SU646355A1 - Coordinate-measuring television method - Google Patents

Description

The invention relates to the field of automation and computer technology, in particular, to television methods for measuring coordinates, and can be used in reading graphic information, in devices for automatic tracking of objects, in contactless measurement, and in linear dimensions and areas.

The known coordinate measuring method based on using the result of comparing the sweep voltage with the reference sawtooth voltage to control the speed of movement of the beam of the television sensor on the formation of counting pulses of a constant frequency and determining the coordinates by the number of counting pulses ij.

This method does not provide a high precision measurement of the coordinates of the nonlinearity of the conversion of control of the voltage to the speed of movement.

neither: the beam, but also because of the dynamic defocusing, the beam and the raster rotation.

The closest in technical essence to the proposed method is a television method of measuring coordinates by comparing the voltage scan with a reference voltage, form counting pulses at the moments of coincidence of these voltages by amplitude and determining the coordinates by the number of counting pulses 2.

The disadvantage of this method is its low speed. According to the techniques of method L2 for quantizing the distances in the direction of the sweep on the Ifl of the discretes, I need to compare the sweep voltage five times with the reference sawtooth voltage, the period of which is n times longer than the sweep period ki; As a result of this measurement within the line (coordinate X) takes time N horizontal scanning periods, and

measure by frame (coordinate Y} rem U of periods of frame scanning.

The aim of the invention is to improve the speed.

This gel is indicated by the fact that the reference voltage is formed in the form of a stepped sawtooth dressing with a constant quantum pitch. OA amplitude.

Timing diagrams of figs, 1 in c-, the essence of the proposed method; in fig. 2 shows a block diagram of the device for its design.

FIG. 1 shows: for example, the lJ j (t) ramp; stepped sawtooth voltage 1T (1) with a constant quantization step in amplitude; voltage d V. the value of the cohort is set depending on the number of samples, which it breaks down with amplitude No. 1. The range of the sweep voltage; point in time to match the start of 1 scan; time instant i.} at which the sweep voltage reaches the value of the first step of the sawtooth strain 1G2. (b) | time t, at which the sweep pressure reaches the level of the second step of the sawtooth voltage tr (t); The pulse pulse detector HocTblJjC i), whose pulses at the time of coincidence of the sweep voltage with the stepped saw-tooth voltage If 2 (b) have a voltage difference U (t) corresponding to the measured coordinate; VG impulses 1G (t), Vl to the direction of the 4th coordinate code.

Shown in FIG. 2, the device for measuring the X coordinate (the device for determining the Y coordinates is similar) consists of a voltage comparator 1, an integration and storage circuit 2 (a cumulative D / A converter), a coincidence circuit 3 and a counter 4.

The voltage comparator 1 generates short pulses only in terms of the coincidence of the sweep voltage with a stepped sawtooth voltage. The output of comparator i is associated with an odium from the inputs of the integration and storage circuit 2 and with the 3 match circuit. The second input 5 of the circuit 2 receives the beginning of a line (or frame) pulses, which set it to its initial state, i.e., set the first step uTJ of the t-shaped voltage and the end of line pulses

(or frames) that set the circuit to the zero state. The number of steps sawtooth naprshken, and hence the number of imishls

in sequence, the TG (t) is determined by the ratio of the amplitude of the sweep voltage to the amplitude of one step of the sawtooth voltage. The integration and memorization circuit 2 ensures the formation of the next step of the sawtooth voltage 13 (t) at the moments of the arrival of each pulse of the sequence ND (t) and the memorization of this voltage

sweep period. The output of the circuit 2 is connected to one input of the comparator 1, to the second input 6 of which is fed a voltage varying in accordance with the change in the current in the deflection.

the coil of the scanning sensor (this voltage is removed from the resistor connected in series with the winding of the deflecting coil). At the input 7 of the scheme 3 matches, a pulse is given,

The scientific research institute whose front corresponds to the temporal position of the image point, the coordinates of which (relative to the beginning of the sweep — the origin) should be determined. This impulse

4 (fig. L) permits the generation of counting pulses 11 "(t) from the output, and the comparator 1 ha. The input of the counter 4.

At the beginning of the measurement cycle, the integration and storage circuit 2 is reset to the initial state by the start of a line (or frame) pulse. When an atom at its output, there occurs an AU drop of the first step of the saw-tooth stress TGLS b) This drop serves

ONE of the inputs of the comparator 1, on the second input of which; From the beginning of the moment of time t, the voltage of the sweep comes from a resistor connected in series with the deflection coil of the scanning sensor. At time t | the sweep voltage reaches the voltage range of the first threshold level (the first step) and the first is formed at the output of the comparator 1

the counting impulse that arrives at the input of the circuit 2 is integrated and memorized, and to one of the inputs of the circuit 3 matches. Scheme 2 at the time of arrival of this pulse provides

the formation of the second step, equal in amplitude initially specified, and their summation. As a result of that order from the scheme 2, the integration /

and and memorizing the input of the comparable ora 1 will be applied to the voltage,. Avno 2 & 1G. In addition, the first counting pulse will pass through a circuit of 3 coincidences to counter 4, since the permitting input 7 of circuit 3 coincides with the scientific research institute at the same time as voltage (C). If the voltage of the sweep coincides with the voltage level of the next step of the sawtooth voltage, the next counting impulse arrives at the counter: The counting pulses of the TGCL sequence will arrive at the counter 4 until the high potential of voltage C) is present at the input 7 of the circuit 3 of the coincidence 1)

As a result, a digital code will be fixed in Counter 4 corresponding to the measured time interval, i.e. the coordinate of the image point relative to the start of the sweep.

Thus, the proposed method provides for the measurement of coordinates in real time, that is, during the sweep period, and therefore increases

measurement speed in comparison with the known method in rm times.

Claims (2)

1. Technique of film and television, No. 11, 1971. 2. To produce universities, instrument making, t. CV, NO 3, 1972. GP -41 ii I I} I {I {I J