CN113746451B

CN113746451B - Filtering operation method of circular filter

Info

Publication number: CN113746451B
Application number: CN202110912651.8A
Authority: CN
Inventors: 武亚雄
Original assignee: Shenzhen Le Medical Technology Co ltd
Current assignee: Shenzhen Le Medical Technology Co ltd
Priority date: 2021-08-10
Filing date: 2021-08-10
Publication date: 2024-06-18
Anticipated expiration: 2041-08-10
Also published as: CN113746451A

Abstract

The invention provides a filtering operation method of a circular filter, which is characterized by comprising the following steps of: taking a continuous sinusoidal signal y=asin (ωx+Φ), wherein a is amplitude, ω is angular velocity, Φ is the initial phase; taking a circle with radius r, wherein the radius r is not more than one quarter of the period of the sinusoidal signal; the circle is inscribed in the wave crest or/and wave trough curve of the sine signal, a signal point is arbitrarily selected on the wave crest or/and wave trough curve between the two tangent points and is connected with the circle center, so that the intersecting circle is in an intersecting point, and the intersecting point is used as the signal value of the corresponding signal point after filtering. The invention can eliminate the pulse interference with large amplitude, can make the signal data smoother, has low realization cost and simple and convenient realization process based on the filtering algorithm of the circular filter, has wide application range and can be widely applied to the field of digital signal processing.

Description

Filtering operation method of circular filter

Technical Field

The invention relates to a filtering operation method of a circular filter, which is applied to signal processing in the fields of voice processing, image processing, audio and video and the like.

Background

In the field of informatization transmission such as voice processing and image processing, an original waveform is changed due to various irresistible interferences in the transmission process of signals, and the situation that an image or an audio signal is distorted is caused. To overcome this, it is necessary to set a filtering operation for the interference component in the signal, that is, to set a filter.

Currently, filters widely used are IIR and FIR. Wherein: IIR filters are not suitable for use when dealing with some signals with high phase requirements due to poor control of the phase characteristics, and have a narrow application space. The FIR filter has better stability and linear phase characteristics because of no feedback circuit, but the FIR filter has higher use of computational resources, memory and power consumption because of high precision, and the high frequency part can be excessively operated when solving the low frequency problem because the width of each processing unit of the FIR filter can not be adjusted. In addition, FIR filters are also relatively complex to implement.

Disclosure of Invention

Aiming at the defects of the filter, the invention provides a filtering operation method of a circular filter, which is realized by the following technical means:

The filtering operation method of the circular filter comprises the following steps:

Taking a continuous sinusoidal signal y=asin (ωx+Φ), wherein a is amplitude, ω is angular velocity, Φ is initial phase, x is time, y is signal value;

Taking a circle with radius r, wherein the radius r is not more than one quarter of the period of the sinusoidal signal;

The circle is inscribed in the wave crest or/and wave trough curve of the sine signal, a signal point is arbitrarily selected on the wave crest or/and wave trough curve between the two tangent points and is connected with the circle center, so that the intersecting circle is in an intersecting point, and the intersecting point is used as the signal value of the corresponding signal point after filtering.

The beneficial effects of the invention are as follows: the method can eliminate large-amplitude pulse interference, can enable signal data to be smoother, is low in implementation cost and simple and convenient in implementation process based on a filtering algorithm of the circular filter, has a wide application range, and can be widely applied to the field of digital signal processing.

Drawings

FIG. 1 is a schematic diagram of a peak curve inscribed in a sinusoidal signal with a circle having a radius of 1/2.

FIG. 2 is a schematic diagram of sample filtering of the peak curve between points within a circle with a radius of 1/2.

FIG. 3 is a schematic diagram of sampling and filtering positive and negative half-axes of a sinusoidal signal.

Fig. 4 is a schematic diagram of a peak curve inscribed in a sinusoidal signal for a circle with radius 1.

Fig. 5 is a schematic diagram of a peak curve inscribed in a sinusoidal signal for a circle with radius 2.

FIG. 6 is a schematic diagram of multipoint sample filtering of peak curves between tangent points within a circle.

FIG. 7 is a graph showing the result of filtering a circle with a radius of 1/2.

Fig. 8 is a schematic diagram of the filtering result of a circle with radius 1.

