Design Method of Adaptive Optimal Phase Angle Notch Filter

Abstract

The invention particularly discloses a design method for a self-adaptation optimal phase angle notch filter. The design method is used for restraining narrow-band signal interference on unknown frequency bands so that a system can have the characteristic of offsetting wide-band random interference signals on a low-frequency band. According to the design method, a system loop module comprises an object model module, a robust controller module and a self-adaptation optimal phase angle notch filter module. The design method comprises the specific steps that (1) object model discretization is established; (2) a robust controller is designed; (3) an optimal phase angle notch filter is designed and is connected to part of a system loop; (4) according to a P(s) C(s) transfer function, an improved minimum mean square value self-adaptation algorithm is adopted, H8 mixing sensitivity control is introduced to design the robust controller, so that a notch center frequency tracks an unknown single-frequency interference frequency, and optimal restraint of the random interference signals and unknown single-frequency interference signals is achieved; meanwhile, multi-source interference signals including the wideband random interference signals, the unknown single-frequency interference signals with a plurality of frequencies and the like can be restrained at the same time.

Description

technical field [0001] The invention belongs to the technical field of control engineering and science, and in particular relates to a design method of an adaptive optimal phase angle notch filter. Background technique [0002] In the servo mechanism used in practice, there are often some interference signals concentrated in narrow frequency bands. Many experts and scholars at home and abroad have also proposed many filtering or control methods. For example, in the low frequency band (100–600Hz), peak filters are often used to effectively suppress low-frequency narrow-band interference. An IF disturbance around the ring crossover frequency, because of its inherent phase loss of phase margin, distorts the system loop sensitivity gain near the disturbance frequency. In the mid-frequency band (about 1.6kHz), the existing technology often uses a phase-leading peak filter to suppress the mid-band narrow-band interference that appears in the system. In order to ensure the phase m...

AI Technical Summary

Problems solved by technology

Although these filter or controller designs have a good ability to suppress narrow-band interference, they can only effectively suppress narrow-band interference in a limited frequency range

The emergence of the adaptive filter has greatly promoted the development of the field of unknown frequency interference, but the main problems in the general adaptive filter method are: the algorithm is complex, the dimension of the filtering parameters is too high, the adaptive time is too long, and the real-time performance of the system Greatly reduced

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