Search Results

Electric power steering systems (EPS) are characterized by high inertia and therefore by a considerably damped transmission behaviour. While this is desirable for comfort-oriented designs, EPS do not provide enough feedback of the driving conditions, especially for drivers with a sporty driving style. The systematic actuation of the electric motor of an EPS makes it possible to specifically increment the intensity of the response. In this context, the road-sided induced forces of the tie rod and the steering rack force provide all the information for the steering system’s response. Former concepts differentiate between use and disturbance information by defining frequency ranges. Since these ranges overlap strongly, this differentiation does not segment distinctively. The presented article describes a method to identify useful information in the feedback path of the steering system depending on the driving situation.

Current innovations in the area of power train engineering for cars are generating significant and unprecedented challenges for the development of acoustically unobtrusive transmissions. As regards relevance for customers, noise phenomena caused by loose parts play a key role. Transmission rattle, whose primary trigger is the pulse-like torque output of conventional combustion engines, also falls into this category. Current trends within the engine development (e.g. down speeding and downsizing) generate significant challenges for the development of acoustically unobtrusive transmissions. The aim of the presented approach is the evaluation and optimization of transmissions regarding the gear rattling noise perceived by the customer/passenger inside the vehicle. The investigation is divided into several experimental parts. The sound characteristics of the perceivable rattling noise is determined and evaluated as well as the transfer of rattling noise into the passenger compartment.

Hybrid electric vehicle (HEVs) represents a promising approach to reduce vehicle fuel consumption and exhaust emissions. However, due to the electric motor (EM) assistance, the engine load could be reduced and intermittent operation of engine is realizable in HEVs powertrain system. Consequently, the HEV powertrain heating-up process and engine fuel consumption will be changed accordingly. Therefore, the influences of the EM power and battery capacity on the hybrid powertrain heating-up process and the engine fuel consumption will be analyzed, and 2 methods for optimizing the heating-up process by applying the auxiliary heaters (AHs) and the modification of the energy management strategy are represented. The application of AHs can improve engine efficiency during heating-up; the controlling of the power flow from the AHs to the ICE cooling system is of special important.