Research On Temperature Characteristics Of Cable Force Detection And Development Of Cable Force Meter

Steel cable is more and more widely used in the field of bridge construction,and cable as the main force components bears the responsibility of the entire bridge safety.Cable force detection is an important means of cable health monitoring and the unbalance of cable force is often the main cause for the occurrence of security incidents.In this paper,the magnetoelastic effect method is used to measure the cable force,and the mechanism of temperature influence on the method is studied.The aim is to improve the precision of cable force measurement.In order to realize the cable force measurement,this paper established the hardware platform of the cable force instrument.Based on the embedded Linux operating system,the application software of the cable force meter is designed,and finally the development of the cable force meter is realized.This paper introduced the principle of force detection based on magnetoelastic effect.Then,the influence of temperature on the magnetization effect is studied based on the theory of Weiss molecular field.The measurement model of a binary quadratic function of stress and temperature is used to correct the force measurement error caused by temperature.The hardware platform mainly includes excitation module and data acquisition module.The excitation module is used to provide the strong current required for the excitation coil of cable force sensor,to generate the voltage on the induction coil.The data acquisition module includes sub-modules of A/D converter,FIFO data cache and CPLD control circuit.The digital signal of the induced voltage is finally stored in the cache chip under the coordination of each sub-module.Application software design of cable force meter includes embedded Linux driver design and application development.On the basis of the Linux Character Device driver framework,the driver design of the cache device is completed,and the device file for connecting the hardware device and the application program is generated.The application software uses the Qtopia graphical user interface application framework,and completed the design as well as the function implementation of the UI interface.The ultimate goal of application development is to generate executable file by cross-compiling.In order to study the temperature characteristics of cable force detection,this paper designed a small loading device,carried out the environmental temperature testing of cable force detection,and fitted the binary quadratic function of cable force measurement according to the experimental data.