For the entire development process
CarMaker applications in the V-cycle
Whether you are still in the concept phase or already performing tests for series production - your development environment always remains the same. The models, test cases and parameters can be reused in all development phases or for other projects. Whether CarMaker is used on the PC or on the test bench does not matter. This continuity can be illustrated with the application of CarMaker during the v-cycle.
The requirements that are defined in terms of a system specification make up the starting point of a development project:
The functions of the system specification are developed in software models using graphically oriented programming systems like MATLAB/Simulink. This phase can be supported by model-in-the-loop (MIL) simulation. In this process software models are validated in the virtual vehicle environment of CarMaker.
All models of CarMaker are fully integrated into Simulink so that the user can easily modify the models, for example by replacing specific components of the models with his own Simulink blocks.
The software model tested with MIL is replaced by the software of the controller and integrated into the simulation environment of CarMaker (software-in-the-loop SIL). The future series code is executed in the virtual vehicle environment in order to analyze the behavior and to reveal implementation mistakes. One major advantage of CarMaker is that the SIL tests can be run on a real-time system in order to check if the software meets the timing constraints imposed by such an environment. In contrast to many other implementations the software does not have to be adapted to do so.
The purpose of component tests is to ensure a perfect interaction of the executable program with the controller hardware and the operating system. The real ECU is integrated into a CarMaker/HIL test bench that simulates the vehicle and generates the signals for the ECU in real-time (hardware-in-the-loop).
The test spectrum on the HIL test bench ranges from performance tests through to security tests where the behavior of the vehicle is analyzed in the case of electrical faults. For these special tests IPG offers the FailSafeTester that enables the user to automatically generate electrical faults at the HIL test bench. The support of CCP (CAN Calibration Protocol) and XCP (Universal Measurement and Calibration Protocol) also allows the acquisition and analysis of internal ECU variables.
The OEM is responsible for the vehicle as an overall system and has to ensure that the different ECUs perfectly interact with each other after their integration into the vehicle. To guarantee this, the systems that often come from different suppliers must be tested in a network. The hardware and software of the CarMaker/HIL systems are designed modularly so that single ECUs can be easily switched on and off.
This allows the test of the overall performance of the network in all relevant driving situations (e.g. cornering or full breaking etc.). The monitoring of the communication between the ECUs (via CAN, FlexRay etc.) plays an important role during these network tests. Not only the normal operation mode but also the fail-safe behavior must be considered. Depending on the goal of the research the units under test are not only ECUs but also mechanical components (e.g. dampers, steering systems, engine). The number of real components integrated into the test system strongly varies from application to application.