Bernard = Arnold. But Ford isn't the one who built him. Arnold created his own bot and uploaded his consciousness. Ford later was able to take control of Arnold 2.0, and instead of destroying him, re-purposed him to be his loyal slave. The now Bernard still maintains his creativity and intellect, which has helped Ford realize his own plans over the years. Ford mentioned that Bernard was good at cleaning stuff up and erasing information. He is so good at it that he was even able to remove every trace of his own existence. But guess what...Ford is also a bot. He mentioned to Bernard that he views a conscious host to be on par with a human, that there was virtually no difference between the two in regard to what "true" consciousness is. Given this opinion, why not upload your consciousness into a robot? Bernard himself is a proof of concept. This also explains why Ford is able to control the robots with just his thoughts. He has an internal link built right in. The link is two-way and allows him to use the hosts as spies. I think the host currently being built in the secret room is actually Ford's new body. He rebuilds himself every few years to add upgrades and make his appearance slightly older.
