JPH01256498A - Wire winch - Google Patents

Abstract

PURPOSE:To shift the position of an object attached to a wire tip smoothly by making rotation of a motor follow that of a pulley so as to cause tension of a wire, which a takeup reel winds up, to the said pulley to become almost constant. CONSTITUTION:A wire being given load varying is wound and rewound by a motor 3 to a takeup reel 2 via a pulley a sheave 31A, pulleys 19, 9 and rails 6A, 6B, and pulleys 20, 22. Control over the motor 3 is performed by a first control circuit 4. The wire 1 installed in and around the reel 2 and the slipless pulley 6 are controlled of their rotational direction and speed at a second control circuit 8 by a second motor 7. An encoder 21 is connected to the pulley 20 and also connected to a console 5 through which operation is commanded to the control circuits 4, 8. Wires 41-43 are operated and controlled likewise. With this constitution, load 32 is smoothly shifted, so that this method is suitable for movements of a camera and a microphone in a studio.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a wire winch that is capable of controlling the length, speed, and tension with which wire is unwound from a take-up reel and subjected to varying loads.

The present invention is particularly suitable for use in a position control device that moves the position of a television camera suspended from four wires.

〔overview〕

The present invention is a wire winch that finely controls the distance and speed of the wire that is fed out from the take-up reel through computer control. By performing control to follow the rotation of the pulley, disturbances in control due to fluctuating loads applied to the wire are minimized.

[Conventional technology]

U.S. Patent Nos. 4.625.938 and 4.710
．． No. 819 (corresponding Japanese patent application JP 60-500551
(No. 1), the shooting position of the television camera was set by wire.
It is known that a winch is used for precise control. This device, as shown in Figure 5, is used to take television shots of stadiums, etc., with wires suspended from poles set up at the four corners of the stadium, and these wires are wound with a wire winch set near the ball. and the tip of each wire is 1
The structure is connected to the support means of each camera.

Wire winches for this purpose require delicate control over a wide range of speeds of the take-up reel that winds the wire, and are equipped with a control circuit including a computer for this control.

[Problem that the invention seeks to solve]

When using the above device, it was found that when used in a large area such as a stadium, large tension waves were generated in the wires suspending the camera. When this wave reached the wire winch, it shocked the take-up reel, causing the wire to become misaligned with the reel. Also, if you reverse the wire and put it back on a reel that is not properly aligned and wound, the overlapping wire on the reel will unravel and create new waves, which will have a negative impact on other wire winches. As well as
A phenomenon was observed where the camera was shaking unreasonably and the image was distorted.

When we investigated the cause of this problem, we found that the heavy weight of the take-up reel created inertia that made fine control impossible, and that to prevent this, we had to use an extremely large motor.

The present invention provides a wire winch and a wire winch that can suppress the waves generated in the wire without significantly increasing the size of the motor, and can control the movement of an object such as a camera connected to the wire without disturbance. The purpose of the present invention is to provide a position control device for a television camera.

[Means for solving problems]

In the present invention, there is provided a take-up reel for winding a wire to which a varying load is applied, a first motor for driving the take-up reel, a first control circuit for controlling the motor, and a winding and unwinding of the wire. A wire winch equipped with a first pulley that is provided near a take-up reel and in contact with the wire wound on the take-up reel with almost no slippage, and a load that changes the pulley. a second motor driven with a force greater than a set maximum value; and a second control circuit that controls the rotational direction and rotational speed of the second motor, and the operating means The first control circuit includes a control means for causing the rotation of the first motor to follow the pulley so that the tension of the wire wound by the take-up reel on the pulley is approximately constant. It is characterized by

A second pulley in contact with the wire is provided on the load side of the wire from the first pulley. A sensor may be provided to detect the load applied to the wire in response to the load.

Preferably, the output of the sensor is connected to the second control circuit as a wire load input.

The first pulley and the second motor are coupled by an elastic drive belt, and in addition to the rotational driving force provided by the second motor via the drive belt, the first pulley is A slipping clutch means may be coupled to provide a rotational driving force from the second motor at a rotational speed substantially greater than the rotational speed applied.

It is preferable to provide a movable guide arm that pulls the wire closer to the load side of the wire than the second pulley, and to provide a third pulley whose axial position is fixed and is rotatable between the guide arm and the second pulley. .

