JP2007214809A - Universal head system, universal head, zoom lens control system, and zoom lens controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a universal head system, a universal head, a zoom lens control system, and a zoom lens controller that eliminate an offset. <P>SOLUTION: The universal head or zoom lens controller which rotates a load under feedback control is equipped with a center control section 250 which calculates an angular speed command value based upon a received electric signal and outputs it, an amplifier 270 which amplifies the angular speed command value output from the center control section 250, a motor 280 which rotates the load with the amplified signal, and an AD converter 290 which detects the angular speed of the motor, extracts the output of the amplifier, and transmits it to the center control section. The center control section subtracts the offset of the amplifier transmitted from the AD converter from the electric signal received by an electric signal reception part and outputs the result to the DA converter. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pan head system, a pan head, a zoom lens control system, and a zoom lens control device.

  An imaging device such as an unmanned remote camera can capture a desired region by providing a pan head that can rotate in the pan direction and / or the tilt direction. Also, by providing a zoom lens capable of zooming, the enlargement and reduction of the image can be adjusted.

  There are a position control method and a speed control method as a method for controlling the camera platform and the zoom lens. The position control method is a method for controlling the positions of the camera platform and the zoom lens in accordance with an input signal. The speed control method is a method for controlling the speed of the camera platform and the zoom lens in accordance with an input signal. As a result, the camera platform and the zoom lens can be operated at a constant speed, for example. The position control method and the speed control method are described in various technical documents (Patent Document 1).

  These control methods should be used properly depending on the application. When a specific direction (position) is specified and the head is pointed in that direction, the position control method is suitable, and when manual control is performed continuously, a speed control method capable of smooth operation is suitable. Yes.

Since the pan head and zoom lens control unit require a large amount of power for the operation of a drive unit such as a motor, the signal input via the operation unit is amplified by an operational amplifier (subtracter). For example, Patent Document 2 discloses a configuration of a zoom lens control device, and the above configuration includes an operational amplifier.
JP-A-9-46556 JP 2001-281523 A

  However, the above operational amplifier causes an offset due to output fluctuation (drift) that is not caused by input fluctuations due to external factors such as ambient temperature and aging. Therefore, in the speed control method, there is a problem that even if the user is not performing an operation input, the pan head rotates unintentionally, or even if the user performs an operation input, the desired operation cannot be obtained. was there.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a new and improved technique capable of eliminating the offset of the camera platform and the zoom lens in the speed control method. It is to provide a pan head system, a pan head, a zoom lens control system, and a zoom lens control device.

  In order to solve the above-described problem, according to one aspect of the present invention, a rotation instruction device for instructing a rotation operation in a desired direction and a rotation instruction device connected to the rotation instruction device via a communication line are provided. A pan head system that rotates a load based on feedback control with an input of a rotation operation instruction of the head, the pan head system comprising: an operation unit that detects an operation amount by a user; and the operation amount An electrical signal transmitting unit that converts the electrical signal into an electrical signal and transmitting the electrical signal to the pan head via the communication line, the pan head including a central control unit that receives the electrical signal from the rotation instruction device; A DA converter that outputs the electrical signal received from the rotation instruction device as an analog signal; an amplifier that amplifies the angular velocity command value output from the DA converter; and the load that is applied by the amplified signal. A motor that rotates; an AD converter that extracts the output of the amplifier and transmits the output to the central control unit; and the central control unit converts the AD conversion from the electrical signal input from the rotation instruction device. A pan head system is provided, which subtracts the offset of the amplifier transmitted from the converter and outputs the result to the DA converter. In such a configuration, the central control unit can directly cancel the offset of the amplifier without requiring manual adjustment by directly reading the offset of the amplifier and further feeding it back as a command.

