A control method for use in an engine braking maneuver for an internal combustion engine (ICE) system including a turbocharger having a variable-nozzle turbine (VNT), the ICE system further including an exhaust flap disposed in an exhaust line downstream of the variable-nozzle turbine. Prior to closing the exhaust flap, the VNT vanes are first parked in a fully open position. After the exhaust flap closes, the vanes are pivoted to a fully closed position and are continuously urged against a hard stop as long as the exhaust flap is closed. Termination of engine braking entails pivoting the vanes back to the fully open position, whereupon the exhaust flap is opened.

A regenerative torque control unit is configured to reduce a regenerative torque and increase a rising gradient of the regenerative torque at a start of regeneration when a road surface friction coefficient acquired by a road surface friction coefficient acquisition unit is low as compared to when the road surface friction coefficient is high. Thus, it is possible to suppress occurrence of a slip on a low μ road, and it is less likely to provide a feeling of strangeness from a change between a low μ road and a high μ road.

A regenerative torque control unit is configured to reduce a regenerative torque and increase a rising gradient of the regenerative torque at a start of regeneration when a road surface friction coefficient acquired by a road surface friction coefficient acquisition unit is low as compared to when the road surface friction coefficient is high. Thus, it is possible to suppress occurrence of a slip on a low μ road, and it is less likely to provide a feeling of strangeness from a change between a low μ road and a high μ road.

Methods and systems are provided for controlling an EGR valve and VGT vanes during engine braking. In one example, a method may include during an engine braking event in an engine, coordinating adjustments of both of a cross-sectional area of an inlet of a turbine and an opening of a valve of an exhaust gas recirculation (EGR) system to achieve a desired braking power and to maintain an exhaust system temperature above a threshold temperature during the engine braking event.

A method of maintaining a temperature of an aftertreatment system of a vehicle, the method including: operating, by a controller, a retarder reducing driving force of a propeller shaft of the vehicle in response to a retarder operation request signal; operating, by the controller, a jake brake device which discharges a fuel-air mixture compressed in an explosion stroke of the engine to an exhaust pipe and decreases revolutions per minute (RPM) of the engine or an exhaust brake device which blocks a discharge of the exhaust gas of the engine to a rear end of the exhaust pipe and decreases the RPM of the engine, in order to remove the output error value; and controlling, by the controller, the engine so that an amount of exhaust gas introduced into the aftertreatment system is decreased.

In an exhaust gas flow control system for an internal combustion engine, with a first exhaust gas duct and a second exhaust gas duct, through both of which exhaust gas from the internal combustion engine can flow to a turbine of an exhaust gas turbocharger with an exhaust gas recirculation line branching off the first exhaust gas duct, a shut-off element is provided which is adjustable between a closed position in which exhaust gas is prevented from flowing into the exhaust gas recirculation line and directing it via a communication passage into the second exhaust gas duct, and at least a first open position in which exhaust gas is directed out of the first exhaust gas duct into the exhaust gas recirculation line while blocking the communication passage between the first and second exhaust gas ducts and a second open position wherein both the first and the second exhaust gas ducts as well as the communication passage between the two ducts is open but the recirculation line is closed.

In an exhaust gas flow control system for an internal combustion engine, with a first exhaust gas duct and a second exhaust gas duct, through both of which exhaust gas from the internal combustion engine can flow to a turbine of an exhaust gas turbocharger with an exhaust gas recirculation line branching off the first exhaust gas duct, a shut-off element is provided which is adjustable between a closed position in which exhaust gas is prevented from flowing into the exhaust gas recirculation line and directing it via a communication passage into the second exhaust gas duct, and at least a first open position in which exhaust gas is directed out of the first exhaust gas duct into the exhaust gas recirculation line while blocking the communication passage between the first and second exhaust gas ducts and a second open position wherein both the first and the second exhaust gas ducts as well as the communication passage between the two ducts is open but the recirculation line is closed.

A method of exhaust braking a vehicle includes determining a wheel slip ratio based on input from vehicle sensors. Based on a determination that the wheel slip ratio is unstable, the method further includes sending a command to reduce exhaust braking. Based on a determination that exhaust braking is reduced, the method further includes determining a change in wheel slip ratio over time based on input from the vehicle sensors. Based on a determination that the change in wheel slip ratio over time is stabilizing, the method further includes sending a command to increase exhaust braking.

A method of exhaust braking a vehicle includes determining a wheel slip ratio based on input from vehicle sensors. Based on a determination that the wheel slip ratio is unstable, the method further includes sending a command to reduce exhaust braking. Based on a determination that exhaust braking is reduced, the method further includes determining a change in wheel slip ratio over time based on input from the vehicle sensors. Based on a determination that the change in wheel slip ratio over time is stabilizing, the method further includes sending a command to increase exhaust braking.

A compression-release engine brake system for effectuating a compression-release engine braking operation of an internal combustion engine. The compression-release system includes a lost motion exhaust rocker assembly including an exhaust rocker arm, an actuation device including an actuation piston and an actuation cavity, and a reset device including a reset check valve and a slider-piston. Hydraulic fluid in the exhaust rocker arm is locked in the actuation cavity when the reset check valve is in the closed position, and flows through the reset check valve when the reset check valve is in the open position. The slider-piston is associated with the reset check valve so that in an extended position of the slider-piston the reset check valve is free to move toward the closed position, and in a retracted position of the slider-piston the reset check valve is moved to the open position thereof by the slider-piston.