Method for controlling a hybrid driveline in order to optimize torque from a combustion engine arranged at the driveline

• US 9,956,952 B2
• Filed: 03/17/2015
• Issued: 05/01/2018
• Est. Priority Date: 03/20/2014
• Status: Active Grant

• Current Assignee: Scania CV AB (Volkswagen AG)
• Original Assignee: Scania CV AB (Volkswagen AG)
• Inventors: Bjrkman, Mathias, Pettersson, Niklas, Lindstrm, Johan, Bergquist, Mikael
• Primary Examiner(s): Kan, Yuri
• Application Number:
  US15/124,831
• Publication Number:
  US 20170015299A1
• Time in Patent Office: 1,141 Days
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60K 6/46 Series type
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/11 Stepped gearings
• CPC Class Codes: B60W 10/115 with planetary gears
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 2510/0208 Clutch engagement state, e.g. engaged or disengaged
• CPC Class Codes: B60W 2510/101 Transmission neutral state
• CPC Class Codes: B60W 2710/021 Clutch engagement state
• CPC Class Codes: B60W 2710/0644 Engine speed
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: B60W 2710/10 Change speed gearings
• CPC Class Codes: B60Y 2200/92 Hybrid vehicles
• CPC Class Codes: B60Y 2300/43 Control of engines
• CPC Class Codes: B60Y 2300/60 : Control of electric machines, e.g. problems related to electric motors or generators
• CPC Class Codes: B60Y 2300/70 : Control of gearings
• CPC Class Codes: B60Y 2400/73 : Planetary gearings
• CPC Class Codes: F16H 2037/102 : the input or output shaft of the transmission is connected or connectable to two or more differentials
• CPC Class Codes: F16H 2200/0047 : the gear ratios comprising five forward speeds
• CPC Class Codes: F16H 2200/2007 : with two sets of orbital gears
• CPC Class Codes: F16H 3/006 : power being selectively transmitted by either one of the parallel flow paths
• CPC Class Codes: F16H 3/728 : with means to change ratio in the mechanical gearing
• CPC Class Codes: F16H 37/042 : change gear transmissions in group arrangement
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y10S 903/911 : with two or more gear sets
• CPC Class Codes: Y10S 903/919 : Stepped shift

Abstract

A method is provided to control a hybrid powertrain that comprises: a combustion engine; a gearbox with input and output shafts; 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; first and second electrical machines, respectively connected to the first and second planetary gears; one gear pair connected with the first planetary gear and output shaft; and one gear pair connected with the second planetary gear and output shaft. The method comprises: disconnecting a first planetary wheel carrier and a first sun wheel or disconnecting a second planetary wheel carrier and a second sun wheel from each other; b) controlling the combustion engine to a predetermined engine speed; and c) controlling the first and second electrical machines so that a desired torque is achieved in the output shaft, while a requested total power consumption of the first and the second electrical machines is achieved.

Claims

1. A method to control a hybrid powertrain to optimize the torque from a combustion engine, arranged in the hybrid powertrain, wherein the hybrid powertrain also comprises;

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 planetary gear and the output shaft; and

at least one gear pair connected 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 method comprising the steps;

a) if connected, disconnecting the moveable parts of the first planetary gear from each other and the moveable parts of the second planetary gear from each other;

b) to control the combustion engine to a predetermined engine speed (n_ice); and

c) to control the first and the second electrical machines in such a way that a desired torque (T_Drv) is achieved in the output shaft, while simultaneously a requested total power consumption (PEM) of the first and the second electrical machines is achieved.

2. A method according to claim 1, wherein in step a) the first and/or the second electrical machine is controlled in such a way that torque balance is achieved in the first planetary gear, wherein a first coupling device is shifted, so that the first planetary wheel carrier, arranged in the first planetary gear, and a first sun wheel are disconnected from each other.

3. A method according to claim 1, wherein in step a) the first and/or the second electrical machine is controlled in such a way that torque balance is achieved in the second planetary gear, following which a second coupling device is shifted, so that the second planetary wheel carrier, arranged in the second planetary gear, and a second sun wheel are disconnected from each other.

4. A method according to claim 1, wherein in step a) the first and the second electrical machines are also controlled in such a way that the desired torque (T_Drv) is achieved in the output shaft.

5. A method according to claim 1, wherein the predetermined engine speed (n_ice) of the combustion engine is determined based on a desired output (P_ice) from the combustion engine.

6. A method according to claim 1, wherein the steps b) and c) are carried out in parallel.

7. 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 planetary gear and the output shaft;

at least one gear pair connected 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; and

an electronic control device configured for;

a) if connected, disconnecting the moveable parts of the first planetary gear from each other and the moveable parts of the second planetary gear from each other;

b) to control the combustion engine to a predetermined engine speed (n_ice); and

c) to control the first and the second electrical machines in such a way that a desired torque (T_Drv) is achieved in the output shaft, while simultaneously a requested total power consumption (PEM) of the first and the second electrical machines is achieved.

8. 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 the torque from a combustion engine, arranged in the hybrid powertrain, wherein the hybrid powertrain also comprises;

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 planetary gear and the output shaft; and

at least one gear pair connected 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) if connected, disconnecting the moveable parts of the first planetary gear from each other and the moveable parts of the second planetary gear from each other;

b) to control the combustion engine to a predetermined engine speed (n_ice); and

c) to control the first and the second electrical machines in such a way that a desired torque (T_Drv) is achieved in the output shaft, while simultaneously a requested total power consumption (PEM) of the first and the second electrical machines is achieved.