Interpolation method and shaft angle encoder

摘要

A method of interpolating between two signals comprising the conversion of each signal into digital form and use of the converted signals to address a memory device at each address of which is pre-stored the result of interpolation for a particular combination of values of the signals. One embodiment of the method resides in a shaft angle encoder having: sensor means regulated by an encoder disc to produce two analogue output signals, analogue to digital conversion means which convert the said analogue signals, a memory device in which the said results are pre-stored and memory addressing means which use the converted signals to cause corresponding pre-stored results to be output from the memory device.