Hardware and software for engine fuel supply control under incomplete information conditions

Abstract

The results of the study are: construction of a deterministic mathematical model of an internal combustion engine; description of the mass movements of the model by a system of linear differential equations, the parameters of which are normalized using similarity theory methods; obtaining transfer functions of mechanical channels using the Mathcad software environment and the method of determinants. The coincidence of the obtained transfer functions is also established and for the first time it is proposed to represent the torque diagram of the power unit by a mechanical system with one degree of freedom; the frequency characteristics of the torque transmission channel are studied in the Matlab software environment. The effectiveness of the developed application software is established. Originality. The scientific novelty consists in the development of the architecture of hardware and software tools for setting the phases of fuel and air supply based on the principle of feedback control based on the state of the frequency-modulated crankshaft speed signal. An information technology for processing an array of experimental data when isolating a fluctuation signal has been developed. An algorithmic support for monitoring cylinder capacities has been built by solving an overdetermined system of incompatible algebraic equations when setting a vector of cylinder weight coefficients. To find its solution, the least squares method and the Seidel iterative method with zero partial derivatives in the components of the generalized functional were used. As a result of mathematical transformations, a symmetric and positive definite Gram matrix was obtained. An uncertainty limit for the solution of the system of algebraic equations was established, upon reaching which the computational process stops. Practical value. The practical significance lies in the development of algorithmic support for monitoring cylinder capacities with a frequency representation of the fluctuation signal using the transfer functions of mechanical channels and approximated torques. Monitoring cylinder capacities is focused on setting the parameters of a curve that passes through all points of measurement information and smoothest possible emissions due to their uncertainty. The Laplace transform under zero initial conditions was used as a mathematical apparatus for establishing information connections between cylinder torques and the fluctuation signal of the first mass of the crankshaft. A computer simulation scheme of the signal of the uneven rotation of the first mass was built in the Mathcad software environment and its parameters were identified using the method of adjusting the length of information connections.