JPH0636324B2 - Spotlight automatic tracking device - Google Patents

Description

The present invention relates to a device for automatically tracking the movement of an actor by a spotlight projected onto the actor on the stage of a theater or on the stage of various halls. It is a thing.

(Prior art and its problems) As a conventional automatic tracking device of this type, a wireless transmission means (ultrasonic wave or ultra-short wave transmitter) is provided on the irradiation target side and movement of this spotlight on the spotlight side is performed. Two or more wireless receiving means which are oscillated in synchronization and arranged on a plane perpendicular to the optical axis of the spotlight (one or a plurality of pairs arranged symmetrically to the optical axis or an axis parallel to the optical axis). Ultrasonic wave or ultra-high frequency wave receiver) is provided, and the difference between the signal amounts of the received signals between the respective radio receiving means (each pair of receivers) is detected by comparison, until the difference between these mutual signal amounts becomes zero. Japanese Patent Publication No. 62-20678 proposes a spotlight control device for controlling the swinging drive device of the spotlight in the receiver arrangement direction for each pair.

However, in the above-mentioned spotlight control device, the ultrasonic detector is synchronized with the movement of the spotlight (specifically, the spotlight is placed at a substantially symmetrical position at least vertically and horizontally about the optical axis of the spotlight. Swing together with multiple pairs fixed. Then, the difference in the amount of signals received by the ultrasonic detectors forming each pair (specifically, the difference in arrival time) is detected, and vertical and horizontal swing control is performed so that the difference becomes zero. It is a thing. That is, the device detects the relative direction between the detection direction of the moving object and the irradiation direction of the spotlight as viewed from the position of the spotlight, and controls so that the difference between the vertical and horizontal directions becomes zero. It is technically difficult to accurately capture and irradiate a moving object for the following reasons.

Since the ultrasonic detector of this device swings in synchronism with the movement of the spotlight, it is considered that the maximum practical distance between the pair of detectors attached to the spotlight is about 1 m. On the other hand, the distance from the spotlight to the moving object is generally 20m to 50m, so
The triangle formed by the individual detectors is a substantially acute-angled isosceles triangle, and it is technically extremely difficult to accurately detect the distance difference between the two sides, which leads to a decrease in the accuracy of automatic tracking.

Furthermore, when performing automatic tracking in the vertical and horizontal directions with the device,
It is necessary to provide at least two sets of four ultrasonic wave detectors, and there is a problem that a drive mechanism for swinging the detectors and spotlights integrally is required.

Further, in Japanese Examined Patent Publication No. 55-25681, a receiver having an electromagnetic wave, a light wave, a sound wave, etc. as a medium is fixedly installed in the vicinity of the illumination lamp or the illumination lamp, the position information of the transmitter is detected, and There has been proposed a medical shadowless illumination device that changes the condensing position of an illumination lamp in a direction that eliminates the difference from the position information indicating the condensing position. However, what is described as an example is that the incident direction of the light wave to the two pairs of light receivers in the horizontal axis direction X and the vertical axis direction Y of the illuminating lamp is determined by utilizing the straightness of the light wave. The position of the transmitter including the height direction Z is detected, and visible light cannot be used as a transmitter on the theater stage or the stages of various halls. Since there are many strong infrared rays, it is extremely difficult in practice to identify and detect modulated infrared rays.

Further, in Japanese Patent Laid-Open No. 52-39982, the horizontal axis direction X of the lamp is indicated.
Ultrasonic receivers are fixedly installed at both ends in the vertical axis direction Y, and the phase difference between the two points in the X-axis direction and the Y-axis direction is detected, the motor is rotated, and the light is collected by the gyro system. There has been proposed a light concentrating device for an operating lamp that operates a single point.

However, in the above device, position detection is performed by phase difference detection by a pair of receivers in the X and Y directions, and if the height at which the transmitter is placed is constant, the position on the plane can be determined, but the concept of distance calculation No, it cannot handle three-dimensional movement.

Further, the former two prior arts regarding the fixed installation of the detector are both integrated with an illumination lamp or arranged in the vicinity of the illumination lamp to detect a small movement of the irradiated object, which is considerable. It is difficult to accurately determine the absolute position of a moving object (actor) that moves three-dimensionally over a wide range, and it is necessary to provide four ultrasonic detectors in two sets.

