SU622040A1 - Non-linear band-pass filter - Google Patents

Description

I

The invention relates to the field of automation and computer technology and can be used to correct automatic control systems, to the dynamic characteristics of which there are increased requirements.

Nonlinear filters are known which are intended to separately form the amplitude and frequency characteristics of the automatic control system 1, 2.

Of the known nonlinear filters, the closest in technical essence is a nonlinear filter containing two correction units, the inputs of which are connected to the input of the filter, and adder 2.

However, the prototype device introduces amplitude and phase distortions in the filtering range, and using it as a low-pass filter results in a slower response of the corrected system, since it suppresses all input signals that follow a frequency higher than the tuning one.

The aim of the invention is to improve the accuracy and expand the scope of application of nonlinear correction devices for the correction of automatic control systems.

The goal is achieved due to the fact that two sigium relays, a matching unit and a multiplication unit, to the first input of which the inputs of correction blocks are connected, are added to a known nonlinear filter; through the first and second signal relays with the outputs of the first and second correction blocks, and the output of the multiplier is connected to the output of the device.

The drawing shows a block diagram of a nonlinear bandpass filter. It contains the first 1 and second 2 correction blocks, the first 3 and the second 4 signal relays, the adder 5, the matching block 6 and the multiplying block 7.

Nonlinear bandpass filter works as follows.

The input signal is supplied simultaneously to both blocks 1 and 2 of the correction and to the first input of block 7 multiplication.

In general, the transfer functions of the 1, 2 correction blocks are as follows:

V (, (p) Tlp + l, W, (p) Tlp + l,

Claims (2)

where p is a symbol of differentiation. A link with a transfer function of the type is characterized in that its phase-frequency characteristic at frequencies ω changes by 180 °, i.e. the sinusoidal signal at the output of such a link is out of phase with respect to the input signal. The outputs of blocks 1, 2 correction connected to the inputs of the signal-relay 3, 4, respectively. The signals from the outputs of Signumrell 3, 4 are fed to the adder 5, the output of which is connected to the input of the matching unit 6, and the output of the latter is connected to the second input of the multiplication unit 7. If the signals at the outputs of the I, 2 correction blocks are in phase with respect to each other, then the output signal corresponds to the input signal. Otherwise, the output signal is zero. The operation of a nonlinear nolocular filter is supposed to be described by the following equation: you: f / Bx., Sign (U, W,) + Sign (U ,. W,), where (Uvh and f / o are input and output signals, respectively. This nonlinear filter structure allows it to be used: as a low-pass filter at 1F, (0- + 1 and W, {p) as a high-pass filter at w, (p) -l and w, (p} TY + i; as bandpass filter, as it allows to skip without distortion at W. (P) - (Tip + 1), W, (p) Tip + 1; or suppress without distortion at ((p), W, (p) Tlp +; T.hT, a certain band of the frequency spectrum of the input signal. This allows not Not only as a low-pass or high-pass filter, but also as a band-pass filter itself, i.e. to pass or suppress a certain narrow band of the frequency spectrum of the input signal, which significantly expands the scope of its use, therefore it can to find application in those automatic control systems, to whose dynamic characteristics increased demands are made. Claims of the invention A non-linear bandpass filter containing two correction units, the inputs of which are connected to the filter input, and an adder, characterized in that, in order to improve the accuracy of the filter, it contains two signal relays, a matching unit and a multiplication unit, to the first input the inputs of the correction blocks are connected to the second input via the matching block — an output of the adder, the first and second inputs of which are connected respectively via the first and second signal-relays to the outputs of the first and second correction blocks, and the output of the block is : Eni is connected to the output of Iltra. Sources of information taken into account in the examination 1. USSR author's certificate 197721, cl. G 05B 5/00, 04.26.66. 2. USSR author's certificate 377725, cl. G 05B 5/01, 06.08.71.