  In order to solve the above-mentioned problem, according to another aspect of the present invention, there is provided a pan head for rotating a load based on feedback control with an electric signal instructing an external rotation operation as an input: An electric signal receiving unit that receives the electric signal; a central control unit that calculates an angular velocity command value based on the electric signal received by the electric signal receiving unit; a DA converter that outputs the angular velocity command value as an analog signal; An amplifier for amplifying the angular velocity command value output from the DA converter; a motor for rotating the load by the amplified signal; an AD converter for extracting the output of the amplifier and transmitting it to the central control unit And the central control unit subtracts the offset of the amplifier transmitted from the AD converter from the electrical signal received by the electrical signal receiving unit. And outputting to the transducer, the pan head is provided. In such a configuration, the central control unit reads the offset of the amplifier directly and feeds it back as a command automatically, as in the pan head system, so that the offset of the amplifier is automatically not required. Can be offset.

  The central control unit includes: an offset estimation unit that estimates an offset from the output of the amplifier; an offset storage unit that stores the estimated offset; an electrical signal received by the electrical signal reception unit, and the stored offset And an offset subtracting unit that subtracts. In this configuration, the offset storage unit operates so that the offset subtraction unit can subtract the offset stored at a predetermined time.

  The central control unit further includes an operation amount determination unit that determines whether the electric signal reception unit receives an electric signal for driving the motor, and the operation amount determination unit receives an electric signal for driving the motor. If it is determined that the offset has been determined, the offset storage unit may stop storing the offset estimated by the offset estimation unit, and may continue to maintain the offset value stored immediately before the stop. In such a configuration, the central control unit acts to avoid erroneously estimating and storing an output in which an original offset and an electric signal for driving the motor are mixed.

  The operation amount determination unit further determines whether or not a forced stop signal for forcibly stopping the motor is received in the electrical signal reception unit, receives an electrical signal for driving the motor, and outputs the forced stop signal. The offset storage unit may stop and stop storing the offset estimated by the offset estimation unit and continue to maintain the offset value stored immediately before the stop. In such a configuration, the central control unit operates so that the original offset can be estimated and stored as an offset.

  The calculation of the central control unit may be performed every predetermined period. With this configuration, the angular velocity command value can be reliably updated to the latest value.

  The rotation operation may be a rotation operation in the pan direction or a rotation operation in the tilt direction. With such a configuration, a desired area can be selectively imaged from a wide area.

  In order to solve the above-described problem, according to another aspect of the present invention, a movement instruction device for instructing a movement operation of a zoom lens so as to obtain an enlarged or reduced image, and movement from the movement instruction device A zoom lens control system that moves the zoom lens based on feedback control with an operation instruction as an input, the zoom lens control system comprising: an operation unit that detects an operation amount by a user; An electrical signal transmission unit that converts the operation amount into an electrical signal and transmits the electrical signal to the zoom lens control device, wherein the zoom lens control device receives the electrical signal from the movement instruction device. A central control unit for calculating an angular velocity command value based on the electrical signal transmitted from the rotation instruction device; and an analog signal for the angular velocity command value. A DA converter that outputs the signal; an amplifier that amplifies the angular velocity command value output from the DA converter; a zoom drive motor that moves the zoom lens based on the amplified signal; and an output of the amplifier An AD converter for extracting and transmitting to the central control unit, the central control unit comprising an offset component of the amplifier transmitted from the AD converter from the electrical signal transmitted to the electrical signal communication unit. A zoom lens control system is provided, which subtracts and outputs the result to the DA converter. In such a configuration, the central control unit can directly cancel the offset of the amplifier without requiring manual adjustment by directly reading the offset of the amplifier and further feeding it back as a command.

  In order to solve the above problem, according to another aspect of the present invention, there is provided a zoom lens control apparatus for moving a zoom lens based on feedback control with an electric signal instructing a moving operation as an input: An electrical signal communication unit that transmits an electrical signal; a central control unit that calculates an angular velocity command value based on the electrical signal transmitted to the electrical signal communication unit; and a DA conversion that outputs the angular velocity command value as an analog signal An amplifier that amplifies the angular velocity command value output from the DA converter; a zoom drive motor that moves the zoom lens based on the amplified signal; and an output of the amplifier that extracts the central control An A / D converter for transmitting to the unit, and the central control unit transmits the electrical signal from the A / D converter to the electrical signal transmitted to the electrical signal communication unit. Was by subtracting the offset of the amplifier and outputting to the DA converter, the zoom lens control device is provided. With such a configuration, the central control unit automatically reads the offset of the amplifier and feeds it back as a command automatically, as in the zoom lens control system, so that the offset of the amplifier is automatically not required. Can be offset.

