[1] In his Ph.D. dissertation, he developed what became known as the Freudenstein equation, which uses a simple algebraic method to synthesize planar four-bar function generators.
During Hitler's blitzkrieg, Freudenstein temporarily moved to Cambridge, England, for safety, and then spent several years in Llandudno, North Wales.
Meanwhile, his father and brother were sent to exile in Australia by the British government which regarded all adult male German citizens as enemy of the state.
In 1942, when he was 16 years old, Ferdinand with his mother and two sisters sailed from England to Trinidad where they remained for six weeks before moving permanently to the United States.
Freudenstein had served on the advisor panels of the National Science Foundation and the United States Army Research Laboratory.