System for detecting a leakage in an intake line of an internal combustion engine

Internal combustion engine (E), having

• an intake line (IL) and an exhaust line (EL),
• means for measuring or for estimating a quantity of fresh air ({dot over (m)}HFM) entering the engine (E),
• means for measuring or for estimating a quantity of fuel ({dot over (m)}FUEL) injected into the engine (E),
• measurement or estimation means (λ and/or NOx), on said exhaust line, adapted to provide a first value (λmeasured) of an air/fuel ratio introduced in the engine (E),
• the system comprising processing means (ECU) interfaced with said measurement or estimation means (HFM, IS, λ e/o NOx) and adapted to calculate a second value (λexp) of said air/fuel ratio, calculated on the basis of said measured or estimated quantities of fresh air ({dot over (m)}HFM) and fuel ({dot over (m)}FUEL) to calculate an error (λerr) between said first and second value of air/fuel ratio (λmeasured−λexp) and to detect a condition of leakage/failure if said error is outside a predefined interval [λerr−, λerr+] containing the value zero.

Vehicle or fixed apparatus, comprising an internal combustion engine having an intake line (IL) and an exhaust line (EL),

• means for measuring or for estimating a quantity of fresh air ({dot over (m)}HFM) entering the engine (E),
• means for measuring or for estimating a quantity of fuel ({dot over (m)}FUEL) injected into the engine (E),
• measurement or estimation means (λ and/or NOx), on said exhaust line, adapted to provide a first value (λmeasured) of an air/fuel ratio introduced in the engine (E),
• the system comprising processing means (ECU) interfaced with said measurement or estimation means (HFM, IS, λ e/o NOx) and adapted to calculate a second value (λexp) of said air/fuel ratio, calculated on the basis of said measured or estimated quantities of fresh air ({dot over (m)}HFM) and fuel ({dot over (m)}FUEL), to calculate an error (λerr) between said first and second value of air/fuel ratio (λmeasured−λexp) and to detect a condition of leakage/failure if said error is outside a predefined interval [λerr−, λerr+] containing the value zero.

Method for detecting a leakage in an intake line (IL) of an internal combustion engine comprising

• an intake line (IL) and an exhaust line (EL),
• means (HFM) for measuring or for estimating a quantity of fresh air ({dot over (m)}HFM) entering said intake line (IL),
• means for measuring or for estimating a quantity of fuel ({dot over (m)}FUEL) injected into the engine (E),
• measurement or estimation means (λ and/or NOx), on said exhaust line,
• the method comprising the steps of:
• calculation of a first value (λmeasured) of a air/fuel ratio introduced in the engine (E) through said measurement or estimation means (λ and/or NOx) on said exhaust line
• calculating a second value (λexp) of air/fuel ratio entering the engine on the basis of said measured or estimated quantities of fresh air ({dot over (m)}HFM) and fuel ({dot over (m)}FUEL) entering the engine and
• calculating an error (λerr) making the difference between said first value and said second value (λmeasured−λexp) and
• detecting a condition of leakage/failure if said error (λerr) is outside said predefined interval [λerr−, λerr+] containing the value zero.