US 12,352,354 B2
Method and control unit for operating a parking lock system
Florian Mühlfeld, Kürnach (DE); Matthias Müller, Haßfurt (DE); Pierre Mesnier, Röthlein (DE); Ramazan Uzunkaya, Bergrheinfeld (DE); and Ulrich Quell, Fulda (DE)
Assigned to ZF Friedrichshafen AG, Friedrichshafen (DE)
Filed by ZF Friedrichshafen AG, Friedrichshafen (DE)
Filed on May 19, 2022, as Appl. No. 17/748,385.
Claims priority of application No. 102021205148.0 (DE), filed on May 20, 2021.
Prior Publication US 2022/0373083 A1, Nov. 24, 2022
Int. Cl. F16H 63/34 (2006.01); F16H 63/48 (2006.01)
CPC F16H 63/3425 (2013.01) [F16H 63/48 (2013.01)] 8 Claims
OG exemplary drawing
 
7. A control unit of a motor vehicle including a transmission with a parking lock system (10) that is integral with the transmission, the parking lock system (10) including a parking interlock gear (11) with recesses (16) distributed over a circumference of the parking interlock gear (11), a parking pawl (12) insertable with an insertion section (20) in a respective one of the recesses (16) of the parking interlock gear (11) in order to interlock a shaft coupled to the parking interlock gear (11) and prevent rotation of the shaft in both rotational directions of the shaft, a parking lock actuator (13) for the parking pawl (12), and a parking lock sensor (14) configured for detecting an absolute rotation angle position of the parking interlock gear (11), the control unit configured for:
actuating the parking pawl (12) with the parking lock actuator (13) in order to engage the parking lock system (10);
receiving the absolute rotation angle position of the parking interlock gear (11) from the parking lock sensor (14);
comparing the absolute rotation angle position with a reference rotation angle position; and
when the absolute rotation angle position is situated behind the reference rotation angle position as viewed in a direction of rotation of the parking interlock gear (11), detecting a rattling process of the parking pawl (12) after actuating the parking pawl (12),
wherein the rattling process of the parking pawl (12) corresponds to a condition of the parking pawl (12) when the parking lock actuator (13) for the parking pawl (12) actuates the parking pawl (12) towards the parking interlock gear (11) while a rotational speed of the parking interlock gear (11) is greater than a limit value.