A method ascertains a characteristic variable of a clutch installed in a drive train of a vehicle for transmitting a transmission torque between a clutch input and a clutch output. A first electric motor is connected to the clutch input and to an internal combustion engine and can assume generator operation, during which it is driven by the internal combustion engine. A second electric motor is connected to the clutch output. The clutch input can have a first rotational speed and the clutch output can have a second rotational speed. The transmission torque during generator operation is ascertained by activating the clutch to adopt a slipping state and in doing so by setting a predefined rotational speed difference between the first and second rotational speed. The clutch input torque present at the clutch input is then ascertained and the transmission torque is determined depending on the clutch input torque.

A vehicle travel control apparatus configured to control a vehicle with a self-driving capability, including a travel state detector configured to detect a traveling state of a forward vehicle in front of the vehicle, and an electric control unit having a microprocessor and a memory. The microprocessor is configured to perform recognizing a drive-mode of the forward vehicle based on the traveling state detected by the travel state detector. The recognizing includes calculating a degree of variance of a vehicle speed or an acceleration of the forward vehicle based on the traveling state detected by the travel state detector, and determining whether the forward vehicle is traveling in a manual drive mode or a self-drive mode based on the degree of variance calculated in the calculating.

Systems and methods for operating a hybrid powertrain that includes an engine and a motor/generator are described. The systems and methods provide a way of estimating driveline disconnect clutch torque so that driveline torque disturbances may be reduced. In one example, driveline disconnect clutch torque capacity and engine torque may be a basis for estimating driveline disconnect clutch torque.

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, in response to an actual engine start time being greater than an upper threshold time for an engine start event, 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 that the actual engine start time is greater than the lower threshold time for the next engine start event.

Transmission torque of a shift progress side engagement device is set based on engine power, shift progressing power, and battery power such that MG1 torque and MG2 torque are limited due to the limitation of the battery power when shifting a stepped transmission is suppressed. The stepped transmission is shifted with the transmission torque which takes into account the input-output balance of the respective powers.

Presented are model-based control systems for operating parallel hybrid powertrains, methods for making/using such systems, and motor vehicles with parallel hybrid powertrains and model-based torque and speed control capabilities. A method for controlling operation of a hybrid powertrain includes receiving a command signal for a hybrid powertrain operation associated with a driver input and a current operating mode of the powertrain. A desired output torque for executing the powertrain operation is then determined. The method determines if a speed differential between an engine speed of an engine and a torque converter output speed of a torque converter is less than a calibrated threshold; if so, the method responsively engages a clutch device to operatively connect the engine's output member to the transmission's input member. Engine torque is then coordinated with motor torque such that the sum of the engine and motor torques is approximately equal to the desired output torque.

A vehicle includes a transmission having a torque converter, an oncoming clutch, and a controller. The controller is programmed to, in response to a torque of the oncoming clutch exceeding an estimated average by a threshold during an engagement, increase the torque of the oncoming clutch via a feedforward command and adjust the torque of the oncoming clutch via a feedback command to compensate for deviations in the torque generated by the feedforward command during the engagement.

A hybrid vehicle includes an engine, an electric machine selectively coupled to the engine, a transmission having a torque converter impeller coupled to the electric machine and a torque converter clutch configured to selectively couple the impeller to a turbine, and a controller configured to control pressure of the torque converter clutch responsive to estimated clutch capacity, which is adjusted by the controller to equal impeller torque responsive to impeller speed exceeding turbine speed during clutch disengagement. A model of estimated torque converter clutch capacity may be stored in memory and adapted to actual clutch capacity by applying a gain or offset determined during opening of the clutch.

A controller commands an engine torque level in response to a driver demanded torque based on an accelerator pedal position. If the driver demanded torque decreases rapidly during or just prior to a torque phase of a shift, the controller commands the engine to temporarily generate torque exceeding the driver demand. The controller sets a nominal engine torque equal to the driver demand torque before the rapid decrease, slowly decreases the nominal engine torque during the torque phase, and decreases the nominal torque at progressively faster rates during the inertia phase to bring the nominal torque back into agreement with the driver demanded torque. The commanded engine torque is based on the nominal torque, but may be less than the nominal torque during the inertia phase to permit the engine speed to decrease faster.

A control apparatus for a four-wheel-drive vehicle is configured to, during braking of the vehicle in a two-wheel-drive state, determine whether or not a degree of a yaw movement for deflecting the vehicle is larger than a predetermined first degree. When the degree of the yaw movement is larger than the first degree, the control apparatus increases a first coupling torque of a first coupling device and a second coupling torque of a second coupling device to a predetermined first torque value which is larger than zero, and controls a ground contact load adjusting device in such a manner that a first ground contact load at a rear wheel at an outer side with respect to the yaw movement becomes larger than a second ground contact load at a rear wheel at an inner side with respect to the yaw movement by a predetermined first load difference or more.