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.

Disclosed are a parallel start control method and system for a hybrid electric vehicle, and a hybrid electric vehicle. The parallel start control method includes: acquiring current working conditions of a clutch and a gearbox of the hybrid electric vehicle, an engine request torque of the hybrid electric vehicle and a start mode of the hybrid electric vehicle; judging whether the hybrid electric vehicle meets an over-heat protection condition according to the current working conditions of the clutch and the gearbox and determining a start basic torque according to a judging result and the engine request torque; determining a start clutch request torque based on the start basic torque according to the start mode of the hybrid electric vehicle and conducting start control on the clutch according to the start clutch request torque. The start security, responsiveness and power performance of the hybrid electric vehicle are improved.

A vehicle driving device mounted on a hybrid vehicle includes an engine coupled to wheels of the vehicle via a power transmission path, a transmission mechanism disposed on the power transmission path, a motor generator, a first power transmission mechanism, and a second power transmission mechanism. The motor generator is disposed on a path coupling the engine and transmission mechanism, the first power transmission mechanism is disposed on a path coupling the engine and motor generator, the second power transmission mechanism is disposed on a path coupling the motor generator and transmission mechanism. These paths are included in the power transmission path. The first power transmission mechanism includes a large-diameter rotator and a small-diameter rotator coupled to the engine and the motor generator respectively. The second power transmission mechanism includes a small-diameter rotator and a large-diameter rotator coupled to the motor generator and the transmission mechanism respectively.

An engine starting system for hybrid vehicle is provided. The engine starting system is applied to a hybrid vehicle in which a friction clutch is disposed between an engine and a power distribution device. In order to reduce gear noise and vibrations, a second motor establishes a cancel torque to cancel a reaction torque acting on an axle when starting the engine. The engine starting system is configured to increase the torque of the second motor in a direction of a drive torque rotating the axle, when starting the engine while bringing the friction clutch into engagement in a slipping manner.

In a vehicle that includes an engine including a starter, an automatic transmission unit having an input shaft coupled to an output shaft of the engine via a first clutch, and a motor generator (hereinafter, referred to as MG) coupled to the input shaft of the automatic transmission unit via a second clutch, an electronic control unit starts up the engine with the use of the starter in a state where the MG is disconnected from the engine by releasing at least one of the first clutch or the second clutch when an IG-on operation has been made in an IG-off state (a state where the vehicle is stopped in a P range) and a power control unit that supplies electric power to the MG has a failure.

A control system for a hybrid vehicle configured to promptly disengage a clutch for halting an engine is provided. A clutch device comprises a reciprocating member having tapered reciprocating teeth, and a rotary member having tapered teeth opposed to the tapered rotary teeth. A controller is configured to turn off an actuator to eliminate the electromagnetic attraction thereby allowing the engine to be started, and to apply a torque of the first motor to the clutch device after the actuator is turned off thereby disengaging the reciprocating teeth from the rotary teeth.

A hybrid drive including a first drive motor coupled by a clutch to a shaft, and a second drive motor coupled rigidly to the shaft. A method for determining the temperature of the clutch in the hybrid drive includes the steps of: determining a temperature of the clutch; determining a temperature of the clutch housing; determining the temperature difference between the clutch and the clutch housing; determining the heat conductivity between the clutch and the clutch housing, wherein the heat conductivity is determined as a function of the rotational speed of the first drive motor and the rotational speed of the second drive motor; determining the heat flow between the clutch and the clutch housing on the basis of the product of the heat conductivity and the temperature difference; and adjusting the ascertained clutch temperature on the basis of the ascertained heat flow.

A method for starting a combustion engine fitted to a hybrid or dual-mode motor vehicle includes starting an additional motor upon a setpoint torque demanded by a driver of the vehicle, with a view to accelerating the vehicle beyond a threshold speed at which the combustion engine is driven beyond a stalling speed threshold when the combustion engine is mechanically coupled to wheels of the vehicle.

A vehicle includes a step-ratio automatic transmission having clutches engageable to provide forward and reverse gears, an electric machine selectively coupled to the transmission, a main pump powered by the electric machine and supplying oil to actuate selected transmission clutches, a gear selector configured for selecting a transmission gear, and a controller configured to stop the electric machine when the gear selector selects park or neutral, to operate the electric machine in a speed control mode using a higher controller gain in response to the gear selector selecting forward or reverse while the electric machine is stopped until the electric machine and the main pump reach a first speed threshold to reduce engagement delay of at least one of the transmission clutches, and to operate the electric machine using a lower controller gain when the electric machine and the main pump exceed the first speed threshold.

A hybrid vehicle includes an engine, a motor, and a belt stepless speed changer device having a driving rotary body, a driven rotary body, a first shaft member supporting the driving rotary body with allowing rotation thereof in unison, a second shaft member supporting the driven rotary body with allowing rotation thereof in unison, and an endless belt wound around the driving rotary body and the driven rotary body. The vehicle further includes a transmission case configured to receive the powers from the engine and the motor via the belt stepless speed changer device and a centrifugal clutch incorporated in a power transmission line extending form the engine to the first shaft member. The motor is disposed on the side opposite the engine across the driving rotary body, and the driving power of the motor is inputted to the first shaft member.