System for estimating engine exhaust pressure

A method of estimating engine exhaust pressure, comprising the steps of:

• determining an intake air pressure corresponding to pressure of air supplied by a turbocharger compressor to an intake manifold of the engine;
• determining a turbocharger control command corresponding to a command for controlling either of a swallowing capacity and a swallowing efficiency of a turbocharger turbine coupled to said compressor;
• and
• estimating engine exhaust pressure as a function of said intake air pressure and said turbocharger control command.

System for estimating engine exhaust pressure, comprising:

• a turbocharger having a compressor fluidly coupled to an intake manifold of the engine via a first conduit, and a turbine fluidly coupled to an exhaust manifold of the engine via a second conduit;
• a pressure sensor producing a pressure signal indicative of air pressure within said first conduit;
• a variable geometry turbocharger actuator responsive to a control command to control a flow geometry of said turbine;
• and
• a control computer estimating engine exhaust pressure within said second conduit as a function of said pressure signal and said control command.

System for estimating engine exhaust pressure, comprising:

• a turbocharger having a compressor fluidly coupled to an intake manifold of the engine via a first conduit, and a turbine fluidly coupled to an exhaust manifold of the engine via a second conduit;
• a pressure sensor producing a pressure signal indicative of air pressure within said first conduit;
• an exhaust throttle receiving engine exhaust therethrough;
• an actuator responsive to a control command to control a flow rate of engine exhaust through said exhaust throttle and thereby through said turbine;
• and
• a control computer estimating engine exhaust pressure within said second conduit as a function of said pressure signal and said control command.

System for estimating engine exhaust pressure, comprising:

• a turbocharger having a compressor fluidly coupled to an intake manifold of the engine via a first conduit, and a turbine fluidly coupled to an exhaust manifold of the engine via a second conduit;
• a pressure sensor producing a pressure signal indicative of air pressure within said first conduit;
• a wastegate valve having an inlet fluidly coupled to said second conduit and an outlet fluidly coupled to ambient;
• an actuator responsive to a control command control said wastegate to selectively divert engine exhaust away from said turbine;
• and
• a control computer estimating engine exhaust pressure within said second conduit as a function of said pressure signal and said control command.