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 method for starting a vehicle having a start-stop system, a bake pedal for braking, a pressure controlled clutch, an accelerator for setting an engine speed, and a control unit for controlling engine operation. The method including detecting brake release after a start-stop process; determining the clutch pressure; determining a required torque from the determined pressure based on a stored pressure-torque characteristic; determining the necessary engine speed requirement from the determined required torque based on a stored characteristic engine torque curve; inquiring whether the necessary speed requirement exceeds the available torque at the current engine speed; if not, then the engine speed is not increased; if so, inquiring whether the necessary speed requirement exceeds the accelerator requested speed; if not, increasing the engine speed with the engine control unit to the determined speed requirement; and if so, increasing the engine speed to the maximum set at the accelerator.

A method and device for controlling an engine clutch of a hybrid vehicle are provided. The method includes setting a target speed of an engine to change a driving mode of the hybrid vehicle from an EV mode to an HEV mode and operating a HSG to adjust an engine speed to reach the target speed. An engine clutch that connects the engine with a driving motor or disconnects the engine from the driving motor is engaged to start when the speed of the engine is maintained at the target speed. A kiss point generated when the engine clutch is in a slip state is detected to learn the kiss point of the engine clutch and an output of the engine is increased based on a driver required torque when the speed of the engine and a speed of the driving motor are synchronized after the kiss point is learned.

A wheel loader includes a forward clutch, an accelerator pedal, a brake pedal, and a controller configured to control hydraulic pressure of hydraulic oil supplied to the forward clutch. The controller performs clutch hydraulic pressure control for reducing the hydraulic pressure of the hydraulic oil supplied to the forward clutch according to an operation amount of the brake pedal on condition that at least the brake pedal is operated while the accelerator pedal is being operated. The controller continues the clutch hydraulic pressure control even after the clutch shifts from a complete engagement state to a semi-engagement state by the clutch hydraulic pressure control.

A system for controlling transmission shifting includes a controller that receives a shift request signal and determines if a clutch has been unapplied for more than a predetermined time. With a yes determination, a maximum fill time value for hydraulic fluid to be applied to a clutch control circuit is determined, the maximum fill time value being a function of time the clutch has been unapplied and temperature. A signal indicative of an amount of engine RPM flare after the transmission executes the requested shift is received and a modified maximum fill time value is determined as a function of this flare. The modified maximum fill time value is stored as a replacement for the maximum fill time value for use with a subsequent transmission shifts using this clutch, and reduces an amount of air in the control circuit and an amount of flare with subsequent transmission shifts.

An apparatus and a method for controlling a driving mode of an HEV are provided. The apparatus releases an HEV mode at an appropriate time before forcibly releasing an engine clutch even when an accelerator pedal is engaged while driving the vehicle on an uphill road in the HEV mode to reduce a shock caused when the engine clutch is forcibly disengaged and improve riding comfort and drivability. The method includes determining whether the vehicle is driven on an uphill road from gradient information of a current road while the vehicle is driven in a HEV mode and determining a clutch engagement impossible speed corresponding to the gradient of the current road when the vehicle is driven on the uphill road. The engine clutch is disengaged to release the HEV mode when the speed of the motor is equal to or less than the determined clutch engagement impossible speed.

A method of selectively controlling a power take-off (PTO) assembly includes positioning a clutch assembly radially between a shaft and a PTO gear, operably controlling the clutch assembly with a controller, and selectively engaging the clutch assembly with the controller. The controller monitors signals received from a plurality of sensors and compares the monitored signals with respective signal thresholds. The clutch assembly is engaged when the compared monitored signals are within the signal thresholds.

A hybrid electric vehicle having a motor and an engine that are selectively connected on a driveline and controlled by a controller. The controller is configured to schedule additional motor torque to compensate for engine inertia drag based upon a clutch pressure value and a clutch slip speed value during a period of clutch engagement. The controller is also configured to maintain vehicle acceleration using a proportional integral controller to adjust the motor torque during a period of clutch engagement.

A transmission is provided having a control module, an input member, an output member, four planetary gear sets, a plurality of interconnecting members, and a plurality of torque transmitting devices. Each of the planetary gear sets includes first, second and third members. The torque transmitting devices include clutches and brakes. The control module includes a control logic sequence for performing a coasting downshift of the transmission.

A method for learning a clutch pedal may include determining whether a clutch pedal is operated; determining at least one of a depressed speed of the clutch pedal, a depressed value of the clutch pedal, and a speed of an engine at a shifting timing when the clutch pedal is operated; determining at least one of a moving average value of the depressed speed of the clutch pedal, a moving average value of the depressed value of the clutch pedal, and a moving average of the speed of the engine for a predetermined time; and storing the moving average value as a correction value for preventing an abrasion of a shift clutch.