It can include a fourth pulley in contact with the wire between the first pulley and the take-up reel, and a take-up distance counting means for counting the rotation of the fourth pulley.

The first control circuit can include means for follow-up control so that the current flowing through the first motor is constant.

The applied invention of the present invention is provided with four wire winches, the ends of the wires of each wire winch are connected to one ring, and the ring is provided with a bracket for mounting the television camera. In the control device, the wire winch is the wire winch according to the present invention, and one operating means for supplying an operating signal to the second control circuit of each wire winch is provided in common for four devices. It is characterized by

[Effect]

In the present invention, the varying load applied from the wire is not received by the take-up reel, but by the first pulley provided in front of the take-up reel. In other words, a first pulley is provided around which the wire is wound a small number of times so that there is almost no slippage, and the tension associated with winding and unwinding of the wire is
It is controlled by a second motor connected to this first pulley. The first motor connected to the take-up reel is a small motor, and the rotation of the take-up reel is automatically controlled to follow the first pulley so that the small tension generated between it and the pulley remains constant. do.

In this state, the tension applied to the take-up reel is small and constant, so winding irregularities do not occur. Since the varying tension applied to the wire is driven and controlled by the first pulley with small inertia, even if the tension fluctuates frequently or in a large range, it can be finely controlled. The waves transmitted from the wire do not reach the take-up reel. Disturbances of the wire winch do not generate new waves.

This first pulley and the second motor that drives it are:
When coupled by a drive belt rather than an axial drive, the elasticity of the drive belt can absorb abnormal tension fluctuations coming from the wire and being transmitted to this pulley.

If a slipping clutch is used in addition to driving the drive belt, it is possible to control the belt so that an appropriate tension is always applied to the belt even if backlash occurs in the belt.

When we used this wire winch to control a television camera, we found that the control of each wire was extremely stable, and even if waves occurred, they were absorbed immediately, and there was almost no disturbance in the screen shot by the camera. Understood.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory diagram showing the constituent elements of one embodiment of the present invention. In this figure, for ease of explanation, parts that are not directly constituent elements of the present invention, such as the support frame and bearing parts, are shown. It is omitted.

FIG. 2 is an explanatory diagram of the operation and control of the above-mentioned embodiment, and shows some of the above-mentioned components separately.

In both figures, this embodiment shows a take-up reel 2 for winding the wire 1 to which a variable load is applied to the tip, and a reel shaft 2B to which the take-up reel 2 is inserted via a key 2A. a first motor 3 driven by a first motor 3, a first control circuit 4 that controls the rotational direction and rotational speed of the first motor, and a console desk that is an operating means for instructing winding and unwinding of the wire by operation. 5.

For example, as shown in FIG. 2, the tip of the wire 1 drawn out from this embodiment is attached to the suspension ring 32 of the television camera via a pulley means 31A provided at the top of the long pole 31. May be installed. Attached to this suspension ring 32 are three wires 41, 42, 43 drawn from three other wire winches (not shown). According to the instructions of this hanging ring and the console desk, for example, when the wire 1 is approached, the wire 1 is pulled in and the wires 41, 42, and 43 are pulled out. In order to prevent the suspension ring from shaking as much as possible during this operation, the tension in each wire must be balanced. In such a case, the tension of the wire, ie, the load on the wire, will constantly fluctuate.

Here, the feature of the present invention is that, in the above-mentioned wire winch, the two rails 6A and 6B are provided near the take-up reel 2 and are connected to the wire 1 wound on the take-up reel with almost no slippage. a drive pulley 6 which is a first pulley in contact with the drive pulley 6; a second motor 7 which drives the drive pulley 6 with a force greater than the set maximum value of the varying load of the wire 1; The console desk 5, which is an operating means, is connected to the second control circuit 8, and the first control circuit 4 is connected to the take-up reel 2. The purpose is to cause the rotation of the first motor 3 to follow the drive pulley 6 so that the tension on the drive pulley 6 of the wire wound by the motor is approximately constant.

