The present invention relates to a hybrid powertrain and method of controlling same, the hybrid powertrain comprising an internal combustion engine; a gearbox with an input and an output shaft; a range gearbox connected to the output shaft; a first planetary gear connected to the input shaft; a second planetary gear connected to the first planetary gear; a first electrical machine connected to the first planetary gear; a second electrical machine connected to the second planetary gear; one gear pair connected with the first planetary gear and the output shaft; and one gear pair connected with the second planetary gear and the output shaft, wherein the internal combustion engine is connected with the first planetary gear via the input shaft. The range gearbox comprises a third planetary gear with a third sun wheel and a third planetary wheel carrier and a fourth clutch device arranged to connect and disconnect the third sun wheel with/from the third planetary wheel carrier.

A method for monitoring a fixed-gear transmission includes deriving a node speed relationship for each of the planetary gear sets based upon a center distance and a gear ratio and determining equivalent speed parameters for nodes of the planetary gear sets based upon a transmission input speed state, an intermediate node speed state and a transmission output speed state. A clutch slip speed relationship is determined for each of the clutches based upon the node speed relationships for the planetary gear sets and the equivalent speed parameters for nodes of the planetary gear sets. Rotational speed sensors monitor the input transmission speed, the intermediate node speed and the transmission output speed. A clutch slip speed for each of the clutches is determined based upon the respective clutch slip speed relationship and the monitored input transmission speed, the monitored intermediate node speed and the monitored transmission output speed.

A method for monitoring a fixed-gear transmission includes deriving a node speed relationship for each of the planetary gear sets based upon a center distance and a gear ratio and determining equivalent speed parameters for nodes of the planetary gear sets based upon a transmission input speed state, an intermediate node speed state and a transmission output speed state. A clutch slip speed relationship is determined for each of the clutches based upon the node speed relationships for the planetary gear sets and the equivalent speed parameters for nodes of the planetary gear sets. Rotational speed sensors monitor the input transmission speed, the intermediate node speed and the transmission output speed. A clutch slip speed for each of the clutches is determined based upon the respective clutch slip speed relationship and the monitored input transmission speed, the monitored intermediate node speed and the monitored transmission output speed.

Provided is a method to control a hybrid powertrain to achieve reverse drive, comprising an internal combustion engine, a gearbox with input output shafts; a first planetary gear connected to the input shaft and a second planetary gear; first and second electrical machines respectively connected to the first and second planetary gears; gear pair connected with the first planetary gear and the output shaft and one gear pair connected with the second planetary gear and the output shaft, wherein the internal combustion engine is connected with the first planetary gear via the input shaft. The method comprises: a) ensuring the moveable component parts in the first planetary gear are connected with each other and the moveable component parts in the second planetary gear are disconnected from each other; b) ensuring the gear pair connected with the second planetary gear and the output shaft are connected, and the gear pair connected with the first planetary gear and the output shaft are disconnected; and c) controlling the second electrical machine to achieve a negative torque in the output shaft.

Provided is a method to control a hybrid powertrain to achieve reverse drive, comprising an internal combustion engine, a gearbox with input output shafts; a first planetary gear connected to the input shaft and a second planetary gear; first and second electrical machines respectively connected to the first and second planetary gears; gear pair connected with the first planetary gear and the output shaft and one gear pair connected with the second planetary gear and the output shaft, wherein the internal combustion engine is connected with the first planetary gear via the input shaft. The method comprises: a) ensuring the moveable component parts in the first planetary gear are connected with each other and the moveable component parts in the second planetary gear are disconnected from each other; b) ensuring the gear pair connected with the second planetary gear and the output shaft are connected, and the gear pair connected with the first planetary gear and the output shaft are disconnected; and c) controlling the second electrical machine to achieve a negative torque in the output shaft.

