Abstract: A valve actuation system for an internal combustion engine The valve actuation system (S) for an internal combustion engine comprises: ?a rocker (6) pivotably mounted around a pivot axis (A6), comprising: ?a driven end portion (62) for cooperating with a rotating cam including a main bump and at least one smaller auxiliary bump; ?an actuating end portion (63) including a piston (8) for opening at least one valve of the engine following the cooperation of the driven end portion (62) with a bump of the cam, the piston (8) being slidably mounted relative to the rocker (6) between a extended position allowing said piston (8) to open said valve when the driven end portion (62) contacts the auxiliary bump, and a retracted position preventing said piston (8) to open said valve when the driven end portion (62) contacts the auxiliary bump; ?a fluid circuit for causing the piston (8) to move from its retracted position to its extended position; ?a reset circuit comprising a reset valve (99) rotatably mounted relative t

Abstract: A valve actuation system for an internal combustion engine The valve actuation system (S) for an internal combustion engine comprises: ·a rocker (6) pivotably mounted around a pivot axis (A6), comprising: ·a driven end portion (62) for cooperating with a rotating cam including a main bump and at least one smaller auxiliary bump; ·an actuating end portion (63) including a piston (8) for opening at least one valve of the engine following the cooperation of the driven end portion (62) with a bump of the cam, the piston (8) being slidably mounted relative to the rocker (6) between a extended position allowing said piston (8) to open said valve when the driven end portion (62) contacts the auxiliary bump, and a retracted position preventing said piston (8) to open said valve when the driven end portion (62) contacts the auxiliary bump; ·a fluid circuit for causing the piston (8) to move from its retracted position to its extended position; ·a reset circuit comprising a reset valve (99) rotatably mounted relative t

Abstract: A method of providing a model which provides air/fuel ratio at a point of an air/fuel sensor located in an exhaust system of an engine includes a) providing a first model which provides a first air/fuel ratio which is outlet from an exhaust manifold of the engine; b) measuring or estimating volumetric flow through the exhaust; c) applying a transfer function to the first air/fuel ratio to provide a model of the air/fuel ratio at the sensor. The transfer function includes a first order filter and is dependent on the volumetric flow. The transfer function has a time constant equivalent to a filter coefficient which is 1/time constant which is determined based on the flow rate.

Abstract: A method of providing a model which provides air/fuel ratio at a point of an air/fuel sensor located in an exhaust system of an engine includes a) providing a first model which provides a first air/fuel ratio which is outlet from an exhaust manifold of the engine; b) measuring or estimating volumetric flow through the exhaust; c) applying a transfer function to the first air/fuel ratio to provide a model of the air/fuel ratio at the sensor. The transfer function includes a first order filter and is dependent on the volumetric flow. The transfer function has a time constant equivalent to a filter coefficient which is 1/time constant which is determined based on the flow rate.