Computer Modeling of the Impact of Redundancy on the Accuracy of Determining the Current Parameters of the Sensor Logarithmic Transformation Function

Determination and control of sensor parameters is one of the main reasons for obtaining reliable information, since it allows timely detection of deviations in the operation of the sensor and the entire automated system as a whole. Therefore, the purpose of the work is to increase the accuracy of measuring the current values of the parameters of the nonlinear sensor transformation function. Computer modeling was carried out using the example of a silicon photodiode FD307 photodiode with a logarithmic conversion function. As a result of the modeling, such values of calibrated fluxes were found, which ensure that the values of the parameters of the conversion function are obtained as close as possible to their real (simulated) values. At the same time, the values of the relative errors of parameter determination are hundreds and thousandths of a percent. The work also considered the influence of the dark flux parameter on the accuracy of determining the current values of the parameters of the conversion function. It was established that the deviation of the value of the dark flux value from its nominal value significantly affects the voltage value on the ohmic elements of the diode and does not affect the value of the thermal potential. For high-precision measurement of the current parameters of the conversion function, the recommended deviation of the dark flux should not exceed one percent. As a result of applying redundant methods for a photodiode with a logarithmic transformation function, the following conclusions were obtained: 1) determining the current value of the thermal potential according to the equation of redundant measurements does not depend on the voltage deviations on the ohmic elements of the diode, 2) determining the current value of the voltage on the ohmic elements of the diode according to the corresponding equation of redundant measurements depends on the thermal potential deviations, 3) the values of the calibrated flows affect the accuracy of determining the current values of the parameters of the logarithmic transformation function, 4) to obtain the values of the parameters of the transformation function that are as close as possible to their current values, it is necessary to set fixed values of the calibrated flows, 5) the accuracy of determining the voltage on the ohmic elements of the diode is also strongly influenced by the value of the dark flux, 6) the deviation of the value of the dark flux from the nominal value indicates structural changes in the sensor, which is a signal to replace it.