SU1670405A1 - Interference method of location of objects - Google Patents

Abstract

This invention relates to instrumentation technology. The purpose of the invention is to enhance the functionality by making it possible to measure the position of fixed objects. The method consists in forming an interference field of the diverging reference and measuring beams and determining the instant of coincidence of the phases of measurements of the radiation intensity in the center and on the edge of the interference field. 1 il.

Description

The invention relates to an instrumentation technique and can be used to control the position of an object.

The purpose of the invention is to enhance the functionality by making it possible to measure the position of fixed objects.

The drawing shows a block diagram of a device implementing the method.

The device consists of an optically coupled laser 1, a lens 2, a beam splitter 3 designed for optical communication with a controlled object, and a mirror 4 with a vibration drive 5, optically coupled to a mirror 4 through a beam splitter 3, a diaphragm 6 and photoreceivers 7 and 8, in series connected amplifier 9, the input of which is connected to the output of the photoreceiver 7, comparator 10 and adder 11, connected in series to amplifier 12, the input of which is connected to the output of the photoreceiver 8. comparator 13 and coincidence circuit 14, the output of which is connected to the first the correct input of the adder 11. generator 15, the first output of which is connected to the input of the vibrodrive 5, a comparator 16 connected between the second output of the generator 15 and the second control input of the adder 11, the encoder 17 of the character, whose input is connected to the second output of the generator 15, and the setpoint 18 code wavelength, the output of which is connected to the reference input of the adder 11.

The method is implemented as follows.

The beam of light from laser 1 is focused by lens 2 through beam splitter 3 on mirror 4 and the surface of object 19. In reverse, reflected beams from mirror 4 and object 19 are combined by beam splitter at zero angle, form an interference field that is analyzed by aperture 6 with openings in the center and on the edge. Photodetectors 7 and 8 register the change in the flux of light passing through the holes. The center of the reference beam reflected from the mirror 4 is moved with the help of the mirror 4, which is caused to oscillate by the vibration actuator 5 from the continuous signal of the reference generator 15. This causes a change in the intensity

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light in the center and on the edge of the interference field, respectively.

The signals from photoreceivers 7 and 8, amplified by amplifiers 9 and 12, are fed to comparators 10 and 13, which sample the phase of the signals so that one pulse period corresponds to one signal period. The pulses thus formed are fed to a coincidence circuit 14. At the same time, the pulses from the comparator 10 are fed to the input of the adder 11, which starts and ends the counting of these pulses by the signals fed to its control inputs. To the second control input, pulses are started from the oscillator 15 through the comparator 16 at the moment when the mirror 4 passes the center of the converging reference beam. The first control input of the adder 11 is supplied with pulses of the end of the counting circuit 14 of the coincidence when the common-mode conditions of the signals

Thus, during the period of oscillation of the mirror 4, the number of pulses in the adder is stored, limited by the moments of the passage of mirror 4 through the center of the converging reference beam and the in-phase condition of the signals from the center and edge of the interference field. This number is directly proportional to the distance of the object from the center of the converging measuring beam. Through a dial 18, a wavelength I code I is entered into the adder 11. The adder 11 multiplies the values of p and I and at its output a code of the distance from the object 19 to the focal plane of the lens 2 is formed. The sign of Z0 is determined by the half-wave sign of the signal from the generator 15 and outputted as a code from the encoder 17.

Claims (1)

The invention The interference method of measuring the position of an object, which consists in forming the interference field by combining the diverging reference beam and the measuring beam, the center of which depends on the position of the object being monitored, converting the radiation intensity at two points that are asymmetrical relative to the center of the interference field to electrical signals and comparing the phases of the electrical signals expanding the functionality by allowing the position of a fixed object to be measured, the center of the divergent bearing beam is moved along the optical axis of the beam from zero to the extreme position determined by the measurement range, the number of periods of one of the electrical signals from the moment the center of the reference beam passes through the zero position until the phases of the electrical signals are equal is recorded, and the position of the object is determined by the registered number of periods.