Method Development for Road Grip Correlation between Different Force Based Sensors

• Main Authors: Lundholm, Marcus, Wallgren, Per
• Format: Bachelor Thesis
• Language: English
• Published: 2016
• Subjects: Technology; Teknik; RT3; Per; Marcus; LTU; Röros; Bilsystemteknik; Norway; Luleå
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-43835

This thesis presents an experimental approach on how to evaluate the correlation between different force based road grip sensors. Road grip sensors are commonly used to evaluate road safety conditions, eliminating uncertainty for road maintenance. Today, different technologies have been developed to measure the interactions between tire and road to generate a friction value that describes the amount of grip a tire has on the measured surface. Different systems generates different friction values, thus depending on the measurement system, the road maintenance requirement specifications varies. A correlation between the systems is therefore important to enable specification translations for nations in the Nordic region. The Norwegian Public Road Administration, NPRA has three types of systems that use the technology of longitudinal slip to measure the friction value, with a pulse braking measurement tire.While Luleå University of Technology has a different system, RT3 Curve, that use the technology of lateral slip, with two toe in set tires causing a slip-angle, forcing the measurement tires to slide continuously. Tests were executed in Røros, Norway for two days during winter conditions. The objectives were to investigate if there was any correlation between the systems and the main depending factors. The results showed that on compact snow and sand covered roads the NPRA systems measured approximately 70 % of the RT3's measured value.A linear regression showed that 77 % of the NPRA systems variations can be explained by the variations of the RT3 system.The main depending factors are the different measurement tires and the sample-rates. Future studies are necessary to cover more different road surfaces. Validerat; 20160612 (global_studentproject_submitter)