SU1239663A1 - Method of checking metrological characteristics of transducers - Google Patents

Abstract

The invention relates to the technique of monitoring the metrological characteristics of measuring transducers and can be used in solving automation problems of self-monitoring of the metrological characteristics of information-measuring systems. The aim of the invention is to increase the reliability of control by ensuring that the average values of the reference signal are equal during the conversion time of the controlled converter at different values of the rate of change. reference signal. To do this, in the control method, which includes cyclically generating a triangular reference signal, repeatedly supplying the generated signal to the input of the tested converter for each rate of change, fixing the errors of the latter in each control cycle at several levels of the reference signal, statistical processing of the results and building a two-dimensional error function the transducer on the level and rate of change of the reference signal, the fixation of the error is carried out during the interval and a time equal to the conversion time of the converter, the middle of which coincides with the moments when the reference signal reaches the reference values. A device that implements the proposed method contains a control unit 1, a reversible counter 2, a digital-to-analog converter 3, valves 4, a generator 5, a divider 6, a measuring converter 7, tires 8, 9.10 and 12. 2 Il. I (L to oo o and cn

Description

The invention relates to a measuring technique 9, namely, to a technique for controlling the metrological characteristics of measuring transducers, and can be used in the field

solving automation tasks. self-monitoring of the metrological characteristics of information-measuring systems,

The purpose of the invention is to increase the reliability of control by ensuring the equality of average values ;; reference signal during the conversion of the controlled converter at different values of the rate of change of the reference signal.

Fig; IQ is represented by the diagram, amma of the reference signal, in FIG. IS, the trigger pulses of the controlled converter j in fig. 1 V shows the distribution of the dynamic error of the converter for the reference values of the reference signal; Fig. 2 shows a device for carrying out the proposed method.

The method is carried out as follows.

With the help of hardware, a reference triangular signal is formed in the form of a series of triangular pulses, the rates of rise and fall of which in each series of pulses are the same in magnitude (fig. La). The number of triangular pulses in each series is determined by the requirements of the statistical processing of the measurement error of the reference signal for each rate of change. The number of series of triangular signals is determined by the number of different rates of change of the signal at which the converter is monitored. The reference signals are fed to the input of the controlled converter and at certain points in time (relative to the moments of time in which the standard-: ngy signal reaches the programmed values of P, for values equal to T, / 2, where Tu is the conversion time of converter J to The starting input of the controlled converter is pulsed. At the beginning of the measurement (Fig, 1), both on the increasing and on the falling sections. Because the different conversion controlled by the converter has a different conversion time, then the shift time of the starting impulses sov also raz.pichnoe. S is discharged onto the recording device such

39663 2

Thus, the array of results is measured. cue reference signals for the same amplitude values of P; at different rates of change of VJ signal. The results of measurements are subjected to standard statistical processing, the values of the modulus of the fractures are determined for all combinations of P, V: and the three-dimensional function of the error in coordinates is constructed amplitude - rate of change - error.

A device that realizes the proposed method (FIG. 2) contains a control block I, the output of which is connected to a reversible counter 2, connected by its information output to a digital-analog converter 3 and another output to the second input of block 1, the output of which

20 is connected to the control input of the valves 4, a geyrator 5, the input of which is connected to the first input of the unit 1, and the output to the divider 6 and the second run of the reversing counter 2, with

35 this output of the divider 6 is the output of the device and is connected to the starting input of the measuring transducer 7j whose output is the information output of the device, and the second input is connected to the output of the converter 3,

The device works as follows.

When giving the start command to the bus

The 3S 8 starts the generator of 5 pulses of the reference frequency, sets the delta zero to zero and the counter 6 (circuit not shown) and at the same time prepares the control unit 1 for expressing the addition command pulse 2 on the peBepcHBHoro operating mode bus 9 and applying the write pulse to the IO bus to the priming inlet of the valves 4, as a result

 of which 33 divider 6 writes a number Oe equal to half the binary code of the measurement time of the monitored transducer. All of the above operations are performed over a time that is pre-50 non-small; compared to the period of the output signal of the generator 5, On the score; the input 1 I of counter 2 starts to receive pulses of the reference frequency, the code in counter 2 increases,

5S: linearly and converted into a digital-to-analog converter 3 to a linearly increasing voltage: (or current, frequency, resistance, etc., depending on the purpose of the controlled converter), which is fed via bus 12 to the measuring input the controlled transducer 7. The GHerve pulse from the output of the divider 6 goes through bus 13 to the starting input of the measuring transducer 7 after a time interval from the moment the device starts up, equal to Т, / 2, since the capacitor of the divider decreased by untuns value. In the subsequent cycles of operation, the capacity of the divider 6 does not decrease and the pulses from its output arrive at equal intervals of time, i.e. The entire series of trigger pulses for a single triangular signal is shifted forward by the amount of time Tc / 2, which ensures equal average values of the reference signal during the rise and fall.

When the counter 2 is filled from the high-bit output 14, a signal is sent to the control unit 1, resulting in bus 9 - the control input of the counter 2 - a subtraction signal is set and the counter 2 performs the counting pulse of the generator 5, as a result of which digital converter 3 is a linearly falling voltage. The digital code — the measurement result, the reference signal — is recorded from the outputs of the controlled converter, for example, upon receipt of the next start pulse from the output of divider 6. Thus, in one cycle of forming a triangular signal from the output of the controlled converter, 1 signal for the same two-digit speed value. The next series of reference triangular signals is generated at. another (increased or decreased) frequency value, which is achieved by applying the appropriate control of the Ny-code to the input of the generator 5, and all of the above operations are repeated.

2396634

When monitoring the measuring pre. Former with measurement time. 0.1 si when the rate of change of the reference signal is 5 V / s, the change in this 5 signal will be 0.5 V / s. Suppose that the reference value of the reference signal P is 4 V, then the converter start pulses must be moved forward 0.05 seconds relative to the time when the reference signal reaches 4 V from below and 4 V.: above, due to which the average value of the reference signal for the connection time of the controlled converter is equal to 4 V. If the start-up pulses were applied to the converter at the times when the reference signal takes 4 V (as in a known method), then the average value of 20 would be equal to 4.25 and 3.75 B.

Claims (1)

Invention Formula The method of control of the metrological characteristics of the measuring converters, including the cyclical formation of a reference signal of a triangular shape, multiple supply the generated signal to the input of the tested converter for each rate of change, fixing the errors of the latter in each control cycle at several levels of the reference signal, statistical processing of the results obtained and building a two-dimensional function of the converter error from the level AND rate of change of the reference signal, different from The goal is to increase the reliability of the control by ensuring the equality of the average values of the reference signal during the conversion of the controlled transform At different values of the rate of change of the reference signal, the converter error is fixed for a time interval equal to the conversion time of the converter, the middle of which coincides with the moments when the reference signal reaches the reference values.