Co-Simulation Framework for the Development of Whole-Machine Integrated Distributed Electronic Control

Efficient management of an agricultural machine as a whole requires coordinated control of several sub-systems, to achieve, in every working condition, the best possible global operating condition, since quasi-independent operation of individually-optimized loosely-coupled elements is inevitably bound to miss the target. Common analysis of hydrostatic-transmission-based powertrain systems are often focused on the hydrostatic unit alone, neglecting the potentials of a tighter interaction with other sub-systems, fitted with dedicated ECUs, which could provide/receive useful information to be used to implement an efficient coordinated actuation sequence (e.g.: synchronized operation of mechanical brakes and hydrostatic unit). Moreover, the specific issues related to the distributed structure of multiple ECUs connected by means of the CAN network are generally neglected in the early stages of machine control development: this way the effects on the control performance induced by the chosen partitioning of functional tasks between ECUs and the communication infrastructure are not properly addressed from the beginning. In the present work a Simulink-AMESim co-simulation framework is implemented, which allows a suitable model-in-the-loop simulation of model-based electronic control system, developed as Simulink diagrams, with a fully-featured AMESim model of the hydro-mechanical system, representing the powertrain of an agricultural machine, including a "2D" vehicle. Different level of details of CAN communication (from a simple rough implementation of communication timing to low-level interaction with ECU hardware) are addressable by the Simulink model and the resulting control is suitable to be subsequently processed by embedded code generation tools and be uploaded to the destination ECUs and benefits from the detailed virtual experiments performed against the AMESim model to reduce in-field testing time.