Effect Of Glue Layer Error And Heat Transfer On Hysteresis Of Miniature Accelerometer

The accelerometer is one of the basic measuring elements in the field of inertial navigation.It measures the acceleration of an object indirectly by measuring the inertial force of the object.Its application has been involved in aerospace and military missiles,and its accuracy has a direct impact on navigation accuracy.In this paper,we study the influence of glue layer error and temperature non-uniformity on its hysteresis for a certain type of Strapdown flexible pendulum miniature accelerometer to obtain the influence law of each type of glue on the temperature hysteresis value,and use this as According to accelerometer glue coating process improvement.Airborne accelerometers are used in variable temperature environments,but their assembly processes use epoxy resin glues to combine components together.Temperature changes cause creep and hysteresis.The temperature hysteresis phenomenon reflects that the zero value of the accelerometer is inconsistent in the same temperature point during the heating and cooling process during the heating and cooling cycle.High-viscosity epoxy resin glues currently use manual assembly mode,which results in errors such as shape and thickness in the glue layer,so the accelerometer bias stability is not high.In this dissertation,the heat transfer simulation of the tiny accelerometer is firstly carried out.The wall surface temperature cycling condition adopts the temperature rising and cooling rate of 0.6°C/min,and the high and low temperature(-45?—80?)heat preservation time is 2h.The temperature curve at the center point of each glue layer is obtained through simulation calculation.The temperature change curve of the glue layer 3 is used as the temperature load in the viscoelastic simulation model.The ABAQUS finite element simulation software was used to model the accelerometer in three dimensions.The temperature curve obtained before was used as the temperature load.The thickness error of the glue layer,the glue layer overflow error,the glue layer tilt error,the glue layer bubble defect and the glue layer spalling defect on the temperature hysteresis value were analyzed and calculated.The results show that the glue layer overflow has a greater impact on the hysteresis value.When the overflow volume is 0.03 mm,the hysteresis value of the first cycle can reach 260?g.The thickness of the glue layer is within the allowable range of the design and decreases with increasing thickness.When the glue layer tilted to half the thickness of the glue layer,the maximum hysteresis value of the hysteresis loop in the first cycle reached 120 ?g.In order to verify the simulation results,16 finished miniature accelerometers were selected to perform the same temperature cycling test as the simulation conditions.The results showed that the temperature hysteresis of the 12 accelerometers was within 100 ?g,which was a qualified product;the temperature hysteresis values of the two accelerometers were within 100?g-200?g,it belongs to inferior products;the hysteresis value of two accelerometers is more than 200?g,which is unqualified.The accelerometer of the qualified product is the same magnitude as the temperature hysteresis value of the simulation result.Two compensation schemes are proposed for temperature hysteresis,namely linear compensation method(Factory test phase)and mutual cancellation compensation method(Production stage).The linear compensation method fits the output curve of the heating process and the cooling process to a quadratic polynomial,extracts its constant term through data processing and integration analysis,and obtains the best linear compensation value of 54?g.The mutual cancellation compensation method uses the two glue layer errors to cancel each other's influence on the hysteresis value,thereby obtaining a lower hysteresis value.The most obvious combination of the thickness of the glue layer 2 is 6?m and the thickness of the glue layer 3 is 6?m.The hysteresis value of the first cycle is reduced by 19%,and the hysteresis value of the second cycle is reduced by 20%.The above research work provides a theoretical basis for the optimization of the assembly process of accelerometers and the selection of temperature hysteresis compensation methods.