US Patent 7322182 Filter regeneration control

A regeneration control device which regenerates a filter (4) which traps particulate matter in the exhaust gas of an engine (1) is disclosed. The regeneration control device includes a first temperature sensor (16, 17), which detects one of an upstream temperature and a downstream temperature upstream and downstream of the filter (4) as a first temperature (Tin, Tout); a second temperature sensor (16, 17), which detects the other temperature as a second temperature (Tin, Tout); and a microcomputer. The microcomputer programmed to compute an estimated value (Tbede2) for the second temperature based on the first temperature detected by the first temperature sensor (16, 17), compute an estimated bed temperature (Tbed2) of the filter based on the second temperature detected by a second temperature sensor (16, 17) and the estimated value (Tbede2) for the second temperature, and perform engine control for increasing the temperature of the exhaust gas based on the estimated bed temperature (Tbed2).