SU1112305A1 - Device for processing frequency pickup signals - Google Patents

Abstract

A DEVICE FOR PROCESSING SIGNALS OF FREQUENCY SENSORS, containing an input driver, whose input is the input of the device, a processor, first and second counters, first and second elements And, trigger, element Sh1I and generator of the reference frequency, the output of which is connected through the first element And with the counting input the first counter, the output of the latter is connected to the first input of the processor, the output of the OR element is connected to the D input of the trigger, the direct output of which through the second element AND is connected to the counting input of the second counter, inverse to The trigger output is connected to the second input of the processor. The third input of the latter is connected to the output of the second counter, characterized by that. that, in order to improve the measurement accuracy and reliability of the information received, a timer, divider, switch, delay element, EXCLUSIVE OR element are entered into it, the generator output of the reference frequency is connected to the first input of the timer and through the divider to the first input of the switch, the second input of which is connected with the output of the input driver, the third input of the switch is connected to the first output of the processor, the output of the switch is connected to the second input of the second element I through a delay element and to the input of the trigger directly In principle, the forward 1 output of which is connected to the second input of the first counter and the first input of the EXCLUSIVE OR element, the second input of which is connected to the timer output, the fourth processor input and the first input of the OR element, the output of the EXCLUSIVE OR element, and the second the processor output will be set to the second timer input, the third processor output is connected to inputs Reset the second and first counters, the sign output of the first counter is connected to the second input of the OR element, the fourth output is tsessora is informa.tsionnym output device.

