Synchronous triggering circuit and method for ultrasonic echo valley measurement

Abstract

This invention discloses a synchronous triggering circuit and method for ultrasonic echo trough measurement, comprising an ultrasonic transmitting device, an ultrasonic receiving device cooperating with the ultrasonic transmitting device, and a counter. The counter includes a trigger and an input voltage signal IS1. One voltage signal, IS11, is output through the ultrasonic transmitting device, and another voltage signal, IS12, is connected to the counter. The ultrasonic receiving device receives the signal from the ultrasonic transmitting device and transmits the echo to a trough detection circuit. The trough detection circuit detects a voltage change and outputs a pulse signal from pin 7 of a second comparator U3 to the trigger. The counter outputs a feedback signal based on the trigger signal. This invention has a simple structure. By replacing the original comparator with a trigger and adding a trough detection circuit, the trigger position is determined by the echo reaching the trough position, eliminating the comparator threshold problem, eliminating measurement errors, and improving measurement accuracy.

Description

Technical Field

[0001] This invention relates to the field of ultrasonic ranging in non-destructive testing, specifically to a synchronous triggering circuit and method for ultrasonic measurement echo valleys. Background Technology

[0002] Ultrasonic testing is often rapid, convenient, computationally simple, and easy to control in real time. It also meets industrial accuracy requirements. Furthermore, due to its strong directivity, slow energy dissipation, and long propagation distance in a medium, ultrasound is frequently used for distance measurement, such as in rangefinders and thickness gauges. Most existing ultrasonic measuring devices employ a single ultrasonic transmitter. The ultrasonic waves travel to the target and return, where they are received by a receiver, and the distance is calculated based on the echo time.

[0003] Existing ultrasonic measuring devices mostly use threshold comparators for echo triggering. Because the amplitude of the echo varies with different distances or thicknesses, trigger point offset can occur, leading to increased measurement errors. In other words, traditional receiver-triggered stop methods use comparators, meaning a stop signal is only triggered upon receiving an echo with a certain signal amplitude. However, the echo amplitude varies with different distances or thicknesses, causing timing errors and affecting measurement accuracy. Figure 2 As shown, the echo is larger when the distance is closer and smaller when the distance is farther. Therefore, the time it takes to reach the same voltage will differ. Figure 1 As shown in T1 and T2, the above defects lead to measurement errors. Therefore, it is very important to obtain a synchronous triggering circuit and method for ultrasonic measurement echo valleys that overcomes the above defects. Summary of the Invention

[0004] To solve at least one of the above-mentioned technical problems, since the position of the trough will not change with the size of the echo, the measurement error will be eliminated, greatly improving the measurement accuracy. Therefore, this invention proposes a trough detection scheme for measurement.

[0005] On one hand, the present invention provides an ultrasonic measurement echo trough synchronous triggering circuit, including an ultrasonic transmitting device, an ultrasonic receiving device cooperating with the ultrasonic transmitting device, and a counter. The counter includes a trigger and a trough detection circuit. After detecting the echo from the ultrasonic receiving device, the trough detection circuit outputs a trigger threshold to the trigger to stop it from working. The counter calculates the time difference between when it starts working and when it stops working.

[0006] The trough detection circuit includes a first comparator and a second comparator. The ultrasonic receiving device receives the signal to the non-inverting input of the first comparator. The eighth output of the first comparator U1 outputs a high level to the D input of the flip-flop. The non-inverting input of the first comparator is connected to the transformer through a first transistor and a delay line and then input to the non-inverting input of the second comparator. The seventh output of the second comparator is connected to the CP input of the flip-flop. The fifth output of the flip-flop outputs a trigger pulse to the counter.

[0007] The ultrasonic receiver is connected to the valley detection circuit through the second operational amplifier circuit. The second operational amplifier circuit amplifies the echo received by the ultrasonic receiver and sends it to the valley detection circuit.

