Adaptive Bandwidth PLL Design Based on Fuzzy Logic Control

Abstract

Based on fuzzy logic control adaptive bandwidth PLL design is presented for the problem of tracking poor stability and low accuracy when a certain type of radar tracking dynamic spacecraft. This method is mainly through fuzzy logic controller, adaptive level is determined by control rule of input respectively, and the outputs of rules are weighted combined to control the coefficient of loop filter, thus adjusting automatically the loop bandwidth, and enhancing the tracking stability of radar equipment and improving ranging accuracy. The simulation results show that the fuzzy logic control adaptive bandwidth PLL has higher tracking stability and accuracy.

An Adaptive Fuzzy-PI Clock Servo Based on IEEE 1588 for Improving Time Synchronization Over Ethernet Networks

“…Using the fuzzy logic, the clock servo can reach a short setting time and guaranteed high time synchronization without training time for updating weights [31]. Our main idea in this paper is to design an adaptive PI controller based on fuzzy logic [32], [33]. Normally, a PI clock servo uses a compensation method that can be described as follows: By combining (9) and 11, the transfer function of the closed loop clock servo can be described as:…”

“…The output for the fuzzy block is between -1 and 0.2 rad. Based on [32] and [33], seven fuzzy sets of absolute offset and skew were designed as super small (SS), small (S), below medium (BM), medium (M), over medium (OM), large (L), and super large (SL). The delta bandwidth is included in six fuzzy sets: SS, S, BM, M, OM, and L. The input and output values are chosen based on algebraic values of those sets.…”