Distance Measuring Sensor Advice

[lasith]

Hi There, I'm looking for ideas on finding the position of objects (such as a hand or foot) placed in a tank. Without using a camera soultion, I think the use of something like a minature laser range finder or IR proximity sensor. My problem is that I need to find distances between 5cm (min resoultion) and 85CM - ideally on one angle (90degrees from mounting plain). As I said, the accuracy needs to be min 5cm resolution.

Has anyone got any advice on devices/sensors I can use. My plan would be to use such sensors on two sides of the tank (x,y - no need to get the depth) Althought the IR ones may work I don't know whether they provide 5cm resolution

Thanks in advance,
Lasith

 

[DragonPetter]

what about acoustic ranging?

 

[tygerdawg]

You don't say if the tank has material in it.

If not, then an ultrasonic sensor with analog output may do nicely.
Or a series of inexpensive photoelectric through-beam sensors.

 

[lasith]

Thank You DragonPetter and tygerdawg for your suggestions. FYI, my tank contains water, and has a set of red dot lasers and phototransistors on two sides each to calculate the position. the problem that I wanted to solve by using a separate sensor(s) was inability to counter occlusion when two objects are inserted. The secondary sensors I am looking for are to be placed above the water surface (10cm above) of the tank. I think the acoustic sensors will pick up the water surface as a object so perhaps the IR is the only solution ?.

 

[alphysicist]

I would recommend using ultrasonic distance measuring sensors for your project. These sensors use sound waves to measure the distance between the sensor and an object, and can provide a resolution of up to 1mm. They are also capable of measuring distances up to several meters, which would cover your desired range of 5cm to 85cm.

Another option could be using Time-of-Flight (ToF) sensors, which use infrared light to measure distances. They can also provide high resolution and cover your desired range. However, they may be more expensive compared to ultrasonic sensors.

In addition to choosing the right sensor, it is important to consider the placement and angle of the sensors in order to get accurate readings. You may need to do some experimenting and fine-tuning to determine the best positioning for your specific project.

I also recommend doing some research on different sensor models and their specifications to find the best fit for your project. You may also want to consult with other scientists or engineers who have experience with similar sensors to get their insights and recommendations.

Overall, using distance measuring sensors is a reliable and efficient way to accurately measure the position of objects in a tank without the use of cameras. With proper research and experimentation, you should be able to find a suitable sensor that meets your resolution and range requirements. Best of luck with your project!