System and method for monitoring civil engineering strained base on CAN network

Abstract

The invention relates to a system and a method for monitoring stress of civil engineering based on a CAN network, belonging to the technical field of civil engineering monitoring. The device comprises a master control computer, a PC-CAN interface module, an acquisition unit and a topology network of a CAN bus, wherein the acquisition unit comprises a microprocessor, a CAN module, a CAN indication setting module, a date and time setting module, a memory extensive module, a wire collecting case, a vibration exciting and pick-up circuit, a shift switch for an analog channel and a power supply management module. The master control computer and the acquisition unit on the CAN network exchange commands and data through the PC-CAN interface module; the acquisition unit receives a command of the master control compute to complete the acquisition of data of a multi-path vibrating wire sensor, and packages the data according to a standard format to be uploaded to the CAN network. The system can acquire the physical quantity of a sub-node distantly, flexibly and reliably. The system and the method can be widely applied to stress monitoring for various civil engineering.

Description

technical field [0001] The invention relates to a monitoring system and method in the technical field of civil engineering monitoring, in particular to a CAN network-based civil engineering force monitoring system and method. Background technique [0002] Exciting vibrating wire sensors are widely used in construction, water conservancy projects, railway transportation, metallurgy, coal and other departments due to their simple structure, long-term stability, reliability, and low cost. Monitoring of force conditions such as pressure and tension. A large number of sensors are arranged in the structure, often ranging from dozens to hundreds. With the rapid development of my country's economic construction, the application of vibrating wire sensors is becoming more and more extensive. Measuring and reading the frequency value of the vibrating wire sensor is a commonly used method at present. The engineering monitoring personnel use the frequency meter to read the output freque...

AI Technical Summary

Problems solved by technology

The civil engineering force monitoring system based on RS485 network composed of the vibrating wire sensor has the following deficiencies: [1] Compared with the ordinary vibrating wire sensor, the cost is greatly increased due to the addition of the internal circuit, and the sensor is buried (concrete poured) It can no longer be reused, thus increasing the cost; [2] The theoretical transmission distance of the RS485 network is 1200 meters, so the monitoring network is difficult to meet the monitoring of dams, tunnels, subways, etc.; [3] RS485 is a half-duplex electrical protocol , at any time, the network can only allow one node on it to send data to the bus. If some nodes on the bus fail, or the scheduling of the upper computer of the system fails, the entire monitoring network will be paralyzed; [4] RS485 It is only an electrical protocol, which does not provide a reliable and efficient communication protocol, which increases the difficulty and development cycle of the system development, and reduces the flexibility of the system; [5] The communication rate of the RS485 bus is directly related to the communication distance. As the transmission distance increases, the common baud rate is 9.6KBPS. When the communication distance reaches hundreds of meters, the reliable communication rate is less than 1.2KBPS, so the data throughput of the monitoring network is low

[0004] Because the civil engineering force monitoring system based on the RS485 network has many shortcomings such as the above, it is difficult to meet the system's requirements for real-time performance, reliability, transmission distance, flexibility, and data exchange volume.

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