MOSSVILLE, Ill., Sept 21 (Reuters) - Mark Pflederer dreams of dancing bulldozers. Pflederer, the chief technology officer at heavy machinery maker Caterpillar Inc. (CAT.N: Quote, Profile, Research), believes that, within a few years, his company's earthmovers will be able to operate without drivers, spinning around each other on worksites like dancers in a robotic ballet choreographed by onboard computers and satellite-based navigation systems. "Ten or 15 years down the road," he says, "it's not too much of a stretch to think that we could run multiple bulldozers, wheel loaders or trucks on a site and move the operators to a...