Hardware in the Loop for a Dynamic Driving System Controller Testing and Validation

Active Chassis Control Engineering with help from ITN/PD at DaimlerChrysler, has been developing a hardware-in-the-loop (HIL) system, for the evaluation and optimization of interaction among the various chassis control systems, and between the chassis control system and the vehicle. This HIL system consists of a transfer case, a hydraulic load box, two differential load boxes, an electronic control unit (ECU), a virtual 14-DOF (Degree of Freedom) vehicle model, and a computer system with a high-speed operating platform. The HIL system simultaneously demonstrates the advantages of both hardware testing and computer modeling. Different from conventional bench tester, the system offers the capability to implement dynamic ECU tests with feedback requirements for the sophisticated control algorithms, CAN diagnostics, fault injection, automatic-operating scenarios duplication and validation. In addition, this HIL enables upfront design and performance assessment of the various chassis control algorithms, as well as their interactions, before vehicle level testing and tuning. Examples will illustrate how the active chassis control HIL system enables the dynamic ECU tests and the study of new control systems over a wide range of conditions.