Friction Measurement System for Hennepin County

A friction measurement system was developed for Hennepin County and installed on a snowplow in their winter road maintenance fleet. The major components of the developed system were a special instrumented wheel, a pneumatic pressure-controlled cylinder, force-measurement load cell and accelerometers, and a data processing micro-processor and LCD display. The project plan initially included interfacing the friction measurement system with an applicator and automatic control of the applicator on detection of a low tire-road friction coefficient on the road. However, due to concerns from Hennepin County about interfacing with the applicator electronics and its potential influence on normal operation of the Force America applicator, the friction coefficient was estimated in real-time and just displayed for the snowplow operator. It was not used for real-time control of the applicator. The stand-alone hardware developed in this project is being used as a platform for development and installation of friction measurement systems on two snowplows in Polk County during the 2012-2013 winter. The Polk County installation is being funded by the Minnesota Local Road Research Board.