A method for adjusting a co-efficient of friction of a disconnect clutch of a hybrid vehicle, the hybrid disconnect clutch separating or connecting an internal combustion engine and an electrical motor, including: delivering, to drive wheels of the hybrid vehicle, a torque output by the internal combustion engine and the electrical motor; determining the co-efficient of friction while the disconnect clutch is in a slipping state; operating the disconnect clutch in first and second operating modes, the first mode including an open state of the disconnect clutch and the second mode including a closed state of the disconnect clutch; and increasing the co-efficient of friction for more rapid adjustment of the slipping state only in the transition from the closed state to the opened state.

A control device that includes an electronic control unit that is programmed such that, when the internal combustion engine is started by the rotary electric machine while output torque from the rotary electric machine is transferred to the wheels in a state in which rotation of the internal combustion engine has been stopped, the electronic control unit: executes second slipping control in which the second engagement device is controlled into a slipping engagement state, executes first slipping control in which the first engagement device which has been in a disengaged state is controlled into a slipping engagement state during execution of the second slipping control, and controls an engagement pressure of the first engagement device so as to lower a rotational speed of the rotary electric machine in the first slipping control.

A vehicle transmission apparatus having a starting engagement friction element, which has friction plates and a hydraulic servo including a piston that is moved according to a supplied oil pressure to press the friction plates, which is controlled to be engaged when a vehicle is started by using at least a driving force of the internal combustion engine, and which transfers creep torque. A control device capable of receiving an accelerator operation amount signal and capable of outputting a command value that controls the oil pressure. The control device executes temporary increase control of temporarily increasing the command value, when the accelerator operation amount signal is turned on from a state where the accelerator operation amount signal is off and the command value is output so that the starting engagement friction element transfers the creep torque.

A multimode clutch may be adapted for selectively connecting and disconnecting front and/or rear axles from respective internal combustion engine and electric motor powertrains connected to such front and rear driving axles in a through-the-road hybrid vehicle. For example, the engine may be part of a front axle driven powertrain connected to the front wheels, while the motor may be part of a separate rear axle driven powertrain connected to the rear wheels, or vice versa. By selective disconnection of an axle not being actively driven, a real time reduction in parasitic losses may be achieved, leading to higher overall operating efficiencies. The multimode clutch offers greater flexibility over the use of standard friction clutches; each multimode clutch may provide four distinct operational modes for accommodating a wide diversity of driving conditions. For example, bi-rotational freewheeling of the rear axle may occur whenever the motor is not in use.

A method ascertains a characteristic variable of a clutch installed into the powertrain of a vehicle for transmitting torque between a clutch input and a clutch output. A first electric motor is connected to the clutch input to introduce a first drive torque into the clutch. The torque is ascertained when the vehicle is at a standstill in that the clutch is first opened; the first electric motor is regulated at a first rotational speed; the clutch output is regulated at a second rotational speed; a counter torque which counteracts the transmission torque is applied to the clutch output; the clutch is then closed in order to assume a slipping state in which a specific differential rotational speed between the clutch input and the clutch output is present; the first drive torque is then ascertained; and the transmission torque is determined on the basis of the first drive torque.

Methods and systems for detecting and clearing battery power failure of an electric clutch actuator (ECA) include use of a capacitor connected to the ECA. The capacitor is connected to the ECA such that when the ECA and a battery configured to output a battery voltage are connected together a capacitor voltage matches the battery voltage and when the ECA and the battery are disconnected from one another the capacitor voltage differs from the battery voltage. A loss of battery connection is detected upon a difference between the capacitor voltage and the battery voltage exceeding a threshold.

A hybrid module for a drive train of a motor vehicle includes an electrical machine, a dry friction clutch for coupling the electrical machine with the drive train, an input shaft arranged to be coupled to an internal combustion engine of the motor vehicle, and an output shaft arranged to be coupled to a vehicle transmission of the motor vehicle. The dry friction clutch is designed to lead away or secure wear debris of the dry friction clutch. The hybrid module may be arranged as a P2 hybrid module within the drive train between an internal combustion engine side of the motor vehicle and a vehicle transmission side of the motor vehicle. The dry friction clutch may be a dry multi-disk clutch.

Provided is a control device for a four-wheel drive which can maintain driving stability while restraining noise and vibration. A control device includes: a second control device that, when at least one of front wheel has slipped, engages a dog clutch after rotating a propeller shaft by a rotational force transmitted via first and second friction clutches; and a third control device that, if a predetermined condition is satisfied when the front wheels are not slipping, engages the dog clutch after rotating the propeller shaft by the rotational force transmitted via the first and second friction clutches. The time required to synchronize the dog clutch by the third control device is longer than that required to synchronize the dog clutch by the second control device.

At the time of changing from an EV mode, in which a hybrid vehicle travels with the use of a second motor provided on an output side of a differential mechanism while torque that acts on any one of rotating elements of the differential mechanism is interrupted by a clutch, to an HV mode, in which the hybrid vehicle travels while transmitting output torque of an engine to a drive wheel, when the engine is started in a state where the clutch is slipped and torque is transmitted from the engine so as to increase the rotation speed of the first rotating element while the clutch is slipped, torque starts being output from a first motor such that torque input from the first rotating element to the differential mechanism to increase the rotation speed of the drive wheel is output from the third rotating element.

A method ascertains a characteristic variable of a clutch installed into the powertrain of a vehicle for transmitting torque between a clutch input and a clutch output. A first electric motor is connected to the clutch input to introduce a first drive torque into the clutch. The torque is ascertained when the vehicle is at a standstill in that the clutch is first opened; the first electric motor is regulated at a first rotational speed; the clutch output is regulated at a second rotational speed; a counter torque which counteracts the transmission torque is applied to the clutch output; the clutch is then closed in order to assume a slipping state in which a specific differential rotational speed between the clutch input and the clutch output is present; the first drive torque is then ascertained; and the transmission torque is determined on the basis of the first drive torque.