Optimal Design And Characteristics Study On Magnetic Fluid Micro Differential Pressure Sensor

Magnetic fluid is a new functional material which has both magnetism and fluidity.It has a broad application prospect in the fields of sealing,damping,sensing and lubrication.The application of novel magnetic fluid material in micro-differential pressure sensor technology is a brand-new idea.But in this research,the unique advantage of magnetic fluid micro differential pressure sensor will clearly lead to new developments in sensor technology.This paper studied a new type of magnetic fluid micro differential pressure sensor.The size parameters affecting the performance of sensor were considered and then the structure sizes of sensor were preliminary designed and optimized.Characteristics of sensor were analyzed through simulation and experiment.The main research contents are as follows:Firstly,it explores the structure model and sensitivity equations of the sensor,then after structure parameters and materials for sensor components are determined.The simulation model of magnetic fluid micro differential pressure sensor is established in the finite element.The influence of sensor pressure resistance on measurement range is analyzed along with the influence of damping force between magnetic fluid and glass tube on the accuracy of sensor.The sensor pressure resistance formula is derived by simulating the magnetic field intensity curve of the intermediate permanent magnet.The damping coefficient formula is derived by analyzing the damping between magnetic fluid and glass tube in the sensor.Secondly,multi-objective optimization algorithm based on Pareto optimum solution is used to optimize the sensor structure.Sensitivity,range,accuracy and dimension of sensor are optimized based on sensor's structure size,then after structural parameters before and after optimization are compared.The optimized dimension is then used into simulation model in order to obtain the relationship between magnetic force and displacement of intermediate permanent magnet.Then after,Hall element output characteristic curve is developed.Multi-range magnetic fluid micro differential pressure sensor is designed and the output characteristics of sensors in three measuring ranges are finally obtained based on simulating magnetic induction detected by hall element under different positions.Finally,the static and dynamic characteristics of the sensor are studied.The static output sensitivity in multiple programs are consistent with finite element simulation results.Simulation model of step pressure response is established in finite element and step response characteristics of sensor are obtained and all of these made calculation of natural frequency and damping ratio of sensor become possible.