Test Rig for the Calibration of Multi-Component Sensors in Three Degrees of Freedom for Drive Monitoring

Inhalt:
This paper presents the development and the validation of a test rig for the calibration of multi-component sensors. The central component is a round shaft mimicking a part of a circular saw blade. The device to be calibrated, mounted on the shaft, is the SB17 sensor chip which is sensitive to mechanical stress in six dimensions (3x force, 3x torque). In order to apply a well-defined mechanical stress, the shaft is mounted such that a two-dimensional bending force or a one-dimensional torsional moment can be applied. The shaft has been designed using finite element simulation so that the test rig covers a major part of the measurement range of the SB17 sensor chip. It is also possible to locally heat the SB17 sensor chip to investigate the influence of temperature variations. Using a linear regression method called “half blind calibration”, a maximum error of lower than 6.4 % and a root mean squared error (RMSE) of lower than 1.2 % could be achieved, both relative to the full scale across all four possible loads (3x mechanical and 1x temperature). In terms of the RMSE, our approach performs significantly better compared to a state-of-the-art publication using a similar load range.