SU976455A1 - Graphic information readout device - Google Patents

Description

one

The invention relates to automation and computer technology, in particular to devices for inputting graphical information into a computer.

According to the main author. St. No. 75b38, a device for reading graphic information is known, comprising a tablet, a reticle-emitter with a launcher, point ultrasound receivers, Q

 connected to amplifiers, reference signal generator, group counter, code output unit, reference square driver, phase shifter, frequency subtraction triggers connected to 15 group counter, reference square amplifier, and group integrators connected to the group counter, divider frequency, connected to the launch of the viewfinder, 20 emitter and to the driver of the reference meanders, and the adder, connected to the outputs of the group integrators and

1 input block output codes.

However, such a device does not preclude the issuance of incorrect codes in case of an error in determining the distance from the center of the transducer emitter to the ultrasound receivers due to external interference, for example, if an ultrasonic signal is accidentally blocked by the operator’s hand on the path from the transducer emitter to the receiver or when the power supply voltage is high and also in case of an error in determining the same distances or when calculating the coordinates of points of an encoded object from these distances because of a failure inside the device for any other reasons.

The purpose of the invention is to improve the accuracy of reading graphic information, i.e., the complete elimination of coding errors due to external interference and internal failures in the calculation of coordinates.

This goal is achieved by introducing into the device a pilot emitter connected to a launching unit 3976 of the target emitter, an integrating element connected to a reference signal generator, a frequency subtraction control trigger connected to an integrating element and a driver of reference meanders, a monitoring receiver connected to the control a frequency subtraction trigger, a tracking integrator unit, connected to a group counter, an adder and a code output unit, and a serially connected shift register are connected a first adder, an adder control, the other input of which is connected to the adder and the block. alarm connected to the block output codes. Using the control adder, the parallelogram is checked continuously during operation of the device: the sum of the squares of all sides of the parallelogram must be equal to the sum of the squares of all its diagonals. The parallelogram sides equate the distance from the center of the sight-emitter to two ultrasound receivers used in the calculation of one of the coordinates. PaccJo between these ultrasound receivers is equal to the diagonal of the parallelogram. The half of the second diagonal is equal to the distance from the center of the sight-emitter to the third receiver of ultrasound, placed on the same straight line with the first and second receivers, equal to the distance from them. The squares of all these distances are computed in the paging device. If there is an error in determining the square of at least one of the three distances (i.e., an error in determining the x and y coordinates expressed by the squares of these operating stations), then the prohibition signal from the signaling unit, connected with a control adder, and, in addition, an audible alarm is triggered. Since only two ultrasound receivers are used to calculate the coordinates, and the third receiver performs only a control function, a block is used to calculate the second coordinate. The following integrator, whose input values are the known first coordinate and one of the distances from the center of the transducer to the ultrasound receiver. In order for the control adder to function correctly, it is necessary that the distance from the center of the crosshead emitter to the ultrasound receiver 5 be measured at a strictly defined scale. Such a measurement provides the location of the reference transmitter and the control ultrasound receiver at a fixed distance from each other. The drawing is a diagram of the proposed device. The device includes a tablet 1, a via-emitter 2, three-point reception of ultrasound 3 on the working field of the tablet, a generator k of reference signals, oB, 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 reference meanders, to the output of the reference signal generator. The divider 7 of the frequency of the reference signals is connected to the output of one of the formers 5 of the reference meanders to the input of the block 8 of the launch of the radiator. The outputs of 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 driver 5 of the reference meanders. The inputs of the group countable 11 are connected to the outputs of the flip-flops 10, and the outputs of the counter are connected to the control inputs of the amplifiers 9 and the input of the group integrator 12, the output of which is connected to the output terminal unit 13 via the adder 14. The drivers 15 of the reference signal conditioners are connected to the intermediate outputs of the frequency divider and to the inputs of two triggers 16 subtraction frequencies, also connected to the outputs of amplifiers 9 and the inputs of the group counter I. Group integrator 17 is connected to the output of group counter 11 and through the adder to the input of output unit 13 to ode In addition, the device contains a monitoring adder 18 connected to the output of the adder 1 directly and through the shift register 19, a signaling unit 20 connected to the output of the control adder 18 and to the input of the output unit 13, and the following integrator unit 21 And, the output of the group counter 11 and. To the input of the block 13 output code. A sound emitter 22 and a control ultrasound receiver 23 with an amplifier 2 are connected to the sound-insulated location, connected to a frequency subtraction control trigger 25, the other inputs of which are connected to the outputs of the driver 15 of the reference meanders and the output connected via an integrating element 26 to the generator 4 of the reference signals. The device works as follows. The coding object is fixed on the tablet 1. Then the center of the emitter of the emitter 2 is fixed with the point O fixed on the tablet and then the initial values of the distance from the center of the viewer-emitter - point M - to the ultrasound receivers 3 at points P., P, P „ in the group counter, 11 and squares of these distances in the group integrator 17- The coordinates of the points of the coded object after these operations are calculated in the coordinate system starting at the point Pa ,. In the process of tracing by the sight-emitter, the lines of the coded object are changed (from the center of the sight to the ultrasound receivers) and, accordingly, the delays of signals sent by the sight-emitter and detected by the receivers are changed. The delay of the circuits (phase shifts) is measured relative to the reference meanders, since the runner 8 emitter trigger unit 8 is connected to the output of the imaging unit 5 of the reference meanders via frequency divider 7. The received ultrasound signal using an amplifier 9, which includes a resonant amplifier tuned to the frequency of the emitted signals and a circuit