  The central control unit includes: an offset estimation unit that estimates an offset of the amplifier from an output of the AD converter; an offset storage unit that stores the estimated offset; and an electrical signal received by the electrical signal reception unit, And an offset subtracting unit that subtracts the stored offset. In this configuration, the offset storage unit operates so that the offset subtraction unit can subtract the offset stored at a predetermined time.

  The central control unit further includes an operation amount determination unit that determines whether the electric signal reception unit receives an electric signal for driving the zoom drive motor or a forced stop signal, and the operation amount determination unit includes the zoom signal. When it is determined that the electric signal for driving the drive motor has been received and the forcible stop signal has not been received, the offset storage unit stops storing the offset estimated by the offset estimation unit, and stops the operation. The offset value stored immediately before may be maintained. In such a configuration, the central control unit operates to avoid erroneously estimating the offset from the output in which the original offset and the electric signal for driving the motor are mixed.

  The movement instruction device may transmit the operation amount to the zoom lens control device via a communication network or a communication line. In such a configuration, the communication line operates so that the zoom lens control device can be remotely operated.

  As described above, according to the present invention, the offset of the pan head and the zoom lens control device can be eliminated.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

  In the embodiment described below, even if there is an offset in the amplifier included in the camera platform and zoom lens control device, the offset of the camera platform and zoom lens control device can be eliminated.

(First embodiment)
FIG. 1 is a perspective view showing an image of a pan head (drive device) in the present embodiment. The pan head 100 includes an imaging unit 110, a tilt gripping unit 120, and a pan rotation unit 130. The pan head control system also includes a rotation instruction device 140 and a monitor 150 connected to the pan head 100 via a communication network or communication line such as the Internet.

  The imaging unit 110 includes, for example, a lens unit 112 and a camera unit (not shown), and captures imaging targets at various angles in accordance with the rotational driving of the tilt gripping unit 120 and the pan rotation unit 130. can do.

  The tilt grip part 120 includes a pair of support parts 122 and a base part 124. The support unit 122 supports the imaging unit 110 so that the imaging unit 110 can rotate in a tilt direction 126 (a direction in which the Y axis rotates in FIG. 1), and the imaging unit 110 corresponds to a target signal in the tilt direction 126. Is driven to rotate. The base part 124 supports the two support parts 122 in the vertical direction.

  The pan rotating unit 130 supports the tilt gripping unit 120 so as to be able to rotate in the pan direction 132 (in FIG. 1, the direction of rotation about the Z axis as a rotation axis), and according to the target signal in the pan direction 132, The tilt grip 120 is driven to rotate. Therefore, the imaging unit 110 supported by the tilt grip unit 120 is rotationally driven in the pan direction 132.

  The rotation instruction device 140 includes, for example, an input unit such as a joystick or a cross key, detects a user operation amount input from the input unit, and uses the detected operation amount as an electric signal to the pan head 100. Send.

  The monitor 150 receives the video signal captured by the imaging unit 110 of the camera platform 100, and the user operates the rotation instruction device 140 while confirming the video.

  Even when the distance between the pan head 100 and the rotation instruction device 140 is increased by the drive system as described above, the user can remotely operate the pan head 100 from the rotation instruction device 140, and various remote places can be operated. It is possible to obtain an image of a proper angle instantly.

  FIG. 2 is a block diagram showing the configuration of the pan head system according to the present embodiment. The pan head system includes a rotation instruction device 140 and a pan head 100.

  The rotation instruction device 140 includes an operation unit 210 and an electric signal transmission unit 220. The operation unit 210 detects an operation amount for controlling the pan / tilt head 100 input by the user. Examples of the operation amount include a rotation operation instruction signal and a forced stop signal. The forced stop signal is a signal for forcibly stopping the driving of the motor regardless of the presence or absence of other input signals.

