Fault tolerant control system for linear combustion engine

This paper presents a fault tolerant control system for a linear combustion engine (LCE). A three-level control system has been proposed and developed for the LCE control. The system consists of four control sub-systems that are spread out into particular levels as a function of their sample time. The low level of the LCE control system is represented by movement control. It determines requested contribution of the force supplied by the linear motor-generator to achieve the requested compression ratio for a given fuel quantity and spark position. The middle level consists of fuel and spark position control. The spark position control minimizes differences between desired and achieved compression ratio for each stroke of the engine cycle. The fuel control then follows spark advance demand by the setting of appropriate fuel rate. Finally, the top level is represented by a throttle control. The throttle control handles amount of inducted air into the cylinders to achieve the requested air/fuel ratio. The proposed control system is able to govern the LCE in all its feasible operating range and is capable to explore its benefits.