Readings of multiple sensors are utilized to estimate transmission output, which is used as a feedback signal to control the torque capacity of a transmission clutch. Some sensor readings, such as transmission output speed, are used to compute an input vector. Then, a current state vector is computed as a linear function of the previous state vector and the input vector. One of the values in the state vector is shaft twist, which is proportional to transmission output torque. Various other sensor readings, including wheel speed, are used to correct for noise. Wheel speed signals are received with a delay. To accommodate this delay, the state vector is expanded to include estimates of wheel speed at various past points in time. An accelerometer reading is used at very low speeds at which the wheel speed sensor and transmission output speed sensor are unreliable.

A vehicle includes an engine, a transmission, a clutch, and a controller. The clutch is configured to couple the engine and transmission during engine starts. The controller is programmed to alter an engine start torque apply schedule for the clutch such that the actual engine start time is less than the upper threshold time for a next engine start event. The controller may be further programmed to, in response to the actual engine start time being less than a lower threshold time for the engine start event, alter the engine start torque apply schedule for the clutch such the actual engine start time is greater than the lower threshold time for a next engine start event.

A method for controlling start of an ISG (idle stop and go) vehicle may include an operation of limiting, when an ISG mode of the vehicle is turned off, an engine torque to less than a preset value for a predetermined time from a point of time at which the IGS mode is turned off.

A vehicle control device calculates a target line pressure based on an instructed torque capacity of a friction engaging element and a belt capacity when the friction engaging element is determined as not engaging. Belt capacity is calculated using an input torque of a continuously variable transmission mechanism. The device calculates torque down in a driving source based on an upper limit line pressure when the calculated target line pressure exceeds such line pressure. A limit torque capacity of the friction engaging element is calculated using the input torque and a belt capacity when the friction engaging element is determined as not engaging. The belt capacity is calculated using an actual line pressure. The device restrains a slip between pulleys and a power transmitting member using the target line pressure, the torque down, and the limit torque capacity when the friction engaging element is determined as not engaging.

A method of controlling a hybrid drive-train of a vehicle having a combustion engine with a driveshaft, a transmission with an input shaft and an output shaft that drives a transfer box. An electric machine has a rotor that is connected to the transmission input shaft. A separator clutch is arranged between the engine driveshaft and the transmission input shaft. For coupling of the engine, the engine is first accelerated, with a rotational speed regulation, toward a target speed until a reference speed is reached or exceeded while the clutch remains disengaged, then, with continuous speed regulation, the engine is adjusted to a corrected target speed while the clutch is engaged until a target torque is obtained, then, with torque control, the engine is adjusted to the target torque while the clutch, with differential rotational speed regulation, is regulated to a target speed difference, and finally the clutch is engaged.

A feedforward control method for an electrified powertrain including a torque transfer device arranged between an electric motor and a transmission includes monitoring a set of operating parameters of the electrified powertrain, determining a desired input speed for the torque transfer device based on the set of operating parameters, determining a desired input torque for the torque transfer device based on a characteristics model or map of the torque transfer device and the desired input speed, performing an observer-based determination of a final feedforward torque for the torque transfer device based on the desired input speed, the desired input torque, a filtered actuator achieved torque for the electric motor, and minimum and maximum torque limits for the transmission, and controlling the electric motor based on the final feedforward torque for the torque transfer device.

A method of controlling a hybrid vehicle including an engine, a motor, a starter, a friction engagement element provided between the engine and the motor, and a mechanical oil pump which is driven by the motor and supplies oil to the friction engagement element, is provided. When the friction engagement element is in a disengaged state, a first traveling mode using the motor is performed. When it is in an engaged state, a second traveling mode at least using the engine is performed. The method includes, when the first traveling mode is unperformable, starting the engine by the starter to perform the second traveling mode, activating the motor and performing a hydraulic pressure control for shifting the friction engagement element from the disengaged to engaged state after starting the engine. The hydraulic pressure control uses at least the hydraulic pressure from the mechanical oil pump driven by activating the motor.

To inhibit clutch engagement during an engine restart from affecting cooperative regenerative braking control and switching of braking in a hybrid vehicle having a P2 module onboard, a control system for the hybrid vehicle includes an engine, a motor, a K0 clutch, drive shafts, a hydraulic friction brake system, and a controller capable of performing cooperative regenerative braking control. When start of the engine is requested during the cooperative regenerative braking control, the controller performs a first process of transitioning to braking only by the frictional brake system, a second process of raising an engine revolution speed while engagement of the K0 clutch is initiated after completion of transitioning to the braking, and a third process of controlling the engine to resume operating at a timing after the engine revolution speed increases to match a motor revolution speed after the engagement of the K0 clutch is initiated.

A method for controlling gear shifting of a hybrid electric vehicle is applied to a transmission control unit, and includes: transmitting, at an interval of a preset time period and via a vehicle control unit (VCU), a first torque control instruction to a first microcontroller unit (MCU) and a second torque control instruction to a second MCU; transmitting, in response to a difference between a rotational speed of an integrated starter and a rotational speed of the clutch being within a preset speed difference range and via the VCU, a rotational speed control instruction to the first MCU and a gear shift instruction to the second MCU; and transmitting, in response to receiving a TM gear-shifting completion instruction, at an interval of a preset time period and via the VCU, a third torque control instruction to the first MCU and a fourth torque control instruction to the second MCU.

A gear-shifting control method includes: determining whether a clutch is overheated; when the clutch is overheated, performing torque unloading, and making a request for transmission gear-shifting; and performing speed regulation on a first electric motor until the speed regulation is completed. By using the method, in a gear-shifting speed regulation stage, transmission gear-shifting can be performed when a clutch is overheated, such that the safety and performance of a gear-shifting process can be improved.