[0008] It also includes a controller that outputs a signal to a counter to start it working. This signal is simultaneously output to the ultrasonic transmitting device via an ultrasonic drive circuit. The counter feeds back the calculated information to the controller.

[0009] Through the above technical solution, the present invention adds a trough detection circuit, and the trigger position is when the echo reaches the trough position, which eliminates the comparator threshold problem, eliminates measurement error, and improves measurement accuracy.

[0010] On the other hand, the present invention provides a method for synchronous triggering of ultrasonic echo valley, including the above-mentioned ultrasonic echo valley synchronous triggering circuit, and further comprising the following steps:

[0011] S1, Input voltage signal IS1, one of which is a first signal IS11 output through the ultrasonic transmitter, and the other voltage signal IS12 is connected to the counter;

[0012] S2. The ultrasonic receiver receives the signal from the ultrasonic transmitter and sends the echo to the trough detection circuit. The trough detection circuit detects the voltage change and outputs a pulse signal to the trigger at pin 7 of the second comparator U3.

[0013] S3, the counter outputs a feedback signal based on the trigger signal.

[0014] The voltage signal IS12 is output to the counter after being filtered out by threshold comparison to remove basic interference.

[0015] When the voltage signal IS12 is sent to the first comparator U1, if it exceeds the threshold voltage of the first comparator U1, the seventh pin of the first comparator U1 outputs a high voltage to the flip-flop of the counter, so that the D pin of the flip-flop is 1. When the voltage of the second comparator pin 2 is higher than the comparison voltage of the third pin of the second comparator U3, the seventh pin of the second comparator U3 outputs a logic high level to the CP input of the flip-flop U2. At this time, the fifth pin of the flip-flop U2 outputs a trigger pulse.

[0016] The voltage signal IS1 is output through the controller. The controller calculates the distance based on the feedback information from the counter.

[0017] Compared with the prior art, the advantages of the present invention are: the present invention has a simple structure, the present invention replaces the original comparator with a trigger, and adds a trough detection circuit. The trigger position is when the echo reaches the trough position, which eliminates the comparator threshold problem, eliminates measurement error, and improves measurement accuracy. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the ultrasonic measurement principle.

[0019] Figure 2 A schematic diagram showing the time required for the echo magnitude to change and reach the comparator threshold voltage.

[0020] Figure 3 A schematic diagram showing that the location of the trough does not change with the size of the echo;

[0021] Figure 4 This is a block diagram illustrating the principle of a traditional comparator.

[0022] Figure 5 This is a block diagram illustrating the principle of the present invention;

[0023] Figure 6 This is a schematic diagram of the invention;

[0024] Figure reference numerals: 1-Ultrasonic transmitting device; 2-Ultrasonic receiving device; 3-Counter; 4-Flip-flop; 5-Trough detection circuit; 6-Second operational amplifier circuit; 7-Comparator; 8-Controller; 9-Ultrasonic driving circuit. Detailed Implementation

[0025] To enable those skilled in the art to better understand the present invention and to more clearly define the scope of protection claimed by the present invention, the present invention will be described in detail below with reference to certain specific embodiments. It should be noted that the following are only some specific embodiments of the present invention, and are merely a part of the embodiments of the present invention. The specific and direct descriptions of related structures are only for the convenience of understanding the present invention, and the specific features do not necessarily or directly limit the scope of the present invention.

[0026] Referring to the accompanying drawings, the present invention adopts the following technical solutions, such as... Figure 5As shown, on one hand, the present invention provides an ultrasonic measurement echo trough synchronous triggering circuit, including an ultrasonic transmitting device 1, an ultrasonic receiving device 2 that cooperates with the ultrasonic transmitting device, and a counter 3. The counter 3 includes a trigger 4 and a trough detection circuit 5. The trough detection circuit 5 detects the echo from the ultrasonic receiving device 2 and outputs a trigger threshold to the trigger 4 to stop it from working. The counter 3 calculates the time difference between its start and stop working.

