Abstract: Methods and systems for operating a tandem axle that includes two electric machine propulsion sources are described. In one example, a controller determines a presence or absence of a beat signal that may be generated via rotating components of the tandem axle. Operation of the tandem axle may be adjusted in response to detection of the beat signal.

Abstract: A method of controlling a continuously variable electric drivetrain (CVED) including a high ratio traction drive transmission and at least one of a first motor-generator and a second motor-generator is disclosed. The method includes the steps of receiving an output speed, determining a kinematic output speed, and determining a slip state of the high ratio traction drive transmission based on a comparison of the output speed to the kinematic output speed.

Abstract: Methods and systems for an electric drive assembly are provided herein. In one example, an electric drive system is provided that includes two multi-motor drive units with associated planetary gear reductions that have asymmetric gear ratios. The planetary gear reduction in each drive unit includes a ring gear and a sun gear that are rotationally coupled to a pair of motors and a carrier rotationally coupled to an output gear that interfaces with a gear reduction of an axle assembly.

Abstract: Methods and systems are provided for an electric drivetrain. In one example, the electric drivetrain system includes a first and a second electric motor-generator rotationally coupled to a planetary assembly that is rotationally coupled to a drive axle via an output gear. The system further includes a controller that is configured to, during a first operating condition, operate each of the first and second electric motor-generators in a motor mode or a generator mode and hold the output gear at a zero speed.

Abstract: Systems and methods are provided for an electric axle assembly. In one example an assembly is provided comprising, a first axle, an electric motor directly mounted to the first axle, a transmission gear train coupling the electric motor to an interaxle output shaft, and a plurality of clutches for selectively coupling the electric motor and the interaxle output shaft, the interaxle output shaft selectively driving one of a second axle and an auxiliary device.

Abstract: Methods and systems are provided for an electric drive train of a vehicle. In one example, a four-node planetary gear set is included in the electric drive train with a first motor coupled to a first input node and a second motor coupled to a second input node of the four-node planetary gear set. The drive train may be operated at a first mechanical point when the first electric machine is operated at a substantially zero speed, and the drive train may be operated at a second mechanical point when the second electric machine is operated at a substantially zero speed, in one or more examples. Operation at either the first mechanical point or the second mechanical point may be achieved without clutches or hydro-mechanical devices.

Abstract: Methods and systems are provided for an electric drive train of a vehicle. In one example, a method may include operating a first motor of a set of motors in a torque control mode at a first speed while operating a second motor of the set of motors in a speed control mode at a second speed. The second speed may be determined based on the first speed and torque may be summed at an output node of a planetary gear set coupled to each of the set of motors.

Abstract: Methods and systems for an electric drive assembly are provided herein. In one example, a method for operation of an electric drive system is provided that includes coordinating operation of a first electric drive unit and a second electric drive unit based on a first power request. In the system, each of the first and second electric drive units include a planetary gear reduction that delivers power from a pair of motors to a set of axle shafts, and the planetary gear reductions have asymmetric gear ratios.

Abstract: A traction device including a ring member, a carrier, and a sun member and an electric motor, wherein the electric motor is coupled to at least one of the ring member, the carrier, and the sun member.

Abstract: A method and system for shifting a transmission that includes one or more mechanical clutches without clutch plates is described. In one example, a torque output of an electric machine is adjusted in response to a request to shift a transmission so that forces that hold the mechanical clutch in an engaged position may be reduced.

Abstract: Methods and systems for an electric drive assembly are provided herein. In one example, an electric drive system is provided that includes two multi-motor drive units with associated planetary gear reductions that have asymmetric gear ratios. The planetary gear reduction in each drive unit includes a ring gear and a sun gear that are rotationally coupled to a pair of motors and a carrier rotationally coupled to an output gear that interfaces with a gear reduction of an axle assembly.

Abstract: Methods and systems for operating a driveline that includes two electric machines are described. In one example, one electric machine is operated in a generator mode and the other electric machine is operated in a motor mode so that electric power that is generated by the electric machine that is operated in the generator mode is consumed by the electric machine that is operated in the motor mode.

Abstract: A method of controlling a continuously variable electric drivetrain (CVED) including a high ratio traction drive transmission and at least one of a first motor-generator and a second motor-generator is disclosed. The method includes the steps of receiving an output speed, determining a kinematic output speed, and determining a slip state of the high ratio traction drive transmission based on a comparison of the output speed to the kinematic output speed.

Abstract: Methods and systems for an electric drive assembly are provided herein. In one example, an electric drive system is provided that includes two multi-motor drive units with associated planetary gear reductions that have asymmetric gear ratios. The planetary gear reduction in each drive unit includes a ring gear and a sun gear that are rotationally coupled to a pair of motors and a carrier rotationally coupled to an output gear that interfaces with a gear reduction of an axle assembly.

Abstract: Methods and systems are provided for an electric drivetrain. In one example, the electric drivetrain system includes a first and a second electric motor-generator rotationally coupled to a planetary assembly that is rotationally coupled to a drive axle via an output gear. The system further includes a controller that is configured to, during a first operating condition, operate each of the first and second electric motor-generators in a motor mode or a generator mode and hold the output gear at a zero speed.

Abstract: Methods and systems are provided for an electric drive train of a vehicle. In one example, a method may include operating a first motor of a set of motors in a torque control mode at a first speed while operating a second motor of the set of motors in a speed control mode at a second speed. The second speed may be determined based on the first speed and torque may be summed at an output node of a planetary gear set coupled to each of the set of motors.

Abstract: Methods and systems are provided for an electric drive train of a hybrid electric vehicle (HEV). In one example, the electric drive train may include a four-node planetary gear set with a first motor coupled to a first input node, a second motor coupled to a second input node and an engine coupled to a third input node of the planetary gear set. The third node is positioned between the first and second input nodes. Torque delivered to each input node is summed at an output node of the four-node planetary gear set.

Abstract: A method of controlling a continuously variable electric drivetrain (CVED) including a high ratio traction drive transmission and at least one of a first motor-generator and a second motor-generator is disclosed. The method includes the steps of receiving a output speed, determining a kinematic output speed, and determining a slip state of the high ratio traction drive transmission based on a comparison of the output speed to the kinematic output speed.

Abstract: Methods and systems for an electric drive assembly are provided herein. In one example, an electric drive system is provided that includes two multi-motor drive units with associated planetary gear reductions that have asymmetric gear ratios. The planetary gear reduction in each drive unit includes a ring gear and a sun gear that are rotationally coupled to a pair of motors and a carrier rotationally coupled to an output gear that interfaces with a gear reduction of an axle assembly.

Abstract: Methods and systems for an electric drive assembly are provided herein. In one example, a method for operation of an electric drive system is provided that includes coordinating operation of a first electric drive unit and a second electric drive unit based on a first power request. In the system, each of the first and second electric drive units include a planetary gear reduction that delivers power from a pair of motors to a set of axle shafts, and the planetary gear reductions have asymmetric gear ratios.