In vehicle dynamics, designing the characteristics of shock absorbers is an important subproblem which determines the overall behavior of the vehicle to a high extent. Their design can be supported by numerical optimization. In the paper the problem of an adequate description is discussed where the mathematical function type used is determined by physical effects. In order to apply efficient optimization algorithms, sensitivities with respect to state variables and control nodes of the characteristics are computed. A suspension design problem based on a multibody system model of a vehicle is formulated and solved by multicriterion optimization. Results for different preferences on comfort and riding safety are shown.

In this work, a simulation framework for virtual testing of autonomous driving functions under the influence of a fault occurring in a component is presented. The models consist of trajectory planning, motion control, models of actuator management, actuators and vehicle dynamics. Fault-handling tests in a right-turn maneuver are described, subject to an injected fault in the steering system. Different scenarios are discussed without and with a fault and without and with counteractions against the fault. The results of five scenarios for different criticality metrics are discussed. In the case of a fault without a counteraction, a pronounced lateral position deviation of the ego vehicle from the reference curve is observed. Furthermore, the minimal and hence most critical time-to-collision (TTC) and post-encroachment time (PET) values are calculated for each scenario together with a parameter variation of the initial position of a traffic agent. The minimum TTC values are lowest in the case of a fault without counteraction. For the lateral position deviation and the TTC, the counteractions cause reduced criticality that can become even lower than in the case without a fault, corresponding to a decrease in the dynamic behavior of the vehicle. For the PET, only in the case of a fault without counteraction, a non-zero value can be calculated. With the implemented testing toolchain, the automated vehicle and the reaction of the HAD function in non-standard conditions with reduced performance can be investigated. This can be used to test the influence of component faults on automated driving functions and help increase acceptance of implemented counteractions as part of the HAD function. The assessment of the situation using a combination of metrics is shown to be useful, as the different metrics can become critical in different situations.

In this paper the multibody model of a railroad passenger coach consisting of two rigid bogies and an elastic car body is presented. The elastic body is introduced by a floating reference frame and superimposed elastic deformations linearized with respect to the reference frame. The governing equations of motion are presented in symbolical form, where the time-invariant matrices describing the elastodynamical behavior are computed numerically in a preprocessor. To increase the computational efficiency, condensation techniques are applied and ten modes are chosen to describe the elastic behavior. Simulations of high speed travelling have been carried out with excitation from measured data of a real track. As a measure of ride comfort the acceleration at characteristic points on the coach are computed. Comparison with results obtained using a less sophisticated rigid body model show significant higher accelerations, depending on the position on the coach, too.