JP2002010244A - Remote control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a remote control system which can control lens zooming and orient a universal head to a target position in a short time by reducing trouble in operation due to the amount of delay in remote controlling the universal head. SOLUTION: In a monitoring system which compresses the image data picked up by a video camera at a transmission side, sends it to a receiving side via transmission route, decodes the image data compressed at the receiving side and remote controls a video camera at the transmission side based on the reproduced image, this remote control system stores a means which detects the compression/transmission mode of the image data at the receiving side and variable controls at least either lens zoom control rate of the video camera or control rate of universal head's revolution, and the transmission delay amount based on the compression/transmission mode of the image data that has been detected, and correction controls either lens zoom control of the video camera or the control rate of universal head's revolution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remote control system for a camera pan in a surveillance system using a video camera, and more particularly to a measure for processing delay in a system for transmitting a compressed video signal.

[0002]

2. Description of the Related Art FIG. 2 is a diagram showing a pan head control system in a conventional monitoring system. In this system, video data taken by a camera unit 221 having a camera mounted on a rotating head is digitally compressed by a compressor (ENC) 222 on a transmission side, and is expanded via a transmission path 223 on a decompressor 224 on a reception side.
(DEC). The DEC 224 on the receiving side expands the video data and sends it to the pan head controller 225. The head control device 225 includes a signal input / output unit 226, a video processing unit 22
7, a monitor unit 228 and a head control unit 229. The data sent from the DEC 224 is transmitted from the signal input / output unit 226 to the head control unit 225.
Is input to Next, the video processing unit 227 displays the video on the monitor unit 228 while performing editing for imposing the date and time, the camera number, and the like on the video data, and performing the recording process. The operator on the receiving side uses the camera platform control unit 229 to view the image data from the camera unit 221 displayed on the monitor screen, and adjusts the direction of rotation of the camera platform, positioning to the target point, and lens zooming. Performs remote control such as switching. The head control unit 229 includes a delay storage unit 231 and a correction unit 23 as countermeasures against operation delay during remote operation.
2, which will be described later. The control signal generated by the camera platform control unit 229 is output to the transmission path 223 through the signal input / output unit 226, and is sent to the camera platform using the upstream line of the transmission path 223. Since the control signal has a much smaller data capacity than the video data sent from the camera unit 221, the control unit 2 outputs the uncompressed data as it is.
21. Therefore, this control signal is not delayed (almost equal to zero) and the camera unit 22
Probably sent to 1.

In addition to the head control device 225, a transmission mode changeover switch 230 is provided externally, and sends a changeover signal to the ENC 222 to change the mode of the compressed data to be transmitted irrespective of the control signal of the head. I was switching. The transmitted compressed data has a transmission delay between the transmission side and the reception side due to a cable length, a transmission compression mode, and the like.
Performing the pan head rotation operation will hinder each operation. Thus, in a system with a large delay, the operator stops the lens zoom operation and the pan head rotation control operation at a position short of the target position in advance, taking into account the transmission delay amount, and performs fine adjustment. Alternatively, the delay amount storage unit 231
The delay amount of the entire system is stored in the
When the operator performs a feedback process at 32 and confirms the video data displayed on the monitor unit 228 and stops the control, the control is returned by the stored delay amount, the lens zoom is adjusted, and the pan head is adjusted. The turning direction is adjusted to the target position. Here, the delay amount means a time from immediately before the video signal from the camera enters the ENC 222 to immediately after the video signal is output from the DEC 224.