Description

The invention relates to automation and digital measurement technology and is intended to automatically correct the measurement error of the signals of the frequency sensors. . A device for processing frequency sensor signals is known, comprising an input driver, element 2I-2ILI, reference pulse generator, element I, counter, output register, display unit, control circuit, timer, control unit, three groups of elements AND, control inputs from Digital computer In this device, an automatic correction of the measurement result is achieved depending on the parameters of the set frequency sensor. In this case, the measurement time is determined from the relation where t is em, the measurement time for a sensor having a slope of characteristic 5,, tpgp is the standard interval of the measurement time, depending on the required resolution SOBP — the slope of the characteristics of the reference sensor. In the counter after the end of the measurement, the value of the measured emog parameter is recorded. and - -j- i where and (p) is the frequency obtained from the watchdog sensor with the value of the parameter P; {- measurement error from the imperfect sensor characteristic caused by the frequency at its output, equal to fo when the measured parameter value is zero 13. Device drawback - low reliability of information while providing speed, - due to the use of the measurement method often by direct impulse counting measured frequency. The closest in technical essence to the present invention is a device for measuring the frequency and period of the Harmonic signal, which simultaneously simultaneously pulses the model and unknown frequencies, comprising a processor, two counters, two code decoders, seven AND elements, an OR element, three triggers, the generator of the reference frequency and the input driver, the device input through the input driver is connected to the first inputs of the third and sixth elements AND, the second input of the last is connected to the processor INPUT, and the output is with the first input of the second trigger, the second input of which is connected to the output of the OR element, its inverse output is connected to the first input of the processor, and its direct output is connected to the second input of the third And element and the first input of the second And element, which, in turn, the second input is connected to the generator output at an exemplary frequency, and the output through the seventh AND element is connected to the first input of the OR element, through the first AND element, the first trigger and the AND element to the second input of the OR element and, moreover, with the counting input of the first sch This output is connected;: the second input of the processor and through the first decoder to the second input of the first element AND, except for that, the output of the third element AND is connected to the first input of the fourth element AND, the second input of the fifth element AND and the counting input,. The second counter, the output of which is connected to the third input of the processor and the input of the second decoder, the output of which, in turn, is connected to the second input of the fourth element I, whose output through the third trigger is connected to the second input of the seventh element C 21. A disadvantage of the known device is Low measurement accuracy due to the lack of automatic correction of the measurement mode depending on the steepness of the characteristics of a particular sensor, which can lead to an error exceeding the allowable one. In addition, the known device does not provide automatic control, which reduces the reliability of the measurement results and the reliability of the operation of the device. 3 The purpose of the invention is to improve the measurement accuracy and increase the reliability of the received information. The goal is achieved by the fact that the device for processing frequency sensor signals containing the input driver, whose input is the input of the device, the processor, the first and second counters, the first and second trigger elements, the OR element and the generator of the reference frequency, the output of which is connected through the first element AND to the counting input of the first counter, the output of the latter connected to the first input of the processor, the output of the element SHIII oedinen with b-input of the flip-flop, which is directly output through the second AND gate is connected to the counting input; the second counter, the inverse trigger output is connected to the second processor input, the third input of the latter is connected to the output of the second counter, a timer, a divider, a switch delay element, an EXCLUSIVE OR element are entered, the generator frequency of the reference frequency is connected to the first timer input and through the divider to the first input the switch, the second input of which is connected to the output of the input shaper, the third input of the switch is connected to the first output of the processor, the switch output is connected to the second input of the second element I through an The delay point and with the trigger input directly direct output of which is connected to the second input of the first counter and the first input of the EXCLUSIVE element OR whose second input is connected to the timer output, the fourth input of the processor and the first input of the OR element, the output of the EXCLUSIVE OR element is connected to the second the input of the first element is And, the second output of the processor is connected to the second input of the timer, the third output of the processor is connected to the inputs Reset the second and first counters, the sign output of the first counter is connected to the second input of the element and Hilti, fourth processor output is a data output device. Figure 1 shows a diagram of a device for processing signals of frequency sensors, figure 2 shows time diagrams explaining the operation of the device. 054 A device for processing signals of frequency sensors contains a processor 1, first 2 and second 3 counters, first 4 and second 5 elements AND, trigger 6, element SHSh 7, input driver 8, generator 9 of exemplary frequency, delay element 10, element EXCLUSIVE OR 11 , switch 12, timer 13, divider 14, input 15 and output 16 of the device. The output of Generator 9 is connected via the first element 4 and 4 to the counting input of the first counter 2, the output of the latter is connected to the first input of processor 1, the output of element 7 is connected to the L input of a trigger 6, the direct output of which through the second element 5 is connected to the counting input of the second counter 3, the inverse output of the trigger 6 is connected to the second input of processor 1, the third input of the latter is connected to the output of the second counter 3, the output of the generator 9 to the first input of the timer 13 and through a divider 14 to the first input of the switch 12, the second input of which is connected to the output the input of the imaging unit 8, the third input of the switch 12 is connected to the first output of the processor 1, the output of the switch 12 is connected through a delay element 10 to the second input of the second element 5 to the input of the C-flip-flop 6, the direct output of which is connected to the second input of the first counter 2 and the first the input element 11, the second input of which is connected to the output of timer 13, the fourth input of processor 1 and the first input of element 7, and the output of element 11 is connected to the second input of the first element 4, the second output of processor 1 is connected to the second input of timer 13, the third you processor 1 is connected to the inputs Reset counters 2 and 3, and the sign output of the first counter 2 is connected to the second input of the terminal 7, the fourth output of processor 1 is the information output of the device. The device works as follows. At a single signal level at the first output of processor 1, the measurement mode is performed, when the signal from input 15 through input driver 8 and switch 12 is fed to the input of Delay element 10 and C-input of trigger 6, at the O input of which, and hence, The output level is set to zero. Before starting the measurement with a pulse from the third output of processor 1, the first 2 and the third 3 counters are set to the zero state, the first counter 2 to the zero level on the reverse control input is switched to the subtraction mode. After entering the value of the time interval computed by processor 1, based on the steepness of the frequency sensor used, the second output of processor 1 informs (second) the input of timer 13, a single level is set at the output of timer 13, which prepares to set to one trigger state 6 and through the element EXCLUSIVE OR 11 allows the passage of pulses of exemplary frequency through the first element 4 to the counting input of the first counter 2, which are subtracted from the contents In order counter. At its sign output, a single level (the sign -) is set after the first incoming pulse. The mode remains with before the arrival of the first pulse from the inlet generator 8. Upon the arrival of the first pulse, the C input of the trigger 6 at its direct output appears to be a single level, which in combination with a single 5F at the output of the timer 13 prohibits the passage of frequency sample pulses to the counting input of the first counter 2, while the first counter 2 is set to the summing mode and permits the passage of pulses from the output of the delay element 10 through the second element 5 to the counting input of the second counter 3. The calculation continues until the end Neither the time interval formed by timer 13. After the formation of a predetermined time interval, the output of timer 13 is set to zero, which permits the passage of exemplary frequency pulses to the counting input of the first counter 2, summing these pulses. When zero appears at its sign (second) output a level, O), the input of the trigger 6, O appears and the trigger 6, on the first pulse arriving at the C input, is set to the zero state, after which the passage of pulses to the counting input is prohibited first 2 and second 3 meters. Thus, the measurement time Tma, η; is not less than the specified time interval iam, 4iVi M M tw5M + 2TV, where T is the period of the pulses at the output of the input driver 8. This condition guarantees the achievement of the required accuracy of the parameter determination. A processor determining from the state of trigger 6 and timer 13 the end of the measurement calculates the frequency -PX of the frequency sensor f Ng from the contents of the first 2 and second 3 counters. Mj is the content of the second counter 3, MI is the content of the first counter 2f TO is the pulse period of the reference frequency, and the value of the parameter itself is as in expression (2). In the control mode, the device is transferred to the zero level at the first output of the processor, while the output of the switch 12 appears pulses of a given frequency from the output of the divider 14. Otherwise, the operation of the device proceeds as described. After calculating the frequency of the pulses coming from divider 14, it is compared with its known value, and if the measured and known value are equal, the device is ready for operation. The information obtained can be transmitted via output 16 to other devices for display or further processing, for example, to generate a control signal in an automatic control system. In the known device, the measurement resolution is determined by code decoders and is set during manufacture of the device. The possibility of its automatic change is missing. However, when processing signals from frequency sensors, the final value is not the frequency, but the value of the parameter. In this case, the resolution of the parameter calculation is determined by the measurement error of the frequency and slope

