Control mathematical model for automatic hydro-mechanical transmission in buses

The article presents a mathematical model of motion of a car equipped with the automatic hydro-mechanical transmission. All possible conditions of transmission operation during car acceleration have been analysed. The model has been applied in a computer program for city bus acceleration simulation. Also the methodology of defining optimal gear shift algorithms for the automatic hydro mechanical transmission has been presented. There have been used two optimization criteria: acceleration time minimization and fuel consumption minimization in the acceleration phase. The methodology has been illustrated by an example of optimal control algorithms synthesis of the automatic hydro-mechanical transmission in a city bus