Anti-lock braking system based on FlexRay protocol
The anti-lock braking system is nowadays a part of almost every vehicle. This system increases safety of the people sitting in the vehicle at the moment of stopping on a slippery or unstable road surface. The point is to assure a good controllability of the vehicle even if the wheels are in slip. In order to work properly, the anti-lock braking system needs to have actual information about the rotation of every single wheel. And the up-to-dateness and certainty of an accurate information is the primary criterion of an appropriate performance. Currently, the information about the frequency of wheel rotation is being transmitted via the current loop. This solution needs a lot of wiring, which means increased purchase costs. This paper describes a method, where the information from the rotation sensors of the wheels are transmitted into the control unit through the FlexRay bus. Additional wireless acceleration sensors located on the wheel are used to improve the ABS performance.
Methods for Verification and Validation of Automotive Distributed Systems
The growth of complexity together with the severity of the potential failure of electronic systems in modern vehicles create pressure on development of powerful validation and testing techniques. This thesis is trying to fill few identified gaps in this field. One of the gaps is the absence of suitable measurement methods for relatively new automotive communication system called FlexRay. In comparison with older communication standards CAN and LIN, each FlexRay communication controller is parametrized by almost hundred of parameters. From the validation point of view, it is necessary to evaluate that the parameters programmed into communication controller are in conformance with the specified parameters values. Such evaluation is not possible without suitable methods capable of measuring the actual parameters values. Another blank space which this thesis is trying to fill is related to the Integration testing of automotive electronics systems. Due to increasing number of electronic control units and number of implemented functions, traditional approach incorporates, the manual test case design is reaching its limits. This thesis proposes several improvements for this specific domain. Namely it is testbed platform based on National Instruments products, a novel approach based on the Model Based Testing techniques using the Timed Automata specification, several test generation algorithms, and implementation of the proposed concept. The presented solutions were experimentally evaluated. The FlexRay measurement methods were validated on the real communication network. Moreover, in the case of Integration testing, the implemented concept was proved by two case studies. The objective of the first one was the car keyless access system. The second study validated the described solution on the automatic trunk opening system.
Nonlinear Control for Semi-Active Road Friendly Truck Suspension
The paper deals with the results of the EC project Copernicus SADTS (Semi-Active Damping of Truck Suspensions and its Influence on Drivers and Road Loads). The objectives of this paper were to investigate the potentials of semi-active suspensions of trucks for reduction of tyre-road forces in order to reduce the road damage or to allow to increase the payload. In particular, the synthesis of new control concepts of Extended Ground Hook (EGH) with state-dependent gains (gain scheduling) is described. The paper includes also the verifications of the results by simulation and by prototype experiments.