Körsimulator

The fast development pace and complex systems in todays automotive industry makes it difficult and costly to evaluate how certain design parameters affect the driver environment. The tests performed are to a large extent done at a pre-serial stage thus rendering in late changes thar are both costly and time consuming. As computer systems gets more powerful the possibility to simulate system behaviour at early stages of the product development process and at a low cost increases. Those simulations only give limited information about the drivers experience of the simulated vehicle. The use of a motion base simulator can provide this information. Technical limitations in the movements of the motion base creates the need to transform the motions from the simulated vehicle in order to create an experience of driving the vehicle. In this thesis the transformation was done by splitting the accelerations by frequency. High frequency accelerations are possible to simulate with the motion base while the low frequency accelerations would generate motions that exceed the limitations of the motion base. Therefore a system that uses the gravitation as a simulated acceleration using body tilt was implemented. The use of filters in the frequency splitters increases the risk of artefacts and noise being introduced to the signal. These errors can accumulate over time and cause the motion base to move around a point other than origo. This can in turn lead to the motion base reaching the end limit of the motion range causing a stop before the entire motion in a certain direction is performed, hence causing a faulty movement. To accommodate this problem a classic washout algorithm was used and tuned to give an as realistic experience as possible. The results presented in this thesis shows a system with a low delay and a system that will give a reasonably good experience of the driving. Comparisons with results from empirical tests with a real car should be performed to ensure the validity of the system.Validerat; 20110609 (anonymous