Compression ignition engine control

An engine system, comprising:

• an engine controller;
• a compression ignition (CI) engine connected to the engine controller, the CI engine configured to receive engine control signals from the engine controller and to transmit current engine operating condition measurements to the engine controller, the CI engine having an engine block, the current engine operating condition measurements including angular position information;
• and
• a vibration sensor placed proximate to the engine block,
• wherein the engine controller comprises at least one processor configured to:
• receive a vibration signal from the vibration sensor;
• determine a non-combustion component of the vibration signal indicative of vibrations in the engine block not caused by combustion;
• determine a combustion component of the vibration signal based on the non-combustion component of the vibration signal and the vibration signal, wherein the combustion component of the vibration signal is indicative of vibrations in the engine block caused by combustion;
• determine an in-cylinder pressure based on the angular position information for a current cycle of the CI engine and on the combustion component of the vibration signal;
• and
• generate revised engine control signals for a next cycle of the CI engine based on the determined in-cylinder pressure.