Arduino HCSR04 Crack Measuring
- Thread starter AJIN NADH
- Start date
DickCappels
- Joined Aug 21, 2008
- 10,170
Not sure I understand exactly what you mean by "crack" (Crack in what material and what item, dimensions, etc.) and by "detect".
If you are finding the distance from the transducers to the crack, isn't that sensing it? <== Clearly, I don't understand the setup.
If you are finding the distance from the transducers to the crack, isn't that sensing it? <== Clearly, I don't understand the setup.
Hi Sir,
Actually am doing a Rail Ultrasonic Flaw Detection System, but the flaw is not traced by the sensor, only the actual distance is getting....
You could try this first, if it doesn't work then you have to turn the direction of transmitters and receiver as cone
Source of picture.
Source of picture.
HC-SR04 Ultrasonic Module:
The Ultrasonic module detects the distance of the closest object in front of the sensor (from 2 cm up to 400cm).
Since the TS has such request, so he got to rty it.
It is doubtful that sensor can find a small crack in a wall. First you need to ping with a wavelength short enough to see the crack. Then the receiver mus be able to see that return echo as you now need to see two echos, fist from the start of the crack, and the next from the end of the crack. That receiver can only sense one return ping for each burst so it is unsuitable without modification.
If you have an oscilloscope you can probe the analog receive signal to see if there is anything you could possibly capture to detect the crack. You may have multiple echos as the signal bounces off the crack several times.
If you have an oscilloscope you can probe the analog receive signal to see if there is anything you could possibly capture to detect the crack. You may have multiple echos as the signal bounces off the crack several times.
My guess is the author wants to detect the discontinuity in the metal rail. Ultrasonic testing is used for such purposes in non-destructive (maybe pre-destruction?) testing of aircraft and other things. Here's a general description: https://en.wikipedia.org/wiki/Ultrasonic_testing
Don't know if the particular device the OP has will do that type of testing though.
John
Don't know if the particular device the OP has will do that type of testing though.
John
The wavelength of the 40kHz ultrasound is ~0.85cm in air, so I doubt such a low frequency would be able to detect a crack unless its width were about that distance. A cracked rail would be highly dangerous long before the crack reached that size. Even to sense a crack 0.85cm wide, I think you would need the transducer(s) in contact with the rail, not >2cm from it. Also, I think you might have to sense the phase of an echo signal, which the HCSR04 may or may not do.
This seems like a woeful misapplication of technology. An ultrasonic rangefinder operates at 40 KHz or so, but ultrasonic testing of solids uses frequencies into the megaHertz range, and requires contact with the material being tested. The WIkipedia article says "In most common UT [Ultrasonic Testing] applications, very short ultrasonic pulse-waves with center frequencies ranging from 0.1-15 MHz, and occasionally up to 50 MHz, are transmitted into materials to detect internal flaws or to characterize materials." A rangefinder will tell you how far it is from the sample, and that's all.
Hi sir,
I will try this
Ok sir,
is this will miss behave because of this cone shape ?
i will try it and revert back to u sir
Hi dear all,
The Ultrasonic ranging module HC - SR04 provides 2cm - 400cm non-contact measurement function, the ranging accuracy can reach to 3mm (i.e. 0.3 cm)
Using IO trigger for at least 10us high level signal,
The Module automatically sends eight 40 kHz and detect whether there is a pulse signal back...
the main thing is your Moving Speed the Stationary parameters is (as per the datasheet) is 10μs ( Trigger Input Signal------------------10uS TTL pulse ) and that to at an Angel of 15°
so now you have to adjust your Speed to DETECT the CRACK in the RAIL
The Ultrasonic ranging module HC - SR04 provides 2cm - 400cm non-contact measurement function, the ranging accuracy can reach to 3mm (i.e. 0.3 cm)
Using IO trigger for at least 10us high level signal,
The Module automatically sends eight 40 kHz and detect whether there is a pulse signal back...
now as per your Design http://forum.allaboutcircuits.com/threads/arduino-hcsr04-crack-measuring.120902/#post-965902
the main thing is your Moving Speed the Stationary parameters is (as per the datasheet) is 10μs ( Trigger Input Signal------------------10uS TTL pulse ) and that to at an Angel of 15°
so now you have to adjust your Speed to DETECT the CRACK in the RAIL
I thing that should solve the problem
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If this method didn't works then you have to adjust the angles of two pipes, when you try it at many angles, but it still didn't works as your wish then you need to take the transmitter and receiver away from the pcb and put their direction as cone, you have to make sure they have a small angles maybe 10~20° between them, you need to adjust the angle to check which angle has the best effective.
Sir,
This is the code actually am using
C:
/*
HC-SR04 Ping distance sensor]
VCC to arduino 5v GND to arduino GND
Echo to Arduino pin 13 Trig to Arduino pin 12
Red POS to Arduino pin 11
Green POS to Arduino pin 10
560 ohm resistor to both LED NEG and GRD power rail
More info at: [URL]http://goo.gl/kJ8Gl[/URL]
Original code improvements to the Ping sketch sourced from Trollmaker.com
Some code and wiring inspired by [URL]http://en.wikiversity.org/wiki/User:Dstaub/robotcar[/URL]
*/
#define trigPin 13
#define echoPin 12
#define led 11
#define led2 10
void setup() {
Serial.begin (9600);
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);
pinMode(led, OUTPUT);
pinMode(led2, OUTPUT);
}
void loop() {
long duration, distance;
digitalWrite(trigPin, LOW); // Added this line
delayMicroseconds(2); // Added this line
digitalWrite(trigPin, HIGH);
// delayMicroseconds(1000); - Removed this line
delayMicroseconds(10); // Added this line
digitalWrite(trigPin, LOW);
duration = pulseIn(echoPin, HIGH);
distance = (duration/2) / 29.1;
if (distance < 4) { // This is where the LED On/Off happens
digitalWrite(led,HIGH); // When the Red condition is met, the Green LED should turn off
digitalWrite(led2,LOW);
}
else {
digitalWrite(led,LOW);
digitalWrite(led2,HIGH);
}
if (distance >= 200 || distance <= 0){
Serial.println("Out of range");
}
else {
Serial.print(distance);
Serial.println(" cm");
}
delay(500);
}
Last edited by a moderator:
