How to connect multiple arduinos to a RPI ?

Hi there !

I'm in the middle of a project for work and I just figured out a huge problem.

Here is the project : We want to use four raspberry pi 3 B+ for each to control four arduino nano. Those arduino nano will control different probes and systems for individuals productions units. So it's very important that we have one Nano per unit... Also, it seems to be the best solution to have four arduinos connected to a single raspberry pi because we gonna put the RPIs in electrics boxes that are placed every four units. The all system is going to be ran with Jeedom. The idea is also to connect the Nanos and RPIs with wires. However, the USB ports can't be used because of the distance. the Nanos will be placed at 5 or 10m (16 to 32ft) from the RPIs. I don't think that a USB signal can travel that far...

My concern is simple : I can't find any documentation or tutorial of any kind suggesting that I can wire four arduinos to a single RPI. So is it even possible ? If yes, How ?

Thanking you in advance. Nico

PS : Sorry for poor English, not my first language...

An RS485 connection would probably be a good solution. It can handle the distance and it can have several devices on a single link.