SU718786A2 - Correlation meter of surface image motion speed - Google Patents

Description

The invention relates to the field of instrumentation and can be used to measure the speed of motion of the image of the underlying surface in the focal plane of the photodetectors of a speed meter / for example, in counters of compensators for high-speed lubrication during aerial photography, etc.

Known correlation speed meter containing a lens, two devices with charge coupling, amplifiers, correlator, extreme controller, shear pulse generator and recorder [1].

The disadvantage of this meter is that during its operation, the surface image in the focal plane is not taken into account in the direction transverse to the line of motion of the speed meter, for example, as a result of a change in the angle of heel. As a result, the accuracy of measuring the speed of image movement decreases.

The purpose of the invention is improving the accuracy of measurements.

This goal is achieved in that the device is additionally introduced in series connected roll angle sensor, a rotary device and a mirror, and the mirror has an optical connection with the lens.

The drawing shows a structural diagram 30

correlation meter for image speed.

The meter contains a mirror 1, a lens 2, linear devices 3 and 4 with a charge 5 connection (CCD), amplifiers 5, 6, a correlator 7, an extreme regulator 8, a multiphase generator 9 of shear pulses (MGSI), a recorder 10, a roll angle sensor 11 and on • the turning device 12.

An optical image of a moving surface using a mirror 1 and a lens 2 is projected onto the photosensitive surface of devices 3 and 4. The linear device 3 with charge coupling consists of N 15 nominal elements. Moreover, the first nominal element of the linear CCD 3 is photosensitive, and the rest are shaded. The charge-coupled linear device 4 consists of one nominal 20 element. The outputs of line devices 3 and 4 through amplifiers 5 and 6 are connected to. separate inputs of the correlator 7, which calculates the cross-correlation function of the input signals. The output 25 of the correlator 7 through the extreme controller 8 is connected to the input A ^ GSI 9, which serves to advance charge packets along linear devices with charge coupling 3 and 4 with an adjustable speed.

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The extreme controller is designed to maintain at its output such a control voltage at which the signal at the output of the correlator 7 is maximum. The output of the MGSI 9 is also connected to the input of the speed recorder 10. The roll angle sensor AND is used to determine the roll angle. The output of the roll angle sensor is connected to the input of the rotary device 12, which has a mechanical connection with the mirror. The rotary device is designed to change the position of the mirror relative to the lens.

A correlation meter for moving image speed is as follows.

The image of the underlying surface is reflected from the mirror 1 and through the lens 2 it falls onto the photosensitive surface of the linear TECs 3 and 4. Depending on the speed of movement of the underlying surface, the same portion of the image due to the separation of the CCD 3 and 4 along the base falls onto the photosensitive surface at various times time, moreover, for a nominal element of a linear CCD 3 earlier than for a single-element CCD 4. With an increase in the speed of movement, this time interval decreases, with a decrease in speed it increases, s o The delay time of the video signal in a linear CCD 3 is inversely proportional to the frequency of the shear pulses and in proportion to the number of its nominal elements. By changing the shear pulse repetition rate, the problem of increasing or decreasing the time shift between the output signals of the CCD 3 and 4 is solved. The video signals from the outputs of the charge-coupled linear devices are amplified by amplifiers 5 and 6 and fed to separate inputs of the correlator 7.

Extreme regulator 8 controls the repetition rate of shear pulses MGSI 9 so that the signal at the output of correlator 7 is maximum. Under this condition, at the 5th output of the linear CCD 3 and 4, the video signals are the same. The speed recorder 10 by the frequency of the shear pulses follows calculates the speed of the image in the focal plane of the photodetectors.

Due to a change in the angle of heel, it may turn out that the surface image point received by the linear CCD 3 may not reach CCD 4. In this case, a false signal is generated to search for exg15 remum of the correlation function. The roll angle sensor determines the roll angle and generates a control signal for the rotary device 12. The rotary device 12 controls the position of the mirror 20 1 so that the same signal as the CCD 3 gets to the linear CCD 4 after a certain period of time. Thus, the measurement accuracy The speed of the image is increased by the correlation speed meter.

Claims (1)

The extreme regulator is designed to maintain such a control voltage at its output, at which the signal at the output of the correlator 7 is maximum. The output of MGSI 9 is also connected to the input of the speed recorder 10. The sensor & roll angle is designed to determine the roll angle. The output of the roll angle sensor is connected to the input of the rotary device 12, which has a mechanical connection to the mirror. The swivel device is designed to change the position of the mirror relative to the lens. The correlation meter of motion of the image operates as follows. The image of the underlying surface is reflected from mirror 1 and through the lens 2 hits the photosensitive surface of linear PES 3 and 4. Depending on the speed of movement of the underlying surface, the same image area due to the spacing of the CCD 3 and 4 at the base hits the photosensitive surface at different moments time, and the nominal element of the linear CCD 3 is earlier than the single-element CCD 4. With increasing speed, this time interval decreases, and with decreasing speed it increases. The delay time of a video signal in a linear CCD 3 is inversely proportional to the frequency of the shift pulses and proportional to the number of its nominal elements. By changing the frequency of the following pulses, the task is to increase or decrease the time shift between the output signals of the CCD 3 and 4. Video signals from the outputs of linear devices with charge coupling are amplified by amplifiers 5 and 6 and fed to the separate inputs of the correlator 7. P 4 Extreme regulator Torus 8 controls the frequency of the shear pulses of MGSI 9 in such a way that the signal at the output of the correlator 7 is maximum. Under this condition, the output of the linear CCD 3 and 4 video chips are the same. The speed recorder 10 calculates the speed of movement of the image in the focal plane of the photodetectors based on the shear pulse frequency. Due to a change in the roll angle, it may be that the image point of the surface taken by the linear CCD 3 may not reach the CCD 4. In this case, a false signal is generated and the search for the extremum of the correlation function. The roll angle sensor detects the roll angle and generates a control signal for the rotator 12. The rotator 12 controls the position of the mirror 1 in such a way that the linear CCD 4 after a certain period of time receives the same signal as the CCD 3. Thus The accuracy of image speed measurements with a correlation velocity meter increases. Claims of the invention. The correlation measuring instrument of speed of movement of the image of a surface according to the author. St. No. 594456, characterized in that, in order to increase the point, it is provided with a mirror mounted between the lens and the surface, a rotating device associated with the mirror, and a roll angle sensor, the output of which is connected to the rotary device. Sources of information taken into account in the examination 1. USSR Author's Certificate No. 594456, cl. G 01 P 3/54, 1976 (prototype).