SU655078A1 - Noise protection device - Google Patents

Description

If, in the registration resolution interval at the input, there is a disturbance in the form of a burst of pulses (P2; PZ), then the first impulse of the P2 interference, passed through the AND 2 element and the OR 6 element, will reset trigger 5 and counter 4 and exit trigger 5 to the element input And 2, the prohibition of all subsequent interfering pulses and the desired signal will be received until the counter 4 counts the pulses from the output of the generator 3. At the same time, the first interfering pulse is recorded as a useful signal (Fig. 2d, d), and the measuring signal C1 does not pass to the registration. Thus, the presence of interference in the recording resolution interval does not change the total number of recorded signals (the number of sensor steps), but only leads to a one-time error in accurate phase determination, but in the next period of the measuring signal the correct phase position will be established, i.e. position information will be restored.

FIG. Figure 2e shows the disappearance of the signal. Since the reset of counter 4 does not occur at the appropriate time (signal C2 did not pass from the input to the output signal bus), then counter 4 has time to count NZ pulses ((j and from the second output of counter 4, an artificial signal P1 is output through the element OR 6) (FIG. 2g, i, i) for registering and resetting the device to the initial state.

 and are selected on the basis of considerations of the maximum possible change in the phase of the measuring signal in one period while the sensor is moving at maximum speed.

Providing noise protection in a wide range of variation of the period Go is ensured by the fact that oscillator 3 is a blockable frequency multiplier with a multiplication factor LG.

An example of a practical implementation of the generator is shown in FIG. 3, which is a phase locked phase locked loop (PLL) of the controlled oscillator.

The key 13 and the trigger 14 allow the signal from the second output of the counter 4 (Fig. 1)

remember the current multiplier frequency

with the disappearance of the measuring signal,

and hence the PLL.

Input 15 is the input to the multiplier and

reset trigger 14 to return from

memorizing in frequency multiplication mode.

In case of no interference, generator 3

gives NQ pulses per input

signal at input 15. If the output signal has disappeared under noise conditions, then after counting by a counter 4 N pulses, a flip-flop 14 trips over bus 16, key 13 opens and connects the input of integrator 10 to the zero potential bus, stabilizing the voltage at the integrator's output 10 and thereby fixing the frequency of the controlled oscillator before the arrival of the useful signal.

The use of the proposed technical solution makes it possible to improve the noise immunity of devices for measuring displacements with phase sensors, thus increasing the accuracy of measurement of RI and ensuring reliable operation of devices in mechanical workshop conditions.

Claims (1)

Invention Formula An interference protection device containing a pulse shaper, a clock pulse generator and a serially connected counter, trigger and AND element, characterized in that, in order to increase the degree of protection, an OR element is inserted into it, and the pulse shaper output is connected to the second input of the AND element The output of which is connected to the combined first inputs of the clock generator and the OR element, the combined second inputs of which are connected to the second output of the counter, the first input of which is connected to the output of the generator the documentary pulses, and the combined second the inputs of the counter and the trigger are connected to the output of the OR element. Sources of information taken into account in the examination 1. V. Gurov and others. The transfer of discrete information and telegraphy. M., “Holy, 1974, p. 66 ; --kg - H:: -: GM-. } about J UlJJ LUlilJlUiilJJlLLL g5