A variety of methods and arrangements for reducing noise, vibration and harshness (NVH) in a skip fire engine control system are described. In one aspect, a firing sequence is used to operate the engine in a skip fire manner. A smoothing torque is determined that is applied to a powertrain by an energy storage/release device. The smoothing torque is arranged to at least partially cancel out variation in torque generated by the skip fire firing sequence. Various methods, powertrain controllers, arrangements and computer software related to the above operations are also described.

A slip control method and arrangement for a drivetrain including a continuously variable transmission, forward-reverse clutch arrangement and an optional three-speed gearbox is described herein. The forward-reverse clutch arrangement includes a clutch that is so controlled as to slip when a torque higher than the usable torque attempts to pass through. Accordingly, the clutch prevents the prime mover from stalling.

The disclosure relates to a method for calibrating a drive system for an axle of a motor vehicle; wherein the drive system includes at least one electric machine as the drive unit, a drive shaft driven by the drive unit, a first output shaft and a second output shaft, as well as a first clutch connecting the drive shaft to the first output shaft and a second clutch connecting the drive shaft to the second output shaft.

In a hybrid vehicle control system, when a first traveling mode using torque of an electric motor is switched to a second traveling mode using torque of an engine, a controller performs an engine start control by applying an engagement pressure to a first clutch and by cranking the engine by the electric motor, so as to start the engine. Specifically, the controller obtains a predicted start time and an actual start time by the engine start control, and corrects the engagement pressure so as to decrease the engagement pressure applied to the first clutch at a subsequent time of starting the engine, when the actual start time is shorter than the predicted start time.

A hybrid vehicle includes an electric motor and a combustion engine. A K0 clutch couples the combustion engine to a drivetrain of the vehicle. A control module of the vehicle calculates a torque to be applied by the motor to the K0 clutch when initiating engagement of the combustion engine to the drivetrain. The control module calculates two separate torque lead values by two separate methods and calculates the torque by combining the two torque lead values.

A method of estimating a load on a vehicle (10), the method comprising: obtaining a first load estimate using a first load estimation technique; obtaining a second load estimate using a second load estimation technique; analysing characteristics of the first load estimate and the second load estimate; and, based on the analysis selecting either the first load estimate or the second load estimate as an output load estimate.

A system and method for operating a hybrid vehicle that shuts down an internal combustion engine during idle and slow speed operations and instead drives a power transmission with an electric traction motor. A vehicle operating at higher speeds, under increased operating demands, or other operating conditions automatically switches from electric propulsion to internal combustion engine propulsion. This operational mode is configurable and at all times seamless to the driver and vehicle operations. By designating the low speed, low demand operation of the vehicle to the more efficient electric mode, fuel consumption can be reduced, and overall vehicle efficiency can be maximized.

Systems and methods for operating a driveline disconnect clutch of a hybrid vehicle are presented. In one example, a driveline disconnect clutch pressure is measured just prior to a request to close the driveline disconnect clutch and a time duration for driveline disconnect clutch boost pressure is adjusted in response to the measured driveline disconnect clutch pressure.

A hybrid vehicle includes an electric motor and a combustion engine. A K0 clutch couples the combustion engine to a drivetrain of the vehicle. A control module of the vehicle calculates a torque to be applied by the motor to the K0 clutch when initiating engagement of the combustion engine to the drivetrain. The control module calculates two separate torque lead values by two separate methods and calculates the torque by combining the two torque lead values.

A method and system of controlling an engine for vehicle interior heating is provided. The method includes performing a first engine control when the engine is not in an engine-on state for vehicle driving, to perform heating control for interior heating at a predetermined range of a reference coolant temperature. Additionally, the method includes performing a second engine control when the engine is in an engine-on state for vehicle driving, to prolong an engine-on time for vehicle driving by setting a minimum value of the range of the reference coolant temperature to a lower value and setting a maximum value of the range of the reference coolant temperature to a higher value and to determine a point of time of engine-off operation based on a real-time lock up time and an average lock up time of an engine clutch for vehicle driving.