Furthermore, the wire 1 of the drive pulley 6 which is the first pulley
A load measuring pulley 9, which is a second pulley in contact with the wire 1, is provided on the load side (suspension ring 32 side), and this load measuring pulley 9 is slightly movable in a direction perpendicular to its rotation axis 9A. Thus, the rotating shaft 9A is rotatably supported by the swinging arm 10, and the swinging arm 10 is rotatably supported by the shaft 10A.

The wire 1 has a center angle of 180 with respect to this load measuring pulley 9.
Since the two wires are in contact with each other at an angle of at least .degree., the amount of movement of the rotating shaft 9A is proportional to the load applied to the wire 1. swinging arms 10
Since the swing arm 10 also moves together with the rotating shaft 9A, the load on the wire 1 is detected by providing a pressure sensor 11 on the swinging arm 10, and its output signal is connected to be input to the second control circuit 8.

Drive pulley 6, which is the first pulley, and second motor 7
is dynamically coupled by an elastic drive belt 14 driven by a drive roller 12 and three idle rollers 13A, 13B, and 13C, and transmits the rotational driving force of the second motor 7 to the drive pulley 6. . That is, as shown in FIG. 2, the drive roller and the idle roller press the drive belt 14 against the drive pulley 6 with the wire 1 in contact with its rails 6A and 6B sandwiched therebetween. On the other hand, rotational driving force is transmitted to the shaft 12A of the drive roller 12 from the shaft 7A of the second motor 7 via the bell 7B. Further, the wire 1 is correctly distributed to the rails 6A, 6B of the drive pulley 6 by the diagonal pulley 15, and the surface of the drive belt 14 in contact with this is lined with polyurethane resin. Therefore, the drive belt 14 accurately transmits the rotational driving force of the second motor 7 to the drive pulley 6 and the wire portion in contact with the drive pulley 6. Although not shown in FIGS. 1 and 2 for simplification, the inner surface of the drive belt 14 actually consists of a rack-shaped protrusion, and the drive roller and idle roller are gears that mesh with this protrusion, respectively. It has a shape.

The second motor 7 is an AC servo motor using a pulse width control method using a sine wave, and as shown in FIG. The direction and speed of rotation are controlled by the comparison voltage value output from the motor.

In accordance with the output of the pressure sensor 11, the second control circuit 8 sets the tension of the wire to a reference voltage (V ref
This is a circuit that is automatically controlled to follow , ). That is, the input of the pressure sensor 11 and the reference voltage are input to a comparator circuit 8A, and the comparison output is amplified by an amplifier 8B, and is applied as a control input to a pulse width control circuit 8D via a low-frequency filter 8C. A power supply terminal 8E is connected to this pulse width control circuit 8D, and the current of this power supply terminal 8E is supplied to the second motor 7 while controlling the pulse width.

The reference voltage (Vref+) is given from the console desk 5. That is, the console desk 5 is coated with one gold film for each of the four wire winches, and is connected to each via the connection terminal 5A.

The console desk 5 has a computer processor 5B.
, a memory circuit C is mounted, and the four wire winches are controlled by a keyboard 5E and two sets of joysticks 5F connected via an interface 5D.

One of the joysticks 5F operates the suspension ring of the television camera tied to the tip of the wire to move in a desired direction, and the other controls the height of the television camera above the ground.

A display section 5G is provided near the console desk 5.

By operating the keyboard, the display section 5G switches to display the currently photographed screen, a graphic screen showing the position of the camera on the plan view of the stadium, and a graphic ink screen showing the height of the camera as seen from the side. Second
Reference numeral 5H shown in the figure is a desk portion for controlling the direction of the lens of the television camera and the zoom depth.

Furthermore, in this embodiment, the shaft 6C of the drive pulley 6 and the shaft 12A of the drive roller 12 are coupled to transmit rotational driving force via a coaxial slip clutch 16 provided on the shaft 12A and a belt 16A. has been done.

This is because if the direction of the load on the wire suddenly changes, backlash may occur in the drive belt 14 due to its elasticity, and the rotational driving force may not be transmitted correctly to the drive pulley 6. In such a case, the slip clutch 16 directly drives the shaft 6C of the drive pulley 6. This prevents the wire between the take-up reel 2 and the drive pulley 6 from becoming slack.

