Method for takeoff of a vehicle comprising a hybrid driveline

A vehicle with a hybrid drive line, said hybrid drive line comprising:

• a combustion engine;
• a gearbox with an input shaft and an output shaft;
• a first planetary gear, which is connected to the input shaft and a first main shaft, wherein the first planetary gear comprises a first set of rotatable components, comprising a first ring gear, a first sun wheel, and a first planetary wheel carrier, and a separate first coupling device configured to selectively connect and disconnect from each other the first sun wheel from the first planetary wheel carrier via selective engagement and disengagement of the first coupling device;
• a second planetary gear, which is connected to the first planetary gear and a second main shaft, wherein the second planetary gear comprises a second set of rotatable components, comprising a second ring gear, a second sun wheel, and a second planetary wheel carrier, and a separate second coupling device configured to selectively connect to and disconnect from each other the second sun wheel from the second planetary wheel carrier via selective engagement and disengagement of the second coupling device;
• a first electrical machine, which is connected to the first planetary gear;
• a second electrical machine, which is connected to the second planetary gear, wherein the electrical machines are configured to supply power to each other;
• at least one first gear pair operatively connected with the first planetary gear and the output shaft;
• at least one second gear pair operatively connected with the second planetary gear and the output shaft, wherein the combustion engine, via the input shaft, is connected with the first planetary wheel carrier of the first set of rotatable components, arranged in the first planetary gear, and wherein the second main shaft is connected with the second planetary wheel carrier of the second set of rotatable components, arranged in the second planetary gear;
• and
• an electric control device, which is installed to control the vehicle's moving off, said electronic control device configured for:
• a) ensuring that the first sun wheel and the first planetary wheel carrier of the first planetary gear are disconnected from each other by disengagement of the first coupling device, and ensuring that the second sun wheel and the second planetary wheel carrier of the second planetary gear are disconnected from each other by disengagement of the second coupling device;
• b) ensuring that one of the at least first one gear pair between the first planetary gear and the output shaft is engaged, and that one of the at least one second gear pair between the second planetary gear and the output shaft is engaged;
• and
• c) activating the first electrical machine and the second electrical machine to create respective torques and to each rotate in such a way that the total electrical power output from the first and the second electrical machines sums to substantially zero, and so that a torque is generated in the output shaft.

A non-transitory computer readable medium readable by a computer having stored thereon a computer program product, said computer program product used for moving off of a vehicle with a 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, wherein the first planetary gear comprises a first set of rotatable components, comprising a first ring gear, a first sun wheel, and a first planetary wheel carrier, and a separate first coupling device configured to selectively connect and disconnect from each other the first sun wheel from the first planetary wheel carrier via selective engagement and disengagement of the first coupling device;
• a second planetary gear connected to the first planetary gear and a second main shaft, wherein the second planetary gear comprises a second set of rotatable components, comprising a second ring gear, a second sun wheel, and a second planetary wheel carrier, and a separate second coupling device configured to selectively connect to and disconnect from each other the second sun wheel from the second planetary wheel carrier via selective engagement and disengagement of the second coupling device;
• a first electrical machine, which is connected to the first planetary gear;
• a second electrical machine, which is connected to the second planetary gear, wherein the electrical machines are configured to supply power to each other;
• at least one first gear pair operatively connected with the first planetary gear and the output shaft;
• and at least one second gear pair operatively connected with the second planetary gear and the output shaft, wherein the combustion engine, via the input shaft, is connected with the first planetary wheel carrier of the first set of rotatable components, arranged in the first planetary gear, and wherein the second main shaft is connected with the second planetary wheel carrier of the second set of rotatable components, 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 the first sun wheel and the first planetary wheel carrier of the first planetary gear are disconnected from each other by disengagement of the first coupling device, and ensuring that the second sun wheel and the second planetary wheel carrier of the second planetary gear are disconnected from each other by disengagement of the second coupling device;
• b) ensuring that one of the at least one first gear pair between the first planetary gear and the output shaft is engaged, and that one of the at least one second gear pair between the second planetary gear and the output shaft is engaged;
• and
• c) activating the first electrical machine and the second electrical machine to create respective torques and to each rotate in such a way that the total electrical power output from the first and the second electrical machines sums to substantially zero, and so that a torque is generated in the output shaft.