Temperature Drift and Instability of a Zero Signal of Pendulum Compensating Q-Flex Accelerometer

Abstract

A main issue in high precision navigation grade accelerometers development is a provision of a zero signal and a scale factor stability and repeatability. A development and research experience for Q-flex and Si-flex compensating accelerometers allows to determine main causes of such instability and non-repeatability. Main causes are as follows: •manufacture errors in beams of an elastic suspension of a pendulum blade such as a non-flatness, a surface roughness, displacements of beam planes to general plane (both parallel displacements forming a box and angular rotations of beams); •deformations and shape distortions of beams during spraying metal of current leads; •a material structure heterogeneity in magnetic housings and pole cups of a plunger torque sensor of a device; •material structure changes in magnetic housings during operation of the device, primarily during temperature cycles. A number of technological errors in accelerometer elements leads to an appearance of stepwise changes in the zero signal and the scale factor, which are not amenable to algorithmic compensation. These errors are associated with features of super invar and quartz elements in devices, as well as with the features of technological processes. The paper describes a number of experimental observations carried out with Q-flex accelerometers from various manufacturers, gives an analysis of errors causes and provides recommendations to eliminate these considered errors.