Hello
I am searching for a budget distance/range sensor. The range is from +- 5cm and 250cm. The SHARP IR sensor are not providing this range and in my opinion, Ultrasound sensors are having too large beam.
The aim is to have a beam of about 2.5 cm at 200cm distance.
Maybe somebody is able to guide me through this process.
Thanks in advance,
Castel
dont know what budget you have in mind?
The Lidar-Lite from PulsedLight3D has a very narrow beam and at least 40 meters range. It is a great buy.
Preferring less than 30 dollars.
The beam should be very narrow. That s why I was thinkinf about IR. Unfortunately none of the IR sensors match my range
As other people said a laser rangefinder could do the job, depending on what surface lies at the other end of that narrow hole/gap/tube of yours. Is it reflective, is it a solid surface or a fluid? But within your budget range, it would be hard I guess. Some further details would help others helping you.
The reflective material is a very solid metal so reflection should not be a problem at all.
castel:
The reflective material is a very solid metal so reflection should not be a problem at all.
Anyone suggesting the right sensor maching my aims?
Best regards,
If you do a bit of googling - you can find a research paper out there about using an infrared laser in place of the IR LED in a Sharp IR sensor; IIRC, the result was somewhat better (but still not as good as an actual LIDAR).
That said - you're not likely going to find a pre-made LIDAR sensor (or any pre-made sensor for your goal) for your budget.
At absolute best you might be able to get a laser-based tape measure (one that uses a real laser - not ultrasonic) and hack it to get serial output (this can be done with some models/brands). Still, expect to spend a minimum of $50.00.
The only other option (which would be bulky, and would require a computer) - would be to use a webcam and a laser pointer, in a parallax LIDAR setup - like so:
You won't be able to easily do the same using only an Arduino. Though it isn't impossible - in theory, with the proper parts - you could do a mash-up of the web-cam system with this:
http://www.seattlerobotics.org/encoder/200110/vision.htm
Whether or not you could do it for $30.00 though is questionable - but probably (if you don't count you time).
castel:
The range is from +- 5cm and 250cm. The SHARP IR sensor are not providing this range and in my opinion, Ultrasound sensors are having too large beam.
This Sharp IR sensor claims a 550cm range. You'd need a second sensor for close range objects.
I also think LIDAR Lite works well.
Parallax sells a laser/camera combo similar to the system suggested by cr0sh. At $99 it certainly isn't inexpensive. I've seen these sorts of laser triangulation sensors done with a camera from a WiiMote.
One problem with the laser and camera method is it doesn't work very well outside on sunny days. I did a little demo video showing Parallax's laser and camera rangefinder along with LightWare's SF02 rangefinder (the SF02 was partial payment of a programming job I did for Parallax). Hopefully the video will give you some idea of the strengths and weaknesses of the rangefinders.
Is it correct to say the LIDAR lite is providing a very narrow beam (the beam of the laser)?
Are there existing affordable measurement sensors (US or IR) using a transmitter and receiver separately?
So you can put the Transmitter on one object and the Receiver on the other one to know the distance?
You could have the transmitter sending its location, the receiver would know its own position and calculate the distance.
One point(A) is fixed and the other part is moving(B). I need to know the "distance" between the two objects.
So the question is how do I know the position of B compared to A. I was thinkin of calculating distances but I think I can never get any reliable measurements because of noise when using an HCSR04 for example
castel:
Is it correct to say the LIDAR lite is providing a very narrow beam (the beam of the laser)?
I have an earlier version of LIDAR-Lite. I could test to see how wide the beam is. How big is your target?
castel:
Are there existing affordable measurement sensors (US or IR) using a transmitter and receiver separately?
So you can put the Transmitter on one object and the Receiver on the other one to know the distance?
I don't know of a device to do this but I think it's possible.
You could have the one device send both a radio transmission and an ultrasound pulse at the same time. The receiving unit would then compare the time when these two signals were received. The distance could then be calculated.
I once worked on a project which involved very precisely timed radio transmissions using inexpensive nRF24L01+ modules. These transceivers can be configured to send very precisely timed messages.
I don't know if you can use the normal nRF24L01+ library to do this sort of thing or not. I wrote the code to send and receive precisely timed messages in assembly (I used a Propeller microcontroller).
It's possible to have one ultrasound sensor receive the pulse from a different sensor. The sensor which is to receive this pulse has its transmitting transducer silenced (covered) so when it is triggered it only receives the signal from the other module.
There would be some overhead to receive the RF signal and to trigger the muted ultrasound sensor so I doubt you could use this technique for very short distances. If you modified the technique so the transmitting unit delayed the ultrasound pulse in order to allow the receiving unit time to get ready, then there needn't be a lower limit on the range.
castel:
I can never get any reliable measurements because of noise when using an HCSR04
There are better ultrasound sensors than the one you're using. Parallax's Ping sensor costs more than the cheap sensors but, in my experience, it works much better than the cheap units. Maxbotix also makes nice ultrasound sensors.
If you want to use the RF plus US technique, make sure you use an ultrasound module with separate transmit and receive transducers.
DuaneDegn:
I have an earlier version of LIDAR-Lite. I could test to see how wide the beam is. How big is your target?I don't know of a device to do this but I think it's possible.
You could have the one device send both a radio transmission and an ultrasound pulse at the same time. The receiving unit would then compare the time when these two signals were received. The distance could then be calculated.
I once worked on a project which involved very precisely timed radio transmissions using inexpensive nRF24L01+ modules. These transceivers can be configured to send very precisely timed messages.
I don't know if you can use the normal nRF24L01+ library to do this sort of thing or not. I wrote the code to send and receive precisely timed messages in assembly (I used a Propeller microcontroller).
It's possible to have one ultrasound sensor receive the pulse from a different sensor. The sensor which is to receive this pulse has its transmitting transducer silenced (covered) so when it is triggered it only receives the signal from the other module.
There would be some overhead to receive the RF signal and to trigger the muted ultrasound sensor so I doubt you could use this technique for very short distances. If you modified the technique so the transmitting unit delayed the ultrasound pulse in order to allow the receiving unit time to get ready, then there needn't be a lower limit on the range.
There are better ultrasound sensors than the one you're using. Parallax's Ping sensor costs more than the cheap sensors but, in my experience, it works much better than the cheap units. Maxbotix also makes nice ultrasound sensors.
If you want to use the RF plus US technique, make sure you use an ultrasound module with separate transmit and receive transducers.
Thank you for the answer. my beam should be about 1cm² at about 2 meters distance