detecting object location inside a tank full of water - Page 1
Forum section: electronics / projects

author: Asim
author_rank: Regular Contributor
timestamp: September 11, 2013, 09:49:24 pm
content: Hi guysSo, I have a project the requires detecting ( for example a ball ) inside a tank of water, and this tank is connected to a motor.I need to know the movement of the ball inside the moving water. any ideas ?

author: JackOfVA
author_rank: Unknown
timestamp: September 11, 2013, 11:39:42 pm
content: Trained fish - fish spots the ball and swims over to the side of the tank and presses its nose against a button signaling the ball location.Or if there is air in the tank and it is sufficiently large, a trained dolphin - much smarter than the average fish.This sounds exactly like a homework problem - you are not going to get my sympathy in asking for solutions here.

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: September 12, 2013, 12:04:39 am
content: Are you detecting water level, or just the presence of objects.Ultrasonic, Infrared, Normal Vision. would be my next choices, after dolphins of course.

author: David_AVD
author_rank: Super Contributor
timestamp: September 12, 2013, 12:35:40 am
content: QuoteWhat does this mean?Also, is the object submerged or floating?

author: mechknoll
author_rank: Contributor
timestamp: September 12, 2013, 04:10:41 am
content: It really depends on what you are after. Is this simply a ball in water... is the ball large? more details please. This sounds like a project I did once in a bio-medical imaging lab. We were building a heterodyne imaging system using infrared light. An idea is to paint the ball with fluorescent compound and use an excitation source and two CCD cameras. That would be a fun labview exercise!

author: IanB
author_rank: Super Contributor
timestamp: September 12, 2013, 04:14:04 am
content: Seems a bit like shooting fish in a barrel?

author: DrEEvil
author_rank: Newbie
timestamp: September 12, 2013, 04:23:52 am
content: IP camera with Infra red illumination and motion tracking software on the recorder.You could have an alarm raise (and output) if the ball goes into a certain area.Requirements:Only one ballStill waterClear waterQuestions:Why

author: mechknoll
author_rank: Contributor
timestamp: September 12, 2013, 04:55:55 am
content: Dolphins are an excellent choice though...buuut you might run into trouble with mounting lasers on their heads....

author: David_AVD
author_rank: Super Contributor
timestamp: September 12, 2013, 04:57:25 am
content: Sharks?

author: DrEEvil
author_rank: Newbie
timestamp: September 12, 2013, 05:14:38 am
content: Don't play ball sports near the tank....come on guys!

author: Asim
author_rank: Regular Contributor
timestamp: September 12, 2013, 05:58:40 am
content: Quote from: HackedFridgeMagnet on September 12, 2013, 12:04:39 ami don't need the water level, only the location of the ballQuote from: David_AVD on September 12, 2013, 12:35:40 amit means that this motor is connected to a propeller> the propeller moves the water hence the ball, the ball is submergedQuote from: mechknoll on September 12, 2013, 04:10:41 amit is a small ball submerged in the water, theapproximatelocation of the ball in the x,y,z plane is needed.

author: kizzap
author_rank: Unknown
timestamp: September 12, 2013, 07:20:37 am
content: Really does sound like a homework question....impossible to solve with the information you have given too.Either way, I'd suggest lasers, always lasers.-kizzap

author: G7PSK
author_rank: Super Contributor
timestamp: September 12, 2013, 07:27:36 am
content: Go and ask the navy, its something they specialise in, tracking under water moving objects. It has to be either sonar or ULF radar.

author: BravoV
author_rank: Super Contributor
timestamp: September 12, 2013, 07:32:29 am
content: Quote from: Asim on September 12, 2013, 05:58:40 amThis should be easy, install a transparent window either glass/acrylic at the water tank, paint/print the inner wall with scale, and then all you need is just sit tight, watch and take note in front of it while the tank busy wobbling.How hard could that be ?

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: September 12, 2013, 08:25:48 am
content: if you know the exact size of the ball you can do it with one camera, otherwise you need a calibrated stereoscopic system. (a pair of cameras).Either way you will also need a fair bit of maths

author: dfmischler
author_rank: Frequent Contributor
timestamp: September 12, 2013, 10:37:05 am
content: How big is the tank? How about the ball? How fast is the water moving? Is the flow turbulent, or do you have a nice laminar flow (i.e. is there cavitation from the propellor)? Is the water thoroughly mixed? Is it pure water? Tap water? Salt water? Rusty hydronic system water? Radioactive cooling system water? What are the walls of the tank made of? What is the ball made of? Is there any electromagnetic radiation or particle emission or other energy coming off the ball? What electromagnetic radiation frequencies (or sound) does the ball reflect? Is there a plan to vaporize the ball after you locate it, or are you going to have to keep tracking it? Does the ball take anti-detection counter-measures? Can the ball shoot back?

author: BravoV
author_rank: Super Contributor
timestamp: September 12, 2013, 10:54:54 am
content: Quote from: dfmischler on September 12, 2013, 10:37:05 am

author: Smokey
author_rank: Super Contributor
timestamp: September 12, 2013, 09:46:51 pm
content: Can you put sensors on/in the ball? One ultrasonic transducer inside the ball acting as a transmitter and three receivers with fixed locations on the tank. Time of flight is easy to measure with a basic microcontroller down to less than cm levels.And I only suggested that option because someone already posed my first thought of sharks with frikken lasers.