Ford began working on the project about three years ago, informally assembling a team of eight engineers with no additional budget, and started using the robots for testing in late 2012.
Ford can run as many as eight vehicles simultaneously at speeds of up to 80 mph.
Besides saving employees from the physical stress of testing, robots don't get bored repeating the same task and can replicate routes more precisely, yielding more accurate data. But Payne says computers can't do everything humans can.
"Replacing the five senses that we have, that's a different task," he said.
Global positioning devices track the vehicles' locations and movements with less than a one-inch margin of error. A command center about a mile from some of the routes monitors the vehicles, and for now Ford bars human drivers from sharing routes with robotic ones.
The vehicles are programmed to stop if they detect a person or another vehicle in their path, though engineers are perfecting ways to avoid deer and other animals that often appear on the 3,880-acre property. ("They recognize two-legged patterns, not four," Payne said.)
During a demonstration of the technology last week, Ford showed a Transit van repeatedly driving itself through a section of road that testers call "Curb Your Enthusiasm." The van traveled over numerous curbs at about 5 mph and over smaller obstacles at 30 mph, much like delivery drivers might do on urban routes, automatically correcting its path as it hit the curbs at varying angles.
Ford also has used the robots to test the F-150, Explorer, Expedition, Fusion and Fiesta, among other nameplates. It installed a second command center this month at the proving ground adjacent to its Dearborn headquarters and expects to start autonomous testing there soon.
Ford is working with supplier Autonomous Solutions Inc. in Mendon, Utah, which was spun off in 2000 by Utah State University to sell self-driving robots to the agriculture and mining industries.
The companies had to adapt that technology to handle much faster speeds -- vs. the crawling pace of a combine or mining truck -- and more stress. They also designed the equipment so it takes only about half an hour to install or disassemble, allowing it to be moved from one vehicle to another.
"They are trying to put thousands of miles of abuse on the vehicle as fast as possible so it really beats up on the system," said Autonomous Solutions CEO Mel Torrie. "It takes the durability to a whole new level with the types of G-forces they're putting on these vehicles."