[0004]

In the above-mentioned prior art, the transmission delay amount of the entire system is stored in advance in a delay amount storage unit inside the pan head controller on the receiving side, and the video data captured by a camera located at a remote place is stored. The operator on the receiving side adjusts the lens zoom and the direction of rotation of the camera platform while watching the image, and performs correction processing. However, the amount of transmission delay depends on not only the delay in the control system such as the cable length, but also the compression mode (high image quality mode, low delay mode) of the image data. However, in the conventional control method, since the transmission mode changeover switch 230 is not incorporated in the pan head controller 225, the delay amount of the entire system must be stored again each time the compression mode of the image data to be transmitted is changed. I had to. Therefore, in many cases, the system maximum delay amount is measured in advance, and based on the measured maximum delay amount, the optimal lens zoom speed and the pan head rotation operation speed are set to constant speeds. In reality, the image data of the camera unit on the transmitting side is displayed on the monitor screen of the receiving side with a delay of this delay amount, so the operator checks the monitor screen and stops the turning operation of the camera. Even so, at this point, the image data that has exceeded the target position has already been captured by the camera on the transmission side. Therefore, even if the rotation of the camera stops at this point, the image data sent with a delay is finally displayed on the monitor, and the image data displayed on the monitor exceeds the target position. Will be. Therefore, it is often the case that the lens zoom speed and the pan head turning operation speed are set to constant low-speed speeds so as to minimize the overrun.
For the above reasons, even if the delay amount of image data from the camera is small and the control signal from the operator is reflected in the pan head rotation control without a time difference, the operation speed is slow, so the lens zoom adjustment and position The time for adjustment was long, and it took considerable time to complete the operation. The present invention eliminates these drawbacks, reduces operability problems due to the delay amount that has been a problem when remotely controlling the camera platform, controls the lens zoom in a short time, and moves the camera platform to the target position. The aim is to realize a remote control method that can be adjusted.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention compresses image data captured by a video camera on a transmitting side, transmits the compressed data to a receiving side via a transmission path, and transmits the compressed data to a receiving side. In a surveillance system that decodes compressed image data and remotely controls the video camera on the transmission side based on the reproduced image, when the video camera is remotely controlled from the reception side, the video data compression / transmission mode depends on the compression / transmission mode of the image data. ,
This is a remote control system that variably controls at least one of the zoom control speed of the lens of the video camera and the control speed of turning the camera platform. Then, on the receiving side, a means for detecting the compression / transmission mode of the image data and variably controlling at least one of the zoom control speed of the lens of the video camera and the control speed of the rotation of the camera platform in response to the detection. ,
A transmission delay amount based on the compression / transmission mode of the detected image data is stored, and at least one of a zoom control speed of the lens of the video camera and a control speed of the rotation of the camera platform is corrected and controlled accordingly. This is a remote control method. That is, a switch for switching the transmission / compression mode is incorporated in a pan head control device provided on the receiving side, and a processing delay amount for each image quality mode to be transmitted is stored in advance as a system delay amount. The remote control method is characterized in that the operation speed when the camera platform is adjusted to the target position is changed according to the transmission / compression mode. Here, as an example, image data is compressed using the MPEG method, which is a unified standard for video compression,
The case of transmission will be described. The MPEG compression modes include a mode that prioritizes image quality (high image quality mode) and a mode that considers delay time (low delay mode). In the high image quality mode, the data is transmitted with a reduced compression ratio, so that the amount of transmission data is larger than that in the low delay mode, and the delay amount is about 500 m.
sec. On the other hand, in the low delay mode, although the image quality is deteriorated as compared with the high image quality mode, it is as small as about 200 msec. Therefore, when remote control of the pan head on the transmission side is performed on the reception side, the delay amount for each compression mode when transmitting video data is considered in advance. It is desirable to switch the turning speed of the platform to a low speed, and to control the switching speed to a high speed when the delay amount is small. Here, for the sake of explanation, the rotation direction of the camera platform is limited to the horizontal direction. However, it is assumed that the camera platform can actually rotate vertically and horizontally.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a basic configuration of a remote control monitoring system using a video camera as an embodiment of the present invention. In the figure, 111 is a camera unit, 112 is a compressor (ENC), 113 is a transmission line, 11
Reference numeral 4 denotes a decompressor (DEC), and reference numeral 115 denotes a pan head controller, which is composed of a total of five blocks. In this system, image data taken by a camera unit 111 having a camera mounted on a swivel head is digitally compressed by a compressor (ENC) 112 on the transmission side, and a decompressor 114 on the reception side is transmitted via a transmission line 113.
(DEC). The image data is expanded by the DECl 14 and sent to the camera platform controller 115. This head control device 1
Reference numeral 15 includes four blocks: a signal input / output unit 116, a video processing unit 117, a monitor unit 118, and a camera platform control unit 119. The video data sent from the DECl 14 is input to the camera platform controller 115 by the signal input / output unit 116. Next, these images are displayed on the monitor unit 118 while the video processing unit 117 performs editing for imposing the date and time, the camera number, and the like on the video data, and performs the recording process. The operator on the receiving side transmits the image data from the camera unit 111 displayed on the monitor screen to the transmission mode changeover switch 121 inside the pan head control unit 119.
To monitor while switching the ENCl12 mode to the high image quality mode or the low delay mode. This switching information is transmitted to the lens zoom speed controller 12.
0, sent to the turning speed control unit 122 at the same time.

