Renovation of the monitoring system for the continuous mining process equipment of bucket wheel excavators

Key words:

The transformation of the centralized monitoring and dispatching system for the complete set of equipment of the continuous mining process of bucket wheel excavators

1. Introduction to the production system and renovation plan

The Buzhiba open-pit mining area of Xiaolongtan Coal Mine in Yunnan Province adopts the advanced continuous mining technology of bucket wheel excavators. It is composed of 48 pieces of equipment to form the topsoil stripping and mining production line, and 42 pieces of equipment to form the coal screening and coordination system, also known as the ground system. After the third and fourth phases of renovation, both systems adopted PLC centralized monitoring. The mining area is also equipped with a command and dispatch system, which can dispatch each single machine of the system.

There is an eight-month-long thunderstorm season in the production process every year. Thunderstorms often damage the remote communication interfaces and even modules of PLCS, causing information interruptions. Dispatchers are unable to understand the on-site production status, which affects production and urgently needs to be resolved. However, the ASI command and dispatch system set up in parallel with it is operating normally.

After analysis, it was found that the remote communication of the PLC uses coaxial cables, and the measures to resist lightning strikes are not effective. The information transmission interface of the all-digital ASI series command and dispatch system adopts three-level protection, effectively preventing lightning strikes. The control of the system transmits information and interlocks mode remotely between the PLC and the single machine through the Peerlink network, ensuring reliable operation and normal running.

If advanced optical cables are used to replace coaxial cables as the communication carrier of this system, damage caused by lightning can be avoided. However, due to the complex terrain of the mining area, this system is long in distance, requires a large amount of laying work, has high costs, and poses certain difficulties in construction.

We select the existing reliable and digitally redundant command and dispatch system as the monitoring information transmission medium to form a centralized monitoring system, as shown in Figure 1.

2. System Working Principle

The dispatching extension remotely collects the operation status information of various types of equipment in each production line. According to the needs of production management, for the main production equipment of the mining and stripping production line, two status signals are taken for each piece of equipment, and two on-site position signals are added to the diversion equipment among them. For mobile equipment such as bucket wheel machines, transfer machines and soil discharge machines, due to their frequent movement, it is difficult to ensure the smoothness of the lines, and their status signals are not collected. For ground production systems, only signals that reflect the operation of the equipment are collected, and another signal indicating that the system is ready is also collected. Each signal is transmitted to the dispatching extension by a pair of audio telephone lines.

The ground system dispatching extension machine collects the status information of each production single machine within its jurisdiction, modulates it using FSK (Frequency Shift Keying) technology, and then transmits it in real time to the dispatching extension machine in the dispatching room through a pair of audio telephone lines. The dispatching extension machine in the dispatching room combines the signals it has collected with those sent by the ground system dispatching extension machine. It is transmitted in real time to the industrial control computer via the RS-·232 or RS-422 serial communication port. After the industrial control computer processes the received signals, it transmits the processed signals in real time to the microcomputer controller of the display screen. The microcomputer controller drives the display module to drive the high-brightness dual-color LED to emit light of different colors.

If the industrial control computer in the monitoring system does not receive the signal from the lower level, it will automatically send a request to the lower-level dispatching extension equipment to retransmit the signal. The microcomputer controller of the display screen has a memory function. In case of power failure, when power is restored, it will automatically apply to the industrial control computer for retransmission of information, and the industrial control computer will automatically request the lower-level dispatching extension to retransmit the information.

3 Software Design

To facilitate the operators' mastery and use, the industrial control computer adopts the WindowS98 operating system, and the application software development uses the Delnhis development tool. Due to the small amount of data, the Access database is adopted. According to the specific requirements of the application, as well as the analysis of the types, sequence and validity period of the collected information, different operation methods are adopted for different production equipment: For each ordinary production piece of equipment, since the information "ready and ready to start" is the most basic working information, it indicates that the equipment is to participate in the system's operation, and it is transmitted first and remains in operation until it no longer participates in the work. The "operation" information reflects the actual working status of the equipment in real time. When designing, in order to reliably reflect real-time information, meet the requirements and facilitate the observation of system dispatchers, the principle of "ready and ready to start" information priority is adopted.

For the split-flow production equipment, since it has two more position pieces of information and one more display light compared to ordinary production equipment, it is diverted to different systems, and different display lights change with the different information. The "Ready and ready to start" and "Position information" still exist after the "Operation" information of this device is uploaded. "Positional information" is a very important piece of information. When designing software, it should be considered as a positional priority principle.

Considering the actual production situation, as the production scale continues to expand, the production process will change, the number of equipment in each production system will also change, and the amount of information collected by each production machine will also change according to the production needs, etc. Therefore, strong flexibility is required in software design. Thus, for some parameters that may need to be changed with production changes, It is designed in a window mode, allowing the monitoring system management personnel to make Settings based on production changes without the need to modify the software. According to the possibility of production changes, the main design parameters that can be set are as follows:

1) Display light Settings

2) Detection point setting

3) Production single machine Settings

4) Setting of interlocking relationships among production equipment

5) Setting of the owner of the production single machine

6) Schedule setting

7) The start and stop times as well as faults of each production system can be queried

8) Time, homework time, etc

9) Unauthorized access or modification of Settings is prohibited. The system is password-protected

10) Global Settings

4. Conclusion

Since the centralized monitoring, command and dispatch system was put into operation in January 2000, it has been working normally and reliably, which proves that the scheme design is reasonable, the system software is reasonable, the calculation is accurate, the data query is convenient, and the parameters are set once without the need for personnel operation. After the application of this monitoring system in the continuous mining process of large open-pit mines, the production efficiency has been significantly improved, and it has the value of promotion and application in similar situations.