  Further, examples of the rotation operation include a pan direction rotation operation and a tilt direction rotation operation. Pan direction means horizontal direction and tilt direction means vertical method. By making the above two directions drivable, a desired area can be selectively imaged from a wide area.

  The electric signal transmission unit 220 converts the operation amount input from the operation unit 210 into an electric signal and transmits the electric signal to the pan head 100. The manipulated variable may be transmitted via SCI (Serial Communicated Interface). With such a configuration, it is possible to perform clock synchronous communication in which communication is performed in synchronization with the clock, and asynchronous communication in which communication is performed by adding a start bit and a stop bit.

  The pan head 100 includes an electric signal receiving unit 246, a central control unit 250, a DA converter 260, a subtractor 270, an amplifier 270, a motor 280, an angular velocity detecting unit 286, and an AD converter 290. It operates based on feedback control.

  The electrical signal receiving unit 246 receives the operation amount converted into the electrical signal transmitted by the electrical signal transmitting unit 220. The electric signal receiving unit 246 may be mounted on the central control unit 250.

  The central control unit 250 subtracts the offset of the amplifier 270 from the operation amount converted into the electrical signal received by the electrical signal receiving unit 246 to control the rotational speed of the motor 280. Is calculated. Details of the calculation method will be described later. The DA converter 260 outputs the angular velocity command value as an analog signal.

  The subtractor 270 subtracts a feedback value from the angular velocity command value. The amplifier 270 amplifies the subtracted minute power. The subtractor 270 and the amplifier 270 can achieve their functions by using operational amplifiers. When an operational amplifier is used, the reference voltage may be input to the inverting terminal and the result of the subtraction may be input to the non-inverting terminal.

  However, an operational amplifier can cause an offset due to various factors. For example, the offset due to temperature change will be briefly described. The operational amplifier includes a plurality of transistors, and these emitter terminals are connected to a power source. However, since the voltage gain of the transistor varies greatly with temperature, the collector voltage also varies, resulting in a difference between the intended output and the actual output.

  The motor 280 may rotate the load (for example, a camera) in the pan direction (horizontal direction) or the tilt direction (vertical direction) based on the amplified signal.

  The angular velocity detector 286 generates an electrical signal based on the rotational speed of the motor 280 and outputs the electrical signal to the subtracter 270 as the feedback value. The angular velocity detection unit 286 may be, for example, a tachometer that is integrally formed with a rotation shaft of a motor and converts the rotation speed into an electric signal.

  The AD converter 290 extracts the output of the amplifier 270 including an offset and transmits it to the central control unit 250.

  FIG. 3 is a circuit configuration diagram showing a specific circuit example of the pan head constituting the pan head system according to the present embodiment. The camera platform further includes a transistor 310 and an operational amplifier 320.

  The transistor 310 may use the output of the amplifier 270 as an input signal, amplify the input signal, and output the amplified signal to the motor 280. In other words, the operational amplifier plays a role as a preamplifier.

The operational amplifier 320 may have an amplification function for obtaining a desired feedback value, and the output of the angular velocity detection unit 286 may be used as an input signal to amplify the input signal and output it to the subtractor 270.

  FIG. 4 is a block diagram illustrating a process of calculating the angular velocity command value in the central control unit 250. The central control unit further includes an offset estimation unit 410, an offset storage unit 420, an offset subtraction unit 430, and an operation amount determination unit 440.

  The offset estimation unit 410 takes in the output of the AD converter 290 and estimates the offset of the amplifier 270 from the output. More specifically, in the stop period, the offset is estimated based on a value obtained by multiplying the output from the AD converter 290 by a predetermined number, or a value obtained by integrating the multiplied value with time. That is, if the output from the AD converter 290 is a positive value, the estimated value is increased, and if the output is a negative value, the estimated value is decreased.

  Further, the offset estimation unit 410 may have a low-pass filter function, and can remove high-frequency components contained in the output from the AD converter 290. This is because the offset to be estimated is not a high-frequency component but a low-frequency component such as the drift. The low pass filter may be provided in front of the AD converter 290. With such a configuration, the burden on the central control unit can be reduced.

