Design And Development Of Multi-channel Isolated Data Acquisition Card For Air-floating Gyro Motor

As the core device of the gyroscope in the inertial navigation system,the gyroscope motor is directly used to drive the gyroscope,which has a decisive influence on the accuracy of the inertial navigation product.It generates back EMF during start to stop,which will cause greater harm to the gyroscope motor and peripheral circuits.,Affect the service life of the motor,and ultimately affect the service life of the inertial navigation products.Relying on the dynamic pressure motor life evaluation system of a certain aerospace institute,this topic designs a multi-channel isolated data acquisition card for the back-EMF monitoring of the air-floating gyro motor.According to the characteristics of back-EMF and the environmental conditions of the field test,this paper designs and develops a two-channel data acquisition card with low noise performance,high dynamic input range,and excellent isolation performance.The paper first introduces the overall scheme of the acquisition system,and then introduces the detailed design schemes of each module,and at the same time introduces the relevant theoretical knowledge involved in the design process,mainly including the relevant knowledge and schemes of low-noise circuit design,system isolation schemes,And system power supply design.The system adopts a portable USB3.0 high-speed interface,FPGA realizes the control of each hardware circuit and the realization of the acquisition card function for the system hardware controller,and finally uses Labview to design the upper computer software to complete the overall function realization of the acquisition system.Through the overall performance test and analysis of the circuit modules and the acquisition system,all indicators meet the design requirements.The system can test signals in the range of 40?V to 200V_pp,with a dynamic range of up to 133d B,and the isolation between the two channels has reached more than 100d B.At the same time,the local noise of the capture card is as low as 10?V,which solves the complex problems of large dynamic range and strong electromagnetic interference in the test site during the back-EMF test of the gyro motor.