| This article describes the research result mainly based on successful cases of Visual Dynamic Chinese Character Overlap System in highway monitor and control system. This product also can be used in video monitor for banks, marketplaces, supermarkets, etc.After a brief introduction of the Dynamic Chinese Character Overlap System principle, its development history and prospects, this article describes in detail the design idea, schema of the system's hardware and software as well as the theory of composition and methodology when it is used in centralized monitor and control system for highways. This article will also discuss problems and solutions for the design and development of the system.1 Target and ContentAs the rapid development of Chinese highway and the increasing demand for advanced management, constructing video monitor system is getting more and more important. Relying on the video monitor system, highway management and operating personnel who sit in the central hall can collect records and output signals of the visual images from many monitor and control points. These signals can be displayed and reproduced lively. The adoption of monitor and control video system in highway can enhance emergency response capability, decrease work hardness of the management, and improve the management effectiveness and efficiency. This is helpful to speed up the development of highway system of our country.To lively record information related to the video signals from monitored points on highway, such as the date/time and place, the system needs the function of overlapping the Chinese character with dynamic Video. Therefore, the Dynamic Video and Chinese Character Overlapping system is one of the important components of the visual monitoring and controlling system. The target of this study is to design a cost-effective system, which can be produced in large volume in practice.This study includes hardware and software design of the systemHardware includes:The circuit of the video passage The circuit of OSD video overlappingThe serial communication system and the auxiliary systemsBesides, the design of multiple passage dynamic video Chinese character overlapping system has also been studied hereby.Software includes:System monitoring programSerial communication programProgram clock chipAnd design of OSD program2 Functions and Features of the system According to the demand of the project and based on the design of OSD which uses fold character chip, this study overcomes the weakness of fewer character display and less flexibility of this design by designing single way dynamic video character overlap system.In order to meet the requirement for dynamic character overlapping system in the application of highway monitor system, SCM 89C51CPU, NEC PD6453, real-time clock chip DS12887 and 27C020 containing character lattice data were adopted in the hardware design of the system. The hardware design of dynamic video character overlapping system consists of video simulating signal circuit and SCM digital circuit. Video simulating signal circuit includes video input/output circuit, synchronized signal separating circuit and OSD character overlapping circuit. SCM digital circuit comprises several interface circuits, i.e. SCM 89C51 and 27C020 EPROM, Real-time clock DS12887, Watchdog MAX813, OSD chip PD6453 and Serial communication. The features of the hardware design are low-cost, high reliability and flexibility, complete functions. The software of the dynamic video overlapping system, which is modularized, has strong interrupt service routine and character overlap display routine. ISR consists of serial communication interrupt and real-time clock chip external interrupt. Character overlap display routine consists of PD6453 order-input program and character lattice data formation program. In addition, in order to apply this system to the tollgate of highway, a set of protocol for communicating with PC was designed. The software designed here has fully utilized the fu... |
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