(Object of the Invention) In view of the above-mentioned conventional circumstances, an object of the present invention is to provide a device capable of accurately determining the absolute position of a moving object and automatically tracking the moving object with a relatively simple system configuration.

(Structure of the Invention) The technical means taken by the present invention to achieve the above object is an ultrasonic transmitter that generates ultrasonic waves at regular intervals by a clock oscillator that holds a spotlight on a moving object that is irradiated, At least three or more ultrasonic wave detectors installed and fixed on a wall surface, a ceiling surface, etc. in a space where a moving object can be tracked, and two or more ultrasonic wave detectors are configured as one set, and the detectors of each set are formed. A time difference detector that detects the difference in arrival time of ultrasonic waves between each other and a calculator that calculates the distance from the detector to the moving object from the time difference between each detector, and the irradiation direction of the spotlight is controlled by the output of the calculator And a control device for

The clock oscillator of the ultrasonic oscillator is a crystal oscillator or the like having an extremely stable oscillation frequency.

In addition, it is desirable that the above-mentioned at least three ultrasonic detectors are installed near a large equilateral triangle in order to track a moving object. For example, in the case of a theater or a hall, the vicinity of the wall on both sides of the audience seats is desirable. You can choose one place for each and three places near the center of the ceiling surface. In the case of a banquet hall or TV studio, you can choose three corners (or four corners) of the ceiling, or two corners of the ceiling and the center of the opposite side. Is mentioned.

(Operation) According to the above configuration, ultrasonic waves are generated at regular intervals by the clock oscillator from the ultrasonic transmitter held by the moving object, and the ultrasonic waves are detected by the plurality of ultrasonic detectors.
The time difference detector detects the arrival time difference of the ultrasonic reception signals between the detectors which are set as a set.

This time difference signal is input to an arithmetic unit including a computer. Here, since the distance between the ultrasonic detectors for which the arrival time difference is obtained is known in the measurement at the time of installation, the relational position between the moving object and the plurality of ultrasonic detectors is calculated by the calculator, The position (absolute position) is fixed. This position signal is guided to the motor control device of the spotlight, and the error from the current light projection direction is corrected by constantly rotating the motor to the left or right to perform automatic tracking of the moving object.

Incidentally, in the case of automatically tracking a plurality of moving objects individually with two or more spotlights, it is possible by a measure such as setting the oscillation frequency of ultrasonic waves for each moving object.

(Example) Hereinafter, the Example of this invention is described based on drawing.

FIG. 1 shows a state in which this device is installed in a theater.
Is a theater, 2 is a stage, 3 is a moving object that is tracked by spotlight projection, 4 is an ultrasonic source, 5 is a spotlight projection surface, 6, 7 and 8 are ultrasonic detectors, 9 is a spot A light controller, 10 is a spotlight whose irradiation direction is controlled by the output of the controller 9.

It is assumed that the moving object 3, the ultrasonic detectors 6, 7, 8 and the spotlight 10 are arranged on the same plane for simplification of description.

As shown in FIG. 2, the ultrasonic wave source 4 held by the moving object 3 in a portable manner is an ultrasonic wave oscillator 11, a clock oscillator 12, and a control means 13.
And an ultrasonic speaker 19, and the output of the ultrasonic oscillator 11 is transmitted from the ultrasonic speaker 19 when the control means 13 is turned on and off by the output of the clock oscillator 12.

As the clock oscillator 12, a crystal oscillator having a stable oscillation frequency is used.

The control device 9 for controlling the spotlight 10 on the basis of the ultrasonic signals detected by the ultrasonic detectors 6, 7, and 8 whose absolute position has been determined includes a time difference detector 14, 15, 16 and a calculator 17 including a computer. , And the motor control device 18, and the ultrasonic signal detectors 6 and 7, the ultrasonic detectors 7 and 8, and the ultrasonic detectors 8 and 6 each have a difference in arrival time of ultrasonic signals, which is a time difference detector. Detected at 14, 15 and 16, and the time difference signal is introduced into the calculator 17. That is, as shown in FIG. 4, arrival of the ultrasonic signal (C) of the ultrasonic detector 6, the ultrasonic signal (D) of the ultrasonic detector 7, and the ultrasonic signal (E) of the ultrasonic detector 8 arrives. time difference _{(t 1 -t 2), (} t 2 -t 3), detects and outputs the _(t3-t 1).

