METHOD FOR DETERMINING THE PRESSURE OF THE EXHAUST GASES UPSTREAM OF A HIGH-PRESSURE TURBOCOMPRESSOR TURBINE OF AN INTERNAL COMBUSTION ENGINE, AND CONTROL SYSTEM EMPLOYING SUCH A METHOD

摘要

Method for determining the pressure of gas upstream of an internal combustion engine boost turbine, and control system implementing this method. This method for determining the pressure of gas upstream of a high-pressure turbocompressor boost turbine (12) of a motor vehicle internal combustion engine comprising a high-pressure turbocompressor (9) and a low-pressure turbocompressor (8) each one comprising a turbine driven by the exhaust gases emanating from the engine and a compressor connected to the turbine, comprises the steps of: - calculating the speed of the high-pressure turbocompressor; - calculating the power of the compressor of the high-pressure turbocompressor; - calculating the power of the turbine of the high-pressure turbocompressor; - calculating the expansion ratio of the turbine of the high-pressure turbocompressor. The gas pressure upstream of the high-pressure turbocompressor turbine is determined from the pressure upstream of the low-pressure turbocompressor turbine and of the calculated expansion ratio.