Further, a guide arm 18 equipped with a pole guide 17 for pulling in the wire 1 is provided on the load side of the wire 1 of the load measuring pulley 9, which is the second pulley, that is, on the wire pulling side of the wire winch. A guide pulley 19 that is a third pulley for guiding the wire is provided between the load measuring pulley 9 and the load measuring pulley 9 . This guide pulley 19 is rotatably provided on a shaft 19A whose shaft position is fixed, and the guide arm 18 is also attached so as to be movable with respect to this shaft 19A. This will be the guide. After the guide arm 18 is installed at a proper position, its angle is fixed by a lock 19B.

Furthermore, the first pulley, drive pulley 6, and the winding
A tachometer pulley 20, which is a fourth pulley in contact with the wire between the tachometer pulley 20 and the tachometer pulley 20, and a rotary joint 20A1 as a winding distance counting means for counting the rotation of the tachometer pulley 20;
0B and an encoder 21.

The wire 1 connects the tachometer pulley 20 and the idle roller 2.
0C and in contact without slipping, the length of the winding distance of the wire is measured by the encoder 21. The output of the encoder 21 is sent to the console desk 5 as shown in FIG.

Also, the wire 1 between the tachometer pulley 20 and the take-up reel 2
A guide ring 22 is provided to regulate the direction of the movement.

The respective shafts of the guide ring 22, the tachometer pulley 20, and the idle roller 20C are attached to an elastically supported hanging arm 23, so that the take-up reel 2 can correctly wind the wire.

A first control circuit 4 that controls the first motor 3 that drives the winding wheel 2 performs follow-up control so that the current flowing through the first motor 3 is constant. That is, a power supply current is supplied to the motor 3 from an inverter 4A, and a current detection circuit 4B is inserted into the current path. The detection output of this current detection circuit 4B is given to a rectifier circuit 4C. The output of the rectifier circuit 4C is compared with a reference voltage Vref2 by a comparator circuit 4D, and the low frequency signal is applied as a control signal to the inverter 4A through a waveform generator 4E and an amplifier 4F. In addition, the rotational speed of the motor 3 is determined by a tachometer 3C that is directly connected to this.
When the take-up reel winds up the wire, the motor 3 is actuated on the drive side, and when the wire is unwound, the current flowing through the motor 3 is actuated on the brake side.
Controlled by G.

In FIG. 1, the take-up reel 2 is attached to the shaft 2B,
It is rotated by key 2A. One end of the support 2C that slidably supports the take-up reel 2 meshes with a double helix shaft 24, and this double helix shaft 24 is rotated synchronously with the shaft 2B via a bell 2D.

Therefore, during rotation, the one end of the support 2C is guided by the spiral groove of the double helical shaft 24 and reciprocates as shown by the arrow.
The take-up reel 2 also reciprocates on its axis 2B. This aligns the wires on the reel 2.

In the above explanation, the contact surface of the drive belt 14 with the drive pulley 6 is lined with polyurethane resin, but the surface of this lining layer is further compounded with a new material such as Kevlar (Dupont), and the surface It is possible to ensure that there is almost no deterioration.

FIG. 5 shows an explanatory diagram of an applied invention of the present invention. In this diagram,
Four wire winches 33 are installed at the four corners of the stadium, which has seats 44, a track 45, and a field 46.
Wire 1.41.42.43 of each wire winch 33
The ends of each of the poles 31 are connected to a hanging link 32 via pulley means 31A at the top of the pole 31, and this hanging ring 32 is provided with a bracket foot 34 to which a television camera is attached. In such a position control device for a television camera, a wire winch 3
3 is a wire winch according to the present invention, and a console desk 5, which is a replica means for supplying an operation signal to the second control circuit (represented by reference numeral 8 in FIG. 2) of each wire winch, is a wire winch according to the present invention. One is provided in common for each.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to prevent waves occurring in the wire due to rapid fluctuations in the load on the wire and deformation of the wire drive portion of the wire winch, and to prevent the alignment of the wire on the take-up reel from being disturbed. By doing so,
The object attached to the tip of the wire can be moved smoothly.