The calculator 17 includes arrival time differences (t ₁ −t ₂ ), (t ₂ −t ₃ ), (t ₃ ) in a set of two ultrasonic detectors 6, 7, and 8.
-T ₁ ) is input.

Motor control device for controlling the light projection direction of the spotlight 10
Reference numeral 18 controls the horizontal rotation of the motor M ₁ directly connected to the rotation shaft 10 ′ of the spotlight 10 and the vertical rotation of the motor M ₂ directly connected to the support shaft for vertically rotating the spotlight 10. , The potentiometer PT ₁ directly connected to the rotary shaft of the spotlight 10 and the potentiometer PT ₂ attached to the support shaft detect the current light projecting direction (optical axis) and are fed back to the motor control device 18 as the current position, and the calculator 17
The optical axis of the spotlight 10 is controlled so as to come to the position specified by, and the spotlight 10 automatically moves so as to track the moving object 3.

With the above configuration, the distance L ₄ between the ultrasonic source 4 and the ultrasonic detector 6 held by the moving object 3 shown in FIG. 1 and the distance between the ultrasonic source 4 and the ultrasonic detector 7 of the moving object 3 are shown. The difference in distance from L ₅ can be obtained by the following equation.

L ₄ −L ₅ = V (t ₁ −t ₂ ), where V is the velocity of the ultrasonic wave, and (t ₁ −t ₂ ) is the arrival time difference of the received signal between the ultrasonic detectors 6 and 7 described above. is there.

The above-mentioned curves with a constant difference in distance are the ultrasonic detectors 6, 7
It becomes a hyperbola whose pole is, and it can be seen that the moving object 3 is on this line. Similarly, the difference in distance between the moving object 3 and the ultrasonic detector 7 and the distance between the moving object 3 and the ultrasonic detector 8 is: L ₅ −L ₆ = V (t ₂ −t ₃ ). The difference in distance between the ultrasonic wave detector 8 and the moving object 3 and the ultrasonic wave detector 6 is L ₆ −L ₄ = V (t ₃ −t ₁ ), which can be expressed as different hyperbolas, and the moving object 3 can be represented as an intersection thereof. The position of can be specified.

The position signal of the moving object 3 is input to the motor control device 18 to control the rotations of the motors M ₁ and M _{2 so} that the moving object 3 is track-irradiated.

FIG. 4 shows a waveform diagram. (A) is an output waveform of the clock oscillator 12 carried by a moving object, (B) is an ultrasonic speaker 19
From the ultrasonic wave, (C) the ultrasonic signal detected by the ultrasonic detector 6, (D) the ultrasonic signal detected by the ultrasonic detector 7, (E) detected by the ultrasonic detector 8. It is the ultrasonic signal.

The ultrasonic signals received by the ultrasonic detectors 6, 7, and 8 include ultrasonic waves reflected from the wall surface, ceiling surface, etc. in addition to the ultrasonic waves directly reaching the detectors 6, 7, and 8 from the ultrasonic speaker 19. Therefore, the reverberation signal is included as shown in FIGS. 4 (C), (D) and (E).

However, since the arrival time of the reflected wave reflected by the wall surface, the ceiling surface, etc. is delayed as compared with the direct wave, FIG. 4 (C), (D), (E)
The ultrasonic signal at the rising edge of can be considered as a direct wave,
By measuring the difference between the clock signal and the rising time, the distance can be measured with a small error.

In the above description, the moving object 3, the ultrasonic detectors 6, 7, 8 and the spotlight 10 are arranged on the same plane, but in reality, a large staircase is used on the stage for the purpose of producing effects. May be placed on the stairs, and the spotlight generally tracks the performer from the rear part of the second-floor seat, and is placed on the same plane as described above. There is no such thing.