for determining the moment of the amplified harmonic signal transition through zero, turns into a periodic sequence of pulses with a duration of not more than 0.2 µs. The three amplifiers 9 are connected in turn to the frequency subtraction triggers 10. Moreover, each amplifier is switched on by one third of the period of the group counter 11 produced by the signals of this counter, arriving at the control inputs of the amplifiers. Total; the signal at the combined output of the amplifiers is alternating. packets, pulses, 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. Separation of unit increments of distances proceeds as follows. With a fixed sight-emitter, for example, at the starting point O, the pulses of each of the three packets coming from the combined output of the amplifiers to the switching inputs of the trigger 10 frequency subtraction are synchronized with the reference meanders arriving at the inhibit inputs of the same trigger from the formers 5- Each of the formers 5 produces a direct and inverse square wave, and due to 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 the other driver. As a result of the action of these signals at the inputs of the trigger 10, subtracting frequencies, these triggers form three pairs of states of the ultrasound receiver during one period of operation of the group counter. Namely, each new packet of pulses from the outputs of amplifiers establishes a pair of triggers 10 in such states O or 1 that 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 t corresponds to the state of the trigger O (even if each burst of the packet coincides with the lower forbidding level of the meander}. The frequency of the pulses in the packets is an integer number of times lower than the frequency of the reference m) of the edges due to the frequency divider connected between the driver 5 and c emoy start reticle irradiator. This does not affect the operation of frequency subtraction triggers, but at the same time, it allows to emit ultrasound at the most favorable frequency from the point of view of the range of acoustic coupling between the sight-emitter and the ultrasound receivers. Three pairs of states of frequency subtraction triggers, (states of ultrasound receivers) are stored in a group counter for one period of operation and compared with the corresponding pairs of states of triggers in the subsequent period of operation of the counter. With a stationary target-emitter state: the triggers are periodically repeated, and the unit does not allocate single increments of distances. If the viewfinder is shifted from the starting point so that the change in the phase shift of a packet at the output of the amplifiers relative to the meanders is equal to a quarter of the meanders following, then one of the triggers is necessarily switched by pulses from this packet to a different state compared to that same trigger defined prior to the displacement of the sight-emitter. Namely, since the length of time between the fronts of two reference meanders is equal to one quarter of the period following them, the tone of the prohibiting inputs of one of the triggers 10 by the time of the switching pulse of this packet is changed. If the state of the trigger 10 does not repeat as compared to the previously determined one period of operation of the counter, then the group counter is allocated when the corresponding distance is increased according to the following rule. The sum modulo 2 of the previous state of one of the triggers 10 followed by (after the period of the counter operation) the state of the other trigger 10 gives a single increment of the distance of one character, and the sum modulo 2 of the second pair of different time states of opposite triggers 10 gives a single increment of the distance no opposite sign. In the event of simultaneous allocation of increments with different signs, they are mutually destroyed. The two formers 15 reference meanders and the two subtractors 16 trigger (often, according to the schemes and the functions, are identical to the 5 FORMULA 5 and the triggers 10 Only the frequencies of the signals at the inputs and outputs of the formers 15 and 5 are different, because the formers 15 are triggered by signals from intermediate outputs a frequency divider 7 whose input is connected to the output of one of the formers 5. The phase shift by -jf of the reference meanders at the outputs of one of the formers 15 relative to the reference meanders at the outputs of the other forming 15 is provided by The signal shifts at the inputs of these drivers connected to different outputs of the frequency divider. So, if the frequency subtraction triggers 10 allow you to count unit increments of distances, the frequency subtractors triggers 16 make it possible to isolate large increments of the same distances, measured by an integer unit increments, equal frequency division ratio when receiving low-frequency meanders from high-frequency reference meanders. 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 serial counting circuit consisting of a single adder and a shift register in which the distance codes representing one another are circulated are the sums of large increments of these distances added to the initial values of the distances established at the beginning of the device operation. Group integrators 12 and 17 are similar in design and function. Each of them contains a ring serial counting circuit consisting of a single adder and a shift register. The circulation periods of the codes in the integrators 12 and 17 and the 1G counter are the same and equal to the polling period of the amplifiers 9. The number of code bits in the integrators and in the counter is the same. Integrators work as follows. Each time the distance is incremented by a single unit, the corresponding code is transmitted once, taking into account the sign of the increment from the group counter to the group integrator 12. The seven integrator accumulates small increments of the squares of the distance, which are located one after another in the integrator register in sequence. Each time you change the distance by a large increment, the corresponding code is transmitted once, taking into account the sign of the large increment from the group counter to the group integrator 17. Thus, the integrator 17 accumulates large increments of the squares of the distance. Simultaneously with the allocation of large increments of the square of the distance, the zero is set in the corresponding part of the register of the group integrator 12. This operation is necessary because in the proposed device the exact values of the distance squares are obtained by adding the corresponding codes from the integrators 12 and 17, Tj, .. e. addition of small and large increments of squares of distances, using an adder 1. The additional inclusion in the state of the proposed device of the control adder 18, the register 19 and the signaling unit 20 allows continuous monitoring of the calculation of the squares of the distance. The values used for the control are already calculated in the known device. The difference between these values is determined using a control adder, one input of which receives a signal directly from the output of the adder AND, and another input - a signal from the output of the shift register, in which this signal was delayed by a third of the device operation period.