  The offset estimation unit 410 estimates the offset in consideration of the amplification degree of the amplifier 270. For example, if the voltage gain of the amplifier 270 is 20 times and a voltage of 4 mV is applied from the AD converter 290, it is estimated that 0.2 mV is an offset to be subtracted later.

  The offset storage unit 420 stores the offset estimated by the offset estimation unit 410 in, for example, a memory. The memory may be RAM, EPROM (Erasable Programmable Read Only Memory), or EEPROM (Electrically Erasable Programmable Read Only Memory). When using a memory that retains the stored values even after the power is turned off, it is possible to estimate the offset while suppressing vibration and dead time.

The offset subtracting unit 430 subtracts the offset stored in the memory or the like from the electrical signal received by the electrical signal receiving unit 246.

  The operation amount determination unit 440 determines whether the electric signal receiving unit 246 has received an electric signal for driving the motor 280 or a forced stop signal. Then, the determination result is output to the offset storage unit 420.

  While the operation amount determination unit 440 determines that the electric signal for driving the motor 280 is not received or the forced stop signal is received, the output voltage amplified by the amplifier 270 is output. Should be 0V. If the output voltage is not 0V, the central control unit 250 stops the motor by outputting the angular velocity command value such that the output voltage becomes 0V.

  When the operation amount determination unit 440 receives an electric signal for driving the motor 280, the central control unit 250 outputs a current angular velocity command value based on the angular velocity command value at the time of stop. A flow of such a series of operations is as follows.

  FIG. 5 is a timing chart for explaining the procedure for removing the offset from the output of the AD converter 290. The vertical axis represents the voltage conversion value, and the horizontal axis represents time.

  FIG. 5A shows the output of the AD converter 290 when the offset removing means according to the present embodiment is not applied. The stop period is a period during which the operation amount determination unit 440 determines that the electric signal for driving the motor 280 is not received or a forced stop signal is received. The operation period is a period other than the stop period.

  Therefore, the output from the AD converter 290 during the stop period is the offset of the amplifier. On the other hand, in the output from the AD converter 290 during the operation period, the offset and the electric signal for driving the motor 280 are mixed.

FIG. 5B shows an offset estimated by the offset estimation unit 410 when the offset removing unit according to the present embodiment is applied. The offset estimation unit 410 estimates the offset following the output from the AD converter 290. Therefore, the offset estimation unit 410 can estimate the offset during the stop period, but erroneously estimates the electric signal for driving the motor 280 and the signal mixed with the offset during the operation period as an offset.

  FIG. 5C shows an offset estimated by the offset storage unit 420 when the offset removing unit according to the present embodiment is applied. The offset storage unit 420 needs not to store the erroneous offset estimated by the offset estimation unit 410 during the operation period as described above. If the erroneous offset is stored in the offset storage unit 420 and subtracted by the offset subtraction unit 430, the central control unit 250 sets the platform 100 in spite of the user trying to operate the platform 100. This is because it acts so as not to operate. Therefore, during the operation period, the offset storage unit 420 stops storing the offset estimated by the offset estimation unit 410 and continues to maintain the offset value stored immediately before the stop.

  FIG. 5D shows the output of the AD converter 290 when the offset removing means according to the present embodiment is applied. The offset subtracting unit 430 can avoid subtracting, as an offset, a mixture of an electrical signal for driving the motor 280 and the original offset by the configuration of the offset storage unit 420.

As a result, the offset in the stop period of FIG. During the operation period, the offset is subtracted and only the electric signal for driving the motor 280 is output. Although a high frequency component remains in the output from the AD converter 290, the motor 280 does not react to the high frequency component, so there is no problem in solving the problem of the present embodiment.

  Note that the offset of the amplifier is expected to fluctuate during the operation period, and it seems that the offset does not disappear during the operation period. However, since the difference in offset between the stop period and the operation period is smaller than the electric signal for driving the motor 280, there is no problem. Further, when the operation period has passed a predetermined period, a stop period may be inserted.