Therefore, the tracking spotlight is often impractical unless it is controlled not only in the horizontal direction on the horizontal plane but also in the vertical direction on the vertical plane.

Therefore, one rotating hyperboloid is generated by the time difference between the ultrasonic detectors 6 and 7, one rotating hyperboloid is generated by the time difference between the ultrasonic detectors 7 and 8, and one rotating hyperboloid is further generated by the time difference between the ultrasonic detectors 8 and 6. And the position of the moving object 3 is specified as the intersection of these three rotating hyperboloids.

And as described above, is identified location of the mobile object 3, it operates the motor controller 18 at the output of the position signal, the control motor M ₁ in the horizontal direction _and each direction control control motor M ₂ in the vertical direction You can

In the above description, the control of the spotlight that irradiates the moving object is performed in the horizontal direction and the vertical direction. However, in some cases, the focus adjustment of the spotlight must be actually performed. In this case also, since the position of the actor, which is a moving object on the stage, has been determined, it is possible to calculate and determine the distance from the spotlight to the actor,
Therefore, it is easy to automatically adjust the focus by operating the motor.

(Advantages of the Invention) As described in detail above, the spotlight automatic tracking device according to the present invention includes an ultrasonic transmitter that generates ultrasonic waves at regular intervals by a clock oscillator that holds a moving object illuminated by the spotlight, At least three or more ultrasonic detectors installed and fixed on a wall surface or ceiling surface in a space where an object can be tracked, and two or more ultrasonic detectors are configured as one set, and the detectors of each set are mutually connected. The time difference detector that detects the arrival time difference of the ultrasonic waves in and the calculator that calculates the distance from the detector to the moving object from the time difference between the detectors, and the irradiation direction of the spotlight is controlled by the output of the calculator. Since it is configured with a control device, the irradiation direction of the spotlight can be tracked by accurately grasping the position of the moving object as an absolute position in three dimensions. .

That is, to determine the position of a moving object, two pairs of the three detectors are paired to form three pairs of detection circuits, and the reception signal (clock signal of the oscillator) to the ultrasonic detector of each pair is formed. The distance difference between each detector and the moving object is calculated from the arrival time difference, and the position of the moving object is detected and determined as the intersection of the three rotating hyperboloids by the distance difference between the transmitter from the three pairs of detectors. A tracking device that is stable and can be put to practical use can be provided.

Since the concept of the above device detects the position of the moving object as a three-dimensional position according to the transmitter regardless of the position of the spotlight, it follows the simultaneous follow-up by a plurality of spotlights and the change of the irradiation distance. It also enables more advanced automatic tracking such as focus adjustment.

Furthermore, since at least three detectors can be installed anywhere in the installation space, it is possible to select a sufficiently large distance between the detectors, which is the base point of the distance difference calculation. Highly accurate position determination is possible regardless of the position, and since the position can be determined by three ultrasonic detectors, at least four detections are required when performing automatic tracking in the up / down / left / right directions in the conventional technology. It is economically beneficial to need a vessel.

[Brief description of drawings]

The drawings show an embodiment of the present invention, FIG. 1 is a plan view of the apparatus installed, FIG. 2 is a block diagram of an ultrasonic wave source to be carried by a moving object, and FIG. 3 is control for controlling a spotlight. A block diagram of the apparatus, FIG. 4 is a waveform diagram. In the figure, 3: moving object 4: ultrasonic source 6, 7, 8: ultrasonic detector 9: control device 10: spotlight 14,15, 16: time difference detector

Claims (1)

[Claims] 1. An ultrasonic transmitter that generates ultrasonic waves at regular intervals by a clock oscillator that holds a moving object illuminated by a spotlight, and is installed and fixed on a wall surface or ceiling surface in a space where the moving object can be tracked. At least three or more ultrasonic wave detectors, and a plurality of sets each including two detectors, and a time difference detector and each detector for detecting a difference in arrival time of ultrasonic waves between the detectors of each set An automatic tracking device for spotlights, comprising an arithmetic unit for calculating a distance from a detector to a moving object based on a time difference between the detectors and a control device for controlling an irradiation direction of the spotlight by an output of the arithmetic unit. .