; R.Dr.,

where l In - measurement error

frequencies;

iLP - calculation error

parameter. Then, subtracting (2) from (5), we get

“From (6) it can be seen that setting a fixed value of the frequency measurement resolution does not guarantee the required accuracy of the parameter determination, without first selecting the sensor on the slope of the characteristic 5 If the resolution is selected based on the use of the sensor with the SOBP slope, then for the sensors with the steepness of the characteristic, less exemplary SiSoep, the absolute error is higher than the permissible.

Thus, for sensors with S SOUP, the required accuracy of the parameter determination will not be achieved. This can be avoided if the resolution in a known device is set based on the minimum possible steepness of the sensor characteristics.

However, it follows from (1) that in this case, in most cases, there is an excess measurement time.

Due to the inputted blocks and mutual relations in the proposed device, the required accuracy is achieved regardless of the parameters of the frequency sensor. In addition, thanks to the automatic control, covering all units of the device (except for the input driver), the reliability of the obtained results is achieved.

The known device is intended to measure the temperature in exact technological processes. At resolution Oh,

and an exemplary frequency of 25 MHz, the measurement time exceeds 1 s and depends on the steepness of the characteristic of the sensor used.

W f f N, - ;, CH iPS

where is the measured frequency; fo is the sample frequency. . For a sensor with a slope of 1000 and a maximum resonant frequency of 5 MHz, the measurement time required to achieve the specified accuracy is

15

S-h &

-0.2s

I1Ch25-10GO, 0 (L 1000

As shown by experimental studies for the formation of a control action according to the proportional-integral-differential law in the system of automatic temperature control for growing single crystals, 50 ms is enough. The proposed device, in comparison with the baseline, makes it possible to reduce the measurement time.

By increasing the sample frequency, the measurement time can be shortened by the same amount of time, in addition, the software execution of the algorithm allows the use of adaptive measurement methods depending on the value of the measured frequency.

Thus, the proposed device allows to achieve significantly greater speed, which is important in the case of its use in control systems.

Another important advantage compared with the MT-1 frequency sensor signal processing device is the presence of an internal processor, which allows it to significantly expand its capabilities (the use of adaptive algorithms, static processing, the calculation of related values, for example, the required control action in the automatic control system).

The proposed device can be widely used for such areas as precision measurement of temperature, pressure, thickness of the deposited film, measured with frequency sensors in order to automatically control the size of the parameters in the process. 11123058 In the proposed device for achieving the indicated indicators, the measurement time is

Claims (1)

DEVICE FOR PROCESSING SIGNALS OF FREQUENCY SENSORS, containing an input driver, the input of which is a part of the device, a processor, first and second counters, first and second AND elements, a trigger, an OR element and a reference frequency generator, the output of which is connected through the first AND element to the counting input of the first counter, the output of the latter is connected to the first input of the processor, the output of the OR element is connected to the D-input of the trigger, the direct output of which through the second element AND is connected to the counting input of the second counter, the inverse output the Igger is connected to the second input of the processor, the third input of the latter is connected to the output of the second counter, characterized in that, in order to improve the accuracy of measurement and the reliability of the information received, a timer, divider, switch, delay element, EXCLUSIVE OR element are introduced into it, while the output the frequency generator is connected to the first input of the timer and through a divider to the first input of the switch, the second input of which is connected to the output of the input driver, the third input of the switch is connected to the first output of the processor , the output of the switch is connected to the second input of the second AND element through the delay element and to the trigger input directly, the direct output of which is connected to the second input of the first counter and the first input of the EXCLUSIVE OR element, the second input of which is connected to the timer output, the fourth processor input and the first input of the element OR, the output of the element EXCLUSIVE OR is connected to the second input of the first element AND, the second output of the processor is connected to the second input of the timer, the third output of the processor is connected to the inputs Reset the second and first count meters, the sign output of the first counter is connected to the second input of the OR element, the fourth processor output is the information output of the device. S08Z II! ' ⁱⁿ P5 1 11