A method includes operating a spark ignition engine and flowing low pressure exhaust gas recirculation (EGR) from an exhaust to an inlet of the spark ignition engine. The method includes interpreting a parameter affecting an operation of the spark ignition engine, and determining a knock index value in response to the parameter. The method further includes reducing a likelihood of engine knock in response to the knock index value exceeding a knock threshold value.

A method includes operating a spark ignition engine and flowing low pressure exhaust gas recirculation (EGR) from an exhaust to an inlet of the spark ignition engine. The method includes interpreting a parameter affecting an operation of the spark ignition engine, and determining a knock index value in response to the parameter. The method further includes reducing a likelihood of engine knock in response to the knock index value exceeding a knock threshold value.

An internal combustion engine is equipped with a downstream temperature sensor arranged in an intake passage, an upstream temperature sensor arranged in the intake passage upstream of the downstream temperature sensor, an EGR temperature sensor arranged in an EGR passage, and an airflow meter arranged in the intake passage. A control device corrects a temperature detected by each of the temperature sensors based on an amount of deviation of the temperature detected by that one of the temperature sensors upon activation of the control device after the lapse of a prescribed time or more since stoppage of the internal combustion engine from a reference temperature. Then, the control device calculates a flow rate of EGR gas based on the corrected temperature of that one of the temperature sensors and a flow rate of intake air, and detects the clogging of the EGR passage based on the flow rate.

Methods and systems are provided for an exhaust-gas arrangement. In one example, a system may include a barrier dividing an intake passage into first and second portions to mitigate exhaust-gas recirculate mixing with charge air upstream of a compressor.

The present disclosure relates to a control apparatus and method for preventing boiling of an exhaust gas recirculation (EGR) cooler, the apparatus including a coolant inflow passage configured to allow coolant to flow into the EGR cooler, a coolant discharge passage having one end connected to the EGR cooler to allow the coolant cooling EGR gas to be discharged, an EGR valve positioned adjacent to the EGR cooler to control a flow rate of gas flowing into the engine, and a control unit configured to determine the flow rate of the coolant flowing into the EGR cooler according to a number of revolutions of the engine, determine an opening amount of the EGR valve, determine whether the EGR cooler is in a micro-boiling condition, and perform compensation to perform boiling prevention when the EGR cooler satisfies the micro-boiling condition.

An exhaust gas recirculation valve warming device includes an exhaust throttle arranged in an exhaust passage, an exhaust gas recirculation passage that extends from a portion of the exhaust passage that is upstream of the exhaust throttle and is connected to an intake passage, an exhaust gas recirculation valve arranged in the exhaust gas recirculation passage, and a branch passage that extends from a portion of the exhaust gas recirculation passage that is upstream of the exhaust gas recirculation valve in a direction in which exhaust gas flows, in which the branch passage is connected to a portion of the exhaust passage that is downstream of the exhaust throttle. The exhaust gas recirculation valve includes a valve passage that forms part of the exhaust gas recirculation passage and a warming passage that forms part of the branch passage.

A control system includes an electronic control unit including a feedback controller and a reference governor. The feedback controller is configured to determine a value of control input such that a value of control output approximates a target value. The reference governor is configured to calculate, with a prediction model, a predicted maximum value of an overshoot amount of the control output that overshoots from the target value. The prediction model is derived assuming that an n-th delay (n is a natural number) occurs in a response of the control output. The reference governor is configured to calculate the target value by correcting the provisional target value of the control output based on the predicted maximum value so as to increase a degree of satisfaction of a constraint condition with regard to the control output.

A control method of a vehicle having an exhaust gas recirculation (EGR) system includes efficiently controlling a temperature of recirculated exhaust gas and, even when the temperature of recirculated exhaust gas excessively increases, damage to hardware, such as an intake manifold or parts of the exhaust gas recirculation system can be prevented. The control method includes: detecting the temperature of exhaust gas recirculated to an engine intake system by the EGR system; entering into a protection mode so as to control the temperature of the recirculated exhaust gas; determining a correction value such that the controller controls the temperature of the recirculated exhaust gas; and correcting an engine control value by using the determined correction value and controlling an engine according to the corrected engine control value.

A system includes a temperature sensor configured to measure a temperature of exhaust gas produced by an engine, and a boost error module configured to determine a boost error of the engine. The system further includes a combustion control module configured to select at least one of a target boost pressure of the engine, a target EGR flow rate of the engine, and a target fuel injection parameter of the engine from a first set of target values when the exhaust gas temperature is less than a predetermined temperature and the boost error is less than a predetermined value, and to select the at least one of the target boost pressure, the target EGR flow rate, and the target fuel injection parameter from a second set of target values when the exhaust gas temperature is less than the predetermined temperature and the boost error is greater than the predetermined value.

An exhaust system for an internal combustion engine includes an EGR cooler having a heat exchange surface exposed to a flow of exhaust, and a second heat exchange surface. A coolant heat exchanger is fluidly connected to a coolant outlet of the EGR cooler and a coolant pump is fluidly connected to a coolant inlet of the EGR cooler. A condensate collector collects condensate from exhaust, and a condensate pump pumps condensate from the condensate collector to a sprayer to spray condensate onto the second heat exchange surface to vaporize the condensate for discharging out through an outgoing exhaust conduit of the exhaust system.