A catalyst control system includes a stop and start module that, during a period that the vehicle is ON between (i) a first time when the vehicle is turned ON and (i) a second time when the vehicle is next turned OFF, selectively shuts down and starts a spark ignition engine of the vehicle. A catalyst light off (CLO) control module initiates a first CLO event for a first engine startup during the period and, when a temperature of a catalyst that receives exhaust output by the engine is less than a predetermined temperature, selectively initiates a second CLO event for a second engine startup during the period. A fuel control module richens fueling of the engine during the first and second CLO events of the period. A spark control module retards spark timing of the engine during the first and second CLO events of the period.

An engine control unit (400) for a full hybrid engine (100, 101) is provided. The full hybrid engine (100, 101) comprises an internal combustion engine (110) and an electric motor (120). The internal combustion engine (110) is coupled to the drivetrain via a clutch (130). The engine control unit (400) is configured to operate the internal combustion engine (110) in a lean-burn mode, to determine a current load level of the full hybrid engine (100, 101), and to compare the current load level to a lean-burn load threshold (210). The lean-burn load threshold (210) defines a load level below which stable operation of the internal combustion engine (110) in the lean-burn mode is impossible and/or undesirable. If the current load level of the full hybrid engine (100, 101) is below the lean-burn load threshold (210), the internal combustion engine (110) is decoupled from the drivetrain and the full hybrid engine (100, 101) is operated in an electric mode.

A vehicle control device includes: a change gear ratio changing circuit configured to execute an up-shift of a change gear ratio in an automatic transmission; a change gear ratio determination circuit configured to determine whether or not an up-shift condition is satisfied based on a change gear diagrammatic view; a combustion mode determination circuit configured to determine whether or not a switching condition for switching from a predetermined combustion mode, in which an air-fuel ratio of the engine is an air-fuel ratio on a rich side than a lean air-fuel ratio, to a supercharged lean combustion mode, in which the air-fuel ratio of an engine is made to the lean air-fuel ratio while executing supercharging by a supercharger, is satisfied; and a change regulating circuit configured to regulate the change gear ratio changing circuit to execute the up-shift at the time both conditions are satisfied.

Systems and methods for improving operation of a hybrid vehicle are presented. In one example, driveline oscillations are reduced during engine air-fuel ratio modulation. The driveline oscillations may be reduced via adjusting torque of a motor.

An oxygen sensor diagnosis control system of a hybrid electric vehicle is provided. The system of a hybrid electric vehicle eliminates an uncertainty of the number of diagnoses of an oxygen sensor and restrains diagnoses of the oxygen sensor in a hybrid electric vehicle. The system of a hybrid electric vehicle includes a hybrid controller operates a vehicle, and determines conversion of an oxygen sensor diagnosis mode based on a result obtained by calculating an oxygen sensor diagnosis index. Additionally, the controller determines whether a condition for diagnosing an oxygen sensor is satisfied when the oxygen sensor diagnosis index decreases to initiate a diagnosis inducing mode or a compulsory diagnosis mode.

A hybrid vehicle has an engine (E) that is capable of changing a combustion mode between a stoichiometric combustion mode and a lean combustion mode and a motor/generator (MG) that is capable of performing torque assist by a power running operation and torque absorption by a regenerative operation. As a boundary between a stoichiometric combustion operating region and a lean combustion operating region, a second boundary (L2) at a torque decrease has a hysteresis at a low torque side with respect to a first boundary (L1) at a torque increase. Upon shift from the stoichiometric combustion operating region to the lean combustion operating region, for delay in increase of an intake-air quantity, decrease in fuel and the torque assist by the motor/generator (MG) are carried out, and an exhaust air-fuel ratio is changed stepwise.

A vehicle control apparatus for a vehicle includes a catalyst deterioration diagnosing unit, an engine controlling unit, and a diagnosis start determining unit. The catalyst deterioration diagnosing unit executes a deterioration diagnosis of a catalyst included in an exhaust system of an engine provided in the vehicle. The engine controlling unit controls an air-fuel ratio of the engine to a lean side and thereafter to a rich side during the deterioration diagnosis of the catalyst. The diagnosis start determining unit prohibits the deterioration diagnosis of the catalyst from being executed when a deceleration rate upon deceleration of the vehicle is high, and permits the deterioration diagnosis of the catalyst to be executed when the deceleration rate upon deceleration of the vehicle is low.

A method of reducing cold start emissions in a series mode hybrid electric vehicle, including an internal combustion engine with an exhaust duct having a catalyst and a downstream oxygen sensor, an output of the combustion engine being connected to an electric generator with a power output of at least 10 kW that is connected to an electric motor which is coupled to a drive shaft of two or more wheels. The method includes detecting a cold start condition, injecting fuel into the engine such that combustion at a lambda value, λ, is achieved for which λ>1, running the engine at a speed of 1000 rpm or higher, determining if the efficiency of the catalyst reaches a first level, setting λ to about 1 after the predetermined efficiency level of the catalyst has been reached, and reducing the speed to working conditions when the catalyst efficiency reaches a second level.

A controller for a vehicle is provided. An air supply passage is connected to a portion upstream of a filter in an exhaust passage. An air supplying process supplies air to the filter through an air supply passage by driving an air pump. An oxygen supplying process supplies oxygen to the filter through the exhaust passage, the oxygen having been passed through a combustion chamber of an internal combustion engine. A reducing process sets an air supply amount per unit time in the air supplying process obtained when the oxygen supplying process and the air supplying process are simultaneously executed to be lower than the air supply amount per unit time in the air supplying process obtained when the oxygen supplying process and the air supplying process are not simultaneously executed.

Vehicle designers are largely walking away from internal-combustion engines to battery and electric motors. Until infrastructure is developed to support total electrification, hybrid-electric vehicles (HEVs) which include both an internal combustion engine and an electric machine are a step toward electrification and higher system fuel efficiency while retaining the expected vehicle range. To obtain even higher system fuel efficiency combustion modes that provide higher efficiency than spark-ignition (SI) operation can be used in HEVs. A problem with such combustion modes is that they cannot be used over as wide an operating range as SI operation and transitions among modes is slow and cumbersome. By having the ICE installed into a HEV be a multi-combustion mode engine and having the EM to coordinate mode switches to be smooth, the high fuel-efficiency of alternative combustion modes can be exploited while providing smooth operation expected by vehicle users.