or in an unsanitary working environment,
A manipulator is used. This manipulator consists of a working manipulator placed in a working environment isolated by a shielding wall or a shielding window, and an operating manipulator placed in an operation room. and,
The operator of the manipulator is provided with visual information captured by an imaging camera on the side of the working manipulator (reference example, Japanese Patent Application Laid-Open No. 61-209889).

A manipulator that provides visual information to the operator of the manipulator provides a sense of realism by displacing the imaging camera according to the displacement (positional displacement and rotational angle displacement) of the operator's head. (The feeling that the operator is actually operating the device on the spot) can be given.To achieve this, it is necessary to track the displacement (movement) of the operator's head at high speed.

Methods for tracking the displacement of the head include a mechanical type using a mechanical link mechanism; and a magnetic type 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 are also optical types that use multiple cameras to image a target attached to the operator's head and process the image data.

3> Problems to be Solved by the Invention However, the mechanical type gives the operator a feeling of wearing and is not comfortable, the magnetic type is easily affected by environmental conditions, and the conventional optical type is not comfortable. Since it takes time to process the image data, it has been difficult to detect displacements in three orthogonal axes directions and angular displacements around these axes at high speed.

In view of the above-mentioned circumstances, it is an object of the present invention to provide a device that does not give the operator a feeling of wearing it, is not easily influenced by environmental conditions, and can track the displacement of the operator's head at high speed.

B1 Structure of the Invention 1) Means for Solving the Problems In order to solve the problems described above, the target tracking system of the present invention includes a target that is displaced within a predetermined spatial area, and a system that is arranged to bring the target into view. a plurality of imaging means, and a head motion compensation unit that calculates displacements of the target in three mutually orthogonal axes directions and angular displacements around those axes from image data of the target taken by the plurality of imaging means. The target tracking system is characterized in that an angular displacement sensor that directly detects the angular displacement of the target around a predetermined axis among the three axes is provided.

2> Effect In the target tracking system of the present invention having the above-mentioned features, since the angular displacement around the predetermined axis is detected by the angular displacement sensor, it is necessary to calculate the angular displacement around the predetermined wheel by image data processing. disappears. Therefore, the time required for image data processing is shortened, so that the displacement of the target can be detected at high speed.

3) Examples Hereinafter, the present invention will be explained in detail with reference to the drawings.

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

This target T has a rod-shaped part extending in the front and back direction (X-axis direction), and has two rods at its front and rear ends. Angular displacement sensor Sl for detecting angular displacement
(See Figure 2) is built-in. This angular displacement sensor
1 detects an angular signal (i.e., roll angular displacement φ) around the X-axis (roll axis) and an angular signal (i.e., pitch displacement θ) around the Y-axis (pitch axis, i.e., left-right axis). The pitch/roll displacement processing section S2 amplifies the angle signals θ and φ to appropriate magnitudes and outputs the pitch angular displacement θ and the roll angular displacement φ of the target T.

In FIG. 1, a detection point T of the target T
CCD cameras A and B that image I and T2 are placed apart in the X-axis direction. Image data obtained by these CCD cameras is input to the head motion calculation section S3. The head motion calculation unit S3 calculates displacement X in the X-axis, Y-axis, and Z-axis (vertical axis) directions from the captured image data.

Y and Z are calculated, and yaw displacement ψ is also calculated.

As mentioned above, the technique of calculating the displacement of a target in the coordinate system (X, Y, Z coordinate system) of the space in which the object is placed from image data obtained by two imaging cameras is conventionally known. For example, "Modern Automatic Control Book 10, Robotics" first edition, 1978, published by Corona Publishing, p.94
~97) are also described. Therefore, the initial values of the coordinates of the detection points Tl and T2 of the target T (time 1 =
0> and the value when time 1=1 can be calculated. The yaw displacement ψ is expressed by how much the mapping on the XY plane of the line segment connecting the detection points T1 and T2 of the target T rotates when 1=1 compared to when 1=0. Therefore, the yaw displacement ψ can be calculated from the coordinates of the detection points TI and T2 of the target T.

