How to design a safety tool monitoring system based on AVR microcontroller

As we all know, safety is an eternal theme of power enterprises, and the quality of safety will directly affect the personal and equipment safety of power enterprises in the production process. The author proposes a design scheme for safety tools based on safety tools, which mainly monitors the status information of safety tools, effective use period, and temperature and humidity conditions in the safety tool cabinet, etc. It can automatically adjust the temperature and humidity in the safety tool cabinet and automatically record the relevant information of safety tools. This paper first explains the overall structure of the system, and then discusses the hardware design and software design of the system in detail.

1 Overall structure of the safety tool monitoring system

1.1 System Structure

The safety tool monitoring system designed in this paper is mainly divided into two parts: lower computer data acquisition and upper computer data management, and the two communicate through the network.

The system first collects the relevant quantities of the safety tool cabinet through the data acquisition board, and then processes the collected data accordingly and transmits it to the host computer management system through the serial port server. The host computer performs corresponding processing after obtaining the data.

Each safety tool cabinet requires 40 data acquisition ports to collect the status information of safety tools. When the status of safety tools changes, the data acquisition board will collect this information and then pass it to the upper computer management system for processing. When the temperature and humidity in the cabinet do not reach the set standard, the system will control the heating and dehumidification device to work, thereby adjusting the temperature and humidity conditions in the cabinet. When the upper computer management system receives the data transmitted by the lower computer, it will start to process accordingly: back up the status information of safety tools for historical query; display the use status, effective use period and temperature and humidity conditions of safety tools in real time on the user interface, so that the staff can monitor the system.

1.2 System Functions

The main functions realized by the system are:

1) Real-time monitoring of the safety tools’ in-place status.

2) Real-time monitoring of temperature and humidity conditions in the safety tool cabinet.

3) Real-time monitoring of the effective use period of safety tools.

2 Hardware Design of Safety Tool Monitoring System

The main functions of the system hardware are to detect the safety tools’ position and status, the temperature and humidity in the cabinet, and the automatic control of the heating and dehumidification devices, and to display the relevant information on the LCD in real time. The system hardware structure is shown in Figure 1.

The system uses ATmega128-16AC of AVR series microcontroller as the main controller and ATmega8-16AC as the data acquisition controller. AVR microcontroller is an enhanced RISC reduced instruction set high-speed 8-bit microcontroller with built-in Flash. It uses Harvard structure internally and the clock speed can reach 16 MHz.

The main control board needs to control 4 data acquisition boards, acting on the same safety tool cabinet. The infrared reflection detection method is used to detect the safety tool's in-place status. When the safety tool is borrowed or returned, the level fed back by the infrared reflection device will change. We can judge the safety tool's in-place or out-of-place status by detecting the level. The main control board obtains the data obtained by the data acquisition board in a polling manner through the RS-485 interface.

After receiving the collected data, the main control board will perform corresponding processing: the specific information of the safety tools in place will be displayed on the LCD display so that the staff can understand the use status of the safety tools in real time; the information on the safety tools in place will be transmitted to the upper computer management system for corresponding processing.

3 Software Design of Safety Tool Monitoring System

The software design of the safety tool monitoring system mainly includes three parts: communication protocol design between the lower computer and the upper computer, lower computer program design and upper computer program design.

3.1 Lower computer program design

The lower computer is mainly responsible for collecting and displaying the status information of safety tools and equipment, collecting and adjusting the temperature and humidity in the safety tool cabinet, and sending relevant information such as the status of safety tools and equipment to the upper computer management system for processing.

1) Design of the master control program of the lower computer

Only when the upper computer management system needs it, the effective use period of the safety tools and the temperature and humidity information in the cabinet will be sent to the upper computer management system. The main control program flow chart of the entire lower computer is shown in Figure 2.

2) Design of data collection and processing program of lower computer

The time interval for data collection of the lower computer is controlled by a timer. The data collection command is sent from the lower computer main control board to the data acquisition board via RS-485, and the collected data is also sent back to the main control board via RS-485 for processing.

FIG3 shows the process of the main control board processing the safety tool position status information.

3.2 Host computer program design

The main function of the upper computer management system is to process the data transmitted from the lower computer: display the in-place status information of safety tools to the user in the form of a user interface so that the staff can understand the use of the tools in time, and save the in-place status information of the relevant tools for users to record the history.

The process of upper computer processing data is shown in Figure 4. The event trigger method is used to process the data transmitted from the lower computer. When data is transmitted, the data processing process begins: first, it is determined whether the start character and check code of the data are correct. Only when both are correct will the data packet be processed to the next step, otherwise the entire data processing process ends and waits for the arrival of new data; then the operation instructions in the data are determined. When the data information does not match the required information, the entire data processing process ends and waits for the arrival of new data; then corresponding processing is performed according to different data information; after the data processing is completed, continue to wait for the arrival of new data.

4 Conclusion

The safety tool monitoring system based on AVR microcontroller designed in this paper can effectively realize real-time monitoring of safety tools, including the use status, effective period, and environmental conditions of safety tools; it can realize automatic adjustment of the temperature and humidity of the environment in which the safety tools are located; it can realize automatic storage of relevant information of safety tools and provide historical query function. This paper technically proposes a safety tool monitoring method, which provides a way to realize scientific and efficient management of safety tools, and is an important part of power enterprises to achieve safe production and scientific management.