Предложена структура двухканальной адаптивной цифровой системы для динамического измерения частоты и амплитуды квазигармонических сигналов с медленно меняющимися параметрами. Показано, что данная система требует небольшого количества операций и может быть реализована как система реального времени на базе современных микроконтроллеров. Приводятся результаты численного моделирования процесса измерения частоты и амплитуды с помощью предложенной системы.

A method for dynamic measurement of frequency and amplitude of quasi-harmonic signals with slowly varying parameters is proposed. Parameter estimates are obtained in the approximation of the limited spectrum of the signal. Expressions describing systematic and random errors of the developed method in the presence of additive noise with a given variance are presented. On the basis of these expressions, the optimal conditions of the method operation are determined and an algorithm is developed that allows updating the frequency and amplitude estimates at each sampling interval. The algorithm is implemented as a two-channel adaptive digital system, which does not require a large number of operations and can be implemented as a real-time system based on modern signal processors and microcontrollers. The results of numerical modeling of the process of frequency and amplitude measurement using the proposed system are presented. It was found that even in the presence of tone amplitude modulation, additive noise, and slow twofold frequency change, the relative errors of frequency and amplitude estimates are 9.2 ・ 10−4 and 3.6 ・ 10−3, respectively. The data obtained show that the adaptive system gives better results than the system without adaptation if at least an approximate frequency value is not known in advance.