Speed Sensors Enhance Control*

Asked to identify the single most important feature of its new AP-655C asphalt paver, Caterpillar points to the precision of the machine's steering/propel system. Speed sensors in the track motors constantly provide information to the system controller, which adjusts the hydrostatic drive system to achieve or to maintain the exact steering attitude or speed selected. The 8-foot (paving width) machine weighs 40,800 pounds and features Cat's Mobil-trac undercarriage. The material-handling system uses no feeder gates, but instead, allows independent control of augers and feeders on both sides of the machine to precisely maintain the optimum head of material. Estimated list price: $300,000 (screed included).