Frequency fitting algorithm of control signals based on Hermite curves

The paper presents the process and methodology of nomination control signals based on the measurement signals. The process was made to allow for the determination of the replacement of the control signal in order to adjust its frequency to the frequency of operation of the control system. The purpose of the algorithm is to adjust the frequency of the measured signal to the frequency control circuit when the frequency of the signals from the measurements is too low. The algorithm is based on Hermite curves taking into account measurement signal and their first derivative. The paper also presents the verification of the algorithm. It has been tested to angular displacement measuring signals and their velocity in the human lower limb joints in the sagittal plane.