Actuator control

The lowest layer of the scalable architecture of the vehicle dynamics control system relates to the actuators. It comprises the physical execution of the control commands of the higher-level motion layer. The Institute's research activities have focused on real-time modelling and code generation using Modelica and the Functional Mockup Interface (FMI) standard as part of several collaborative research projects together with industrial partners (mainly Robert Bosch GmbH). The focus was on the development and testing of a tool chain for model-based controller development for embedded systems in the automotive sector. Together with Dassault Systèmes, new technologies were developed for solving non-linear inverse dynamic models and non-linear feedback linearisation controllers under real-time requirements. As part of the international ITEA project EMPHYSIS, which was initiated by Bosch and the Institute, the Institute and other partners are currently developing a new embedded FMI standard (eFMI).

This interface standard will simplify the exchange of physics-based non-linear models between modelling and simulation environments and software development environments for ECUs and other embedded systems. In one use case of the project, the institute has created a tool chain to implement both a state estimator and a controller for a high-performance semi-active damper on a pre-development ECU. The tool chain, shown in the figure below, is based on controller and prediction models in Modelica, generated eFMI code from Dymola (algorithm code) and TargetLink (C code), and an in-house library of C functions for the implementation of non-linear Kalman filter variants on embedded systems. The C code is configured in an AUTOSAR environment and finally compiled for the target platform.