Therefore, it can be used as a position control device for a television camera suspended above a stadium or the like to take pictures of athletic events.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the components of an embodiment of the present invention. FIG. 2 is an explanatory diagram of the operation and control of the above embodiment. FIG. 3 is a block diagram mainly showing the second control circuit of the above embodiment. FIG. 4 is a block diagram of the first control circuit of the above embodiment. FIG. 5 is an explanatory diagram of the applied invention. 1... Wire, 2... Take-up reel, 2A... Key, 2B, 6C, 7A, 9A, IOA, 12A, 19A
...Axis 1.2C...Support, 2D, 3A, 7B, 1
．． 6A...Belt, 3...First motor, 4...
First control circuit, 4A... Inverter, 4B... Current detection circuit, 4C... Rectifier circuit, 4D, 8A... Comparison circuit, 4E, 8C... Low frequency waveform generator, 4F, 8B ...
Amplifier, 4G...Reversing circuit, 5...Console desk as operation means, 5A...Connection terminal, 5B...Processor, 5C...Memory circuit, 5D...Interface, 5E... Keyboard, 5F...joystick, 5G...display section, 5H...television operation desk part, 6...drive boo IJ which is the second pulley, 6A, 6B...rail, 7... - Second motor, 8... Second control circuit, 8D... Pulse width control circuit, 8E... Power supply terminal, 9... Load measuring pulley which is the second pulley, 10... Swinging arm, 11... Pressure sensor, 12... Drive roller, 13C13B, 13
C, 20C...Idle roller, 14...Drive belt, 15...Oblique pulley, 16...Sliding clutch, 17...Pole guide, 18...Guide arm, 19...No. Guide pulley, which is the third pulley, 19B
...Lock, 20...Tachometer pulley which is the fourth pulley, 20A...Rotating joint, 20B...Flexible rotating shaft, 21...Encoder, 22...Guide ring, 23...・
・Hanging arm, 24...Double spiral shaft, 31...Pole, 3
1A... Pulley means, 32... Hanging ring, 33...
- Wire winch, 34... Television camera bracket, 41-43... Wire, 44... Audience seat, 45... Truck, 46... Field.

Claims (1)

[Claims] 1. A take-up reel for winding a wire to which a varying load is applied, a first motor for driving this take-up reel, and a first motor for controlling the rotation direction and rotation speed of this motor. A wire winch equipped with a control circuit and an operating means for operationally supporting winding and unwinding of the wire, the wire winch being provided near the take-up reel so as not to slip substantially against the wire wound on the take-up reel. a first pulley that is in contact with the pulley in a free state; a second motor that drives this pulley with a force greater than the set maximum value of the variable load; and controlling the rotational direction and rotational speed of the second motor. a second control circuit, the operating means is connected to the second control circuit, and the first control circuit is configured to maintain substantially constant tension of the wire wound by the take-up reel with respect to the pulley. A wire winch comprising control means for causing the rotation of the first motor to follow the rotation of the pulley. 2. A second pulley in contact with the wire is provided on the load side of the wire from the first pulley, and this second pulley has a structure that allows it to move slightly in a direction perpendicular to its rotation axis, and The wire winch according to claim 1, further comprising a sensor for detecting the load applied to the wire according to the amount of directional movement. 3. The wire winch of claim 2, wherein the output of the sensor is connected to the second control circuit as a wire load input. 4. The wire winch of claim 1, wherein the first pulley and the second motor are connected by a resilient drive belt. 5. In addition to the rotational driving force provided by the second motor via the drive belt, the first pulley is provided with a rotational driving force having a substantially higher rotational speed than the rotation provided by the drive belt. 5. A wire winch according to claim 4, further comprising slip clutch means provided by a motor. 6. A movable guide arm that pulls the wire closer to the load side of the wire than the second pulley is provided, and a third pulley whose shaft position is fixed and is rotatable is provided between the guide arm and the second pulley. A wire winch according to claim 2. 7. The wire winch according to claim 6, further comprising a fourth pulley in contact with the wire between the first pulley and the take-up reel, and a take-up distance counting means for counting the rotation of the fourth pulley. . 8. The wire winch according to claim 1, wherein the first control circuit includes means for follow-up control so that the current flowing through the first motor is constant. 9. In a position control device for a television camera, which is equipped with four wire winches, the tip of the wire of each wire winch is connected to one ring, and the ring is provided with a bracket for mounting the television camera, as described above. The wire winch is a wire winch according to claim 1, characterized in that one operating means for supplying an operating signal to the second control circuit of each wire winch is provided in common for four devices. Television camera position control device.