In modern vehicles, wheel slip control systems from the anti-blocking system (ABS) via the traction control down to the driving-dynamics controls have been developed. In this last named system, the driving condition of the vehicle is monitored by sensorics and the vehicle stabilised in critical driving situations by purposeful interventions individual to each wheel by the brake as well as a reduction of the engine torque. As the brake interventions can be critical to safety, a sophisticated inherent diagnosis monitors the system. In disturbances, the driving-dynamics controller can thus partly or totally be deactivated before faulty interventions result. The driver is advised of the disturbance of the system by a warning light going on. In addition, the disturbance recognised is stored in the error memory of the system. However, the inherent diagnoses cannot cover all the imaginable malfunctions, and they also react very late to creeping deteriorations of the system. During the periodical vehicle monitoring, all the electronically controlled systems can currently only be tested insufficiently. Alongside a visual check of sensors, wiring and actuators, there is only a check of the warning lamp. However, the meaningfulness of this is only minimal, in addition only possessing an extremely low manipulation safety. For this reason, the "International Motor Vehicle Inspection Committee (CITA)“ commissioned the "Institut für Kraftfahrwesen Aachen (ika)“ with developing a test procedure for vehicle dynamics controllers. The test procedure is to be as simple as possible and to enable a qualitatively meaningful analysis of the state of the vehicle dynamics controller within a short period. In addition, the apparatus needed for the implementation of the tests is to be within reasonable limits. The development of this test procedure is done with the help of simulation models. For this, two vehicles are selected to start with which have a distinct difference in their vehicle class, their drive concept and the structure of the vehicle dynamics controller. This mode of procedure is to provide a certain "universality" of the results. After this, both the vehicles themselves as well as the intervention conduct of the vehicle dynamics controller are examined in test-bench and driving tests. With the help of the information gained in this way, the simulation models are drawn up and verified. The simulation models are especially well suited for drawing up a test procedure, as a large number of tests can be carried out in a short time here. In addition, the conduct of the systems in disturbances can be examined free of risks (Author/publisher)
Abstract