Development of the control of a fully automized hybrid drive

Abstract

This paper presents the control system of a fully automatized hybrid vehicle which has been realized as a prototype. The hybrid vehicle has been developed at the ika for the Ford Motor Company. It is well-known under the term Ford-EHV. The “electric hybrid vehicle” contains a parallel hybrid driveline which is either powered by a combustion engine or by an electric motor. The power can even be combined in a torque addition gear box. The output is transferred via an automatic transmission to the wheels. This mechanical system has many degrees of freedom concerning the operating strategy. In intensive simulations using longitudinal simulation tools like “STAR”, a so-called 2-dimensional strategy was developed to achieve best efficiency and drivebility.

The simulation forms the basis for the final “run-time” operating strategy. Because of the complexity of this mechatronical system, the implementation requires special standards for the hardware and software basis. To achieve great modularity and best efficiency for the implementation and maintenance process, a special high-end microcontroller system, based on the microcontroller SAB80C166 was developed. An optimized multitasking operating system is the basis of the control system, which realizes a task-depending observation and control of the various units in the powertrain. An additional element in this control forms the finite state description.

This great effort leads to the realized Ford EHV which has already shown its qualities on various test bench drives and in real life situations.