Fig. 9 is a schematic diagram of the filtering result of a circle with radius 2.

Detailed Description

The scheme of the application is further described as follows:

Referring to fig. 1 to 3 and fig. 6, the filtering operation method of the circular filter includes the following steps:

S1, taking a section of continuous sinusoidal signal y=10sin (pi x/4), wherein x is time and y is a signal value;

s2, taking a circle with a proper radius r, wherein the size of the circle can meet the requirement of being inscribed in a waveform curve, and the radius r is not more than one quarter of the period of a sinusoidal signal; in the embodiment, a circle with the radius r of 1/2 is taken, and the unit is seconds;

S3, the circles are respectively arranged on positive and negative half shafts of the amplitude of the sinusoidal signal, and the two circles are symmetrical relative to the origin of coordinates of the signal; respectively inscribing circles on a positive half-shaft crest curve and a negative half-shaft trough curve of the sinusoidal signal, and intersecting at two tangent points;

S4, any signal point is taken on a wave crest or/and wave trough curve between two tangent points and is connected with a circle center, so that the intersecting circle is at an intersecting point, and the intersecting point is used as a signal value of the corresponding signal point after filtering; namely, taking the highest point of a peak or trough curve between two tangent points, connecting the highest point with the circle center, and intersecting the circle at an intersection point, wherein the intersection point is used as a signal value of a corresponding signal point after filtering; similarly, connecting the rest points on the wave crest or wave trough curves with the corresponding circle centers to obtain a plurality of intersection points, namely the signal values of the points after filtering;

And S5, correspondingly generating a filtered map as shown in fig. 7.

The filter operation method is characterized in that the circles are respectively arranged in the positive area and the negative area of the sinusoidal signal so as to realize tangency and filtering with the crest curve of the opposite positive half axle and the trough curve of the negative half axle; the radius r of the circle may be generally selected from (0, 4) in seconds, see fig. 4, which shows a schematic diagram of a circle of radius 1 inscribed in the peak curve of the sinusoidal signal, correspondingly generating a filtered map as shown in fig. 8, and fig. 5, which shows a schematic diagram of a circle of radius 2 inscribed in the peak curve of the sinusoidal signal, correspondingly generating a filtered map as shown in fig. 9.

As shown in fig. 7 to 9, after the circular filtering with the radius of 1/2, the peaks and the troughs of the sinusoidal signals are slightly gentle, and the peaks and the troughs of the sinusoidal signals are gentle along with the increase of the radius, so that the radius of the circular filter can be reasonably selected according to the filtering requirement in the actual production and research and development process.

In order to obtain a better filtering effect, the radius of the selected circle is in a proper range, r is more than or equal to 0 and less than or equal to T/4 between the radius r of the circle and a sine signal, r is the radius of the circle, T is the period of the sine wave, and the filtering effect can be better realized under the condition; the coordinate position of the circle only needs to meet the requirement of inscribing the wave crest and wave trough curves of the sinusoidal signals.

The above-mentioned preferred embodiments should be regarded as illustrative examples of embodiments of the present application, and all such technical deductions, substitutions, improvements made on the basis of the same, similar or similar embodiments of the present application should be regarded as the protection scope of the present patent.

Claims

1. The filtering operation method of the circular filter is characterized by comprising the following steps of:

the circle is inscribed in a wave crest or/and wave trough curve of a sinusoidal signal, a signal point is arbitrarily selected on the wave crest or/and wave trough curve between two tangent points and is connected with a circle center, so that the intersecting circle is arranged at an intersecting point, the intersecting point is used as a signal value of the corresponding signal point after filtering, the circle is respectively arranged on a positive half-axle and a negative half-axle of the amplitude of the sinusoidal signal, and the circle is used for being respectively tangent with the wave crest curve of the positive half-axle and the wave trough curve of the negative half-axle of the sinusoidal signal;

The two circles tangent to the positive half-shaft peak curve and the negative half-shaft trough curve of the sinusoidal signal are symmetrical relative to the origin of coordinates of the signal;

the radius r of the circle is (0, pi/omega) in seconds.

2. The method of claim 1, wherein the radius r of the circle is 1/2, 1 or 2 in seconds.