I think this is a fascinating project, but I have to ask. How do you get your foot in the door with consumers? I'd feel a bit sketched out if someone showed up and just asked to follow me around for a while. What's the incentive?
With that being said, you might get a handful of, "no, absolutely not that's creepy" responses to the request, but if you ask enough people someone will say yes and be excited about it.
Do not be discouraged by the no’s. Starting with friends and network is an option.
It also helps if you have a code of conduct/governance documentation for them to read and understand how their data is gathered and used.
I usually send a copy of all data to my subjects with a thank you letter and how it helped (with a gift card).
It also helps to build a network, for starters I partner-up with many prominent content producers on YouTube and Twitter and pay them a small fee for introductions.
I also pay the people I study on the field (but not always, some are happy to help once they understand what it's for). A lot say no, but you only need a few yes. It's about drawing insights from a small set of data.