A method for operating a motor vehicle having an internal combustion engine. The internal combustion engine is started. A drive power requirement is ascertained. A takeoff delay for reaching a predetermined minimum temperature for an exhaust aftertreatment system is determined, the predetermined minimum temperature being a function of a setpoint internal combustion motor drive power that is to be provided by the internal combustion engine to meet the drive power requirement. After the takeoff delay elapses, a release signal for releasing a takeoff block is outputted. Provided is also a control unit and a motor vehicle.

A hybrid vehicle includes an internal combustion engine, a filter, an electrical storage device, a rotating electric machine, and a controller. The filter is configured to trap particulate matter in exhaust gas of the internal combustion engine. The rotating electric machine is configured to generate electric power using power from the internal combustion engine so as to charge the electrical storage device, and drive the internal combustion engine using electric power from the electrical storage device. The controller is configured to control the internal combustion engine and the rotating electric machine, so as to warm up the electrical storage device when regeneration control needs to be performed and when the temperature of the electrical storage device is lower than a reference value. The regeneration control is control for raising the temperature of the filter to a predetermined temperature so as to burn the particulate matter. The controller may be configured to execute the regeneration control when the temperature of the electrical storage device exceeds the reference value.

Methods and systems are provided for synergizing the benefits of an engine exhaust driven fuel reformer in a hybrid vehicle system. A vehicle controller may hold the engine in a narrow operating range where fuel reformer operation is optimal while using motor and/or CVT adjustments to address transients generated as driver demand varies. The controller may also adjust an operating range of temperatures of the reformer to enable extended fuel reforming even after the engine of the hybrid has been shutdown.

A controller of a hybrid vehicle is configured to operate the internal combustion engine with ignition timing of the internal combustion engine during the execution of the first warm-up control for operating the internal combustion engine at a first operating point further on a retard side than ignition timing of the internal combustion engine during the execution of the second warm-up control for operating the internal combustion engine at a second operating point, regardless of the driving force required for traveling after the execution of the first warm up control. The controller is configured to set the output of the internal combustion engine and the operation characteristic of the intake valve in accordance with a predetermined characteristic relationship in which the output of the internal combustion engine and the operation characteristic of the intake valve correspond to each other during the execution of the second warm-up control.

A control method for a hybrid vehicle is provided. The hybrid vehicle includes: a generator configured to charge a battery by using power of an engine; an electric motor configured to drive a driving wheel by electric power of the battery; and a particulate filter configured to collect particulate matter contained in exhaust gas from the engine. In the control method, the engine is driven to raise a temperature of the particulate filter when a first temperature rise condition is satisfied in which a first predetermined amount or more of the particulate matter is accumulated in the particulate filter and the temperature of the particulate filter is equal to or lower than a predetermined temperature. Drive of the engine is prohibited, when a predetermined first condition that a driver does not intend to drive the engine is satisfied.

Methods and systems are provided for using compression heating to heat a cylinder piston before cylinder combustion is resumed. Cylinder heating is achieved using combinations of slow unfueled engine rotation where the engine cylinders are heated via compression stroke heating, and slow compressor rotation where the cylinders are heated via compression heating. One or more intake or exhaust heaters may be concurrently operated to expedite cylinder heating.

A method and a system for improving operation of a hybrid vehicle are presented. In one example, an engine exhaust after treatment device is cooled at an opportunistic time. The approach may provide improved cooling for exhaust after treatment devices and it may also improve vehicle emissions.

A method for starting and operating an engine of a mild hybrid vehicle following start-up is disclosed for an engine having low and high voltage starting devices, and controlled by an electronic controller. The method comprises using the high voltage starting device as a motor to crank the engine whenever possible so as to partially discharge a high voltage battery. The method further comprises using the high voltage starting device as a generator after starting the engine if the exhaust gas temperature needs to be increased so as to assist with light-off of one or more exhaust gas after treatment devices.

A method for regulating a temperature in an exhaust stream in a motor vehicle through control of its driveline. The motor vehicle includes a driveline having a combustion engine connected to a gearbox via a clutch device. The gearbox has several discrete gears. The driveline includes an exhaust system configured for the removal of an exhaust stream from the combustion engine. The method steps are: obtaining one or several first parameters P.sub.1, wherein at least one of first parameters P.sub.1 is a first temperature difference between a first temperature T.sub.1 in the exhaust system and a reference temperature T.sub.Ref; and controlling the gearbox, and thus controlling an operating point in the combustion engine, through downshift to a lower gear, and thus increasing engine speed and reducing a load on the combustion engine, if a value of the one or several first parameters P.sub.1 exceeds a first threshold, and an upshift to a higher gear, and thus reducing an engine speed and an increase of a load on the combustion engine, if a value for the one or several first parameters P.sub.1 is below a second threshold value. Further, a computer program, a computer program product, a system and a motor vehicle comprising such a system are disclosed.

A method and a system for improving operation of a hybrid vehicle are presented. In one example, an engine exhaust after treatment device is cooled at an opportunistic time. The approach may provide improved cooling for exhaust after treatment devices and it may also improve vehicle emissions.