It's good that you have already identified companies you want to work for. Now, scour your current employer's organization for people who can introduce you to the companies you want to meet. If you poke around diligently, you'll find either an employee, or a friend of an employee, or a vendor or a customer who knows people at your target companies. Use these contacts to get introduced. Third, exploit your school's alumni roster.
Alumni are usually glad to advise students at their alma maters.
Ask your alumni office to introduce you to engineers who have been out there working for a few years. Alumni are a very under-utilized resource for new grads. The chain of contacts you develop can lead you to the companies of your choice. Don't worry about the cost of travel when interviewing. Yes, companies routinely pay for such trips, if they have reason to think you're a good candidate, and young engineers commonly move for a good job.