SU475638A2 - Graphic reading device - Google Patents

Description

one

This invention relates to automation and computational technology.

According to the main author. St. No. 453715, a device for reading graphic information is known.

However, the known device does not eliminate the nonlinear distortions of the coordinate codes arising from changes in the speed of sound in air due to fluctuations in its temperature, humidity and pressure. In addition, the well-known device is not protected from failures in the case when the speed of the counters is insufficient due to excessive movement of the sighting device or large disturbances in the air environment. These disadvantages of the known device reduce its practical accuracy and reduce reliability.

The aim of the invention is to improve the accuracy and reliability of the device.

This is achieved by the fact that the proposed device additionally contains two reference square drivers connected to the intermediate outputs of the reference signal frequency divider, two frequency subtraction triggers connected to the outputs of the additional reference square drivers, and the outputs of the amplifiers of the ultrasound receivers and the inputs of the group counter, a group integrator connected to the output of the group counter, and the adder connected to output 2

further group

mi main and with the input of the output unit of cointengrators and Dov.

The drawing shows a block diagram of the proposed device.

The device includes a tablet 1, a reticle-emitter 2, three point ultrasound receivers 3, a generator of 4 reference signals, two formers 5 reference squares, one of which is connected to the output of phase shifter 6, connected in parallel with the other driver of the reference meanders to the output of the reference signals generator. A frequency divider 7 of the reference signals is connected to the output of one of the drivers 5 of the reference meanders and to the input of the launching circuit 8 of the inside-emitter. The outputs of the amplifiers 9 connected to the ultrasound receivers are combined and connected to the inputs of two trigger 10 frequency subtraction, the other inputs of which are connected to the outputs of the drivers 5 of the reference meanders. The inputs of the group counter 11 are connected to the outputs of the trngers 10, and the outputs of the counter are connected to the control inputs of the amplifiers and the input of the group integrator 12, the output of which is connected to the block 13 output codes through the adder 14.

In addition, the device contains two formers 15 reference meanders connected to the intermediate outputs of the divider

frequencies, two triggers 16 subtracting frequencies connected to the outputs of the formers 15 of the reference meanders, the outputs of the amplifiers and the inputs of the bulk counter, and the group integrator 17 connected to the output of the group counter and through an adder to the input of the code output unit.

The device works as follows.

The coding object is attached to the tablet 1. Then the center of the sight-emitter 2 is combined with a point O fixed on the tablet and, for example, equidistant from the three ultrasound receivers 3, and then the zeros in the group integrator 17 and the initial distances from the center of the visc - emitter - points M to ultrasound receivers at points P, Yag, Yaz - in a rough counter 11. The coordinates of the points of the coded object after these operations are calculated in a coordinate system starting at point O.

In the process of traversing the lines of the object to be encoded with the sight-emitter, the distances / g (t 1, 2, 3) from point M to points Yai Yaa, Yaz are changed and, accordingly, the delays of signals sent by the sight-emitter and detected by ultrasound receivers meanders, as the viewfinder 8 emitter circuit 8 is connected to the output of the imaging unit 5 of the reference meanders via a frequency divider 7. The received ultrasonic signal by means of amplifier 9, which includes a resonant amplifier tuned to the frequency of the emitted signals and determining the moment of transition of the amplified harmonic signal through zero, revolves into a periodic sequence of pulses with a duration of no more than 0.2 microsecond.

Three amplifiers 9 operate in turn, and each amplifier is switched on by one third of the period of operation of the ground counter 11 by signals from this counter, which are fed to the control inputs of the amplifiers. In this case, the sum signal at the combined output of the amplifiers is an alternating pulse packet, corresponding to three sequences of pulses with an equal period, but with an arbitrary phase shift of the pulses of one packet relative to the pulses of the other packet.

The selection of single increments of the distance / g proceeds as follows. With a fixed sight-emitter, for example, at the initial point O, the pulses of each of the three packets coming from the combined output of the amplifiers to the switching inputs of the frequency subtraction triggers 10 are synchronized with the reference meanders arriving at the inhibitory inputs of the same triggers from the formers 5. Each of the drivers 5 gives a direct and inverse square wave, and due to the operation of the phase shifter 6 at the input of one of the drivers, the signals of this driver are shifted in phase by

relative to the signals of another driver. As a result of the action of the indicated signals at the inputs of the trigger 10, subtraction of frequencies, these triggers form three pairs of states of the ultrasound receivers during one period of operation of the group counter. Namely, each new pulse packet from the outputs

amplifiers sets a pair of triggers 10 to such states as "O or" 1, which correspond to the phase shifts of the pulses of this packet relative to two reference meanders provided, for example, that the phase shift

