SU1635002A1 - Device for checking periodic displacements - Google Patents

Abstract

The invention relates to a control and measuring technique. The purpose of the invention is to improve the accuracy by averaging the measurement results and performance when monitoring a piezoceramic transducer by automating the transducer training operation. The device consists of a series-connected generator 1, an electronic key 3, a voltage divider 4, an electronic key 5 and a two-threshold comparator 6, counters 7 and 8, and a laser interferometer 10. Counter 8 starts counter 7 after completing the workout of converter 14 corresponding to a specified number of generator periods 1, the counter 7 counts the number of pulses of the interferometer 10, corresponding to the displacement of the converter 14. 1 Il.

Description

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The invention relates to an instrumentation technique and can be used to control the movements of piezoceramic transducers during their dynamic tests.

The purpose of the invention is to improve accuracy by averaging the measurement results and improving performance when monitoring piezoceramic transducers by automating the transducer training operation.

The drawing shows the block diagram of the device.

The device consists of a series-connected generator 1, amplifier 2, electronic key 3, voltage divider 4, electronic key 5 and two-threshold comparator 6, counter 7, the first control input of which is connected to the output of comparator b, counter 8, the counting input of which o is connected to the output of comparator 6, and the output is connected to the second control-input of counter 7, switching unit 9, the input of which is connected to the output of counter 8, laser interferometer 10 with an electric pulse former, the output of which is connected to to the main input of the counter 7, a serial but connected electronic key 11, a micro-operation sensor 12 and an electronic key 13 connected between the output of the body 2 and the input of the comparator 6, the control inputs of the keys 11 and 13 are combined 3 and 5 are combined, the outputs of switching unit 9 are connected to the control inputs of switches 3 and 11 and the installation inputs of counters 7 and 8, respectively.

The device works as follows.

In the measurement mode, the surface of the controlled piezoceramic transducer 14 is optically coupled to the interferometer 10. By the signals from block 9, keys 3 and 5 are turned on, and keys 11 and 13 are turned off. The output signal of the generator 1, amplified by the amplifier 2, is fed to the controlled piezoceramic transducer 14, causing it to move according to the harmonic law. The movement of the piezoceramic converter is controlled by the interferometer 10, at the output of which electrical pulses are generated, the number of which is proportional to the displacement of the piezoceramic converter 14 on the monotonic portions of each half-period of oscillation.

The voltages are also fed to the input of the two-threshold comparator 6. The threshold values of the tripping voltage of the comparator Ui and 1) are set depending on the desired range of variation of the control voltage during the control. As a result of the operation of the comparator 6, rectangular pulses are formed at its output, the leading edge

0 which is formed at values, and the back - at. The sequence of rectangular pulses from the comparator 6 is fed to the first control input of the counter 7 and to the counting

5 input of counter 8. Counter 8 calculates the specified number of half-periods required for training controlled piezoceramic transducer 14, and then gives permission to the second

0 control input of the counter 7. As a result of the appearance of the permissive signals at both control inputs of the counter 7, it is filled with electrical pulses from the output of the interferometer 10 to the countable

5 entrance. In this case, the filling occurs only in the time interval between the front and rear edges of the rectangular pulses from the output of the comparator 6. The number of half-periods of the variable reference

0 effects used to obtain the measurement result is set from the output of block 9 connected to the installation inputs of the counter 8. In this case, the counter 8 calculates the specified number of rectangular

5 pulses from the output of comparator b in the measurement mode. The averaged measurement result generated using counters 7 and 8 is indicated by counter 7 in absolute terms

0 displacement of a controlled piezoceramic converter in a given range of control voltage.

In the calibration mode, the surface of sensor 5 is optically coupled to the interferometer 10. Electronic keys 3 and 5 are turned off, and keys 11 and 13 are turned on, The control voltage from the output of amplifier 2 is fed to the input of the set point.

0 12, causing the displacement of its surface, controlled by the interferometer 10. At the same time, the electrical signal from the output of the setting device 12 is fed to the input of the comparator 6, the measurement result is calibrated

5, the movement is generated and indicated by the counter 7 in accordance with the described principle of operation of the device. If the measurement result of the calibrated displacement deviates from its true value, the threshold values of comparator 6 are adjusted accordingly, or compensation is carried out in the pre-installation circuits of the electric pulse number counter.

Claims (1)

Claims An apparatus for monitoring periodic movements, comprising a laser interferometer with an electric pulse former, the first counter, the counting input of which is connected to the output of the interferometer, and a generator, characterized in that, in order to improve the accuracy and performance when monitoring piezocherical transducers serially connected by the first electronic key, the input of which is connected to the generator output, a voltage divider, a second electronic key and a two-threshold a comparator connected in series by a third electronic key, a microdisplacement setting device and a fourth electronic key connected between the generator output and the comparator input, a second counter, the counting input of which is connected to the output of the comparator, and the switching unit, the input of which is connected to the output of the second counter, the first counter is made with two control inputs connected to the outputs of the comparator and the second counter, respectively, and the installation input connected to the first output of the switching unit, the installation input of the second counter is connected to the second output of the switching unit, the control inputs of the first and second electronic keys are combined and connected to the third output of the switching unit, the control inputs of the third and the fourth electronic keys are combined and connected to the fourth output of the switching unit.