On the basis of this information, the lens zoom speed control unit 120 and the turning speed control unit 122 reduce the operation speed of the camera unit 111 to a low speed and a low delay In the mode, a signal that changes to high speed is sent to the correction unit 124. Further, the spinning information of the transmission mode changeover switch 121 is also transmitted to the delay amount storage unit 123 at the next stage,
The delay amount is switched to a delay amount corresponding to each mode stored in advance. The correction unit 124 stores the delay amount storage unit 12 in the signals sent from the lens zoom speed control unit 120 and the turning speed control unit 122.
Feedback is performed in consideration of the delay amount of No. 3 to correct the pan head control signal. In this way, the control signal generated by the pan head control unit 119 is output from the signal input / output unit 116 to the transmission path 113 and sent to the pan head using the uplink of the transmission path 113. However, at this time, the control signal has a much smaller data capacity than the camera video signal,
The data is sent to the camera unit 111 as uncompressed data. For this reason, the delay amount of the control signal sent to the camera unit 111 is almost equal to zero.

[0008]

As described above, according to the present invention, the difference in processing delay between image data to be transmitted depending on the compression mode is stored in advance in the system as a delay amount, and the compression mode is switched by the operator using the switch. Switching and operability have been improved, so that the lens zoom speed and the turning speed when aligning the direction of the camera platform with the target position can be changed according to the transmission compression mode selected by the operator. Remote control can be performed comfortably.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of a remote control monitoring system according to the present invention.

FIG. 2 is a block diagram showing a basic configuration of a conventional remote control monitoring system.

[Explanation of symbols]

111: Camera unit, 112: Compressor (ENC), 113:
Transmission line, 114: decompressor (DEC), 115: pan head controller, 117: video processing unit, 118: monitor unit, 119:
Pan head controller, 120: lens zoom speed controller, 1
21: transmission mode changeover switch, 122: turning speed control unit, 124: correction unit.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) H04Q 9/00 301 H04Q 9/00 301E

Claims (2)

[Claims] An image data captured by a video camera on a transmission side is compressed, transmitted to a reception side via a transmission path, and the compressed image data is decoded on the reception side. In the surveillance system for remotely controlling the video camera, when the video camera is remotely controlled from the receiving side, the zoom control speed of the lens of the video camera and the control of the rotation of the camera platform are controlled according to the compression / transmission mode of the image data. A remote control system wherein at least one of the speeds is variably controlled. 2. The video data compression / transmission mode according to claim 1, wherein at least one of a zoom control speed of a lens of the video camera and a control speed of rotation of a camera platform is detected on the receiving side. Means for variably controlling one of them, and storing the transmission delay amount based on the compression / transmission mode of the detected image data, and in response to this, controlling the zoom control speed of the lens of the video camera and the control speed of the rotation of the camera platform. A remote control system characterized in that at least one of them is corrected and controlled.