  In addition, a latch that maintains the estimated offset may be used so that the offset storage unit 420 performs the above function. That is, the estimated offset at the time may be latched by using the transition from the stop period to the operation period as a trigger. In the stop period, the offset estimated every predetermined period may be latched.

  Such calculation by the central control unit 250 may be performed every predetermined period. With this configuration, the angular velocity command value can be reliably updated to the latest value.

  FIG. 6 is a flowchart showing a flow of outputting the angular velocity command value in the central control unit according to the present embodiment. In the calculation method, first, the storage offset stored in the offset storage unit is initialized. In this embodiment, as an initialization setting, the initial value of the storage offset is set to 0 (S610).

  Subsequently, the offset estimation unit 410 estimates the offset of the amplifier 270 from the output of the A / D converter, and sets the estimated value as an estimated offset value (S620). Next, the operation amount determination unit determines whether the current period is an operation period (S630).

  If it is determined in the above determination (S630) that it is not an operation period, the offset storage unit 420 overwrites the stored offset value with the estimated offset value and maintains it (S640). Thereafter, the offset subtracting unit subtracts the overwritten storage offset from the electrical signal received by the electrical signal receiving unit 246 to calculate an angular velocity command value (S650). Then, the D / A converter outputs the angular velocity command value as an analog signal (S660).

  If it is determined in the determination (S630) that it is an operation period, the offset subtraction unit subtracts the maintained stored offset from the electrical signal received by the electrical signal reception unit 246 to calculate an angular velocity command value (S650). ). Then, the D / A converter outputs the angular velocity command value as an analog signal (S660).

  As described above, since the offset of the pan head 100 can be eliminated and automated, the step of adjusting the offset artificially becomes unnecessary.

(Second Embodiment)
FIG. 7 is an external view showing an image of the zoom lens control system 700 in the present embodiment. The zoom lens control system 700 includes a drive unit 740 as a movement instruction device and a zoom lens control device 750. The zoom lens control device 750 includes a lens barrel 710, and a zoom ring 720 is provided on the outer periphery of the lens barrel 710. In addition, a zoom lens (not shown) or the like is provided inside the lens barrel 710.

  In such a configuration, the zoom ring 720 rotates based on the amount of operation by the user detected by the zoom seesaw (operation unit) 730 included in the drive unit 740, and the zoom lens moves back and forth along the optical axis to perform zoom adjustment. Is called. The zoom ring 720 is driven based on a zoom drive motor provided in the drive unit 740.

  FIG. 7 shows a zoom lens control system in which the movement support device and the zoom lens control device are integrated, but the zoom adjustment is performed via wireless communication instead of the drive unit 740 as the movement instruction device. Is also possible. Hereinafter, a zoom lens control system in which the movement support device and the zoom lens control device are separated will be described.

  FIG. 8 is an explanatory diagram of the zoom lens control system according to the present embodiment. The zoom lens control system includes a movement instruction device 840 and a zoom lens control device 800.

  The movement instruction device includes an operation unit 810 and an electric signal transmission unit 820. The operation unit 810 detects an operation amount for controlling the zoom lens control device 800 input by the user. Examples of the operation amount include a movement operation instruction signal and a forced stop signal.

  The electric signal transmission unit 820 converts the operation amount input from the operation unit 810 into an electric signal and transmits the electric signal to the zoom lens control device 800. The operation amount may be transmitted via SCI.

  Even when the movement instruction device 840 and the zoom lens control device 800 are separated by the zoom lens control system as described above, the user can remotely operate the zoom lens control device 800 from the movement instruction device 840. This makes it possible to instantly obtain various images from remote locations.

  The zoom lens control device 800 includes an electrical signal communication unit 846, a central control unit 850, a DA converter 860, a subtractor 870, an amplifier 870, a zoom drive motor 880, an angular velocity detection unit 886, and an AD conversion. And operates based on feedback control.

