Abnormal Combustions in Internal Combustion Engines: Review on the Latest Patents Eliminating Knock Conditions

Abnormal combustions occurred since the invention of internal combustion engines. Knock was intensively studied by researchers and engineers since this date. First patents were taken out on fuel quality (defined by octane index nowadays). After patents on sensors itself, engine settings were piloted to eliminate knock conditions in 1979-1980. Many companies followed this pathway. Latest patents on knock are reviewed. A highlight on a preventive protection (open loop control) is proposed for stationary engines fuelled natural gas, see Le Corre et al. [1]: this patent is a new concept in rupture with curative protection (closed loop control). Preventive protection is based on a gas quality sensor.