Patent ID: 7337052

Claim:
A method for controlling and regulating a transmission brake of an automatic gearbox designed as a gear reduction unit to perform a gearshift the gearbox including a gear input shaft, at least one countershaft that can be driven by the gear input shaft and a gear output shaft, and having loose cog wheels seated on at least one of the gear input shaft, the countershaft and the gear output shaft, and having at least one of loose rotational cog wheels and stationary cogwheels seated non-rotatably on at least one of the gear input shaft, the countershaft and the gear output shaft, at least one pair of cogwheels being in tooth engagement, and the loose cogwheels non-rotatably connected to at least one of the gear input shaft, the countershaft and the gear output shaft by a clutch to perform a gearshift, the method comprising the steps of: determining for a time frame t i . a gradient of a rotational speed difference Δn i between an actual rotational speed n lst and a target rotational speed n Soll of one of the gear input shaft and the countershaft, and a gradient of the gear output shaft rotational speed, determining over at least one program time cycle t p a total rotational speed gradient {dot over (n)} as a gradient of a summation of the gradient of the rotational speed difference Δn i between the actual and the target rotational speeds of the one of the gear input shaft and the countershaft and the gradient of the output shaft rotational speed, determining from the total rotational speed gradient {dot over (n)} a synchronization time t S at which the target and the actual rotational speeds of the gear input shaft and the countershaft will be within a predetemined difference, and during an upshift process, controlling a countershaft brake so that the target and the actual rotational speeds of the gear input shaft and the countershaft are within the predetermined difference at a predetermined engagement time.