Multipurpose Strain Signal Synchronous Scquisition System

Strain sensors have been widely used in the field of scales and monitoring of low and medium frequency vibration signals.Different application scenarios require dedicated different electronic measurement circuits,For example,multi-channel strain signal acquisition are required for roads,bridges,and industrial production,but foreign products are dominant and the market price is ecpensive.For solving this problem,a new type of multi-purpose strain signal synchronous acquisition system implementation scheme is designed in this paper,which can be directly used for real-time acquisition of low-frequency vibration signals,weighing of large-space objects,monitoring of IF vibration signal stability,etc.It will help for meeting requirement of market and replacing foreign products.The designed circuit included digital part and analog part.In analog part,the drivering excitations of multi-channel sensors can be programmed.The provided excitations are derived from the internal reference.When the module is powered on,the excitation voltage can be modfied from low to high,at the same time,the output of the sensor can be samely changed to realize the power-on inspection of the sensor and report the fault.The strain signal chains for acquisition can be programmable selected.The slowly changing strain signal uses a completely symmetrical differential excitation drive and a differential amplification structure of the strain signal.The rapidly changing strain signal is extracted by low-frequency components using the switch multiplication difference frequency shift technology and then filtered and sent to the ADC;A 24-bit multi-channel synchronous sampling ADC is adopted,and the strain signals of multiple channels are transmitted to STM32F103RBT6 through a single SPI;the digital part is Realize the processing and transmission of the collected data.After testing,the real-time transmission rate can reach 5k SPS,the data collection resolution can reach 0.01%,and human-computer interaction can be achieved through the host computer Lab VIEW and touch screen.This solution is multi-purpose,multi-channel,lower cost,supports field operations,and has rich interface communication functions.It can be used to collect low frequency strain signals,it can be used for vibration monitoring of building bridges,it can be used for vibration stability monitoring of electromechanical equipment,and it can support multi-point fusion weighing systems.