Patent ID: 7182710

Claim:
An observer-based control method for automatically shifting a synchromesh transmission having an input shaft connected to an engine through a disengageable clutch, an output shaft, a plurality of drive gears mounted on the output shaft , a shift fork adapted to move a selected one of a plurality of synchronizers arranged to bring a selected drive gear mounted on the output shaft to a rotational speed substantially equal to that of the output shaft prior to connecting the selected drive gear to the output shaft, a clutch actuator, and a shift fork actuator, said method comprising: first monitoring an intrinsic operating parameter of said clutch actuator and determining the status of clutch disengagement corresponding to an observed value of said intrinsic operating parameter of the clutch actuator to disengage said disengageable clutch when a shift decision is made; second monitoring at least one intrinsic operating parameter of said shift fork actuator and determining a spatial position of said shift fork corresponding to an observed value of said at least one intrinsic operating parameter of the shift fork actuator to engage a next gear in said plurality of drive gears upon synchronization; and third monitoring said intrinsic operating parameter of said clutch actuator and determining the status of clutch engagement corresponding to an observed value of said intrinsic operating parameter of the clutch actuator to engage said disengageable clutch for smooth interpolation.