I'm doing a senior project about automating the braking system in cars and make it smarter
OBD stands for On Board Diagnostics. It is used to provide vehicle diagnostic information. It is read-only, except for specific log entries and specific fault codes that can be reset. So no, you cannot control the braking system of a car through the OBD port.
That does not however mean that a vehicle cannot be hacked through its diagnostic interface, but this is heavily dependent on car make/model and is not legal in any way.