  When an electric signal for instructing a moving operation is input to the electric signal communication unit 846, the zoom drive motor 880 rotates and controls the zoom lens at the moving direction and speed according to the electric signal. The operations of the other central control unit 850, DA converter 860, subtractor 870, amplifier 870, angular velocity detection unit 886, and AD converter are described in the first embodiment and are substantially functional. Will be omitted because they are the same.

  The central control unit further includes an offset estimation unit 410, an offset storage unit 420, an offset subtraction unit 430, and an operation amount determination unit 440. These operations have been described in the first embodiment and are substantially the same in function.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  For example, in the above-described embodiment, the offset estimation unit, the offset storage unit, the offset subtraction unit, or the central control unit is described. However, at least one of the above may be provided outside the central control unit. That is, processing may be performed in an analog stage instead of digital.

  In the above-described embodiment, the case where the present invention is applied to the pan, tilt, and zoom functions has been described. However, the present embodiment is not limited to such a case, and the present embodiment can also be applied to other focus functions.

  Furthermore, in the above embodiment, only the operation by the speed control method has been described, but it can also be applied to the position control method. That is, by using a potentiometer in place of the tachometer for the angular velocity detector, the position of the load is converted into an electric signal, and the offset is detected by comparing it with an electric signal input to the pan head or zoom lens control device. , Can be removed.

  The present invention is applicable to a pan head system, a pan head, a zoom lens control system, and a zoom lens control device.

It is the perspective view which showed the image of the pan head as a drive device in this embodiment. It is explanatory drawing of a pan head system and a pan head concerning this embodiment. It is explanatory drawing of a pan head system and a pan head concerning this embodiment. It is the block diagram which showed the structure of the central control part concerning this embodiment. It is a timing chart explaining the procedure which removes an offset from the output of an AD converter. It is the flowchart which showed the flow which outputs an angular velocity command value in the central control part by this embodiment. It is the external view which showed the image by which the zoom lens control system in this embodiment was comprised integrally. It is explanatory drawing of the zoom lens control system concerning this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Head 140 Rotation instruction device 210,810 Operation part 220 Electric signal transmission part 230 Communication network or communication line 246 Electric signal reception part 250,850 Central control part 260 D / A converter 270 Subtractor, Amplifier 280 Motor 286,886 Angular velocity detection unit 290 A / D converter 800 Zoom lens control device 840 Movement instruction device 820 Electric signal transmission unit 846 Electric signal communication unit 880 Zoom drive motor

Claims (12)