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

As shown in FIG. 2, the angle signals (θ, φ) detected by the angular displacement sensor S1 are transmitted to the pitch/roll displacement processing section S2.
is amplified to an appropriate magnitude and output as pitch displacement θ and roll displacement φ. On the other hand, the initial positions (positions when t=0) PI and P2 of the detection points TI and T2 of the target T imaged by the CCD cameras A and B are time 1=
1, the head motion calculation unit S3 performs a three-dimensional coordinate calculation to determine the detection point TI of the target T and the position PI of T2.
.

P2. Calculate the coordinates of Pi' and P2'. Each of the positions PI, P2. Suppose that PI' and P2' are as follows.

PI (Xl, Yl, 21), P2 (X2.Y2, 22), PI'(XI',Yl',Zl'),P2' (X
2', Y2', X2'), these detection points TI, the positions of T2 Pi, P2゜PL', P2
From the coordinates of ', the detection point TI of the target T,
Displacement X, Y in the x, y, z directions of the intermediate position f of T2 (i.e. the position of the target T).

Z is calculated using the following formula.

Also, the positions PL of the detection points Tl and T2.

The angle between the mapping on the XY plane of the line segment connecting P2 and the mapping on the XY plane of the line segment connecting PL' and P2', that is, the yaw displacement, is the detection point Tl, the position PL of T2,
P2. It is calculated from the coordinates of PI' and P2'.

Therefore, in this embodiment, x, y, z displacements and yaw displacements can be detected by processing image data obtained by imaging the two detection points TI and T2 of the target T.

By the way, as in the above embodiment, the CCD camera A.

When detection points TI and T2 of B and target T are both placed in the X-axis direction, the length of the mapping on the XY plane of the line segment connecting PL and P2 and the line connecting PI'' and P2' is long, so the yaw Although the calculation accuracy of displacement ψ is sufficient,
Since the length of the mapping on the Yz plane is small, it is difficult to calculate the roll displacement, or even if it is possible to calculate it, it is inaccurate. In addition, CCD cameras A, B and target T
Changing the arrangement direction causes problems in calculating pitch displacement.

Therefore, all displacements (X, Y.

2, θ, φ, ψ) with high accuracy, detection points T1. T2 and this Tl, T2
Detection points T3 and T4 are provided which are orthogonal to the line segment connecting T3. It becomes necessary to calculate x, y, and z displacements for T4 as well.

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

From the above explanation, optical target tracking systems using imaging means can be classified into three types:
The advantages and disadvantages are shown in the table in Figure 4. In addition, 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 embodiments described above, and various design changes can be made without departing from the scope of the invention described in the claims. is possible.

For example, the present invention can be used to track targets other than targets mounted on the head of a manipulator operator. Furthermore, it is also possible to arrange the two imaging means apart from each other in an axial direction other than the X-axis (front-back axis) direction. In that case, the angular displacement directly detected by the angular displacement sensor may be a displacement other than the yaw displacement. Furthermore, it is also possible to employ imaging means other than a COD camera.

C0 Effects of the invention In the target tracking system of the invention described above,
Since the angular displacement around the predetermined axis is detected by the angular displacement sensor, there is no need to calculate the angular displacement around the predetermined axis by image data processing.

Therefore, the time required for image data processing is shortened, so that the displacement of the target can be detected at high speed.

Furthermore, unlike mechanical tracking systems using links, the tracking system does not give the operator an uncomfortable wearing feeling, and unlike magnetic tracking systems, it does not depend on environmental conditions.

[Brief explanation of drawings]

Fig. 1 is an overall diagram of the target tracking system of the present invention, Fig. 2 is a functional explanatory diagram 1 of the system, Fig. 3 is a functional explanatory diagram of a conventional system, and Fig. 4 is an illustration of an embodiment of the present invention and a conventional example. This is a table for explaining the differences in the functions. A, B...imaging means (CCD camera), Sl...angular displacement sensor, S3...head motion calculation unit, T.
··target,

Claims (1)

[Scope of Claims] A target that is displaced within a predetermined spatial region, a plurality of imaging means arranged so as to bring the target into view, and a target that is captured from image data of the target captured by the plurality of imaging means. In a target tracking system equipped with a head motion calculation unit that calculates displacement in three axes perpendicular to each other and angular displacement around these axes, the angular displacement of the target around a predetermined axis among the three axes is directly calculated. A target tracking system equipped with an angular displacement sensor for detection.