Method for controlling a driveline in order to optimize fuel consumption

A vehicle with a hybrid powertrain, said hybrid powertrain comprising:

• a combustion engine;
• a gearbox with an input shaft and an output shaft;
• a first planetary gear, connected to the input shaft and a first main shaft;
• a second planetary gear, connected to the first planetary gear and a second main shaft;
• a first electrical machine, connected to the first planetary gear;
• a second electrical machine, connected to the second planetary gear;
• at least one gear pair connected with the first main shaft, and therefore with the first planetary gear and the output shaft;
• at least one gear pair connected with the second main shaft, and therefore with the second planetary gear and the output shaft, wherein the combustion engine is connected with a first planetary wheel carrier, arranged in the first planetary gear via the input shaft of the gearbox, and wherein the second main shaft is connected with a second planetary wheel carrier, arranged in the second planetary gear;
• and
• an electronic control device configured for:
• a) ensuring that moveable parts comprised in the first planetary gear are disconnected from each other, and that moveable parts comprised in the second planetary gear are disconnected from each other;
• b) bringing the combustion engine to a predetermined engine speed;
• and
• c) controlling the first and the second electrical machine in such a way that a desired torque is achieved in the output shaft.

A computer program product comprising computer program code stored on a non-transitory computer readable medium readable by a computer, said computer program product used to optimize fuel consumption, wherein such hybrid powertrain comprises a combustion engine;

• a gearbox with an input shaft and an output shaft;
• a first planetary gear, connected to the input shaft and a first main shaft;
• a second planetary gear, connected to the first planetary gear and a second main shaft;
• a first electrical machine, connected to the first planetary gear;
• a second electrical machine, connected to the second planetary gear;
• at least one gear pair connected with the first main shaft, and therefore the first planetary gear and the output shaft;
• and at least one gear pair connected with the second main shaft, and therefore with the second planetary gear and the output shaft, wherein the combustion engine is connected with a first planetary wheel carrier, arranged in the first planetary gear via the input shaft of the gearbox, and wherein the second main shaft is connected with a planetary wheel carrier, arranged in the second planetary gear,
• said computer program code comprising computer instructions to cause one or more computer processors to perform the operations of:
• a) ensuring that moveable parts comprised in the first planetary gear are disconnected from each other, and that moveable parts comprised in the second planetary gear are disconnected from each other;
• b) bringing the combustion engine to a predetermined engine speed;
• and
• c) controlling the first and the second electrical machine in such a way that a desired torque is achieved in the output shaft.