Probleam in distance measurement using ultrasonic sensor

Thread Starter

Ronak Vyas

Joined May 15, 2012
8
Hello Friends
I want to measure distance of an object from sensor, I am using ultrasonic sansor HC-SR04, due to uneven surface of an object(bottle in my case) I am not getting accurate result, anyone has any idea about the beam angle of an ultrasonic sensor, is there any other ultrasonic sensor available which has narrow beam angle compare to HC-SR04, if anyone knows about it please help me
Thanks.
 

Thread Starter

Ronak Vyas

Joined May 15, 2012
8
Thanks Eric
I want to use the ultrasonic sensor for my application do u know any other sensor which has narrow beam compare to HCSR04 so that the range of measurement area can be small.
 

Thread Starter

Ronak Vyas

Joined May 15, 2012
8
hi,
Check this link.
http://www.robot-electronics.co.uk/htm/srf235tech.htm

What range measurement accuracy do you require.?
Have you considered higher frequencies to achieve a narrow beam angle.
E
Thank u very much for the link.
I want to measure the distance from 4cm to 100cm.
Is there any problem to consider the higher frequency?
SRF235 is too much costly is there any other low cost solution?
 

jpanhalt

Joined Jan 18, 2008
10,080
As pointed out by Eric, higher frequencies give a narrower target, but have less range. I have used a sensor that operated at 500 kHz and had a range of only 50 mm. But then, its target size was quite small too. It was made by HydePark, which is now owned by Schneider (http://stevenengineering.com/Tech_Support/PDFs/45HYDEPARK.pdf).
You just need to search though the many options and pick a sensor with both the range of distances and target size you need.

The idea of focusing or collimating the ultrasonic beam may seem attractive, but can be difficult to implement. See this discussion:http://electronics.stackexchange.com/questions/94908/how-to-collimate-ultrasonc-beam-from-proximity-sensor-hc-sr04-in-measurng-distan

John
 

Thread Starter

Ronak Vyas

Joined May 15, 2012
8
Thanks John
So if I am using the ultrasonic sensor with higher centre frequency can I measure the distance of bottle (curved object) from sensor correctly?
 

GopherT

Joined Nov 23, 2012
8,012
Thanks John
So if I am using the ultrasonic sensor with higher centre frequency can I measure the distance of bottle (curved object) from sensor correctly?
Not necessarily. Sound reflects and finds multiple paths back to the sensor and can, at any particular point in 3D space, give you come unexpected results. Imagine a case of bottles, lots of reflection opportunities.

One improvement is to put a tube (wave guide) on the output and receive cylinder on the HC-04.
 

Thread Starter

Ronak Vyas

Joined May 15, 2012
8
Not necessarily. Sound reflects and finds multiple paths back to the sensor and can, at any particular point in 3D space, give you come unexpected results. Imagine a case of bottles, lots of reflection opportunities.

One improvement is to put a tube (wave guide) on the output and receive cylinder on the HC-04.
how can I put a tube , should this use at both transmitter and receiver side ?have u explore this thing ?please guide me to do this thing
Thanks
 

dcj3616

Joined Jul 30, 2017
1
how can I put a tube , should this use at both transmitter and receiver side ?have u explore this thing ?please guide me to do this thing
Thanks
I have had good luck using coin rollers (US dime, penny and nickel). If your coin rollers have pre-rolled ridges,
only the nickel (or larger) will work. I had my best luck with penny and nickel.

Before using these tubes (one each over the TX and RX shiny cylinders), I had problems with "multi-path", where
the signal was being reflected by objects in the 15 degree signal cone. With the rollers in place, I get more of the
targets I want rather than undesirable objects.
 

DickCappels

Joined Aug 21, 2008
6,533
I am pretty sure this sort of this is usually done optically. An array of lasers can detectors can give you a coarse reading. A video camera would give even more resolution.
 

Picbuster

Joined Dec 2, 2013
1,020
I agree with DickCappels however; measurement interval and calculation are the 'bottleneck' so to speak and showing up when curves/objects are unknown to the system.
Picbuster
 
Top