GNSS precision vid kinematisk mätning - och möjliga användningsområden för maskinstyrd vinterväghållning.

This thesis evaluates the potential for machine guidance in winter road maintenance. The proposed benefits would be a reduction in material- or time needs. It should also reduce accidents with benefits for both property damages and personal injuries. The work methods and organisational structure of winter road maintenance is described through literature studies and interviews. The interviews are done with representatives from both the administration and contractor side of winter road maintenance in Malmö city, Sweden. Possible areas deemed suitable for machine guidance in winter road maintenance were optimizing the distribution of salt and offering visual guidance for the drivers. The cost of machine guidance equipment is fairly high and the necessity for winter road maintenance is confined to only a part of the year. Therefore there is a need to search for synergies with other users or applications. In order to facilitate an analysis the work has included an assessment by which expected precision a kinematic GNSS measurement is possible. The analysis is based on a measurement with RTK capable equipment mounted on a van traveling on roads in Skåne, Sweden. The resulting measurement points have been analysed in respect to their individual radial standard deviation. It investigates whether measurement precision differs depending on road surroundings in both urban and rural areas. The results have shown a good reception capability in speeds up to Swedish highway speed. The reception quality is in large parts retained while in an urban environment. There are larger problems when in a surrounding with vegetation in close proximity to the road. For a primarily open surrounding the resulting measurements ends up having a radial standard deviation up to 0,74 meters in 95 % of the time. It also stays below a radial standard deviation of 0,05 meters in 80 % of the time. To simulate its effectiveness in a plowing situation a road line was constructed of previous measurement points. A safety zone of 0,25 meters to the left and 0,3 meters to the right of the road line. The ability to stay inside this safety zone was then evaluated. The result of eight runs ended up in the order of 20-50 % of the time