The present disclosure relates to a method for determining at least one shift parameter of a vehicle transmission (3), the vehicle transmission (3) comprising a first clutching device (8a) and a first speed ratio (9a); a second clutching device (8b) and a second speed ratio (9b); an input; and an output, wherein the input and the output of the transmission are connectable by the engaging first clutching device (8a) or the second clutching device (8b). The method comprises the steps: performing a shift by disengaging the first clutching device (8a) and/or engaging the second clutching device (8b), wherein the first clutching device (8a) stops transferring torque through the transmission at a first time point, wherein the second clutching device (8b) starts transferring torque through the transmission at a second time point, and determining the shift parameter at the first time point and/or at the second time point.

A method for operating a multi-clutch transmission for a motor vehicle, having at least the following steps: a) closing a first clutch of the multi-clutch transmission, in order to transfer an input torque (M_k1) between a drive machine of the motor vehicle and at least one first sub-transmission of the multi-clutch transmission; b) applying a drag torque (M_k2) to a second sub-transmission of the multi-clutch transmission, which is coupled to the first sub-transmission, via a second clutch of the multi-clutch transmission; c) detecting a clutch slip of the second clutch, which is dependent on the drag torque (M_k2); and d) determining a current gear selection of the multi-clutch transmission by evaluating the clutch slip. The disclosure further relates to a multi-clutch transmission and to a motor vehicle having a multi-clutch transmission.

A temperature estimation device for friction engaging elements including an execution device and a storage device is provided. The storage device stores mapping data that defines mapping. The mapping includes, as an input variable, a heat amount variable that is a variable indicating an amount of heat generated by the friction engaging elements during the shifting of the transmission and a shifting variable indicating the friction engaging elements to be engaged at the time of the shifting of the transmission, and, as an output variable, the temperature. The execution device executes an acquisition process of acquiring a value of the input variable and a calculation process of inputting the value of the input variable acquired by the acquisition process into the mapping to calculate a value of the output variable.

A vehicle drive device including an engagement pressure flow channel, a lubrication flow channel, a first pump having a discharge port connected to the engagement pressure flow channel, a second pump, and a flow channel control valve. The flow channel control valve selectively switches flow channels between a first state in which an outflow destination of oil discharged from the second pump is the engagement pressure flow channel and a second state in which the outflow destination is the lubrication flow channel. When a failure in which the flow channel control valve is fixed in the second state has occurred, a control device for a vehicle control device performs fail-safe control in which a rotational speed of at least one of an internal combustion engine and a rotating electrical machine is increased to supply oil to the engagement pressure flow channel by the first pump.

A temperature estimation device for friction engaging elements including an execution device and a storage device is provided. The storage device stores mapping data that defines mapping. The mapping includes, as an input variable, a heat amount variable that is a variable indicating an amount of heat generated by the friction engaging elements during the shifting of the transmission and a shifting variable indicating the friction engaging elements to be engaged at the time of the shifting of the transmission, and, as an output variable, the temperature. The execution device executes an acquisition process of acquiring a value of the input variable and a calculation process of inputting the value of the input variable acquired by the acquisition process into the mapping to calculate a value of the output variable.

A method of controlling a continuously variable electric drivetrain (CVED) including a high ratio traction drive transmission and at least one of a first motor-generator and a second motor-generator is disclosed. The method includes the steps of receiving a an output speed, determining a kinematic output speed, and determining a slip state of the high ratio traction drive transmission based on a comparison of the output speed to the kinematic output speed.

An automatic transmission is arranged in a hybrid driveline employing an EV mode and an HEV mode, and establishes transmission ratio positions by engaging or disengaging frictional elements. A system or method includes: determining, based on a vehicle deceleration and a relationship between a requested transmission ratio position and an actual transmission ratio, whether or not interlocking is occurring, when the automatic transmission is in a state out of transmission shifting, wherein the interlocking is due to erroneous engagement of one of the frictional elements; and inhibiting the determination about interlocking, during a period from start of slip of a first frictional element of the automatic transmission to confirmation of convergence of slip of the first frictional element, in a situation that the first frictional element is slip-engaged for starting the engine in response to a request for mode transition from the EV mode to the HEV mode.

A method of controlling a continuously variable electric drivetrain (CVED) including a high ratio traction drive transmission and at least one of a first motor-generator and a second motor-generator is disclosed. The method includes the steps of receiving a an output speed, determining a kinematic output speed, and determining a slip state of the high ratio traction drive transmission based on a comparison of the output speed to the kinematic output speed.

A method to control a road vehicle provided with a clutch, which connects an internal combustion engine to drive wheels and is arranged upstream of a servo-assisted transmission; the control method comprises the steps of: checking whether the tyres of the drive wheels are close to a grip limit; and opening the clutch so that the clutch transmits a torque to the drive wheels with a slip of the clutch that is constant and other than zero when the tyres of the drive wheels are close to the grip limit.

A hybrid vehicle drive system including an internal combustion engine, a motor-generator, a speed shift mechanism including a first and second frictional engagement mechanisms, a torque limiter interposed the motor generator and the speed shift mechanism in a power transmission path transmitting from the internal combustion engine to an axle, and a controller controlling the speed shift mechanism so as to disengage the first frictional engagement mechanism and engage the second frictional engagement mechanism. The controller is configured to perform controlling the speed shift mechanism so as to increase an engaging force of the second frictional engagement mechanism during switching from high speed stage to low speed stage when an occurrence of slipping is detected than when the occurrence of slipping is not detected.