Problems using multiple HC-SR04?

I’m starting to work on a project where I will be wanting to track a moving objects location in a small room and because of ultrasonics resolution I think I’ve decided to use that. I found the module HC-SR04, and was wondering how I could go about this without having multiple units(3-4 or more) interfere with each other. Am i right in assuming that they could potentially catch each others signals and how could I attempt correcting this?

You're absolutely right. The only reliable way I've found to avoid interference is to wait long enough between output pulses, to allow echoes from previous pulses to die away. Long enough depends on the environment.

AWOL: You're absolutely right. The only reliable way I've found to avoid interference is to wait long enough between output pulses, to allow echoes from previous pulses to die away. Long enough depends on the environment.

Understandably it would depend on the environment, if I was talking about an average size bedroom what kind of delays could I expect? if it isn't too long I could still look into this tech I think.

It also depends on what is in the environment. Soft furnishings absorb echoes quickly. Of course, the longer the wait, the lower the pulse repetition rate, and the slower you need to run your vehicle. Experiment is really the only way.