from O to corresponds to the state of the trigger "O (even if each pulse of the packet coincides with the lower level of the meander). The fact that the frequency of the pulses in the packets turns out to be an integer number of times lower than the frequency of the reference meanders due to the frequency divider connected between the driver 5 and the starter emitter trigger circuit does not affect the operation of frequency subtraction triggers. Therefore, the division ratio of the frequency divider 7 is selected only from the condition of ultrasound emitting at the most favorable frequency from the point of view of the range of the acoustic communication between the sight-emitter and the ultrasound receivers. Three pairs of states of trigger subtraction frequencies (states of ultrasound receivers) are stored in a groove counter for one period of its operation and compared with the corresponding pairs of states of triggers in

subsequent period of the counter. With a fixed sight-emitter, the states of the triggers are periodically repeated, and the unit does not allocate single increments of the distance / j. If the viewfinder emitter is displaced from the starting point so that the change in the phase shift of the pulses of a packet at the output of the amplifiers relative to the meanders is equal to a quarter of the meandering period, then one

from the flip-flops, the pulses are necessarily switched from this packet to a different state compared to the state of the same flip-flop defined before the viewfinder emitter is displaced. Namely, since the length of time between the fronts of two reference meanders is equal to one quarter of the period following them, the prohibiting inputs of one of the triggers 10 by the time of the switching impulse of this packet will necessarily change the signals - direct to inverse.

If the state of the trigger 10 did not repeat as compared with the previously defined one period of operation of the counter (for the same ultrasound receiver), then the group counter

the increment of the corresponding distance is selected according to the following rule. Sum modulo 2 of the previous state of one of the triggers 10 followed by (through the period of the counter operation) the state of the other

the trigger 10 gives a single increment of the distance of one sign, and the sum modulo 2 of the second pair of different-time states of opposite triggers 10 gives a single increment of the distance of the opposite sign. In the event of simultaneous allocation of increments with different signs, they are mutually destroyed.

The two formers 15 of the reference meanders and the two triggers 16 for subtracting frequencies are identical in terms of circuits and functions to the formers 5 and the triggers 10. Only the frequencies of the signals at the inputs and outputs of the formers 15 and 5 are different, as the formers 15 are triggered by signals from the intermediate outputs of the frequency divider 7 whose input is connected to the output of one of the formers 5. The phase shift on the - reference meanders at the outputs of one of the formers 15 relative to the reference meanders at the outputs of the other shaper 15 is provided by signal shifts at the inputs of these drivers connected to different outputs of the frequency splitter. So, if the frequency subtraction triggers 10 allow you to count single increments of distances, the frequency subtraction triggers 16 make it possible to isolate large increments of the same distances, measured by an integer number of single increments equal to the frequency division factor when receiving low-frequency reference meanders from high-frequency reference meanders.

Additional inclusion of low-frequency reference meanders and triggers of 16 low frequency subtractors into the device of the shaper 15 allows you to record in the group counter 11 distances of the distances in large units, and the unit increments of these distances, selected with the help of triggers 10, can only be used as control signals.

Group counter 11 contains an alternate polling circuit of amplifiers 9, a single increment allocation circuit, a large increment allocation circuit, as well as a ring sequential counting circuit consisting of one adder and a shift register in which the following distance codes circulate. 2, 1h, which are sums of large increments of these plants, added to the initial values of the distances set in the counter register at the beginning of the device operation.

Group integrators 12 and 17 are similar in design and function. Each of them contains an annular sequential counting circuit consisting of one adder and a shift register. Circulation periods of codes in integrators 12 and 17 and counter 11 are the same and equal to the polling period of amplifiers 9.

Integrators work as follows.

Each time the distance is incremented by a single increment, the corresponding code is transmitted once;

the sign and the increment sign from the group counter to the group integrator 12 in the same way as this operation is performed in a known device. Thus, integrator 12 accumulates small increments of squares.

the distances that are located one after another in the integrator register in the form of successive codes.

Additional inclusion in the composition of the proposed device group integrator

17 allows to accumulate large increments of squares of distances / g - with each change of distance / g by a large increment, a single transfer of the corresponding code /, 1 takes into account its sign and the sign

large increments from the group counter to the group integrator 17. Simultaneously with the allocation of the large increments of the square of the distance li, the zero is set in the corresponding part of the group register

integrator 12. This additional operation (as compared with the known device) is necessary for the user to receive the exact squares of the distances li in the proposed device by adding the corresponding codes from integrators 12 and 17, i.e. adding the small and large increments of the squares of the distances with using an additional adder 14, Automatic issuance of coordinates on the punch and in the computer is performed by block 13 output codes.

Subject invention

A device for reading graphic information on the author. St. No. 453715, characterized in that, in order to increase the accuracy and reliability of the device, it contains two additional shapers of the reference meanders connected to the intermediate outputs of the frequency divider of the reference signals, two frequency subtraction triggers connected to the additional shapers of the reference meanders, amplifiers of ultrasound receivers and to a group counter, a group integrator connected to a group counter, an adder connected to the outputs of the group integrators and to the input of the code output unit.