Multimedia Teaching Evaluation System

System function description

As an auxiliary means of modern management, CCTV monitoring system has been increasingly entering various application fields in various industries in recent years. It has also been widely used in the teaching field and has become an important means of modern teaching management. Designed for the school classroom teaching monitoring system, it can meet various modern school norms such as college entrance examination setting, multimedia teaching, teaching evaluation, and distance teaching.

The system can perform spot monitoring on any designated classroom. The on-site conditions of these classrooms can be transmitted to the sub-controllers in the control room or sub-control room (such as the principal ’s office, e-classroom, academic affairs office, etc.) in real time. Through the control of the multimedia host, automatic loop switching or manual switching To complete the monitoring of various classrooms, or to record demonstration teaching materials on the control side, you can also transmit the image and sound of the teaching site to the classroom or other designated locations for teaching demonstration or evaluation in real time. The system will make teachers and students more strict with themselves, and will greatly help improve the quality of teaching.

System design

The control terminal adopts multimedia computer control, friendly interface, rich functions, easy to learn and use. Multiple sub-control terminals can be set up and placed in the principal's office or the school's designated location. Each sub-control computer can perform background control of the actions of each monitoring point, and can randomly choose any monitoring point to watch the picture without interfering with Different control priorities can be set through the host, which can be used with the TV wall. The integrated hard disk video recorder function realizes the archiving of teaching content and facilitates backup to any other storage.

Schematic diagram of the overall structure of the system

The following describes each part of the system.

1. Front-end system

The front-end system mainly includes a CCD camera, an electric zoom lens, a highly sensitive audio detector, an all-round gimbal, a control signal decoder, a protective cover, a bracket, and a power supply, etc., and is installed in the classroom. The functions and parameters of each component are as follows:

1.1 Camera

The camera intends to use JC-420C color CCD camera of Japan Conjet (JETCOM brand). The core component of the camera, the CCD photosensitive chip, is a product of SONY Japan. Some key integrated circuit chips are also SONY chips, which makes its main performance indicators such as resolution, minimum illumination, etc. rank among the best in similar products. JC- The 420C has a resolution of 420 lines, a minimum illumination of 0.5 Lux, and has automatic electronic shutter and automatic white balance functions.

1.2 Power zoom lens

The electric zoom lens is planned to use JC-0742, which has a focal length of 7 to 42MM and six times three variable electric adjustments. It can also control the aperture and focus in the background. It is easy to operate and has excellent performance, which can meet the special requirements of teaching video.

1.3 Indoor protective cover

The protective cover can choose Japanese JETCOM JC-602 aluminum alloy medium-sized protective cover, which is used for the dust protection of the camera and the lens, and the appearance is beautiful.

1.4 Indoor Omni-directional PTZ

The indoor omni-directional pan / tilt head JC-3000 produced by JETCOM in Japan has a horizontal range of 350 degrees and a vertical range of 60 degrees. It is a direct wall-mounted type with beautiful appearance and can save the pan-tilt bracket. The gimbal has stable performance and reasonable price. It is one of the most used brands in the company's current projects. There is no record of repair in the model of the gimbal used or sold in the company's previous projects.

1.5 Sound sensor

The sound sensor uses the highly sensitive domestic SF-08 type monitoring head, which is used for on-site pickup of the classroom. The price is only about 1/3 of the imported product.

1.6 Decoder

The intelligent codec, also known as a small intelligent center, has a self-checking function and its own monitoring program. The equipment selected this time is JETCOM and JC100. It can provide data decoding for signals such as pan / tilt, lens, etc., so that the front-end system is integrated, which is convenient for central linkage control. Complete the control of the gimbal and lens, and support a variety of AC power sources.

2. Back-end system (main control system)

Multimedia master control system

The system has multi-screen windows, 1-16 screens can be divided randomly, Chinese characters can be superimposed in English at random, image identification, dynamic prompts, and true-color images are gorgeous and colorful.

The system uses virtual reality technology, hierarchical management, tree structure, easy access, for specific monitoring pixels (video, audio, switching TV walls, etc.) real-time operation, full dynamic display, as if in the real scene.

The system has multi-level control and multi-master control, provides each operator with the corresponding authorization password to avoid conflicts, and can automatically complete the handover work without exiting the system, generate the work log on duty, and have clear responsibilities, which provide an important basis for future evidence collection.

On the basis of the school's existing network, there is no need to change the line. The use of JETCOM2000 can form a video surveillance network to realize video network transmission, make full use of network resources, and maximize the potential.

Multimedia sub-control system

The sub-control computer in the principal's office can be installed to control the front-end gimbal lens only by adding software, and can monitor the monitoring point image and listen to the corresponding sound on the network. There can be two-way intercom between the main control and the sub-control, and also between the sub-control. It can also be combined with Ethernet, PSTN, ISDN, DDN, and SDH. Various methods can be combined for simultaneous use. It supports the TCP / IP transmission protocol and allows images and sounds to be uploaded to a remote computer.