Advantages of using FPGA Components for innovative Control Systems Implemented on Automotive Engines

Within the last few years, new reliable and low-cost solutions faced the market of in-cylinder pressure measurement sensors. These are going to provide extended potential and flexibility in engine control and diagnosis applications, being able to realize a better monitoring of the combustion phase. Spark advance, pressure peak angular position control, knock and misfire detection are some of the task that could be easily carried out with such sensors. In order to develop these control and diagnosis algorithms, the rapid prototyping system already present in the engine test cell has been upgraded with the addition of an FPGA (Field Programmable Gate Array) board, that is particularly suited to manage tasks based on angular windowing signal sampling. In the paper it is first highlighted how the basic tasks of crankshaft angular position monitoring and cycle synchronization can be simply realized by means the FPGA board that, in parallel, can also perform signal windowing and data processing, deterministically. Then, as an applicative example, it is presented the calibration procedure for misfire detection algorithm, taking advantage of the FPGA board. Using this board it is possible to obtain in real time the map of the optimal values in terms of angular window width and positioning within the cycle, which is usually obtained by an off-line data processing. The task of correcting the angular velocity irregularities, due to the engine torsional dynamic, is also carried out by the FPGA. The system has been developed for a four cylinder in line engine.