Accelerometer-Based Feedback for the Control of an HCCI Engine

79703S Homogeneous Charge Compression Ignition (HCCI) engines have been shown to reduce NOx, fuel consumption, and CO2 production. However, control of this technology outside of the laboratory is difficult to achieve cost-effectively. In order to control combustion processes, it will be necessary to develop small, cost-effective, real-time broadband sensors to monitor the HCCI proces and provide rapid feedback. This project will use low-cost externally-mounted accelerometers on the engine to provide feedback that will allow the cylinder pressure trace to be reconstructed using advanced signal processing techniques. From the reconstructed pressure trace, information regarding the start of combustion and the location of peak pressure can be determined, which can then be passed to the Engine Control Computer to make adjustments for the next cycle, allowing closed loop control of the HCCI engine. Phase I will: (1) generate a large population of HCCI pressure traces using computer simulation, in order to optimize the signal processing techniques; (2) equip an existing dynamometer-mounted V-8 spark-ignition engine with low-cost accelerometers and generate HCCI-like traces from a variety of operating conditions; and (3) identify combustion parameters. Commercial Applications and Other Benefits as described by the awardee: Commercial applications should include automotive engines (for cars, trucks, and buses) in the 50-250 kW range and stationary engine generating sets in the 100-2000kW range. Public benefits would include lower ambient pollutant levels in urban areas and lower fuel consumption. The Homogeneous Charge Compression Ignition engine also could be used to improve the fuel economy of hybrid vehicles.