Method and apparatus for regeneration of an exhaust gas after-treatment device

To regenerate the particle filter, in the exhaust gas flow path from a diesel motor, the temperature and/or hydrocarbon concentration in the exhaust gas is raised by at least two successive injections of fuel into the gas, synchronized with the motor firing cycle. The control structure (10) is software or an electronic circuit as part of the motor management system. A fuel injection field (12) is activated according to motor signals (14) to generate an injection signal (20) while a correction field (18) generates a correction signal (22), and an adding unit (24) gives an injection control signal (26) from both signals.