Method for the open-loop control of a pump system

A method for open-loop control of a pump system (5) in a transmission (2) for a motor vehicle (3), the transmission (2) including a hydraulic system (1) and an electronic control unit (42), the hydraulic system (1) having a primary circuit (11) for supplying shift elements of the transmission (2) and a secondary circuit (12) for lubricating and cooling the transmission (2), the pump system (5) including a first pump (P) and a second pump(S), the method comprising:

• accessing with the electronic control unit (42) a hydraulic calculation model (41), the hydraulic calculation model (41) including, for various operating states of the transmission (2), information regarding oil supplies of the first and second pumps (P, S) and information regarding oil demands of the transmission (2);
• ascertaining with the electronic control unit (42) a certain oil supply ({dot over (V)}supply) of the oil supplies that the first and second pumps (P, S) provide in a certain operating state of the various operating states of the transmission (2) according to the hydraulic calculation model (41);
• ascertaining with the electronic control unit (42) a certain oil demand ({dot over (V)}demand) of the oil demands that the hydraulic system (1) requests of the first and second pumps (P, S) in the certain operating state of the transmission (2) according to the hydraulic calculation model (41);
• and
• controlling output pressures (Pprim, Psek) of the first and second pumps (P, S) by an open-loop control adjusting a system pressure valve (8) based on the certain oil supply ({dot over (V)}supply) and on the certain oil demand ({dot over (V)}demand), each of the first and second pumps (P,S) being fluidly couplable to the primary circuit (11) by the system pressure valve (8).