[0027] The trough detection circuit includes a first comparator and a second comparator. The ultrasonic receiving device receives the signal to the non-inverting input of the first comparator. The eighth output of the first comparator U1 outputs a high level to the D input of the flip-flop. The non-inverting input of the first comparator is connected to the transformer through a first transistor and a delay line and then input to the non-inverting input of the second comparator. The seventh output of the second comparator is connected to the CP input of the flip-flop. The fifth output of the flip-flop outputs a trigger pulse to the counter.

[0028] The ultrasonic receiving device 2 is connected to the valley detection circuit 5 through the second operational amplifier circuit 6. The second operational amplifier circuit 6 amplifies the echo received by the ultrasonic receiving device 2 and sends it to the valley detection circuit 5.

[0029] It also includes a controller 8, which outputs a signal to the counter 3 to start it working. This signal is also output to the ultrasonic transmitting device 1 through the ultrasonic driving circuit 9. The counter 3 feeds back the calculation information to the controller 8.

[0030] Through the above technical solution, the present invention adds a trough detection circuit 5, and the echo reaching the trough position is the trigger position, which eliminates the comparator threshold problem, eliminates measurement error, and improves measurement accuracy.

[0031] On the other hand, the present invention provides a method for synchronous triggering of ultrasonic echo valley, including the above-mentioned ultrasonic echo valley synchronous triggering circuit, and further comprising the following steps:

[0032] S1, Input voltage signal IS1, one of which is a first signal IS11 output through ultrasonic transmitter 1, and the other voltage signal IS12 is connected to counter 3;

[0033] S2. The ultrasonic receiver 2 receives the signal from the ultrasonic transmitter 1 and transmits the echo to the valley detection circuit 5. The valley detection circuit 5 detects the voltage change and outputs a pulse signal to the trigger 4 from pin 7 of the second comparator U3.

[0034] S3 and counter 3 output feedback signals based on the signal from trigger 4.

[0035] The voltage signal IS12 is output to counter 3 after being filtered out by threshold comparison to remove basic interference.

[0036] The voltage signal IS12 is sent to the first comparator U1. If it exceeds the threshold voltage of the first comparator U1, the seventh pin of the first comparator U1 outputs a high voltage to the flip-flop 4 of the counter 3, so that the D pin of the flip-flop 4 is 1. When the voltage of the second comparator pin 2 is higher than the comparison voltage of the third pin of the second comparator U3, the seventh pin of the second comparator U3 outputs a logic high level to the CP input of the flip-flop U2. At this time, the fifth pin of the flip-flop U2 outputs a trigger pulse.

[0037] The voltage signal IS1 is output through controller 8. Controller 8 calculates the distance based on the feedback information from counter 3.

[0038] like Figure 6 As shown in the figure, the input voltage signal INPUT SIGNAL is output through pin 7 of the first comparator U1 to pin D of the trigger U3, and through the ultrasonic transmitter 1. After the ultrasonic receiver 2 receives the signal, when the signal reaches the top, the voltage of transformer P5 changes, and the pin 7 of the second comparator U3 outputs a pulse to the trigger U3.

[0039] The emitter of the first transistor is connected to the main side of the transformer via a delay line. The emitter of the first transistor is connected to the secondary side of the transformer via the fifteenth resistor. The two ends of the secondary side of the transformer are connected to the sixteenth resistor. The secondary side of the transformer is connected to the second pin of the second comparator. The base of the first transistor is connected to the eighth resistor.