Claims (1)

If an error is made in determining the square of at least one of three 15 distances, then a prohibition signal from the signaling unit connected to the control adder is immediately received at the code output unit. Restoration of the device-20 is performed at the position of the viewer at point O by setting the initial values of the distances, and their squares in the counter 11 and the integrator 17. Since only two ultrasound receivers are used to calculate the coordinates 25 in the proposed device, and the third receiver performs only the control function, the tracking integrator block 21 is applied to calculate the coordinate. The input values for the tracking integrator block are the x coordinate and one of the distances from the center of the transducer to the ultrasound receiver. Therefore, the inputs of the following integrator are connected to both the Output of the adder C and the output of the group counter. The action of the control channel is based on adjusting the frequency of the signals of the generator 4 in accordance with the sign of the phase shift of the signals of the control receiver relative to the reference meanders. Such adjustment is POSSIBLE within one wavelength of the distance from the reference emitter to the control receiver of the ultrasound. After switching on the device into operation / at the trigger 25 is set to one of two possible states - O or 1. The trigger state corresponding to the output of the trigger 25 through the integrating element 2b affects the control input of the generator k. The frequency control of the generator signals will make the phase shift sign of the control receiver signal. Let, for example, the state O indicates a negative phase shift, in which the calculated number of waves plus the fractional part of the wave is placed at a distance from the reference emitter to the reference receiver. The error — the fractional part — is eliminated by decreasing the frequency of the generator signal t; the signal is, for example, by connecting a control voltage through a resistor to the collector of the generator transistor. The frequency reduction of the oscillator signals continues until the phase shift of the control receiver signals relative to the reference meanders is zero. The oscillator is then kept in a state in which the wavelength of the signal wave remains constant. The invention is a device for reading graphic information on the author. St. .fP 75638, characterized in that, in order to improve the accuracy of reading graphic information, a control emitter connected to the unit for launching the target emitter, an integrating element connected to a reference signal generator, a control subtractor of frequency subtraction connected to an integrating element and a driver of the reference meanders, a control receiver connected to a frequency subtraction control trigger, a tracking integrator unit connected to a group counter, an adder and a code output unit, and been consistent connected shift register coupled to the adder, the adder control, the other input of which is connected to the adder, and alarm unit connected to the code output unit.