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In the presented paper we deal with an important problem in active safety systems, which is the multi-rate processing of different signals. Automotive systems are usually very complex, involving multiple subsystems, in which typically it is very difficult to obtain equal sampling rates. In many cases, this problem is ignored, which means that the signals samples stored in different time moments are silently assumed to be to sampled in the same time. Looking from the point of view of signal processing, this incorrect assumption often causes large harmonic distortions artifacts of processed signals. These distortions, in turn, generate harmonics of different frequencies. As a result, if processed signals are used to calculate the trajectories of objects seen by systems associated with the vehicle, may differ from the real world trajectories. This may cause occurrence of false positives or no reaction of the vehicle in case of emergency situation.

In this paper we present an example design process of filters used in automotive industry. Signal preprocessing is very important operation in active safety algorithms. Such algorithms usually take into account the vehicle state that includes position, velocities and accelerations of the car. On the basis of these data, as well as the parameters and trajectories of external objects “observed” by the car, the algorithms make decisions about various safety actions. Designer of such algorithms must assure an appropriate quality of such signals, which usually means a proper filtering. In this paper we focus on selected important aspects of the filter design process. The main objectives of the presented investigations is to obtain such filters that ensure a sufficient rejection of undesired components from the signal and at the same time that do not introduce too high delay to the processed signals.

Active Safety (AS) and Advanced Driver Assistance Systems (ADAS) can nowadays be considered as distributed embedded software systems where independent microprocessor systems communicate together using different communication protocols. Typical AS or ADAS functionality is then realized by several microprocessors communicating with each other. AS and ADAS systems interact with other Electronic Control Units in a vehicle via communication networks and gather vehicle's surroundings via camera, radar or laser sensors. Quality assurance and safety standards combined with increasing complexity and reliability demands related to vision sensing, radar sensing and data fusion, often together with a short time to market, make the development of such systems challenging. As the number of important road scenarios for the system grows, mathematical modelling and computer simulation become important engineering tasks that aim to assure the required quality and compliance with safety standards.

The paper presents a model-based approach to testing embedded automotive software systems in a real-time. Model-based testing approach relates to a process of creating test artifacts using various kinds of models. Real-time testing involves the use of a real-time environment to implement test application. Engineers shall use real-time testing techniques to achieve greater reliability and/or determinism in a test system. The paper contains an instruction how to achieve these objectives by proper definition, implementation, execution, and evaluation of test cases. The test cases are defined and implemented in a modeling environment. The execution and evaluation of test results is made in a real-time machine. The paper is concluded with results obtained from the initial deployment of the approach on a large scale in production stream projects.