[0040] like Figure 6 As shown, after the input voltage enters the first connector P1, it enters the first comparator for basic threshold comparison to filter out basic interference. If the voltage exceeds the threshold voltage of the first comparator, a high voltage is output from its pin 8 to the D pin of the flip-flop U3. The D pin of the flip-flop is at a high level. The input voltage passes through the eighth resistor and then the first transistor is connected to the eighth capacitor. It is then connected to the main side of the transformer through a delay line. After being mixed by the fifteenth and sixteenth resistors, the signal is injected into the second comparator's pin 2. When the voltage at the second comparator U3's pin 2 is higher than the basic noise comparison voltage at its pin 3, the second comparator's pin 7 outputs a logic high level to the CP pin of the flip-flop. At this time, the CP pulse causes the flip-flop's pin 5 to output a trigger pulse.

[0041] Compared with the prior art, the advantages of the present invention are: the present invention has a simple structure, the present invention replaces the original comparator with the trigger 4, and adds a trough detection circuit 5. The trigger position is when the echo reaches the trough position, which eliminates the comparator threshold problem, eliminates measurement error, and improves measurement accuracy.

[0042] The above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions, or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. An ultrasonic measuring echo valley synchronous trigger circuit, comprising an ultrasonic transmitting device (1), an ultrasonic receiving device (2) cooperating with the ultrasonic transmitting device, and a counter (3), characterized in that: The counter (3) includes a flip-flop (4), and further includes a wave trough detection circuit (5), which outputs a trigger threshold signal to the flip-flop (4) to stop the flip-flop (4) from working after detecting the echo from the ultrasonic receiving device (2), and the counter (3) calculates the time difference between the start and stop of the working.

2. The ultrasonic measurement echo trough synchronization triggering circuit of claim 1, wherein: The ultrasonic receiving device (2) is connected to the wave trough detection circuit (5) through a second operational amplifier circuit (6), which amplifies the echo received by the ultrasonic receiving device (2) and then sends the echo to the wave trough detection circuit (5).

3. The ultrasonic measurement echo trough synchronization triggering circuit of claim 1, wherein: The ultrasonic wave driving circuit (9) is connected to the controller (8), which outputs a signal to the counter (3) to start working, and the signal is also output to the ultrasonic sending device (1) through the ultrasonic wave driving circuit (9).

4. An ultrasonic measurement echo valley synchronous triggering method, characterized in that: The ultrasonic wave measuring echo wave trough synchronous trigger circuit comprises the following steps: S1, input a voltage signal IS1, which is output to the ultrasonic sending device (1) through a first signal IS11, and the other voltage signal IS12 is connected to the counter (3); S2, the ultrasonic receiving device (2) receives the signal of the ultrasonic sending device (1), sends the echo to the wave trough detection circuit (5), and the wave trough detection circuit (5) detects the voltage change, and then the pin 7 of the second comparator U3 outputs a trigger pulse signal to the flip-flop (4); S3, the counter (3) feeds back a signal according to the signal output by the flip-flop (4).

5. The ultrasonic measurement echo trough synchronization triggering method of claim 4, wherein: The voltage signal IS12 is output to the counter (3) after being filtered to remove basic interference through threshold comparison.

6. The ultrasonic measurement echo trough synchronization triggering method of claim 4, wherein: The voltage signal IS12 is input to the first comparator U1, and when the voltage exceeds the threshold voltage of the first comparator U1, the pin 7 of the first comparator U1 outputs a high voltage to the flip-flop (4) of the counter (3) to make the D pin of the flip-flop (4) be 1, and when the voltage of the pin 2 of the second comparator is higher than the comparison voltage of the pin 3 of the second comparator U3, the pin 7 of the second comparator U3 outputs a logic high level to the CP input end of the flip-flop U2, and at this time, the pin 5 of the flip-flop U2 outputs a trigger pulse.

7. The ultrasonic measurement echo trough synchronization triggering method of claim 4, wherein: The voltage signal IS1 is output through the controller (8) of the ultrasonic wave measuring echo wave trough synchronous trigger circuit.

8. The ultrasonic measurement echo trough synchronization triggering method of claim 4, wherein: The controller (8) of the ultrasonic wave measuring echo wave trough synchronous trigger circuit calculates the distance measurement according to the feedback information of the counter (3).

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