A system includes a clutch state module and a clutch torque module. The clutch state module is configured to determine whether a clutch of an electronic limited slip differential is locked or unlocked. The electronic limited slip differential couples an engine of a vehicle to left and right wheels of the vehicle. The clutch torque module is configured to estimate an actual torque transferred by the clutch using a first clutch torque model when the electronic limited slip differential is unlocked, and estimate the actual clutch torque using a second clutch torque model when the electronic limited slip differential is locked. The second clutch torque model is different than the first clutch torque model.

Engine combustion mode-switching transitions are controlled through a coordination control of an electric machine and a multi-combustion mode engine coupled to each other with a hybrid propulsion system by following predetermined combustion mode-switching strategies and control algorithms.

A method of distributing driving force of a four wheel drive (4WD) eco-friendly vehicle includes determining a first allowable range of driving force for each driving force based on determination of travel stability, determining a second allowable range of driving force for each driving wheel based on system limitations of at least one of the first driving source or the second driving source, determining a range of available driving force of the first driving wheel based on the first allowable range of driving force and the second allowable range of driving force, determining first target driving force of the first driving wheel in consideration of efficiency of the first driving source within the range of available driving force, and determining second target driving force of the second driving wheel based on the first target driving force and requested torque.

A method of distributing driving force of a four wheel drive (4WD) eco-friendly vehicle includes determining a first allowable range of driving force for each driving force based on determination of travel stability, determining a second allowable range of driving force for each driving wheel based on system limitations of at least one of the first driving source or the second driving source, determining a range of available driving force of the first driving wheel based on the first allowable range of driving force and the second allowable range of driving force, determining first target driving force of the first driving wheel in consideration of efficiency of the first driving source within the range of available driving force, and determining second target driving force of the second driving wheel based on the first target driving force and requested torque.

Systems and methods are provided herein for operating a vehicle in a K-turn mode. The K-turn mode is engaged in response to determining that an amount that at least one of the front wheels of the vehicle is turned exceeds a turn threshold. While operating in the K-turn mode, forward torque is provided to the front wheels of the vehicle. Further, backward torque is provided to the rear wheels of the vehicle. Yet further, the rear wheels of the vehicle remain substantially in static contact with a ground while the front wheels slip in relation to the ground.

A through the road (TTR) hybridization strategy is proposed to facilitate introduction of hybrid electric vehicle technology in a significant portion of current and expected trucking fleets. In some cases, the technologies can be retrofitted onto an existing vehicle (e.g., a truck, a tractor unit, a trailer, a tractor-trailer configuration, at a tandem, etc.). In some cases, the technologies can be built into new vehicles. In some cases, one vehicle may be built or retrofitted to operate in tandem with another and provide the hybridization benefits contemplated herein. By supplementing motive forces delivered through a primary drivetrain and fuel-fed engine with supplemental torque delivered at one or more electrically-powered drive axles, improvements in overall fuel efficiency and performance may be delivered, typically without significant redesign of existing components and systems that have been proven in the trucking industry.

A through the road (TTR) hybridization strategy is proposed to facilitate introduction of hybrid electric vehicle technology in a significant portion of current and expected trucking fleets. In some cases, the technologies can be retrofitted onto an existing vehicle (e.g., a truck, a tractor unit, a trailer, a tractor-trailer configuration, at a tandem, etc.). In some cases, the technologies can be built into new vehicles. In some cases, one vehicle may be built or retrofitted to operate in tandem with another and provide the hybridization benefits contemplated herein. By supplementing motive forces delivered through a primary drivetrain and fuel-fed engine with supplemental torque delivered at one or more electrically-powered drive axles, improvements in overall fuel efficiency and performance may be delivered, typically without significant redesign of existing components and systems that have been proven in the trucking industry.

A transmission may include an input shaft, a first output shaft, a second output shaft, a first planetary gearset, and a second planetary gearset connected to the first planetary gearset. The input shaft, the first and second output shafts, and the planetary gearsets may be arranged such that a torque input via the input shaft is converted and distributed in a defined ratio to the two output shafts, and the formation of a combined torque is prevented. At least one element of the first planetary gearset may be connected to at least one element of the second planetary gearset with a shaft for conjoint rotation, and at least one element of the second planetary gearset may be fixed in place on a non-rotating component. A connector may be arranged and configured to passively, and therefore without a control unit and without an actuator, connect the first output shaft and second output shaft.

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.

A vehicle includes an electric machine and a controller. The controller is programmed to responsive to a threshold difference, indicative of wheel slip, between average wheel speed and a vehicle speed that is based on a difference between wheel acceleration and measured vehicle acceleration, command a speed to the electric machine to reduce the wheel slip.