Method for determining a flow rate of fluid in a vehicle engine system

A system for determining an injected quantity of a fluid of interest, this fluid of interest flowing in use in an engine system of a vehicle of interest, said quantity not being measured directly by a sensor, the engine system comprising at least a fluid tank (3), a pump (2), a fluid injection member (1), with a fluid flow path from the pump to an injected zone (4) downstream of the injection member, and an electronic control unit (5) that is able to command opening of the injection member, which is otherwise closed in the absence of a command, the fluid of interest being a liquid fluid that is incompressible or exhibits low compressibility, the system comprising a supervised-learning (RNN, IA) hydraulic loss estimation module (52), taking as input a plurality of parameters (dP, P1, P0, T, X) and supplying as output a hydraulic loss coefficient CP relating to a hydraulic loss introduced by the fluid injection member (1), the electronic control unit (5) being configured for:

• /b/—carrying out a plurality of N sequences of fluid injection, during which values of said plurality of parameters (dP, P1, P0, T, X) are collected,
• /c/—calculating a theoretical quantity (QTH) of fluid injected during these N sequences of fluid injection, with the aid of at least some of said values of the plurality of parameters (P1, P0, T, X), the theoretical calculation using a so-called Bernoulli module for an incompressible fluid,
• /d/—transmitting, to the loss estimation module, said values of the plurality of parameters (dP, P1, P0, T, X), and obtaining, at the output of the loss estimation module, the loss coefficient CP,
• /e/—calculating an estimated actual quantity of fluid injected during the N sequences of fluid injection, by applying the loss coefficient CP to the calculation of the theoretical quantity of fluid.

A diagnostic method for an engine system of a vehicle of interest, the engine system comprising at least a fluid tank (3), a pump (2), a fluid injection member (1), with a fluid flow path from the pump to an injected zone (4) downstream of the injection member, and an electronic control unit (5) that is able to command opening of the injection member, which is otherwise closed in the absence of a command,

• the method comprising the following steps:
• providing a supervised-learning (RNN, IA) loss estimation module (52), taking as input a plurality of parameters (dP, P1, P0, T, X) and supplying as output a hydraulic loss coefficient CP relating to a hydraulic loss introduced by the fluid injection member (1),
• /b/—carrying out a plurality of N sequences of fluid injection, during which values of said plurality of parameters (dP, P1, P0, T, X) are collected,
• /d/—transmitting, to the loss estimation module (52), said values of the plurality of parameters (dP, P1, P0, T, X), and obtaining, at the output of the loss estimation module, the loss coefficient CP,
• /e′/ comparing the loss coefficient CP with a predetermined value, and generating an alert if the difference in absolute value exceeds a predetermined threshold.