Kf. Lyahou et al., A NONITERATIVE POLYNOMIAL 2-D CALIBRATION METHOD IMPLEMENTED IN A MICROCONTROLLER, IEEE transactions on instrumentation and measurement, 46(4), 1997, pp. 752-757
Output signal handling of a smart sensor usually involves a calibratio
n facility to correct for input-output nonidealities which comprise of
fset, gain errors, nonlinearity errors, and cross sensitivity. In this
paper, a calibration method is presented which features a progressive
improvement in the sensor calibrated transfer toward the desired tran
sfer as the user proceeds from one calibration point to the next, The
method is based on a set of mathematical formulas whereby a calibratio
n coefficient is calculated at a selected calibration point and used t
o calculate a first correction of the sensor transfer curve, Further i
mprovement in the sensor transfer is obtained by repeating the process
for a second calibration point using the transfer resulting from the
first calibration, without the need to review the calibration already
carried out at the first point, The process can be repeated until the
desired error reduction is obtained, Step by step, the calibration met
hod builds up a polynomial transfer correction, Simulation results are
shown to demonstrate the performance of the method. A software implem
entation of the method for two-dimensional (2-D) calibration in an 8-b
it microcontroller is presented, The microcontroller with calibration
program can be incorporated in a compact smart sensor system.