A method is provided to control a hybrid powertrain comprising an internal combustion engine; a gearbox with input and output shafts; a range gearbox, connected to the output shaft; a first planetary gear, connected to the input shaft; a second planetary gear, connected to the first planetary gear; 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 planetary gear and the output shaft; and at least one gear pair, connected with the second planetary gear and the output shaft, wherein the internal combustion engine is connected with the first planetary gear via the input shaft. The method comprises the steps: a) engaging a gear by way of connecting two rotatable components in the first planetary gear; b) connecting the at least one gear pair, connected with the second planetary gear and the output shaft; c) connecting a sixth gear pair, arranged between a countershaft and the range gearbox with the countershaft, so that the countershaft is connected with the output shaft via the range gearbox; d) controlling the range gearbox from a low range position to a neutral state, in which no torque transmission occurs through the range gearbox; e) controlling two rotatable components in the range gearbox towards achieving a synchronized rotational speed with the assistance of the first electrical machine; f) connecting the rotatable components with the use of a shiftable third clutch device; and g) engaging a gear by way of connecting two rotatable components in the second planetary gear.

A method is provided to control a hybrid powertrain comprising an internal combustion engine; a gearbox with input and output shafts; a range gearbox, connected to the output shaft; a first planetary gear, connected to the input shaft; a second planetary gear, connected to the first planetary gear; 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 planetary gear and the output shaft; and at least one gear pair, connected with the second planetary gear and the output shaft, wherein the internal combustion engine is connected with the first planetary gear via the input shaft. The method comprises the steps: a) engaging a gear by way of connecting two rotatable components in the first planetary gear; b) connecting the at least one gear pair, connected with the second planetary gear and the output shaft; c) connecting a sixth gear pair, arranged between a countershaft and the range gearbox with the countershaft, so that the countershaft is connected with the output shaft via the range gearbox; d) controlling the range gearbox from a low range position to a neutral state, in which no torque transmission occurs through the range gearbox; e) controlling two rotatable components in the range gearbox towards achieving a synchronized rotational speed with the assistance of the first electrical machine; f) connecting the rotatable components with the use of a shiftable third clutch device; and g) engaging a gear by way of connecting two rotatable components in the second planetary gear.

A method is provided to control a hybrid powertrain comprising an internal combustion engine; a gearbox with input and output shafts; a range gearbox connected to the output shaft; a first planetary gear, connected to the input shaft; a second planetary gear, connected to the first planetary gear; first and second electrical machines, respectivley connected to the first and second planetary gears; a gear pair connected with the first planetary gear and the output shaft; and a gear pair, connected with the second planetary gear and the output shaft, wherein the internal combustion engine is connected to the input shaft. The method comprises: a) engaging a gear by connecting two rotatable components in the first planetary gear; b) connecting the second or the fourth gear pair; c) connecting a sixth gear pair, arranged between a countershaft and the range gearbox to the countershaft, so that the countershaft is connected with the output shaft via the range gearbox; d) synchronising the rotational speed between two rotatable components in the range gearbox; e) connecting the rotatable components with a shiftable third clutch device; and f) engaging a gear by way of connecting two rotatable components in the second planetary gear.

A method is provided to control a hybrid powertrain comprising an internal combustion engine; a gearbox with input and output shafts; a range gearbox connected to the output shaft; a first planetary gear, connected to the input shaft; a second planetary gear, connected to the first planetary gear; first and second electrical machines, respectivley connected to the first and second planetary gears; a gear pair connected with the first planetary gear and the output shaft; and a gear pair, connected with the second planetary gear and the output shaft, wherein the internal combustion engine is connected to the input shaft. The method comprises: a) engaging a gear by connecting two rotatable components in the first planetary gear; b) connecting the second or the fourth gear pair; c) connecting a sixth gear pair, arranged between a countershaft and the range gearbox to the countershaft, so that the countershaft is connected with the output shaft via the range gearbox; d) synchronising the rotational speed between two rotatable components in the range gearbox; e) connecting the rotatable components with a shiftable third clutch device; and f) engaging a gear by way of connecting two rotatable components in the second planetary gear.

A method for operating an automatic transmission is provided. The method includes initiating a synchronization of a positive shifting element of the automatic transmission while the automatic transmission is operating at less than a threshold output speed. The method also includes closing a first non-positive shifting element of the automatic transmission and positioning a second non-positive shifting element of the automatic transmission at an engaged configuration of the second non-positive shifting element during the synchronization of the first positive shifting element in order to synchronize the first positive shifting element.