The remote fault diagnosis system for weighing instruments can achieve real-time monitoring of all sensor equipment parameters of the weighing instruments, and promptly detect fault issues. This system can display the operating status of all weighing instruments in real time without power interruption, and has data analysis and abnormal diagnosis functions.
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System structure composition 
The remote fault diagnosis intelligent monitoring system for weighing instruments consists of: edge node sensing and processing module, classified centralized management database, and intelligent decision application layer. The overall block diagram of the large-scale weighing instrument remote fault diagnosis intelligent monitoring system
The remote fault diagnosis intelligent monitoring system for weighing instruments: based on the actual detected electrical parameters of the weighing instrument operation, with the accuracy of fault level diagnosis as the goal, through precise monitoring of edge sensing devices combined with wireless communication modules, realize the low error of data acquisition and the reliability of transmission lines, and through the classification and storage of the database, realize the intelligent classification and invocation of data, thereby achieving high accuracy in fault monitoring of large-scale weighing instruments, and ultimately achieving the effect of actually detecting faults.
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System working principle 
Working principle of the weighing instrument fault monitoring system: the changes in sensor angle, total current of the sensor, internal temperature of the sensor, humidity change of the limit detection box, limit distance change of the scale platform, and internal code change of the sensor are used to determine the fault type. The collected signals are converted into 0-5V AC voltage signals through signal conditioning circuits, and this signal passes through the A/D sampling circuit to be converted into discrete signals sent to the central processor. The central processor processes the discrete signals according to the designed algorithm and calculates the current operating status of the weighing instrument. Different monitoring terminals' central processors respond to the response signals from the monitoring master station and send the operating electrical parameters of each weighing instrument through the wireless bus to the monitoring master station. The monitoring master station receives the data of the weighing instrument operating status parameters sent by the central processors of each monitoring terminal in a loop and processes the data. On the monitoring display, the electrical parameters of the weighing instrument are displayed and the historical data curves of the electrical parameters of the weighing instrument can be viewed. The remote fault intelligent diagnosis monitoring system sensing unit monitoring terminal
The hardware circuit of the sensing terminal mainly includes: angle sensor (Figure 3), displacement sensor (as shown in Figure 4), temperature sensor, current transformer, signal conditioning circuit, A/D sampling circuit, central processor, wired and wireless communication module, key input module, power module, clock module, display module, alarm module. The input end of the signal conditioning circuit is connected to the above multi-source transformers, the signal conditioning module receives the angle deviation, current, temperature and displacement signals collected by the transformers and converts them into standard signals that can be recognized by the A/D chip and sends them to the A/D conversion module. The A/D conversion module converts the analog signal into discrete digital signal and sends it to the central processor for data processing and calculation. Compared with the conventional systems that do not have various sensing and monitoring sensors in addition to this system, this system does not damage the structure of the weighing instrument, does not affect its normal operation, and ensures a safe distance. It selects the most suitable sensors and measurement devices for each monitoring content and installs them in a compact and narrow location near the weighing instrument to achieve accurate collection of the operating parameters of the weighing instrument as an important basis for online monitoring. The parameter collection units of the on-site weighing instruments mainly consist of various sensors pre-arranged at the collection end of the weighing instrument, mainly to send the physical information of the weighing instrument to the corresponding edge processing end for corresponding processing, select RS-485 bus to transmit data, and send it to the cloud platform database management through the low-power wide-area IoT for comprehensive analysis and intelligent processing. To meet the actual requirements of on-site weighing equipment monitoring, it is necessary to build an intelligent monitoring system software for weighing equipment failure diagnosis. Based on low-power wide-area Internet of Things, the system can achieve reliable transmission of distributed information: The communication strategy is the basis and main means for the coordinated control of multiple intelligent monitoring terminals. Through a combination of wired and wireless methods, information can be reliably transmitted. The wired communication network has the advantages of wide communication range, stable signals, and good confidentiality. However, the wired communication network is more susceptible to the constraints of wired transmission lines and cannot be conveniently applied to mobile devices. Moreover, once the communication line is damaged, communication immediately stops. While wireless communication technology, as a new way of information acquisition, can transmit various parameter information within the network area in real time, and send it to the coordinator through broadcast, multicast or point-to-point methods, thereby achieving data collection and remote control of nodes within the working area. 
The system realizes functions such as on-site weighing, scale platform status, alarm history, parameter adjustment display, equipment remarks, opening the shell and sealing, weighing equipment information and pre-operation operations through the interactive interface. During monitoring, the monitoring personnel can precisely and real-time grasp the operation dynamics of the weighing equipment and the working conditions of each device by viewing the real-time data displayed on the human-computer interaction interface (as shown in Figures 7 and 8). The use of the human-computer interaction interface of the weighing equipment remote fault diagnosis monitoring system greatly improves the convenience of staff work and reduces the workload of the staff, facilitating timely fault handling and ensuring the accuracy and efficiency of measurement. 
Figure 8: Diagram of the login interface on the mobile phone 
According to this, enterprises can reduce the loss and maintenance costs of each track scale by 1 million yuan per year. Currently, there are a total of 6 mining areas being monitored, and there are 9 track scales being measured, which can reduce the economic losses of enterprises by at least 9.45 million yuan annually. This
The system has achieved intelligent, unmanned, and highly accurate monitoring of weighing instrument failures, significantly enhancing the accuracy and reliability of large-scale weighing instruments in coal mines. This has brought substantial social and economic benefits to coal enterprises.
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Economic and Social Benefit Analysis
This system was piloted in 3 mines within the group, involving a total of 9 static truck scales. Originally, 4 people were required for maintenance. Now, the monitoring of weighing instruments in each mine has reduced the number of workers by 3 people each. Based on an annual human resource cost of approximately 150,000 yuan per person, the savings amount to 3 workers per mine × 150,000 yuan per person = 450,000 yuan.