The project presented in this report is a master's thesis performed at Scania CV. The main purpose is to develop an algorithm that estimates the offset of the values that the steering wheel angle sensor reports in a truck or tractor, and also to investigate the possibility to estimate the steering wheel angle in real-time. The developed algorithm successfully estimates the offset to an accuracy on the order of degrees, and the uncertainty of the estimate is ultimately determined by the backlash in the steering system, which may range up to approximately 15 degrees or more depending on service standards. The investigation also shows that two general approaches to estimate the steering wheel angle in real-time can produce unbiased estimates only when the vehicle is cornering at low speeds.

A stationary or temporary offset in the steering system of a vehicle can result in functions, relying on the steering wheel angle, performing poorly. Due to the wide range of different vehicle configurations at Scania CV, all sensors with relevant information regarding vehicle direction are not available on all vehicles. By using a statistical approach, including common sensors installed on the vehicle, a conceptual algorithm calibrating the Steering Wheel Angle Sensor offset in real- time has been developed. The algorithm is simple and relies on the assumption that a vehicle is driving straight ahead most of the time above a certain minimum vehicle speed, thus the most frequent steering wheel angle is the straight ahead angle. The algorithm is only active above the certain minimum vehicle speed and consists of two moving windows comprising steering wheel angle samples in which the calculations are performed. The results show that the algorithm is able to detect offsets with a short calibration time. Storage of samples is required but no vehicle specific parameters are needed.

This work is focused on the development of a thorough study about ISO standards focused on the vehicle dynamics, standardized tests of vehicle dynamics and measured variables that allow us to describe and model the behaviour of riding vehicles properly. In the Appendix A of the thesis, there is a list of all known ISO standards dealing with given topic. The standard ISO 15037-1 Road vehicles – Vehicle dynamics test methods, Part 1: General conditions for passenger cars is described in detail, including the forms for test reports and the Appendix C and D. In the thesis, there is also described a model of minimal needed measuring system that is still in good accordance with the standard ISO 15037-1 and fulfills all its requirements. Detailed description of all used sensors that are used to measure required variables is given, as well as a short description of all sensors that are used for measurement of other variables. After that, measurement abilities of the instrumentation of measuring system RIO used in ÚADI FSI Brno is compared and confronted with requirements given by the standard, to see, if all given criteria are properly fulfilled. Because of the fact that standard-given criteria are quite mild, while the equipment of the faculty is high-level technology, mostly made directly for measuring of dynamic parameters of the vehicles, including racing vehicles, the system is in full accordance with the standard ISO 15037-1.