RU1838765C - Ultrasonic level gauge - Google Patents

Abstract

) Summary of the invention: the device comprises a pulse excitation generator, a radiating converter, a receiving converter, two binary counters, two triggers, a crystal oscillator, a recording unit, a multiplexer, and two 2-yl data registers.

Description

| The invention relates to measuring equipment, in particular to liquid level meters.

 The introduction of modern technological processes into the industrial production requires the creation of level control devices with enhanced metrological characteristics and high information reliability.

The technical essence of the invention consists in maintaining an ultrasonic level gauge comprising a pulse generator connected to a radiating ultrasonic transducer and a mounting input of a first binary counter, a receiving ultrasonic transducer, a second binary counter, quartz | a generator, a second trigger and a first trigger, I connected to the recording unit, I of the first and second data register connected to I ports of the input interface of the re- | the recording unit, and the multiplexer, to the first, second and third inputs of which the output of the emitting and the first and second outputs of the receiving ultrasonic transducers are connected, the output of the multiplexer is connected to the counting input of the first binary counter, the output of which is connected to the control input of the multiplexer, and the input data of the first trigger, the counting input of which is connected to the output of the crystal oscillator, also connected to the counting input of the second binary counter, the output of which is connected to the inputs data of the first and second data registers, the direct and inverse outputs of the first trigger are connected respectively to the recording permission inputs, while the installation input of the second binary counter is connected to the inverse output of the second trigger, the counting and installation inputs of which are connected respectively to the direct output of the first trigger and control output of the recording unit. In this case, the recording unit is made comprising a microprocessor, read-only memory, random access memory,

ate

with;

00 CA 00 VI

Cj

control command decoder, input and output interfaces interconnected by a combined address-data bus and control bus.

As a result of the introduction of new elements and connections during the proposed implementation of the recording unit in the proposed ultrasonic level gauge, the processing time of the information signal is reduced, as a result of which the dynamic measurement error is eliminated.

In the proposed ultrasonic level gauge, it is possible to obtain information about the holding time 337 in one measurement step (by one probe pulse). a probe pulse in the reference and measuring channels of the receiving ultrasonic transducer and at the same time information on the probe pulse duration (Tc), which is necessary to determine the middle of the probe pulse and reduce the error 53ap, depending on the value of Tc (as in the prototype). Moreover, if the prototype requires a signal processing time to ensure a minimum value of 5sap. equal to five repetition periods of the probe pulse, in the proposed device the signal processing occurs in one clock cycle.

Figure 1 presents a block diagram of the proposed ultrasonic level gauge; figure 2 - timing diagrams of his work.

The ultrasonic level gauge contains a pulse generator 1, an emitting ultrasonic transducer 2, a receiving ultrasonic transducer 3, a first binary counter 4, a first trigger 5, a crystal oscillator 6. a second trigger 7, a second binary counter 8, a registering unit 9 and a multiplexer 10 input, a first data register 11 and second data register 12.

The recording unit 9 includes a microprocessor 13, read-only memory 14, random access memory 15, control command decoder 16, input interface 17, output interface 18, which are interconnected by a combined data address bus (SDA) and control bus (SHU). The pulse generator output is connected to the emitting ultrasonic transducer 2 and the installation input R of the first binary counter 4. The output of the emitting ultrasonic transducer 2 and the first and second outputs of the receiving ultrasonic transducer 3 are connected

respectively, with the first, second and third inputs of the multiplexer 10., the output of which is connected to the counting input C of the first binary counter 4 and the data input D of the first trigger 5. The data output of the counter 4 is connected to the control input of the multiplexer. The direct output Q of the first trigger 5 is connected to the interrupt input RST of the recording unit 9, the counting input C of the second trigger 7, and the write enable output CE of the first register 11. This is the inverse output Q of the first trigger 5 is connected to the write enable input CE of the second data register 12 The output of the crystal oscillator 6 is connected to the counting inputs C of the first trigger 5 and the second binary counter 8, the installation input R of the second is connected to the inverse output Q of the second trigger 7, The output of the second binary code 8 is connected to the data inputs ervogo and second data registers 11 and 12. The output of the first data register 11 is connected -. are connected to port B, and the output of the second data register 12 is connected to port A of the input interface 17 of the recording unit 9. The output E of the command decoder 16 of the recording unit 9 is connected to the installation input R of the second trigger 7.

The emitting ultrasonic transducer 2 is acoustically coupled to the receiving ultrasonic transducer 3. The ultrasonic pulse emitted by the transducer 2 propagates through the sound transducer of the sensor (not shown in the drawing), which is a magnetostrictive delay line with a receiving ultrasonic transducer 9, consisting of a measuring and reference channels. . The permanent magnet of the measuring channel of the transducer 3 is located on the float, and the reference channel at the end of the sensor. With the passage of the ultrasonic pulse at the location of the float in the receiving transducer 3 due to the inverse magnetostrictive effect, a delayed pulse of the measuring channel is formed, and with the passage of the permanent magnet at the end of the sensor, the pulse of the reference channel is generated.

The device operates as follows.

When the device is turned on, the microprocessor 13, according to the program recorded in the read-only memory 14, generates in the decoder of the control commands 16 a signal of zeroing E of the second trigger 7, setting at its output Q a unit level, which is fed to the input R of the second binary counter 8 (diagram 6 ),

prohibiting his work. The first counting pulse coming from the output of the crystal oscillator 6 to the counting input C of the first trigger 5 sets the zero level on its direct output Q, because there is no signal at its input D. At the outputs of the first 11 of the second 12 registers, null codes are set.

