A Wireless Apparatus For Monitoring The Strain On Moving Objects

In term of monitoring mechanical system work condition, monitoring the stress and strain of moving objects(such as rotating object) is of great importance. However, there are problems in the methods of monitoring because the wire can't connect directly with the strain gauge during monitoring. If choose the carbon brush to connect, the strain signal would be missing because of the fluctuation of carbon brush's resistance. To solve this problem, a wireless monitoring system is designed to achieve the signal acquisition, processing and wireless transmission in this paper. Analyze the working principle of resistance strain slice and bridge circuit theory to know the specific process that the strain signal becomes the electrical signal. Achieve the signal conditioning process and result through the design of amplifying circuit and second-order active low-pass filter circuit, the selection of hardware and the circuit simulation in NI Multisim. Choose ATmega 328P-AU as the system apparatus controller chip. Choose HC-05 Bluetooth chip to realize the wireless connection between the system device and display module. Use the Arduino to program to implement the system device for strain signal acquisition, processing and wireless transmission. Design the PCB of system apparatus through Altium Designer and complete the whole model of the system apparatus. Set up an experimental platform to verify the feasibility and reliability of the apparatus. Experimental results and the data show that the strain value measured by the system apparatus designed in this paper is proportional to the loading and the strain value measured by static resistance strain gauge, which means this system apparatus can provide practically reference of strain value.