The application relates to a method for stall-starting a hybrid vehicle comprising a combustion engine (12), an electric machine (14), a transmission (16) and two clutches (20, 22). In a first stall phase torque output of the combustion engine (12) is increased and compensated by the electric machine (14) operating as a generator. In the second start phase the method comprises configuring the electric machine (14) not to operate as a generator, in particular to operate as a motor. A further independent claim is directed to a stall-start apparatus. This avoids overheating the clutches (20, 22) and battery depletion, while at the same time providing high acceleration.

A control process including the following steps is executed. The control process includes, at the time of switching from series-parallel mode to series mode, a step of reducing an engine torque, a step of releasing a clutch, a step of reducing a reaction torque of a first rotary electric machine and a step of increasing a torque of a second rotary electric machine, and, when synchronization is started and a step of increasing a positive torque of the first MG, a step of starting engagement of a clutch, and, when a rotation speed of the first rotary electric machine and a rotation speed of an engine are synchronous with each other, a step of engaging the clutch.

A method for calibrating engine clutch delivery torque of a hybrid vehicle includes: determining an engagement control amount of an engine clutch which connects an engine with a driving motor or disconnects the engine from the driving motor based on a difference between speeds of the engine and the driving motor; determining a current delivery torque corresponding to the engagement control amount of the engine clutch that controls the engine clutch to be in a lock-up state and a temperature of the engine clutch; extracting a previous delivery torque that corresponds to the engagement control amount that controls the engine clutch to be in the lock-up state and the temperature and is included in a map table; and applying a weighted value to each of the extracted previous delivery torque and the determined current delivery torque to calibrate the delivery torque included in the map table.

A method for learning engine clutch kiss point of a hybrid vehicle is provided. The method includes adjusting a speed of a driving motor to be reduced when a deceleration event is generated in front of the hybrid vehicle and adjusting a speed of an engine to be synchronized with the speed of the driving motor. An engine clutch that connects the engine with the driving motor or disconnects the engine from the driving motor is engaged to start and then a kiss point of the engine clutch is learned by detecting the kiss point that is generated when the engine clutch is in a slip state.

A method of controlling a mode transition of a hybrid vehicle includes determining whether a mode transition from a first mode to a second mode is required based on a first torque, the first torque being a current required torque. A second torque, which is a required torque expected to be generated at a near-future time from a current time, is also determined. A predicted gear shift time point and a predicted engagement time point of an engine clutch are determined based on the second torque. The mode transition to the second mode is performed when it is determined that the mode transition to the second mode is required and the predicted engagement time point is earlier than the predicted gear shift time point.

A method for learning a touch point of an engine clutch of a hybrid electric vehicle including a motor connected to a transmission and an engine selectively connected to the motor through the engine clutch includes determining whether a learning condition of the touch point of the engine clutch is satisfied, releasing a transmission clutch and controlling a motor speed when the learning condition is satisfied, increasing a coupling pressure of the engine clutch when a change amount of the motor speed is less than a first predetermined value, comparing a change amount of a motor torque according to the increased coupling pressure of the engine clutch with a second predetermined value, and learning the touch point of the engine clutch when the change amount of the motor torque is greater than or equal to the second predetermined value.

A system and method are provided for hybrid electric internal combustion engine applications in which a motor-generator, a narrow switchable coupling and a torque transfer unit therebetween are arranged and positioned in the constrained environment at the front of an engine in applications such as commercial vehicles, off-road vehicles and stationary engine installations. The motor-generator is preferably positioned laterally offset from the switchable coupling, which is co-axially-arranged with the front end of the engine crankshaft. The switchable coupling is an integrated unit in which a crankshaft vibration damper, an engine accessory drive pulley and a disengageable clutch overlap such that the axial depth of the clutch-pulley-damper unit is nearly the same as a conventional belt drive pulley and engine damper. The front end motor-generator system includes an electrical energy store that receives electrical energy generated by the motor-generator when the coupling is engaged. When the coupling is disengaged, the motor-generator may drive the pulley portion of the clutch-pulley-damper to drive the engine accessories using energy returned from the energy store, independent of the engine crankshaft.

An engine clutch control system of a hybrid vehicle includes a driving information detector for detecting vehicle information and road environment information according to operation of the hybrid vehicle. An engine clutch is disposed between an engine and a motor. A hybrid controller provides an EV (electric vehicle) mode or an HEV (hybrid electric vehicle) mode by controlling engagement or disengagement of the engine clutch. The hybrid controller sets a slip estimation region of the engine clutch from an accumulated value of an APS (Accelerator Pedal position Sensor), an engine clutch temperature, or a road inclination when engagement of the engine clutch is required, and extracts a speed variation of the engine and the motor in the slip estimation region. The hybrid controller compares the speed variation of the engine and the motor with each other, and determines the engine clutch is engaged when a maximal peak is detected.

A hybrid vehicle control device is provided with at least one controller programmed to control outputs of the engine and the electric motor, an engagement and disengagement of the clutch, and a transmission ratio of the continuously variable transmission in accordance with a driving state. The at least one controller is further programmed to restart the engine while maintaining a released state of the clutch, and downshift the continuously variable transmission to a predetermined transmission ratio for passing over the level difference upon determining that the level difference is present while traveling by a drive force of the motor with the clutch released and the engine stopped.

Provided is a control device for a hybrid vehicle including a controller that performs a control of the hybrid vehicle including an engine and an electric motor that serve as driving sources, a transmission, and first and second clutches. The first clutch is provided between the engine and the transmission. The second clutch is provided between the transmission and driving wheels. The controller includes first and second control units. The first control unit performs a control, in a motor traveling mode, to bring the first clutch to a disengaged state. The motor traveling mode includes traveling solely with the electric motor being driven. The second control unit performs a control, in the motor traveling mode, to bring the second clutch to a mildly engaged state in which input, from the driving-wheel side, of torque larger than driving torque causes the second clutch to slide.