Design Of Electromagnetic Balanced Type Pull And Pressure Force Sensors

Force sensors play an important role in the field of force measurement and they are the most widely used sensors in the field of force measurement.The sensor can measure mass,moment of inertia,force,moment,acceleration,and more.They widely used in auto,aviation,ship and other fields.This mainly aimed of design is that the current sensor has poor sensitivity and low precision.According to the principle of electromagnetic balance,a new type of electromagnetic balanced pull and pressure force sensor is designed.The measurement principle is simple,and it has high measurement accuracy,small volume and anti-interference ability,so it can be used in harsh environments such as low temperature and wet.This thesis first briefly describes the types of force sensors and the development status at home and abroad,and briefly introduces the advantages of electromagnetic balance pull force and pressure force sensors.The basic principle of the electromagnetic balanced type pull and pressure force sensor is expounded in detail,and the block diagram of the overall structure of the sensor and the block diagram of the sensor system design are given.Secondly,the three constrained conditions of the coil design are expounded,and the coil set and skeleton are designed according to the constraints.The flexible beam is modeled to obtain the parameters of the flexible beam and the appropriate materials are selected.Briefly describes the design and selection of the loading rod.According to the needs of the sensor design,the appropriate electromagnetic structure is selected.And the size of the magnetic circuit and the magnetic yoke is determined by theoretical calculation.Then the size of the permanent magnet is determined according to the calculation of the magnetic circuit.Thirdly,the signal processing circuit and software system are designed according to the design requirements of the measurement scheme.In the circuit construction process,experiments on some circuits are carried out,the experimental results are given for some circuits.The software system includes an A/D conversion program,an LCD program and the main program.An operation procedure for the piecewise linear interpolation function in the main program.Finally,a hardware test platform for the sensor was built.The measurement circuit of the system was verified by the experimental platform.The experimentalresults show that the designed circuit meets the actual needs.The analog signal results of the circuit show that the linearity of the sensor is ±0.07%,the sensitivity is24.99mV/g,and the repeatability error is ±0.5%.The experimental results of the analog quantity corrected by software show that the maximum relative error of the weight of the weight within 1.96 N is 0.045%.According to the data comparison before and after software correction,the software calibration method is effective.