Daniel C. McCarthy, News Editor
Computer modeling has aided in the design of large construction vehicles and farm equipment, but no computer can model the real-world conditions of mud, strain and uneven terrain under which Caterpillar Inc.'s vehicles must perform and endure. Consequently, the company puts these designs to the test on its Peoria, Ill., proving grounds, where computer-designed vehicles are validated in the real world by a noncontact, laser tracking system from SMX Corp.
Caterpillar is using laser tracking technology as a noncontact means to validate real-world performance of its computer-designed vehicles. Courtesy of SMX Corp.
The technology proved useful recently, when Caterpillar sought a way to monitor and measure how one of a bulldozer track's 44 shoes was displaced as the tread gripped the soil to propel the vehicle forward. "Soil has an effect on pull, ride, steering," said Ted Kingham, a Caterpillar research engineer at the facility. "Everything that touches the dirt affects how the machine behaves."
Earlier, the engineers had tried mechanical transducers to gain this information, but the devices couldn't withstand the forces and accelerations exerted on them. Kingham asserted that the most important benefit of laser tracking is that it's nonmechanical, so there are no failures of mechanical linkages. Close behind this is the tracker's ability to obtain noncontact measurements.
From a distance of about 60 feet, the SMX tracker measured the position of a target attached to a moving track shoe as a function of time. These measurements were used to verify computer predictions of the track shoe's performance.
Kingham acknowledged that laser tracking technology is not infallible -- the laser beam is sometimes broken by mud or dirt that rolls off the tread or by rain and dust. Getting stable, clean electrical power to the site is still a problem; the tracker runs off 110 V from a field generator. "It's not an ideal solution," he pointed out. "But it's the best one we have."