Errors Analysis Of Zero Deviation And Scale Factor Of Miniature Accelerometer

The miniature accelerometer is a sensitive component to measure the line acceleration in the inertial navigation system,and its accuracy directly affects the precision of the navigation system.Onboard accelerometer is manually assembled,and the connection mode of each part is mainly adhesive bonding.The thickness of the adhesive is at the ?m level,and the uniformity of assembly is poor,which affects the measurement accuracy of the accelerometer.This paper analyzes the effect of the uncertainty of the miniature accelerometer on the performance of the accelerometer in the assembly and the dimensions of the part itself.According to the structure of the accelerometer,its working principle and assembly process are analyzed,and the main factors affecting the measurement accuracy of accelerometer are determined.On the one hand,it is the error of zero bias of accelerometer,which determines that the major factors are the mismatch of material coefficient between parts of accelerometer and the assembly error of the adhesive;on the other hand,the nonlinear error of the scale factor of accelerometer is mainly affected by the uniformity of the magnetic field distribution of the working air gap of the torque converter.Due to the size of accelerometer is small and the thickness of the adhesive layer is thin,it is difficult to use the test method for quantitative analysis.Therefore,the method of finite element analysis is used to analyze the error of zero offset and the scale factor error of the accelerometer.Analyze the degree of influence of several assembly error forms produced by the adhesive layer on zero bias value during the actual coating process.The error forms include the edge spillover of adhesive,tilting error of adhesive layer assembly,and thickness and angle error of the glue block at the coil.It is concluded that the edge spillover of adhesive and tilting error of adhesive layer assembly have a greater influence on zero bias value.The edge spillover of adhesive layer at different positions can be compensated to a certain extent,but the edge spillover of adhesive layer should be controlled within 40?m as far as possible so that zero bias error can be controlled within 200?g.The tilting error of adhesive layer assembly has an obvious influence on the value of zero bias of accelerometer.It is necessary to ensure that the pendulum is parallel to the base to reduce the magnitude of the bias error.For the accelerometer's torque device,there are dimensional deviations of parts in the machining process and assembly deviations in the assembly process.Analyze the effect of the above deviation on the magnetic field performance.It is found that there is a negative deviation in the thickness of the magnetic steel,which has a greater influence on the uniformity of the magnetic field.The deviation of the height of the upper magnetic cap has great influence on the force of the coil in the magnetic field and the uniformity of the magnetic field,so it has a great influence on the nonlinear error of the accelerometer.According to the results,reasonable and feasible suggestions are put forward for the assembly process and machining of the torque converter.The above research work provides a basis for establishment of assembling technics,accelerometer improvement and performance enhancement.