Systems and methods for operating a hybrid powertrain that includes an engine and a motor/generator are described. The systems and methods align in time an estimated motor torque and an actual motor torque to provide an estimated driveline torque. The alignment compensates for communications delays between different controllers over a controller area network.

A method for controlling a line pressure of a hybrid vehicle includes applying, by a controller, a set current corresponding to a target pressure to a first solenoid valve controlling the line pressure, driving, by the controller, a second solenoid valve to open an engine clutch after the applying step, comparing, by the controller, a difference value between a real pressure of the engine clutch sensed by a pressure sensor and the target pressure with a preset pressure after the driving step, and as a result of performing the comparing step, if the difference value is equal to or greater than the preset pressure, controlling, by the controller, an increase of a revolution per minute (RPM) speed of the electric oil pump and an increase of a pressure of the first solenoid valve to be alternately generated.

At the time of changing from an EV mode, in which a hybrid vehicle travels with the use of a second motor provided on an output side of a differential mechanism while torque that acts on any one of rotating elements of the differential mechanism is interrupted by a clutch, to an HV mode, in which the hybrid vehicle travels while transmitting output torque of an engine to a drive wheel, when the engine is started in a state where the clutch is slipped and torque is transmitted from the engine so as to increase the rotation speed of the first rotating element while the clutch is slipped, torque starts being output from a first motor such that torque input from the first rotating element to the differential mechanism to increase the rotation speed of the drive wheel is output from the third rotating element.

A drive train for a vehicle includes a first electromagnetic device, a second electromagnetic device electrically coupled to the first electromagnetic device by an electrical power transmission system, and an engine coupled to the first electromagnetic device and configured to drive the first electromagnetic device to provide electrical energy. In all modes of operation where the engine drives the first electromagnetic device to provide the electrical energy, the first electromagnetic device operates without providing the electrical energy to an energy storage device.

An engine clutch disengagement control method for a hybrid electric vehicle is disclosed to overcome a sense of discontinuous travel caused when an engine clutch is disengaged due to influence of the inaccuracy of model engine torque. The method includes: acquiring vehicle acceleration information during engine clutch disengagement control of the hybrid electric vehicle, determining whether a predetermined condition for determining inaccuracy of model engine torque required for engine clutch disengagement control is satisfied from the acquired vehicle acceleration information, when the predetermined condition is satisfied, determining a situation in which the model engine torque is inaccurate and calculating target compensation torque using the vehicle acceleration information, calculating a target slippage amount in a transmission clutch using the calculated target compensation torque, and performing transmission clutch torque control for inducing slippage in a transmission clutch based on the target slippage amount and a current transmission speed.

A method of controlling a hybrid power train may include: driving a first input shaft connected to a second motor-generator by the second motor-generator to synchronize a speed of a driven gear of a target gear position with a speed of an output shaft; moving a sleeve to directly connect the second input shaft, the output shaft, and the driven gear of the target gear position; decreasing torque of the first motor-generator and increasing torque of the second motor-generator to converge torque transferred from the second motor-generator to the output shaft, to torque of the output shaft; moving the sleeve to release the second input shaft and maintain only the output shaft and the driven gear; and increasing torque of an engine and decreasing the torque of the second motor-generator to converge torque transferred from the engine to the output shaft, to the torque of the output shaft.

A utility vehicle includes a frame assembly defined by a lower frame assembly and an upper frame assembly coupled to the lower frame assembly. The frame assembly supports a plurality of body panels. A roof, front windshield, rear windshield, and doors may be coupled to the frame assembly to enclose the operator area.

A vehicle is operable in three modes of operation. The vehicle includes a first electromagnetic device, a second electromagnetic device electrically coupled to the first electromagnetic device, and an engine coupled to the first electromagnetic device and configured to drive the first electromagnetic device to provide electrical energy. In each of the three modes of operation, whenever the engine drives the first electromagnetic device to provide the electrical energy, the first electromagnetic device operates without providing the electrical energy to an energy storage device.

A vehicle is operable in three modes of operation. The vehicle includes a first electromagnetic device, a second electromagnetic device electrically coupled to the first electromagnetic device, and an engine coupled to the first electromagnetic device and configured to drive the first electromagnetic device to provide electrical energy. In each of the three modes of operation, whenever the engine drives the first electromagnetic device to provide the electrical energy, the first electromagnetic device operates without providing the electrical energy to an energy storage device.

A method of controlling a hybrid power train may include: driving a first input shaft connected to a second motor-generator by the second motor-generator to synchronize a speed of a driven gear of a target gear position with a speed of an output shaft; moving a sleeve to directly connect the second input shaft, the output shaft, and the driven gear of the target gear position; decreasing torque of the first motor-generator and increasing torque of the second motor-generator to converge torque transferred from the second motor-generator to the output shaft, to torque of the output shaft; moving the sleeve to release the second input shaft and maintain only the output shaft and the driven gear; and increasing torque of an engine and decreasing the torque of the second motor-generator to converge torque transferred from the engine to the output shaft, to the torque of the output shaft.