A rotation instruction device for instructing a rotation operation in a desired direction, and a rotation instruction device connected to the rotation instruction device via a communication line, and rotating a load based on feedback control using the rotation operation instruction from the rotation instruction device as an input A pan head system consisting of:
The rotation instruction device
An operation unit for detecting an operation amount input by a user;
An electrical signal transmitter that converts the manipulated variable into an electrical signal and transmits the electrical signal to the camera platform via the communication line;
With
The head is
An electrical signal receiving unit for receiving the electrical signal from the rotation instruction device;
A central control unit that calculates an angular velocity command value based on the electrical signal received by the electrical signal receiving unit;
A DA converter that outputs the angular velocity command value as an analog signal;
An amplifier for amplifying the angular velocity command value output from the DA converter;
A motor for rotating the load by the amplified signal;
An AD converter for extracting the output of the amplifier and transmitting it to the central control unit;
With
The central control unit subtracts the offset of the amplifier transmitted from the AD converter from the electrical signal input from the rotation instruction device and outputs the result to the DA converter. Stand system. A pan head that rotates a load based on feedback control that receives an electric signal for instructing a rotation operation:
An electrical signal receiving unit for receiving the electrical signal;
A central control unit for calculating an angular velocity command value based on the electrical signal received by the electrical signal receiving unit;
A DA converter that outputs the angular velocity command value as an analog signal;
An amplifier for amplifying the angular velocity command value output from the DA converter;
A motor for rotating the load by the amplified signal;
An AD converter for extracting the output of the amplifier and transmitting it to the central control unit;
With
The central control unit subtracts the offset of the amplifier transmitted from the AD converter from the electrical signal received by the electrical signal receiving unit and outputs the result to the DA converter. Stand. The central control unit
An offset estimator for estimating an offset of the amplifier from an output of the AD converter;
An offset storage unit for storing the estimated offset;
An offset subtractor for subtracting the stored offset from the electrical signal received by the electrical signal receiver;
The pan head according to claim 2, comprising: The central control unit further includes an operation amount determining unit that determines whether or not an electric signal for driving the motor in the electric signal receiving unit is received,
When the operation amount determination unit determines that the electric signal for driving the motor is received, the offset storage unit stops storing the offset estimated by the offset estimation unit and is stored immediately before the stop. 4. The pan head according to claim 3, wherein the offset value is continuously maintained.   The operation amount determination unit further determines whether or not a forced stop signal for forcibly stopping the motor in the electrical signal reception unit is received, receives an electrical signal for driving the motor, and outputs the forced stop signal. The offset storage unit stops storing the offset estimated by the offset estimation unit and continues to maintain the offset value stored immediately before the stop when the offset storage unit determines that the offset is not received. The pan head according to claim 4.   3. The camera platform according to claim 2, wherein the calculation of the central control unit is performed every predetermined period.   4. The pan / tilt head according to claim 3, wherein the rotation operation is a rotation operation in a pan direction or a rotation operation in a tilt direction. A movement instruction device for instructing a movement operation of the zoom lens so that an enlarged or reduced image can be obtained, and a zoom lens control for moving the zoom lens based on feedback control with a movement operation instruction from the movement instruction device as an input A zoom lens control system comprising:
The movement instruction device includes:
An operation unit for detecting an operation amount by a user;
An electrical signal transmission unit that converts the operation amount into an electrical signal and transmits the electrical signal to the zoom lens control device;
With
The zoom lens control device includes:
An electrical signal communication unit to which the electrical signal is transmitted from the movement instruction device;
A central control unit that calculates an angular velocity command value based on the electrical signal transmitted from the rotation instruction device;
A DA converter that outputs the angular velocity command value as an analog signal;
An amplifier for amplifying the angular velocity command value output from the DA converter;
A zoom drive motor for moving the zoom lens based on the amplified signal;
An AD converter for extracting the output of the amplifier and transmitting it to the central control unit;
With
The central control unit subtracts the offset of the amplifier transmitted from the AD converter from the electrical signal transmitted to the electrical signal communication unit, and outputs the subtracted offset to the DA converter. Zoom lens control system. A zoom lens control device that moves a zoom lens based on feedback control that receives an electrical signal that instructs a moving operation:
An electrical signal communication part to which the electrical signal is transmitted;
A central control unit that calculates an angular velocity command value based on the electrical signal transmitted to the electrical signal communication unit;
A DA converter that outputs the angular velocity command value as an analog signal;
An amplifier for amplifying the angular velocity command value output from the DA converter;
A zoom drive motor for moving the zoom lens based on the amplified signal;
An AD converter for extracting the output of the amplifier and transmitting it to the central control unit;
With
The central control unit subtracts the offset of the amplifier transmitted from the AD converter from the electrical signal transmitted to the electrical signal communication unit, and outputs the subtracted offset to the DA converter. Zoom lens control device. The central control unit
An offset estimator for estimating an offset of the amplifier from an output of the AD converter;
An offset storage unit for storing the estimated offset;
An offset subtractor for subtracting the stored offset from the electrical signal received by the electrical signal receiver;
The zoom lens control device according to claim 9, comprising: The central control unit further includes an operation amount determination unit for determining whether the electric signal receiving unit receives an electric signal for driving the zoom drive motor or a forced stop signal,
When it is determined that the operation amount determination unit has received an electrical signal for driving the zoom drive motor and has not received the forced stop signal, the offset storage unit stores the offset estimated by the offset estimation unit. 10. The zoom lens control device according to claim 9, wherein the storage is stopped and the offset value stored immediately before the stop is maintained. 9. The zoom lens control system according to claim 8, wherein the movement instruction device transmits the operation amount converted into the electric signal to the zoom lens control device via a communication network or a communication line.

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