Methods and systems are provided for leveraging the pressure dependency of an oxygen sensor for estimating an engine ambient pressure. An intake or exhaust oxygen sensor is used for ambient pressure estimation by applying a reference voltage to the sensor while the engine is being pulled-down in a hybrid vehicle, and correcting an output of the sensor for dilution effects due to ambient humidity. The estimated ambient pressure is used to correct or confirm pressure estimated by other sources, such as other pressure sensors or a pressure model, as well as to tune the performance of the engine.

A system for correcting engine torque includes: a torque correction value generator generating a torque correction value for correcting output torque of an engine; a torque correction determination unit determining applicability of the generated torque correction value; and a torque applying unit determining a final engine output torque by applying the generated torque correction value to the output torque of the engine based on the determined applicability of the generated torque correction value.

A vessel propulsion apparatus includes an engine that rotates a crankshaft in a forward rotation direction, a rotation speed detector that detects a rotation speed of the crankshaft, a propeller shaft coupled to a propeller, a shift switch that switches between a shift-in state and a neutral state, a shift state detector, an intake passage, a throttle valve, an intake pressure sensor, and a controller. The controller determines that the crankshaft is reversely rotating by an external force input from the propeller shaft when a predetermined reverse rotation recording condition is satisfied, and stores reverse rotation information. The reverse rotation recording condition includes a condition that an intake pressure after the shift switch switches from a neutral state to a shift-in state while the crankshaft rotates in the forward rotation direction is larger than a value equal to or higher than atmospheric pressure.

Methods and systems are provided for determining barometric pressure. In one example, an onboard vacuum pump is utilized to draw a vacuum at a constant flow rate across a reference orifice, and the resulting vacuum level is converted to a barometric pressure. In this way, other sensors for determining barometric pressure in a vehicle may be rationalized without the use of engine operation, and in an example where the other sensors for determining barometric pressure are not functioning as desired, barometric pressure as inferred from the onboard pump may be utilized to adjust engine operation.

Methods and systems are provided for determining barometric pressure. In one example, an onboard vacuum pump is utilized to draw a vacuum at a constant flow rate across a reference orifice, and the resulting vacuum level is converted to a barometric pressure. In this way, other sensors for determining barometric pressure in a vehicle may be rationalized without the use of engine operation, and in an example where the other sensors for determining barometric pressure are not functioning as desired, barometric pressure as inferred from the onboard pump may be utilized to adjust engine operation.

Methods and systems are provided for leveraging the pressure dependency of an oxygen sensor for estimating an engine ambient pressure. An intake or exhaust oxygen sensor is used for ambient pressure estimation by applying a reference voltage to the sensor while the engine is being pulled-down in a hybrid vehicle, and correcting an output of the sensor for dilution effects due to ambient humidity. The estimated ambient pressure is used to correct or confirm pressure estimated by other sources, such as other pressure sensors or a pressure model, as well as to tune the performance of the engine.

A compression ignition engine, commercial vehicle comprising such an engine, and a method for improving starting behaviour of such an engine. The engine is operable in a normal mode or a cold start mode. In the normal mode, a fuel injection system is controlled to inject a main fuel injection in a single pulse. In the cold start mode, the main fuel injection is split into a first split main and a second split main. The fuel injection system is controlled to inject the first and second split main in two distinct pulses, wherein the first split main is injected at a delayed timing for initiating a diffusion combustion phase in the pressurized combustion chamber, and wherein the second split main is injected during the diffusion combustion phase into the already combusting air-fuel mix.

A method for determining atmospheric pressure AMP during operation in a partial load state of a turbocharged engine (1) including an air intake line (2) incorporating a butterfly valve (16), and an exhaust line (3) including a bypass duct (20) incorporating an exhaust gas discharge valve (21), the method includes measuring the air pressure PUT upstream of the butterfly valve (16), and for a given speed of N rpm of the engine (1), when the boost pressure PUT corresponds substantially to the natural boost pressure, determining the atmospheric pressure AMP=AMP(0)+PUTPUT(0), wherein AMP(0) is the atmospheric pressure previously measured, and PUT(0) is boost pressure naturally obtained for the speed N rpm of the engine (1) for the atmospheric pressure AMP(0).

A vessel propulsion apparatus includes an engine that rotates a crankshaft in a forward rotation direction, a rotation speed detector that detects a rotation speed of the crankshaft, a propeller shaft coupled to a propeller, a shift switch that switches between a shift-in state and a neutral state, a shift state detector, an intake passage, a throttle valve, an intake pressure sensor, and a controller. The controller determines that the crankshaft is reversely rotating by an external force input from the propeller shaft when a predetermined reverse rotation recording condition is satisfied, and stores reverse rotation information. The reverse rotation recording condition includes a condition that an intake pressure after the shift switch switches from a neutral state to a shift-in state while the crankshaft rotates in the forward rotation direction is larger than a value equal to or higher than atmospheric pressure.

In a control device of an internal combustion engine, an atmospheric pressure estimation portion includes an effective opening area calculation portion calculating an effective opening area corresponding to a throttle opening, a throttle opening learning value calculation portion calculating a learning value in a relation of the effective opening area and the throttle opening, an error variation calculation portion calculating an error variation from an error from the corrected learning value, a variation range determination portion determining whether the error variation is within a predetermined range, an atmospheric pressure estimated value update portion updating an atmospheric pressure estimated value, and a target throttle opening calculation portion calculating a target throttle opening using the updated atmospheric pressure estimated value. The throttle opening is controlled to be the target throttle opening. An exact atmospheric pressure can be thus estimated even in the presence of a variation in throttle machine difference.