A system and method for modifying the engine pull-up (EPU) logic within a hybrid vehicle based on max motor torque that accounts for the drop or change in available motor torque due to the opening/slipping of a torque converter bypass clutch during engine starts is disclosed. An engine pull-up threshold is determined from max available motor torque at a virtual impeller speed, where the virtual impeller speed is the impeller speed that would result if the torque converter bypass clutch was open/slipping and transferring the same amount of torque.

A method for operating a hybrid vehicle includes, determining a shift element to be utilized for decoupling of slip and a decoupling differential speed depending on whether a starting process is carried out, depending on whether the transmission is transferred from a torque-transmitting state into a non-torque-transmitting state or from a non-torque-transmitting state into a torque-transmitting state, depending on whether a gear ratio change is carried out, and depending on whether the hybrid vehicle includes a hydrodynamic starting component.

Systems and methods for operating an engine and a torque converter are presented. In one example, slip of a torque converter is adjusted via at least partially closing or opening a torque converter clutch in response to vehicle vibration. The vehicle vibration may be based on road surface conditions and an actual total number of operating cylinders of the engine.

A control device of a hybrid vehicle of the disclosure includes a clutch controller configured to perform slip control of a hydraulic clutch in response to satisfaction of a start condition of an engine and to perform pressure increase control of increasing a hydraulic pressure to the hydraulic clutch with elapse of time after a rotation speed difference between the engine and a motor enters a predetermined range; and an engine controller configured to start fuel injection and ignition of the engine before the rotation speed difference enters the predetermined range, to control the engine such that the rotation speed of the engine becomes equal to a target rotation speed after the start of the fuel injection and the ignition, and to increase the target rotation speed of the engine as an angular acceleration of the motor becomes larger during execution of the pressure increase control.

A method for shifting a transmission in a machine. The method includes detecting a request for a directional shift of the transmission and determining a ground speed of the machine in response to the request. The method further includes overriding the request if the ground speed is above a ground speed threshold. Further, the method includes preparing the machine for the directional shift by limiting an output speed of a power source of the machine and by issuing a command to a brake unit of the machine to reduce the ground speed of the machine. Furthermore, the method includes validating and raising the request to the transmission to execute the directional shift if the ground speed is below the ground speed threshold.

The method includes, based on a torque variation of a drive shaft after an engagement timing of an engine clutch 21 and before a release timing of a motor clutch 19 when switching a power transmission path from a first power transmission path 24 to a second power transmission path 25, increasing a slope of a torque increase of a power generation motor 4 in an absolute value with respect to a slope of a torque decrease of a traveling motor 2 in at least a part of a period from a timing T12 to a timing T14, and increasing a slope of a torque decrease of the power generation motor 4 in the absolute value with respect to a slope of a torque increase of the traveling motor 2 in at least a part of a period from the timing T14 to a timing T16.

A control device of a hybrid vehicle including an engine, motor that receives power from the engine via an engine connecting and disconnecting device, and automatic transmission, starts the engine in a first starting method in which the engine performs ignition and rotates by itself after the engine speed is increased to be equal to or higher than a predetermined rotational speed through slipping engagement of the engine connecting and disconnecting device, or a second starting method in which the engine performs ignition and rotates by itself from a stage before the engine speed reaches the predetermined rotational speed, and controls the automatic transmission to permit a lower gear position to be established according to shift conditions when the engine is started in the second starting method during a downshift of the automatic transmission, as compared with when the engine is started in the first starting method during the downshift.

A method of controlling uphill driving of a hybrid vehicle provided with a dual clutch transmission (DCT) may include determining, by a controller, a driving state of a vehicle on the basis of information collected from the vehicle; when the vehicle is determined as being in a uphill driving state, performing, by the controller, high torque control on an engine of the vehicle by increasing an engine torque to control the engine at a predetermined high torque engine operating point and reducing a motor torque of a motor in the vehicle to satisfy a driver request torque; and during the performing of the high torque control on the engine, comparing, by the controller, a state of charge (SOC) value of a battery with a set first SOC threshold value, and when the SOC value of the battery is less than or equal to the first SOC threshold value, performing engine and motor speed control to defend the SOC value of the battery.

A hybrid vehicle of the disclosure includes an engine, a motor that outputs a torque to a driving system, a hydraulic clutch that connects the engine with the motor and disconnects the engine from the motor, and a control device that performs slip control of the hydraulic clutch in response to satisfaction of a start condition of the engine and controls the motor to output at least a cranking torque to the engine. The control device sets a target value of a rotation speed difference between the engine and the motor during execution of the slip control, and increases at least one of a hydraulic pressure to the hydraulic clutch, an output torque of the motor and an output torque of the engine when a difference between the rotation speed difference and the target value is out of an allowable range. This configuration ensures good startability of the engine.

An active purge system (APS) according to a driving state of a hybrid vehicle includes an active purge unit (APU) configured to pressurize a vaporized gas generated in a fuel tank of the hybrid vehicle and supply the pressurized vaporized gas to an intake pipe, and a control unit configured to control the APU, where the control unit gradually controls a processing amount of the vaporized gas according to the driving state of the hybrid vehicle. The processing amount of the vaporized gas is gradually controlled using the APS according to the driving state of the hybrid vehicle, particularly, a number of places at which slip occurs in a power transmission system of the hybrid vehicle so that degradation of driving ability due to the occurrence of slip is reduced.