摘要:
An improved engine fuel control method which divides the liquid fuel into a plurality of components characterized by relative volatility. The mass and evaporation characteristics of each fuel volatility component are determined separately within the fuel puddle, with the overall puddle behavior being characterized as the sum of the behaviors of the individual volatility components. The method involves determining, for each engine cycle, the mass of fuel that will evaporate from the puddle, the mass of vapor required to achieve the desired air/fuel ratio for the engine cylinder, the fraction of the injected fuel that will vaporize, and the mass of fuel that needs to be injected in order to achieve the desired air/fuel ratio in the cylinder. Finally, the puddle mass is updated for the next intake event. In a preferred implementation, the liquid fuel is divided into first, second and third components respectively characterized by high, medium and low volatility, and the volatility is inferred based on a measure of the fired-to-motored cylinder pressure ratio.
摘要:
An improved engine control in which the fuel volatility is detected based on a measure of the fired-to-motored cylinder pressure ratio, and used to trim fuel and spark timing controls during engine warm-up and transient fueling periods. In a first embodiment, a matrix of empirically determined pressure ratio values that occur with fuels of differing volatility is stored and compared to the measured pressure ratio to identify the closest stored pressure ratio, and the fuel volatility is determined based on the fuel volatility associated with the identified pressure ratio. In a second embodiment, the actual fuel vapor-to-air equivalence ratio is computed based on the measured pressure ratio, and the fuel volatility is determined based on the deviation between the actual ratio and the desired fuel vapor-to-air equivalence ratio.
摘要:
A method for diagnosing combustion within an engine includes monitoring pressure cylinder pressure and generating a measured combustion phasing value for the cylinder at a predetermined metric selected to index the combustion cycle. The measured combustion phasing value is calculated through a Fast Fourier Transform and compared to an expected combustion phasing value.
摘要:
A method for controlling operation of an internal combustion engine operating lean of stoichiometry is described. The engine is a multi-cylinder direct-injection engine operative in repetitive cycles each cycle including intake, compression, expansion, and exhaust strokes. The method includes adapting a plurality of fuel injectors to directly inject a first and a second mass of fuel into the cylinders during each cycle. Pressure sensing devices monitor in-cylinder pressure in the cylinders during ongoing operation. The first mass of fuel is injected into one of the cylinders. A cylinder pressure ratio is determined in the cylinder subsequent to injecting the first mass of fuel based upon the monitored pressure. The first mass of fuel injected is adjusted during a subsequent cycle based upon the cylinder pressure ratio.
摘要:
An internal combustion engine is configured with combustion chamber pressure sensing and exhaust gas recirculation apparatus. Exhaust gas recirculation control includes closed-loop controlling exhaust gas recirculation apparatus in accordance with a predetermined control target. Adjustments to the control target are made based on combustion chamber pressure information.
摘要:
A method for adjusting fuel injection quantities in an internal combustion engine configured to operate multi-pulse fuel injections in a cylinder of the engine includes monitoring in-cylinder pressure, determining a burnt fuel mass for main combustion based upon the in-cylinder pressure, determining a burnt fuel mass for post combustion based upon the in-cylinder pressure, determining a main fuel quantity offset based upon the burnt fuel mass for main combustion, determining a post fuel quantity offset based upon the burnt fuel mass for post combustion, and controlling fuel injections into the cylinder based upon the main fuel quantity offset and the post fuel quantity offset.
摘要:
A method for distinguishing between combustion issues and sensor faults within an engine includes monitoring pressure sensor data from a cylinder within the engine, monitoring engine data describing combustion health from a source other than a pressure sensor, analyzing the pressure sensor data to diagnose an anomalous combustion event, comparing the anomalous combustion event to analysis of the engine data, and indicating a pressure sensor fault warning if the comparison diagnoses a pressure sensor fault.
摘要:
The invention comprises a method to determine a position of a piston in a cylinder of an engine during ongoing operation, comprising adapting pressure sensing devices to monitor in-cylinder pressure, and, operating the engine. In-cylinder pressure is monitored along with a corresponding engine crank position. The engine is operated in a motoring mode and in a cylinder firing mode, and a plurality of instantaneous in-cylinder pressure states are determined during compression and expansion strokes. Pressure ratios are determined based upon the instantaneous in-cylinder pressure states, which are used to determine an engine crank angle and compression ratio error and, adjust the monitored engine crank position based upon the crank angle error and readjust engine operation according to these sensed errors.
摘要:
A method for distinguishing between combustion issues and sensor faults within an engine includes monitoring pressure sensor data from a cylinder within the engine, monitoring engine data describing combustion health from a source other than a pressure sensor, analyzing the pressure sensor data to diagnose an anomalous combustion event, comparing the anomalous combustion event to analysis of the engine data, and indicating a pressure sensor fault warning if the comparison diagnoses a pressure sensor fault.
摘要:
An engine control system comprises a fuel diagnostic module and a fuel control module. The fuel diagnostic module determines a pressure-ratio difference average (PRDA) based on a pressure in at least one cylinder and determines a cetane number (CN) of a fuel based on the PRDA. The fuel control module actuates fuel injectors based on the CN.