A hybrid vehicle includes an engine with cylinders generating driving power and a turbocharger having a turbine in an exhaust line, and a compressor which rotates with the turbine and compresses intake gas. An electric supercharger is disposed in the intake line upstream from the compressor, a catalytic converter is disposed in the exhaust line downstream from the turbine. A post processing bypass line connects the exhaust line at a downstream portion of the catalytic converter and the intake line at a downstream portion of the electric supercharger. A low pressure EGR device includes a low pressure EGR line branching off from the exhaust line and merging into the intake line and a low pressure EGR cooler disposed therein. A high pressure EGR device includes a high pressure EGR line branching off from an exhaust system and merging into an intake system, and a high pressure EGR cooler disposed therein.

Methods and systems are provided for determining whether an exhaust gas recirculation (EGR) valve is degraded and being held open in a vehicle system. In one example, a method may include, in response to an engine pull-down request, closing a throttle coupled to an intake manifold of the engine, closing the EGR valve, propelling the vehicle via an electric motor, and checking operation of the EGR valve based on both intake manifold pressure and exhaust pressure. For example, if the intake manifold pressure does not decrease by a threshold amount relative to the exhaust pressure, EGR valve degradation may be indicated.

Power system optimization is disclosed. An example power system described herein may include an engine control module that receives measurements associated with sensors, identifies settings associated with control devices, determines that a first set of parameters associated with the one or more control devices is to be optimized according to a first optimization process, iteratively performs the first optimization process until the first set of parameters are optimized, determines that a second set of parameters associated with the one or more control devices are to be optimized according to a second optimization process, iteratively performs the second optimization process until the second set of parameters are optimized, and, after the second set of parameters are optimized according to the second optimization process, configures one of the control devices to operate using an optimized value for the control device determined using the second optimization process.

Methods and systems are provided for on-board diagnostics of an exhaust gas recirculation (EGR) system of an engine coupled to a hybrid vehicle. In one example, a method may include, upon receiving an engine shut-down request, prior to engine spin-down, rotating the engine at an idling speed via an electric motor and carrying out diagnostics of the EGR system. EGR diagnostics may include estimating a ratio of accumulated difference between a measured EGR flow and an EGR limit to accumulated intake air flow, over a duration of time, and indicating EGR system degradation in response to the ratio being higher than a threshold.

A system and method for providing torque-assist to a rotary shaft of an internal combustion engine control an electric machine in response to operation of an exhaust gas recirculation (EGR) valve to assist the rotation of the rotary shaft. The system and method facilitate periodic operation of the EGR valve to purge condensation without objectionable torque reduction when the engine is operating near full load.

An engine includes an EGR device and a water-cooled heat exchanger. The water-cooled heat exchanger is provided on a downstream side of an EGR gas-introduction portion of an intake passage into which EGR gas is to be introduced and exchanges heat with gas flowing in the intake passage. A control device is programmed to execute condensed water-suppression control that supplies coolant having a temperature higher than the temperature of the gas heat-exchanged in the water-cooled heat exchanger to the water-cooled heat exchanger while a hybrid vehicle is traveling in a state in which the engine is stopped.

Methods and systems are provided for expediting EGR purging in a hybrid vehicle during transient operations, such as tip-out to lower load conditions. In response to decreasing engine torque demand, engine fueling is disabled and a motor is used to spin the engine unfueled until a desired LP-EGR rate is achieved. Alternatively, engine operation is maintained with EGR disabled until the desired LP-EGR rate is achieved, and the excess engine torque generated is stored in a system battery.

Methods of operating internal combustion engines are provided. A controller detects a coasting event while an associated vehicle is in motion. In response to the coasting event, the controller directs at least a portion of an exhaust gas output by an exhaust system of an internal combustion engine of the vehicle into an intake system of the internal combustion engine.

A hybrid vehicle including one or more in-wheel motors, a power electronics supplying power to the one or more in-wheel motors, and a Rankine cycle system is described. The Rankine cycle system includes a pump driving a working fluid through the Rankine cycle system, a heat exchanger receiving the working fluid from to the pump and connected to the power electronics to cool the power electronics, an evaporator heating the working fluid received from the heat exchanger utilizing heat from an exhaust gas from an engine, an expander receiving the working fluid from the evaporator, and a radiator cooling the working fluid received from the expander.

A hybrid vehicle including one or more in-wheel motors, a power electronics supplying power to the one or more in-wheel motors, and a Rankine cycle system is described. The Rankine cycle system includes a pump driving a working fluid, a first three-way valve having an input, a first output, and a second output. The Rankine cycle system also includes, a second three-way valve having a first input, a second input, and an output, an evaporator receiving the working fluid from the output of the second three-way valve and heating the working fluid utilizing heat from an exhaust gas from an engine, an expander receiving the working fluid from the evaporator, and a radiator cooling the working fluid received from the expander.