A vehicle includes an engine having an intake manifold and an exhaust manifold. An exhaust system is connected to the exhaust manifold and has an aftertreatment device. The aftertreatment device has a body defining inlet and outlet cones, a heating element, and a catalyst disposed in the body between the cones. An air-circulation system has conduit extending from downstream of the catalyst to the intake manifold and an air-circulation device configured to circulate air from the outlet cone, through the conduit to the intake manifold, through the engine, to the inlet cone, and through the aftertreatment device.

Provided is a control device for a vehicle, the vehicle including an internal combustion engine, a generator capable of being rotated by the internal combustion engine, a battery that stores power generated by rotation of the generator, and a motor that is supplied with power from the battery and outputs a driving force to a drive wheel, wherein, at a timing at which a requested output, which is requested when the internal combustion engine is operating with the internal combustion engine and the drive wheel not mechanically connected to each other and the internal combustion engine is performing a stoichiometric operation that operates in accordance with a theoretical air-to-fuel ratio, is equal to or greater than a threshold value, the control device starts to increase the number of rotations of the internal combustion engine to the number of rotations set in a rich operation where a ratio of a fuel of the internal combustion engine to oxygen is higher than the theoretical air-to-fuel ratio.

A control unit configured to control an electric turbocharger and an EGR valve. While an internal combustion engine is stopped, an oxygen-free period, which is a period during which oxygen surrounding an exhaust gas purifier used for an oxidation reaction runs out, is estimated based on a temperature of the exhaust gas purifier. Before entering the oxygen-free period, the EGR valve is opened and the electric turbocharger is driven. Air surrounding the exhaust gas purifier is replaced with fresh air. After replacement with the fresh air has been completed, the electric turbocharger is stopped.

Methods and systems are provided for providing secondary air to an exhaust system during catalyst warm-up. In one example, a method may include, during a cold start condition, operating an engine with a first number of cylinders unfired and a remaining number of cylinders fired during an engine cycle, opening an intake valve of an unfired cylinder of the first number of cylinders during an expansion stroke of the unfired cylinder, and opening an exhaust valve of the unfired cylinder during a compression stroke of the unfired cylinder. In this way, the unfired cylinders may provide the secondary air to the exhaust system during a stroke that increases mixing of the secondary air with burned exhaust gas from fired cylinders, thus increasing exotherm production in the exhaust system to increase a temperature of the catalyst.

Systems and methods for estimating a temperature of an after treatment device in an exhaust system of an engine are described. In one example, the temperature is estimated during condition when an engine exits a fuel cut-out mode and excess fuel is delivered to the after treatment device for the purpose of increasing after treatment device efficiency.

Engine systems which are safer and have reduced risk of fire are desirable in a wide range of equipment markets. The present engine systems utilize sensors and control systems which reduce the probability of fire or spark exiting the exhaust system. The sensors may monitor a wide range of conditions within the exhaust system to alter the operating parameters of the engine to prevent ignition of objects adjacent the engine system during use. By altering operation of the engine, conditions such as exhaust temperature or unburned fuel can be controlled to minimize risk of undesired ignition.

Systems and methods provide deceleration fuel cutoff regeneration of a gas particulate filter. A powertrain system includes an exhaust system containing the gas particulate filter, which is configured to collect particulate matter from an exhaust gas stream of the powertrain system. A temperature sensor is configured to monitor a temperature of the gas particulate filter. A loading monitor, such as a sensor and/or a model, is configured to provide a loading input of particulate loading of the gas particulate filter. At least one controller is configured to: determine, by comparing the loading input to stored values, whether the gas particulate filter requires the regeneration; effect a warmup of the gas particulate filter when the determination shows the gas particulate filter requires the regeneration; and initiate the regeneration when a value received from the temperature sensor meets a minimum threshold level.

Methods and systems are provided for heating a catalyst via a catalyst heater are presented. In one example, the catalyst may be heated to provide a minimum amount of time for the catalyst to reach a threshold temperature. In another example, the catalyst heater may be heated to minimize an amount of power that is used to heat the catalyst.

A method for heating a first exhaust gas purification device and a second exhaust gas purification device of an exhaust system of an internal combustion engine of a motor vehicle, has the following steps: determining a first actual temperature of the first device and a second actual temperature of the second device, determining a first setpoint temperature of the first device and a second setpoint temperature of the second device by means of a heating coordination device, determining a first heat demand of the first device and a second heat demand of the second device, creating a heating specification for the first device and for the second device, relaying the heating specification to an engine control device of the motor vehicle, and controlling the internal combustion engine by means of the engine control device as a function of the heating specification.

Methods and systems are provided for a turbocharger. In one example, a method may include bypassing exhaust gases flowing to the turbocharger in response to a catalyst temperature being less than a threshold temperature. The bypassing includes opening a bypass valve and adjusting a position of one or more turbine nozzle vanes.