Next, the processor enters the interrupt standby mode.

Pulse generator 1 generates an ideal pulse (plot 1), which nullifies the first binary counter 4 and excites 1 emitting ultrasonic transducer 2, at the output of which an ultrasonic probe pulse FI is generated. When the ultrasonic pulse F 1 is propagated through the sensor’s sound path, when the measuring magnet reaches the measuring channel and the receiving ultrasonic transducer 3, a delayed 1 pulse F 2 is formed (plot 3), and when the permanent channel of the transducer channel’s magnet passes through 3, the impulse Рз is formed (diagram 4),

After zeroing counter 4 with a pulse from excitation generator 1, a zero / zero code is set at its data output, probing pulse FL is cut through multiplexer 10. When pulse F / про passes through multiplexer 10 (plot 5), it goes to counting the input from the first binary counter 4 and the data input D of the first trigger 5. After that, the code 4 is installed at the output of the counter 4, allowing the storage of the delayed ultrasonic pulse of the measuring channel F. When the first trigger is fed to the data input D 5 and FI front pulse edge after the arrival of the first count pulse from crystal oscillator 6 at its counting input C at the outputs of the flip-flop 5 is straight and inverted Q signal Q. by which time interval starts miscalculation

)AT.

In this case, when the signal Q from the input of the first flip-flop 5 arrives at the counting input of the second flip-flop 7, the positive potential is pre-set on the inverse output Q by the control signal E from the recording block on the left (diagram 6).

Of the blocking unit 9, the microprocessor 13 switches to the interrupt processing mode by reading the Do data from the output of the register 11 through the port B of the input interface 17 and entering this data into the random access memory 15.

Upon receipt at the input R of the second binary counter 8 from the output of the trigger 7 of the zero level, the counter 8 starts counting the counting pulses (plot 7). arriving at its counter input C from the output of the crystal oscillator 6. At the end of the pulse FI, the inverse output Q of trigger 5 generates a positive voltage jump, by which the output data D of counter 8 is recorded in register 12 (diagram 9) and the interrupt request is removed from input RST of the recording unit 9 coming from the output Q of the trigger 5.

When the RST interrupt request is removed by the first command, after the interrupt has been serviced, a read command is written to the read-only memory 14 through the port A of the input interface 17. to which the data entered in register 12 is received.

Data DI from register 12 is placed in the next memory cell of random access memory 15. Then, when the second pulse FZ arrives, the process proceeds as described above, while the output of the first binary counter 4 increases the code by one, allowing the passage of the third pulse Pz, and into the next cells in the random access memory 15, data Da and Oz corresponding to the beginning and end of the pulse Fa are entered.

A similar process occurs when a pulse FS arrives, after which data D4 and Ds corresponding to the beginning and end of the pulse Fa are recorded in RAM 15. After the passage of the pulse RH, the recording unit 9 generates a signal for zeroing E and switches to the level calculation mode. In this case, in the recording unit 9, the following is determined: the middle of the first pulse FI:

DF,

When a signal Q is received from the output, the middle of the second pulse F2 of igger 5 is at the recording permission input CE 55

Histra 11 records output

the second counter 8 in the data register 11 (plot 8).

Upon receipt of the signal Q from the output, the middle of the third pulse Рз of igger 5 to the interrupt input RST register 0Р2 з-Ж

Df3

 ps - Rl 2

"Is

probe pulse delay in the measuring channel5

On -Df2 -DFL probe delay

nom channel:

Di2 ARI - DFI;

the level of the controlled environment is calculated

T2

 AND

The calculated value of the level of the monitored medium is transmitted to the output interface 18 for indicating and generating the necessary external signals for signaling and control.

After the calculation is completed, the microprocessor enters the standby mode for interruption and, when the next clock pulse is generated, the process repeats,

Thus, in the proposed level gauge, as in the prototype, the delay time of the probing ,, pulse in the middle of the pulse is fixed, which eliminates the influence of the duration of the probing

pulse to the measurement result, and information processing takes place in one clock cycle, which eliminates the dynamic error. 1 The duration of the calculation process when using a microprocessor of the K1821 4d series is several tens of microseconds and the duration of the measurement process is determined only by the measurement range

o

5

0

5

d

neither. In addition, it should be noted that the proposed level gauge has high information reliability through the use of the principle of measurement using ultrasound and digital processing of information signals.

Claims (1)

SUMMARY OF THE INVENTION An ultrasonic level gauge comprising a pulse generator connected to a radiating ultrasonic transducer and a mounting input of a first binary counter, a receiving ultrasonic transducer, a second binary counter, a crystal oscillator, a second trigger and a first trigger connected to a re-recording unit, characterized in that that the first and second data registers are connected to it, connected to the ports of the input interface of the recording unit, and the multiplexer, to the first, second c, and third input which is connected respectively to the output of the emitting and the first and second outputs of the receiving ultrasonic transducers, the output of the multiplexer is connected to the counting input of the first binary counter, the output of which is keyed to the control input of the multiplexer, and the data input of the first trigger / counting input of which is connected to the output of quartz generator, also connected to the counting input of the second binary counter, the output of which is connected to the data inputs of the first and second data registers, to the recording enable inputs the direct and inverse outputs of the first trigger, respectively, are connected, while the installation input of the second binary counter is connected to the inverse output of the second trigger, the counting and installation inputs of which are connected respectively to the direct output of the first trigger and the control output of the recording unit,