System for estimating absolute boost pressure in a turbocharged internal combustion engine
First Claim
1. System for estimating absolute boost pressure in a turbocharged internal combustion engine, comprising:
- a turbocharger having a compressor defining a inlet and an outlet fluidly coupled via an intake conduit to an intake manifold of an internal combustion engine;
a pressure sensor producing a pressure signal indicative of pressure of air entering said compressor inlet;
a temperature sensor producing a temperature signal indicative of temperature of air entering said compressor inlet;
a first speed sensor producing a first speed signal indicative of engine rotational speed;
a second speed sensor producing a second speed signal indicative of rotational speed of said turbocharger; and
a control computer estimating absolute boost pressure within said intake conduit as a function of said first and second speed, pressure and temperature signals.
1 Assignment
0 Petitions
Accused Products
Abstract
A system for estimating absolute boost pressure in a turbocharged internal combustion engine includes a pressure sensor producing a pressure signal indicative of the pressure of air entering a turbocharger compressor inlet, a temperature sensor producing a temperature signal indicative of the temperature entering the compressor inlet, a first speed sensor producing a first speed signal indicative of the rotational speed of the turbocharger, a second speed sensor producing a second speed signal indicative of the rotational speed of the engine, and a control computer estimating the absolute boost pressure as a function of the pressure signal, the temperature signal, the first speed signal and the second speed signal.
-
Citations
7 Claims
-
1. System for estimating absolute boost pressure in a turbocharged internal combustion engine, comprising:
-
a turbocharger having a compressor defining a inlet and an outlet fluidly coupled via an intake conduit to an intake manifold of an internal combustion engine;
a pressure sensor producing a pressure signal indicative of pressure of air entering said compressor inlet;
a temperature sensor producing a temperature signal indicative of temperature of air entering said compressor inlet;
a first speed sensor producing a first speed signal indicative of engine rotational speed;
a second speed sensor producing a second speed signal indicative of rotational speed of said turbocharger; and
a control computer estimating absolute boost pressure within said intake conduit as a function of said first and second speed, pressure and temperature signals. - View Dependent Claims (2, 3, 4)
and wherein said control computer is operable to estimate said absolute boost pressure within said intake conduit by mapping current values of said temperature-corrected turbocharger speed, said first speed signal and said pressure signal to corresponding values of said absolute boost pressure via said map stored within said memory.
-
-
4. The system of claim 1 wherein said control computer includes:
-
means for determining a temperature value as a square root of said temperature signal;
means for determining a temperature-corrected turbocharger speed value as a ratio of said second speed signal and said temperature value;
means responsive to said temperature-corrected turbocharger speed value for determining a first function thereof;
means responsive to said speed signal for determining a second function thereof; and
means for estimating said absolute boost pressure within said intake conduit as a product of said first function, said second function and said pressure signal.
-
-
5. A method of estimating absolute boost pressure in a turbocharged internal combustion engine, the method comprising the steps of:
-
determining an inlet pressure corresponding to pressure of air entering an inlet of a turbocharger compressor;
determining an inlet temperature corresponding to temperature of the air entering the inlet of the turbocharger compressor;
determining a first speed corresponding to turbocharger rotational speed;
determining a second speed corresponding to engine rotational speed; and
estimating an absolute boost pressure of air supplied by an outlet of the turbocharger compressor to an intake manifold of the engine as a function of the inlet pressure, the inlet temperature, the first speed and the second speed. - View Dependent Claims (6, 7)
computing a temperature-corrected turbocharger speed as a ratio of the first speed and a square root of the inlet temperature;
mapping current values of the temperature-corrected turbocharger speed and the second speed to a compressor pressure ratio using a map stored within a memory unit; and
estimating the absolute boost pressure as a product of the compressor pressure ratio and the inlet pressure.
-
-
7. The method of claim 5 wherein the estimating step includes:
-
computing a temperature-corrected turbocharger speed as a ratio of the first speed and a square root of the inlet temperature;
determining a first function of the temperature-corrected turbocharger speed;
determining a second function of the second speed; and
estimating the absolute boost pressure as a product of the first function, the second function and the inlet pressure.
-
Specification